Medical School · Year 3 · Emergency Medicine · includes a quiz and discussion video

Seminar 16: Emergency Procedures

Emergency Medicine Clerkship

Learning Objectives

By the end of this seminar, students will be able to:

1. Demonstrate competency in basic airway management including bag-valve-mask ventilation, oropharyngeal and nasopharyngeal airways, and supraglottic devices
2. Describe the preparation, pharmacology, technique, and confirmation steps of rapid sequence intubation and recognize indications for surgical airway
3. Establish emergency vascular access through peripheral intravenous, intraosseous, and central venous routes with appropriate site selection
4. Perform and describe indications for chest procedures including needle decompression, tube thoracostomy, and thoracentesis
5. Apply procedural sedation safely using appropriate agent selection, monitoring, and recovery criteria
6. Execute wound management including assessment, anesthesia selection, closure technique, and suture material choice for common laceration types

Seminar Outline

Section 1: Basic Airway Management

Bag-valve-mask (BVM) ventilation is the foundational airway management skill and serves as both a temporizing measure and a definitive rescue technique when endotracheal intubation fails. The technique employs the C-E grip, in which the thumb and index finger form a C shape pressing the mask against the face while the middle, ring, and pinky fingers form an E shape lifting the mandible forward to maintain airway patency. A two-person technique is preferred whenever possible, with one provider dedicating both hands to maintaining the mask seal and jaw thrust while a second provider squeezes the bag. The patient should be positioned in the sniffing position with the neck flexed and head extended to align the oral, pharyngeal, and laryngeal axes, unless cervical spine injury is suspected, in which case a jaw thrust without head extension is performed. Ventilations are delivered at a rate of 10 to 12 breaths per minute with sufficient volume to produce visible chest rise, avoiding excessive volumes that cause gastric distention and increase aspiration risk.

The oropharyngeal airway (OPA) is a rigid curved device inserted into the mouth to displace the tongue anteriorly and prevent obstruction of the oropharynx. It is indicated exclusively for unconscious patients who lack a gag reflex, as insertion in a patient with an intact gag reflex will provoke vomiting and potential aspiration. Sizing is determined by measuring from the corner of the mouth to the angle of the mandible, and insertion is performed by introducing the device with the curve directed cephalad (toward the palate) and then rotating 180 degrees once past the tongue. An incorrectly sized or improperly inserted OPA can push the tongue posteriorly and worsen obstruction rather than relieve it.

The nasopharyngeal airway (NPA) is a soft, flexible tube inserted through the naris to maintain a patent airway from the nostril to the posterior pharynx. It is better tolerated than the OPA in obtunded patients who retain some protective reflexes and is particularly useful in patients with clenched jaws or trismus that precludes oral airway placement. Sizing is determined by measuring from the tip of the nose to the tragus of the ear, and the device is lubricated and inserted along the floor of the nasal cavity with the bevel directed toward the septum. The NPA is relatively contraindicated in patients with suspected basilar skull fracture due to the theoretical risk of intracranial placement through a disrupted cribriform plate, though this complication is exceedingly rare.

Supraglottic airways represent an intermediate level of airway management that bridges basic techniques and definitive intubation. The laryngeal mask airway (LMA) is the most widely used supraglottic device, seated over the laryngeal inlet to create a low-pressure seal that allows ventilation without the need for direct visualization of the vocal cords. The King laryngeal tube is a blind-insertion device with two inflatable cuffs that isolate the laryngeal inlet between them. The i-gel is a newer design that uses a non-inflatable anatomically shaped gel cuff that conforms to the laryngeal framework. These devices are indicated in the "cannot intubate, cannot oxygenate" scenario as rescue airways, and they are used as primary airways in out-of-hospital cardiac arrest and by providers who do not regularly perform endotracheal intubation. Their primary limitation is that they do not provide definitive airway protection against aspiration and cannot be used for prolonged ventilation.

<image>Panel A: Demonstration of the C-E grip for bag-valve-mask ventilation showing proper hand positioning with the thumb and index finger creating a C-shape seal on the mask and the remaining fingers lifting the mandible, alongside the two-person technique with one provider managing the mask and another squeezing the bag. Panel B: Oropharyngeal airway sizing from the corner of the mouth to the angle of the mandible, with insertion sequence showing initial placement with the curve directed upward followed by 180-degree rotation into final position displacing the tongue anteriorly. Panel C: Nasopharyngeal airway sizing from the nasal tip to the tragus, with insertion along the nasal floor showing the bevel orientation toward the septum and final positioning in the posterior pharynx. Panel D: Comparison of supraglottic airway devices including the laryngeal mask airway, King laryngeal tube with dual cuffs, and i-gel with its anatomic gel cuff, each shown in cross-sectional placement within the airway.</image>

Section 2: Endotracheal Intubation

Equipment preparation for endotracheal intubation follows a systematic checklist to ensure readiness for both the primary attempt and rescue scenarios. The endotracheal tube (ETT) is selected by size, typically 7.0 to 8.0 mm internal diameter for adults, and the cuff integrity is tested by inflating with a syringe and checking for leaks. The laryngoscope is assembled with the chosen blade, either curved Macintosh or straight Miller, and the light is verified to be bright and secure. Suction must be on and immediately available at the head of the bed with a rigid Yankauer tip. A malleable stylet is inserted into the ETT and shaped into a hockey stick configuration to facilitate anterior elevation of the tube tip during laryngoscopy. End-tidal carbon dioxide (ETCO2) detection equipment, either colorimetric or waveform capnography, must be at bedside for immediate confirmation of tube placement. A backup plan including a supraglottic airway device and a surgical airway kit should be prepared before any intubation attempt, embodying the principle that every intubation plan should include a rescue strategy.

Rapid sequence intubation (RSI) is the standard method for emergent endotracheal intubation in the emergency department, designed to achieve rapid airway control while minimizing the risk of aspiration. The sequence begins with preoxygenation using 100 percent oxygen for 3 to 5 minutes via non-rebreather mask or, in hypoxic patients, non-invasive positive pressure ventilation to denitrogenate the functional residual capacity and extend the safe apnea time. An induction agent is then administered to produce rapid unconsciousness: etomidate at 0.3 mg/kg is hemodynamically neutral and widely used, ketamine at 1 to 2 mg/kg provides hemodynamic stability with bronchodilatory properties making it ideal for asthmatic or hypotensive patients, and propofol provides excellent intubating conditions but causes dose-dependent hypotension. A neuromuscular blocking agent is given simultaneously or immediately after induction: succinylcholine at 1.5 mg/kg provides rapid onset (45 seconds) and short duration (6 to 10 minutes) but is contraindicated in hyperkalemia and certain neuromuscular conditions, while rocuronium at 1.2 mg/kg provides comparable onset with longer duration and can be reversed with sugammadex.

Confirmation of endotracheal tube placement is a critical patient safety step that must be performed immediately after every intubation using multiple methods. Waveform capnography demonstrating a characteristic square-wave ETCO2 tracing is the gold standard for confirmation and should be continuously monitored throughout the patient's course. Direct visualization of the tube passing between the vocal cords during laryngoscopy provides real-time confirmation but may be limited by view grade. Auscultation should confirm bilateral breath sounds over both lung fields and absent sounds over the epigastrium, though this can be unreliable in noisy emergency department environments or in obese patients. A chest radiograph is obtained to confirm proper depth of the tube, which should sit 2 to 4 cm above the carina, typically at the level of the aortic arch on a properly centered film. Pulse oximetry should demonstrate improving or stable oxygen saturation following successful intubation, though it is a lagging indicator that does not confirm tracheal placement.

Troubleshooting during difficult intubation requires a systematic approach and familiarity with rescue techniques. When the vocal cords cannot be visualized, external laryngeal manipulation using the BURP maneuver (backward, upward, and rightward pressure on the thyroid cartilage) or bimanual laryngoscopy can improve the glottic view, and switching to a video laryngoscope provides a superior view in the majority of difficult airways. When the cords are visualized but the tube cannot be passed, a bougie (tracheal introducer) should be used as a guide over which the ETT is railroaded into the trachea, with the characteristic clicks from the tracheal rings and a holdup at the bronchus confirming tracheal placement. Esophageal intubation, recognized by the absence of ETCO2 waveform, requires immediate removal of the tube, bag-valve-mask ventilation to reoxygenate the patient, and a second attempt with optimized conditions. Right mainstem bronchus intubation is identified by unilateral right-sided breath sounds and is corrected by deflating the cuff, withdrawing the tube 1 to 2 cm, reinflating the cuff, and confirming bilateral breath sounds and appropriate depth on chest radiograph.

<image>Panel A: Equipment layout for endotracheal intubation showing a properly sized endotracheal tube with stylet in hockey stick configuration, laryngoscope handle with Macintosh and Miller blades, syringe for cuff inflation, tape for securing, and ETCO2 detector ready for use. Panel B: Rapid sequence intubation timeline showing preoxygenation phase (3-5 minutes), induction agent administration, neuromuscular blocker injection, apneic period (45-60 seconds), and laryngoscopy with intubation, with common drug options and doses listed at each step. Panel C: Methods of endotracheal tube placement confirmation showing waveform capnography tracing with characteristic square-wave pattern, auscultation points on the chest bilaterally and epigastrium, and chest radiograph with tube tip positioned 2-4 cm above the carina. Panel D: Difficult airway troubleshooting algorithm showing BURP maneuver hand positioning, video laryngoscope blade view, bougie insertion technique through the glottis, and the decision pathway from failed intubation to supraglottic rescue to surgical airway.</image>

Section 3: Surgical Airway

The surgical airway is the final rescue technique in the emergency airway management algorithm, indicated when all other methods of oxygenation and ventilation have failed. The primary indication is the "cannot intubate, cannot oxygenate" (CICO) scenario, which represents a failed airway where bag-valve-mask ventilation, supraglottic airway placement, and endotracheal intubation have all been unsuccessful. Additional indications include massive facial trauma that distorts anatomy and renders oral or nasal approaches impossible, and complete upper airway obstruction from tumors, angioedema, or foreign bodies that cannot be bypassed with an endotracheal tube. The decision to proceed to surgical airway must be made without undue delay, as prolonged attempts at other techniques in the face of critical hypoxemia result in preventable mortality from hypoxic brain injury and cardiac arrest.

The cricothyrotomy technique follows a systematic approach beginning with identification of surface landmarks. The cricothyroid membrane is located between the thyroid cartilage superiorly and the cricoid cartilage inferiorly, and it is the preferred site because it is relatively superficial, avascular at the midline, and positioned below the vocal cords. The larynx is stabilized with the non-dominant hand while a vertical skin incision is made through the skin to allow identification of the cricothyroid membrane, followed by a horizontal incision through the membrane itself. The vertical skin incision reduces the risk of vascular injury compared to a horizontal skin incision and allows the operator to palpate and redirect if the initial cut is off midline. After the membrane is incised, the opening is dilated using the handle of the scalpel rotated 90 degrees or a tracheal hook or Kelly clamp, and a cuffed tracheostomy tube or a 6.0 to 7.0 endotracheal tube is inserted with the cuff inflated. Placement is confirmed with end-tidal capnography and bilateral breath sounds.

Complications of cricothyrotomy can be minimized through meticulous technique and knowledge of the surrounding anatomy. Hemorrhage from the incision is managed by maintaining a midline approach and applying direct pressure; the superior and inferior cricothyroid arteries run along the upper and lower borders of the membrane, respectively. False passage occurs when the tube is inadvertently placed into the pretracheal soft tissues rather than through the membrane and into the airway, recognized by the absence of ETCO2 and the presence of subcutaneous emphysema. Posterior tracheal wall injury results from inserting the tube or dilating instrument too deeply, and can be prevented by directing the tube anteriorly along the curve of the trachea. Long-term complications include subglottic stenosis, which is why cricothyrotomy is considered a temporary airway and should be converted to a formal tracheostomy within 72 hours when the patient is stabilized.

Alternative surgical airway techniques exist for specific clinical scenarios where standard cricothyrotomy may not be appropriate. Needle cricothyrotomy involves inserting a large-bore (12 to 14 gauge) catheter through the cricothyroid membrane and connecting it to a high-pressure jet ventilation system; this is the preferred technique in children under 10 to 12 years of age because their cricothyroid membrane is too small and their cartilage too soft for a surgical approach. Needle cricothyrotomy is considered a temporizing bridge that provides oxygenation but inadequate ventilation, and CO2 will accumulate over time. Retrograde intubation involves passing a wire cephalad through the cricothyroid membrane, retrieving it from the mouth or nose, and using it as a guide over which an endotracheal tube is advanced into the trachea. When time permits and the clinical situation allows, an awake tracheostomy performed in the operating room by a surgeon provides the most controlled surgical airway but is not feasible in the emergency cannot-intubate-cannot-oxygenate scenario.

<image>Panel A: Surface anatomy of the anterior neck showing the thyroid cartilage prominence, cricothyroid membrane depression, and cricoid cartilage ring, with finger palpation technique for landmark identification in the emergency setting. Panel B: Step-by-step cricothyrotomy procedure showing the vertical skin incision, horizontal membrane incision, dilation with scalpel handle rotation, and insertion of a cuffed tube through the cricothyroid membrane into the trachea. Panel C: Complications of cricothyrotomy illustrated including hemorrhage from cricothyroid vessels with midline avoidance technique, false passage into pretracheal tissue with subcutaneous emphysema, and posterior wall injury from over-insertion. Panel D: Alternative surgical airway techniques showing needle cricothyrotomy with catheter-over-needle through the cricothyroid membrane connected to jet ventilation, retrograde wire-guided intubation with wire passed cephalad through the membrane, and operating room setup for formal tracheostomy.</image>

Section 4: Vascular Access

Peripheral intravenous access is the first-line approach for vascular access in most emergency situations and should be attempted before advancing to more invasive techniques. The antecubital fossa provides large, accessible veins that are ideal for rapid fluid resuscitation and medication administration. Forearm veins, particularly the cephalic vein, provide stable access that is less prone to positional flow changes. The external jugular vein is a useful alternative when peripheral upper extremity access is difficult, accessed by placing the patient in Trendelenburg position with the head turned contralaterally. For resuscitation purposes, catheter gauge is more important than catheter length, with 14 to 18 gauge catheters providing the high flow rates necessary for volume resuscitation according to the Hagen-Poiseuille equation, which demonstrates that flow is proportional to the fourth power of the radius.

Intraosseous (IO) access is an essential emergency vascular access technique that provides a non-collapsible pathway into the medullary venous sinusoids of bone, making it particularly valuable when peripheral intravenous access cannot be rapidly established. The proximal tibia is the most commonly used site, accessed 1 to 2 cm below the tibial tuberosity on the flat medial surface, providing a broad area of cortical bone for stable needle placement. Alternative sites include the distal femur at 2 cm above the superior border of the patella at the midline, and the proximal humerus at the greater tuberosity, which provides the fastest drug delivery to the central circulation due to its proximity to the heart. IO needles are placed using either a powered drill device or manual insertion with a twisting motion, and placement is confirmed by stable positioning of the needle, ability to flush saline without subcutaneous infiltration, and aspiration of marrow. All medications and fluids can be administered via the IO route at the same doses used for intravenous administration, including vasopressors, blood products, and RSI medications.

Central venous access is indicated when peripheral and IO access are insufficient or when specific clinical needs require central venous pressure monitoring, large-bore multi-lumen access, or administration of vasoactive medications and hypertonic solutions. The femoral vein is the most accessible site during cardiopulmonary resuscitation because it does not require interruption of chest compressions and carries no risk of pneumothorax, though it has a higher infection rate with prolonged use. The internal jugular vein is the preferred site for ultrasound-guided placement, offering real-time visualization of the needle entering the vein and a lower pneumothorax risk compared to the subclavian approach. The subclavian vein provides the lowest infection rate of the three sites and the greatest patient comfort for long-term use, but carries the highest risk of pneumothorax and is not compressible if arterial puncture occurs. Ultrasound guidance is now the standard of care for central venous access, as it significantly reduces complication rates and improves first-pass success.

Complications of vascular access procedures require prompt recognition and management to prevent patient harm. Pneumothorax is the most feared complication of subclavian and internal jugular central line placement, prevented by using ultrasound guidance and confirmed by post-procedure chest radiograph; a tension pneumothorax requires immediate needle decompression followed by chest tube placement. Arterial puncture is recognized by pulsatile bright red blood flow, prevented by ultrasound visualization of the needle entering the vein, and managed by immediate withdrawal of the needle and application of direct pressure for a minimum of 10 minutes. Catheter-related bloodstream infection is minimized through strict sterile technique including full barrier precautions during insertion and removal of the catheter as soon as it is no longer needed. Air embolism occurs when air enters the venous system through an open hub, prevented by placing the patient in Trendelenburg position during insertion and removal and ensuring all ports are capped or occluded at all times.

<image>Panel A: Peripheral intravenous access sites showing the antecubital fossa, cephalic vein of the forearm, and external jugular vein with patient positioned in Trendelenburg and head turned, alongside catheter gauge comparison demonstrating flow rate differences between 14-gauge and 20-gauge catheters. Panel B: Intraosseous access sites showing the proximal tibia with insertion point 1-2 cm below the tibial tuberosity on the medial flat surface, the distal femur site, and the proximal humerus at the greater tuberosity, with powered drill insertion technique demonstrated. Panel C: Central venous access comparison showing ultrasound-guided internal jugular vein cannulation with real-time needle visualization, femoral vein access below the inguinal ligament, and subclavian vein approach with anatomic landmarks. Panel D: Complications of vascular access including chest radiograph showing iatrogenic pneumothorax from subclavian line placement, ultrasound image demonstrating arterial puncture with bright pulsatile flow, and proper sterile technique setup with full barrier precautions for central line insertion.</image>

Section 5: Chest Procedures

Needle decompression is a life-saving emergency procedure performed for tension pneumothorax, a clinical diagnosis characterized by hypotension, distended neck veins, absent breath sounds on the affected side, and tracheal deviation away from the affected side. The traditional insertion site is the second intercostal space at the midclavicular line, though evidence increasingly supports the fourth or fifth intercostal space at the anterior axillary line where the chest wall is thinner and the success rate is higher. A 14 to 16 gauge needle of at least 5 cm length for adult patients is inserted perpendicular to the chest wall, directed over the superior border of the rib to avoid the neurovascular bundle that runs along the inferior rib margin. Successful decompression is confirmed by a rush of air through the needle and improvement in hemodynamic parameters. Needle decompression is a temporizing measure that must always be followed by tube thoracostomy for definitive management.

Tube thoracostomy (chest tube insertion) is the definitive procedure for management of pneumothorax, hemothorax, and empyema. The standard insertion site is the fourth or fifth intercostal space at the anterior to midaxillary line, within the safe triangle bordered by the anterior border of the latissimus dorsi, the lateral border of the pectoralis major, and a horizontal line at the level of the nipple. Tube size selection depends on the indication: 28 to 36 French tubes are used for traumatic hemothorax to allow drainage of blood and clot, while 20 to 28 French tubes are adequate for pneumothorax. The patient is positioned with the ipsilateral arm abducted and the hand behind the head to widen the intercostal space. A 2 to 3 cm skin incision is made over the rib, one intercostal space below the intended pleural entry point, allowing for a subcutaneous tunnel that reduces the risk of recurrent pneumothorax after tube removal.

The chest tube insertion technique involves a stepwise approach that prioritizes safety and confirmation at each stage. Blunt dissection is performed through the subcutaneous tissue and intercostal muscles using a Kelly clamp, spreading in the direction of the muscle fibers until the pleura is reached. The pleura is punctured with the clamp and a rush of air or fluid confirms entry into the pleural space. A finger sweep is then performed through the incision to confirm that the lung is not adherent to the chest wall and to rule out abdominal contents that could indicate a diaphragmatic hernia. The chest tube is directed posteriorly and superiorly using a clamp or finger guidance, and the tube is connected to an underwater seal drainage system with or without suction. The tube is secured with a suture, and an occlusive dressing is applied. A post-insertion chest radiograph confirms proper tube position and resolution of the pneumothorax or hemothorax.

Thoracentesis is performed for both diagnostic and therapeutic purposes in patients with pleural effusion. The procedure is performed at the seventh or eighth intercostal space in the posterior or lateral chest, with the needle inserted just above the rib to avoid the intercostal neurovascular bundle. Ultrasound guidance is strongly recommended for thoracentesis, as it reduces the complication rate and identifies the optimal insertion site by confirming the presence and depth of the effusion. The needle is advanced while aspirating until pleural fluid is obtained, and fluid is sent for cell count, protein, glucose, LDH, pH, culture, and cytology as clinically indicated. Therapeutic drainage is limited to approximately 1.5 liters at a single session to prevent re-expansion pulmonary edema, a rare but potentially fatal complication characterized by the development of unilateral pulmonary edema in the re-expanded lung. Post-procedure chest radiograph is obtained if the patient develops symptoms such as dyspnea, cough, or chest pain to evaluate for iatrogenic pneumothorax.

<image>Panel A: Needle decompression for tension pneumothorax showing the two insertion sites (second intercostal space midclavicular and fourth-fifth intercostal space anterior axillary), needle insertion technique directed over the superior rib border, and the clinical signs of tension pneumothorax including tracheal deviation and distended neck veins. Panel B: Tube thoracostomy safe triangle anatomy bordered by the latissimus dorsi, pectoralis major, and nipple line, with the skin incision one intercostal space below the pleural entry point creating a subcutaneous tunnel. Panel C: Chest tube insertion technique sequence showing blunt dissection with Kelly clamp, pleural puncture with fluid drainage, finger sweep confirming the pleural space, tube insertion directed posteriorly and superiorly, and connection to underwater seal drainage system. Panel D: Ultrasound-guided thoracentesis showing probe positioning to identify the effusion, needle insertion above the rib with syringe aspiration, fluid collection for laboratory analysis, and post-procedure chest radiograph confirming absence of pneumothorax.</image>

Section 6: Cardiac Procedures

Pericardiocentesis is an emergency procedure performed to relieve cardiac tamponade, a life-threatening condition in which fluid accumulation in the pericardial sac compresses the cardiac chambers and impairs diastolic filling. The classic clinical presentation is Beck's triad of hypotension, muffled heart sounds, and distended neck veins, though all three findings are present in only a minority of cases. The subxiphoid approach is the standard technique: a long spinal needle or catheter-over-needle is inserted to the left of the xiphoid process at a 45-degree angle, directed toward the left shoulder. Ultrasound guidance has become the standard of care, allowing real-time visualization of the needle entering the pericardial space, and even small volumes of fluid removal (as little as 20 to 50 mL) can produce dramatic hemodynamic improvement due to the steep portion of the pressure-volume relationship of the pericardium. Complications include right ventricular laceration and coronary artery injury, which are significantly reduced with ultrasound guidance.

Emergency department thoracotomy (EDT) is the most aggressive resuscitative procedure performed in emergency medicine and is reserved for patients with penetrating thoracic trauma who have recent loss of vital signs or who are in cardiac arrest. Contraindications include blunt trauma with no signs of life, prolonged cardiac arrest of more than 10 to 15 minutes, and non-survivable injuries such as massive head trauma. The approach is a left anterolateral thoracotomy through the fifth intercostal space, providing access to the pericardium, heart, left lung hilum, and descending aorta. The goals of EDT include relieving cardiac tamponade by opening the pericardium, controlling cardiac hemorrhage with direct repair or stapling, clamping the pulmonary hilum to control massive pulmonary hemorrhage, and cross-clamping the descending aorta to redirect blood flow to the brain and coronary arteries. Survival rates are best for isolated cardiac stab wounds (approximately 30 to 40 percent) and decrease substantially for gunshot wounds and blunt mechanisms.

Transcutaneous pacing is the emergency treatment for symptomatic bradycardia when pharmacologic interventions such as atropine are insufficient. Pacing pads are placed in the anterior-posterior configuration, with the anterior pad on the left parasternal area and the posterior pad on the left infrascapular region. The pacer is set to an initial rate of 60 to 80 beats per minute, and the output current is gradually increased from the minimum until electrical capture is achieved, identified by a QRS complex immediately following each pacing spike on the monitor and a palpable pulse correlating with each complex. Mechanical capture must always be confirmed because electrical capture on the monitor does not guarantee effective cardiac contraction. Transcutaneous pacing is painful, and conscious patients require sedation and analgesia, typically with fentanyl and midazolam or ketamine. Transcutaneous pacing serves as a bridge to transvenous pacing or resolution of the underlying bradycardia.

Synchronized cardioversion is the treatment for hemodynamically unstable tachyarrhythmias including unstable atrial fibrillation, atrial flutter, supraventricular tachycardia, and monomorphic ventricular tachycardia. The synchronized mode ensures that the electrical shock is delivered on the R wave of the QRS complex, avoiding the vulnerable period of the T wave that could trigger ventricular fibrillation. Energy selection for biphasic defibrillators typically begins at 100 to 200 joules, with escalating energy for subsequent attempts if the initial shock is unsuccessful. Procedural sedation is required for conscious patients, with propofol, etomidate, or ketamine providing rapid onset and short duration of unconsciousness. The synchronization mode must be reactivated after each shock on most defibrillators, as they default to asynchronous mode after delivery. The distinction between synchronized cardioversion for organized rhythms and unsynchronized defibrillation for ventricular fibrillation and pulseless ventricular tachycardia is critical, as delivering a synchronized shock during ventricular fibrillation may delay therapy while the device searches for an R wave to synchronize with.

<image>Panel A: Pericardiocentesis technique showing the subxiphoid needle insertion point, 45-degree angle directed toward the left shoulder, ultrasound image demonstrating pericardial effusion with the needle tip visible entering the pericardial space, and hemodynamic tracings before and after fluid aspiration showing blood pressure improvement. Panel B: Emergency department thoracotomy showing the left anterolateral incision through the fifth intercostal space, pericardiotomy with clot evacuation, cardiac repair with direct suture, and aortic cross-clamping technique on the descending aorta. Panel C: Transcutaneous pacing setup showing anterior-posterior pad placement, monitor display with pacing spikes followed by captured QRS complexes, and the process of increasing output current until electrical and mechanical capture are confirmed by palpable pulse. Panel D: Synchronized cardioversion showing pad placement, monitor display with the synchronization marker on the R wave, energy selection dial, and rhythm strip comparison before and after successful cardioversion of atrial fibrillation to sinus rhythm.</image>

Section 7: Wound Management

Wound assessment is the essential first step in laceration management and determines the appropriate closure technique, timing, and need for specialty consultation. The mechanism of injury is critical: sharp lacerations from knives or glass have clean edges amenable to primary closure, crush injuries create devitalized tissue prone to infection, and bite wounds carry polymicrobial contamination requiring specific antibiotic coverage. The degree of contamination is assessed by examining for foreign material, soil, and debris, and heavily contaminated wounds require aggressive irrigation before closure. The time since injury affects infection risk, with the traditional teaching that wounds older than 6 to 8 hours on the body and 12 to 24 hours on the face carry increased infection risk with primary closure, though well-irrigated wounds in healthy patients may tolerate longer closure windows. The depth of the wound must be assessed for involvement of deeper structures including tendons, nerves, blood vessels, joint capsules, and bone, and the anatomic location determines both the cosmetic significance and the functional implications of the injury.

Anesthesia for wound repair employs multiple techniques tailored to the wound location, size, and patient characteristics. Local infiltration with lidocaine (1 to 2 percent, maximum dose 4.5 mg/kg without epinephrine or 7 mg/kg with epinephrine) is the most common technique, injected directly into the wound edges. The field block, injecting anesthetic around rather than into the wound, is preferred for larger areas and in contaminated wounds to avoid tracking bacteria through tissue. Digital blocks using lidocaine without epinephrine at the base of the finger or toe provide complete anesthesia for digit lacerations, nail injuries, and foreign bodies. Regional nerve blocks provide anesthesia to larger anatomic territories: the infraorbital nerve block anesthetizes the upper lip and nose, the mental nerve block anesthetizes the lower lip and chin, and the supraorbital and supratrochlear blocks anesthetize the forehead. For pediatric patients, topical LET gel (lidocaine, epinephrine, tetracaine) applied to the wound for 20 to 30 minutes provides effective atraumatic anesthesia for face and scalp lacerations.

Wound closure techniques are selected based on wound characteristics, location, tension, and desired cosmetic outcome. Simple interrupted sutures are the most versatile technique, appropriate for the majority of lacerations, with each suture independently placed to allow selective removal if infection develops. Horizontal and vertical mattress sutures are used for high-tension wounds and areas where wound edge eversion is important for optimal cosmetic outcome, with the vertical mattress particularly effective for thick skin such as the back and extremities. Subcuticular (running subcutaneous) closure provides excellent cosmetic results for low-tension wounds in cosmetically sensitive areas. Staples offer rapid closure for scalp lacerations and other low-cosmetic-priority locations. Tissue adhesive (cyanoacrylate) is applied to clean, low-tension wounds with well-approximated edges, providing the equivalent tensile strength of 5-0 suture. Adhesive strips (Steri-Strips) are reserved for very superficial, low-tension wounds and are frequently used as reinforcement after subcuticular closure.

Suture selection involves matching the suture material, size, and removal timing to the anatomic location and wound characteristics. Facial lacerations require fine suture material (5-0 or 6-0 nylon) with early removal at 3 to 5 days to minimize suture track marks on this cosmetically important area, often with adhesive strips applied after suture removal for continued wound support. Scalp lacerations are repaired with 3-0 or 4-0 nylon or staples, with removal at 7 to 10 days. Extremity lacerations use 4-0 nylon with removal at 10 to 14 days, reflecting the slower healing and greater tension in these areas. Lacerations over joints require 4-0 suture and extended retention of 14 days due to the repetitive mechanical stress during joint motion. Deep dermal sutures using absorbable material such as polyglactin (Vicryl) or poliglecaprone (Monocryl) are placed to reduce dead space, relieve tension on the skin closure, and provide long-term wound support. Patients should receive wound care instructions including keeping the wound clean and dry, signs of infection to monitor for, and a specific date for suture or staple removal.

<image>Panel A: Wound assessment checklist illustrated with examples of sharp laceration with clean edges, crush injury with irregular devitalized margins, and bite wound with puncture marks, alongside depth evaluation showing structures at risk including tendon, nerve, and bone. Panel B: Local anesthesia techniques showing local infiltration along wound edges, field block injection pattern around the wound perimeter, digital ring block at the base of the finger, and regional nerve block landmarks for the infraorbital and mental nerve blocks on the face. Panel C: Wound closure techniques comparison showing simple interrupted sutures with proper needle trajectory, vertical and horizontal mattress sutures with tissue eversion, running subcuticular closure, scalp staple application, tissue adhesive application, and Steri-Strip placement. Panel D: Suture selection guide organized by anatomic location showing the face (5-0/6-0, remove 3-5 days), scalp (3-0/4-0, remove 7-10 days), extremity (4-0, remove 10-14 days), and over joints (4-0, remove 14 days), with deep absorbable Vicryl suture placement illustrated.</image>

Section 8: Lumbar Puncture

Lumbar puncture is an essential diagnostic procedure in emergency medicine with several key indications that demand timely performance. Suspected bacterial meningitis is the most urgent indication, as cerebrospinal fluid (CSF) analysis provides critical diagnostic information including cell count, protein, glucose, Gram stain, and culture that guides antibiotic therapy. When subarachnoid hemorrhage is suspected but the CT scan is negative, lumbar puncture is performed to detect xanthochromia or elevated red blood cell count with a characteristic non-clearing pattern across sequential tubes. Pseudotumor cerebri (idiopathic intracranial hypertension) is diagnosed by demonstrating an elevated opening pressure on lumbar puncture, and therapeutic CSF drainage can provide symptomatic relief. Guillain-Barre syndrome demonstrates the characteristic albuminocytologic dissociation with elevated protein but normal cell count in the CSF. The timing of lumbar puncture relative to antibiotic administration in suspected meningitis is important: antibiotics should not be delayed for the procedure, as CSF culture may remain positive for several hours after antibiotic administration.

The technique of lumbar puncture requires careful attention to positioning, landmarks, and procedural steps. The patient is positioned either in the lateral decubitus position with the knees drawn to the chest and the spine maximally flexed to open the intervertebral spaces, or in the seated upright position leaning forward over a bedside table, which is easier for obese patients but does not allow accurate opening pressure measurement. The insertion point is identified at the L3-L4 or L4-L5 interspace, located by palpating the iliac crests and identifying the spinous process at the level of a line connecting them (Tuffier's line), which approximates the L4 spinous process. After sterile preparation and local anesthesia, a spinal needle (20 to 22 gauge, atraumatic pencil-point design preferred) is inserted with the bevel oriented parallel to the longitudinal fibers of the ligamentum flavum to spread rather than cut the dural fibers. The stylet is intermittently removed to check for CSF flow as the needle is advanced. Upon entering the subarachnoid space, the opening pressure is measured with a manometer, and CSF is collected into four sequential tubes for cell count, protein and glucose, culture, and special studies.

Contraindications to lumbar puncture must be carefully evaluated before proceeding. Signs of elevated intracranial pressure with mass effect, including papilledema, focal neurologic deficits, or altered level of consciousness, require CT imaging before lumbar puncture to rule out a mass lesion that could lead to brain herniation upon CSF removal. Coagulopathy, including an INR greater than 1.5 or platelet count below 50,000, increases the risk of epidural or subdural hematoma and should be corrected before the procedure when possible. Skin infection at the planned insertion site is a contraindication due to the risk of introducing bacteria into the subarachnoid space, and an alternative interspace should be selected. Significantly elevated intracranial pressure is a relative contraindication, though in cases of suspected meningitis with elevated pressure, the lumbar puncture may still be necessary and can be performed with careful technique and limited fluid removal.

Complications of lumbar puncture are generally uncommon but include several important entities. Post-lumbar puncture headache is the most common complication, occurring in approximately 10 to 30 percent of patients, characterized by a positional headache that worsens with upright posture and improves with recumbency, caused by ongoing CSF leak through the dural puncture site. Prevention includes using an atraumatic (Sprotte or Whitacre) needle rather than a cutting (Quincke) needle, using the smallest gauge needle appropriate, and replacing the stylet before withdrawing the needle. Treatment of persistent post-LP headache includes caffeine, analgesics, and ultimately an autologous epidural blood patch, in which 15 to 20 mL of the patient's own blood is injected into the epidural space to seal the dural leak. Infection is rare with proper sterile technique. Bleeding ranges from trivial traumatic tap to epidural hematoma in coagulopathic patients. Herniation is the most catastrophic complication but is extremely rare when appropriate pre-procedure imaging has been obtained in patients with risk factors.

<image>Panel A: Lumbar puncture indications illustrated with CSF findings for each condition: bacterial meningitis showing turbid CSF with elevated WBCs, low glucose, and elevated protein; subarachnoid hemorrhage showing xanthochromic supernatant in sequential tubes; pseudotumor cerebri showing elevated opening pressure on manometer; and Guillain-Barre showing elevated protein with normal cell count. Panel B: Lumbar puncture positioning and technique showing the lateral decubitus position with knees drawn to chest, landmark identification using Tuffier's line at the iliac crests, needle insertion at the L3-L4 interspace with bevel parallel to the spine, and opening pressure measurement with manometer. Panel C: Contraindications evaluation showing CT scan with mass lesion and midline shift contraindicating LP, coagulation parameters that require correction, and cellulitis at the insertion site requiring alternative site selection. Panel D: Post-lumbar puncture headache pathophysiology showing CSF leak through the dural puncture site, comparison of atraumatic versus cutting needle tip designs, and epidural blood patch technique with blood injection sealing the dural defect.</image>

Section 9: Procedural Sedation

Pre-sedation assessment is a critical safety evaluation that must be completed before initiating procedural sedation in the emergency department. NPO (nil per os) status is assessed, with traditional guidelines recommending 2 hours for clear liquids and 6 to 8 hours for solids, though emergency department practice frequently requires procedural sedation in patients who have recently eaten, and risk-benefit analysis guides decision-making in urgent situations. The airway is assessed using the Mallampati classification, neck mobility, thyromental distance, and the presence of facial hair or obesity that might complicate bag-valve-mask ventilation if rescue airway management is required. ASA physical status classification provides a standardized assessment of the patient's overall health and comorbidity burden that correlates with sedation risk. Allergies to sedative medications are reviewed, and informed consent is obtained from the patient or surrogate decision-maker, including discussion of the risks of respiratory depression, aspiration, and the possibility of conversion to general anesthesia.

Sedation agent selection is tailored to the procedure, patient characteristics, and clinical context. Propofol (0.5 to 1 mg/kg intravenously) provides ultra-short-acting sedation with excellent amnesia and rapid recovery, making it ideal for brief procedures such as cardioversion and joint reduction, though its dose-dependent hypotension and respiratory depression require careful titration and vigilant monitoring. Ketamine (1 to 2 mg/kg intravenously) produces a dissociative state that maintains protective airway reflexes, spontaneous respirations, and hemodynamic stability, making it the agent of choice for pediatric sedation and for patients with hemodynamic compromise. Etomidate (0.1 to 0.2 mg/kg intravenously) provides cardiovascular stability with rapid onset and short duration, though it may cause myoclonus and adrenal suppression. The combination of fentanyl (1 mcg/kg) and midazolam (0.05 mg/kg) provides moderate sedation with the advantage of reversibility using naloxone and flumazenil, but has a longer duration of action and greater risk of respiratory depression, particularly in elderly patients.

Monitoring during procedural sedation must be continuous and include multiple physiologic parameters to ensure patient safety. Continuous pulse oximetry detects oxygen desaturation, though it is a lagging indicator that may not reflect real-time ventilatory status. Capnography (ETCO2 monitoring) is strongly recommended as it detects hypoventilation and apnea before oxygen desaturation occurs, providing an earlier warning of respiratory compromise. Blood pressure is monitored at regular intervals, typically every 3 to 5 minutes, to detect hypotension from sedative agents. Continuous cardiac monitoring detects arrhythmias that may occur as a direct medication effect or secondary to hypoxemia. Level of responsiveness is assessed regularly using verbal and tactile stimulation to confirm the appropriate depth of sedation. A dedicated provider whose sole responsibility is monitoring the patient's cardiopulmonary status must be present throughout the procedure, separate from the provider performing the procedure.

Recovery and discharge criteria ensure that patients are safe to leave the monitored setting after procedural sedation. The patient must demonstrate return to baseline mental status, including orientation, appropriate verbal responses, and the cognitive function present before sedation. Vital signs must be stable without hypotension, tachycardia, or oxygen desaturation on room air. Protective airway reflexes including swallowing and the gag reflex must be intact. The patient should be able to ambulate without assistance when appropriate for their baseline mobility. Discharge requires the presence of a responsible adult who can transport the patient and observe them for the remainder of the day, as residual sedative effects may impair judgment, coordination, and reaction time for several hours. Patients and their caregivers should receive written discharge instructions including activity restrictions, dietary guidelines, medication instructions, and clear parameters for when to seek emergency care.

<image>Panel A: Pre-sedation assessment components showing Mallampati classification views (classes I through IV), ASA physical status classification table, NPO guidelines timeline for clear liquids and solids, and informed consent discussion elements listed. Panel B: Comparison of procedural sedation agents showing dose-response characteristics for propofol (rapid onset/offset with hypotension risk), ketamine (dissociative state with preserved airway), etomidate (cardiovascular stability), and fentanyl-midazolam combination (moderate sedation with reversibility), with onset times and durations graphed. Panel C: Monitoring setup during procedural sedation showing pulse oximetry on the finger, nasal cannula capnography tracing on the monitor displaying ETCO2 waveform, automated blood pressure cuff, cardiac monitor tracing, and the dedicated monitoring provider positioned at the head of the bed. Panel D: Recovery and discharge criteria checklist showing assessment of baseline mental status, stable vital signs, intact protective reflexes, successful ambulation test, presence of responsible adult, and example written discharge instruction sheet.</image>

Section 10: Other Emergency Procedures

Arthrocentesis is the aspiration of synovial fluid from a joint space, performed in the emergency department primarily to evaluate for septic arthritis, crystalline arthropathy (gout or pseudogout), or hemarthrosis following trauma. The knee is the most commonly aspirated joint, accessed via the superolateral or inferomedial approach with the patient supine and the knee in slight flexion. The shoulder is accessed via the posterior approach inferior to the acromion or the lateral approach. The ankle is accessed via the anteromedial approach, medial to the tibialis anterior tendon. The procedure requires full sterile technique including skin preparation, sterile drapes, and sterile gloves. Synovial fluid analysis includes cell count with differential (white blood cell count greater than 50,000 with neutrophil predominance is highly suggestive of septic arthritis), crystal analysis under polarized microscopy (negatively birefringent needle-shaped crystals in gout, positively birefringent rhomboid crystals in pseudogout), Gram stain, and culture. The presence of blood in the aspirate (hemarthrosis) in the absence of trauma should raise concern for coagulopathy or pigmented villonodular synovitis, and fat globules floating on the bloody aspirate suggest an intra-articular fracture.

Paracentesis is performed for diagnostic evaluation or therapeutic drainage of ascitic fluid. The preferred insertion site is the left lower quadrant, lateral to the rectus abdominis muscle, which avoids the inferior epigastric vessels that run within the rectus sheath. Ultrasound guidance is recommended to identify the largest accessible fluid pocket and to mark the insertion point, reducing the risk of bowel injury and dry tap. For large-volume therapeutic paracentesis, drainage of 5 to 6 liters is generally considered safe, though albumin replacement at 6 to 8 grams per liter removed is recommended for large-volume paracentesis exceeding 5 liters to prevent post-paracentesis circulatory dysfunction. Diagnostic fluid analysis includes cell count (spontaneous bacterial peritonitis is diagnosed by a polymorphonuclear cell count greater than 250 cells per microliter), albumin (for calculating the serum-ascites albumin gradient), total protein, culture, and cytology when malignancy is suspected. Complications include bleeding from abdominal wall vessels, bowel perforation, and persistent ascitic fluid leak from the puncture site.

Incision and drainage (I&D) is the definitive treatment for cutaneous abscesses and is one of the most commonly performed emergency department procedures. Adequate anesthesia is achieved through field block infiltration around the abscess periphery, as injection directly into the inflamed, acidic abscess cavity is painful and less effective due to the low pH environment inactivating the local anesthetic. The incision is made over the point of maximal fluctuance, extending the full length of the abscess cavity to allow complete drainage. The cavity is explored with a hemostat to break up all loculations and septations, ensuring that all compartments of the abscess communicate with the drainage incision. The cavity is then irrigated with normal saline to remove residual purulent material. For deep cavities, gauze packing is loosely placed as a wick to prevent premature skin closure and promote drainage from the base of the wound outward. The patient returns in 24 to 48 hours for wound check and repacking, continuing until the cavity has granulated sufficiently. Adjunctive antibiotics are indicated for abscesses associated with significant surrounding cellulitis, systemic signs of infection, immunocompromise, or high-risk locations.

Fracture reduction is a fundamental emergency department skill for restoring anatomic alignment, relieving neurovascular compromise, and reducing pain. Anesthesia options include hematoma block (direct injection of local anesthetic into the fracture site), regional nerve block, or procedural sedation, with the choice depending on the fracture location, patient factors, and expected difficulty of reduction. The reduction technique generally involves applying traction along the long axis of the extremity to disengage the fracture fragments, then recreating the mechanism of injury to unlock the deformity, and finally reversing the mechanism to reduce the fracture into anatomic alignment. Specific fracture patterns have well-established reduction techniques: Colles fracture reduction involves traction, exaggeration of the dorsal angulation, and then palmar-directed force; ankle fracture-dislocation reduction involves traction on the heel with anterior force on the posterior tibia; and hip dislocation reduction (Allis technique) involves flexion and longitudinal traction. Post-reduction assessment includes neurovascular examination, immobilization in a splint in the position of function, and post-reduction radiographs to confirm acceptable alignment. Orthopedic follow-up is arranged for definitive management decisions regarding operative versus non-operative treatment.

<image>Panel A: Arthrocentesis approaches for the knee (superolateral approach with the needle entering above the patella), shoulder (posterior approach below the acromion), and ankle (anteromedial approach medial to the tibialis anterior), with synovial fluid analysis showing cloudy septic fluid, needle-shaped gout crystals under polarized microscopy, and bloody hemarthrosis with fat globule. Panel B: Paracentesis technique showing left lower quadrant insertion site lateral to the rectus muscle, ultrasound image of the ascitic fluid pocket, Z-track needle insertion technique, and drainage setup for large-volume paracentesis with albumin infusion running alongside. Panel C: Abscess incision and drainage procedure showing field block anesthesia around the abscess periphery, full-length incision over the point of maximal fluctuance, hemostat exploration breaking up loculations, saline irrigation, and loose gauze packing placement as a wick. Panel D: Fracture reduction principles showing hematoma block injection at the fracture site, traction along the long axis to disengage fragments, reduction maneuver for a Colles fracture with directional force arrows, post-reduction splint application in position of function, and comparison pre- and post-reduction radiographs demonstrating restored alignment.</image>

Summary

• BVM ventilation uses the C-E grip with a two-person technique preferred and ventilation rate of 10 to 12 breaths per minute
• Rapid sequence intubation follows the sequence of preoxygenation, induction, paralysis, and intubation, with placement confirmed by waveform ETCO2 as the gold standard
• Surgical cricothyrotomy is indicated for the cannot-intubate-cannot-oxygenate scenario and involves a vertical skin incision with horizontal membrane incision through the cricothyroid membrane
• Intraosseous access via the proximal tibia or humeral head provides immediate vascular access with all medications given at standard IV doses
• Needle decompression for tension pneumothorax at the second or fourth-fifth intercostal space is a temporizing measure that must be followed by chest tube placement
• Tube thoracostomy at the fourth-fifth intercostal space at the anterior axillary line uses blunt dissection, finger sweep, and posterior-superior tube direction
• Pericardiocentesis via the subxiphoid approach directed toward the left shoulder under ultrasound guidance can produce dramatic hemodynamic improvement with small-volume fluid removal
• Suture removal timing depends on location: face 3 to 5 days, scalp 7 to 10 days, extremities 10 to 14 days, joints 14 days
• Procedural sedation with ketamine maintains airway reflexes and hemodynamics while propofol provides rapid onset and offset with hypotension risk
• Abscess incision and drainage requires full-length incision, loculation breakdown, irrigation, and packing with follow-up in 24 to 48 hours

Key Terms

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