Hippo ERcast June 2022

C Spine clearance in intoxicated patients

A normal high-quality CT cervical spine is highly predictive against clinically significant injury, even in intoxicated trauma patients. For alert, non-polytrauma patients found down or after minor trauma, prolonged collar immobilization may cause more harm than benefit. Clearing the Intoxicated C-Spine CT-based clearance argument: Prospective Western Trauma Association data support CT-based clearance in intoxicated patients, with a 99.9% negative predictive value for clinically significant cervical spine injury. Traditional teaching challenge: Classic emergency medicine teaching says intoxicated or obtunded patients cannot be clinically cleared, but newer evidence supports a different pathway after a negative CT. Minor trauma pathway: In intoxicated patients with minor trauma or simply found down, collar removal after a negative CT is a defensible practice rather than waiting for clinical sobriety. We walk through the practical pathway in the episode. Polytrauma exception: Advanced multisystem trauma is a different population; in those patients, keeping the collar on until formal trauma-service clearance remains the safer default. Alcohol level debate: Checking an ethanol level may help estimate disposition timing, but bedside decisions still hinge on clinical sobriety, capacity, and safe ambulation rather than a lab number. C-Collar Harms and Limited Benefit Unproven collar benefit: The benefit of routine cervical collar use has never been convincingly demonstrated, especially in lower-risk intoxicated patients without major trauma. Airway and aspiration burden: Cervical collars make airway management harder and increase aspiration risk, a meaningful tradeoff when the anticipated benefit is small. Intracranial pressure effects: Collars can impair venous return and raise intracranial pressure, adding physiologic downside in patients who may already be vulnerable. Pressure injury risk: Prolonged immobilization increases pressure sores to the head and neck, one of the clearest tangible harms of leaving collars on for hours. Imaging cascade effect: The mere presence of a collar increases the likelihood of CT imaging, which can push patients into unnecessary tests and prolonged ED stays. Self-Extrication and Spine Protection Self-protection mechanism: Alert ambulatory patients with neck injury appear to protect their own cervical spine, limiting motion rather than worsening injury during movement. Less motion with self-extrication: Narrative review data suggest patients allowed to self-extricate move their cervical spine no more than standard extrication, and sometimes substantially less. Guided extrication preference: Biomechanical work suggests guided self-extrication may be the best option for suspected cervical spine injury when the patient can cooperate. Rescue device alternative: If a patient cannot self-extricate, a rescue board may reduce cervical spine movement compared with traditional extrication methods; the practical nuances are worth hearing in the chapter.

Burn Resuscitation

Major burns cause capillary leak, intravascular hypovolemia, and burn shock, making early fluid management a dynamic resuscitation problem rather than a fixed formula. In adults, burns over 20% TBSA usually trigger formal burn resuscitation; in children, the threshold is lower and urine output remains the key endpoint. Initial Burn Resuscitation Principles Resuscitation threshold by TBSA: Formal burn resuscitation usually begins at more than 20% TBSA in adults and about 10-15% TBSA in children, with TBSA counting burns worse than superficial partial thickness. Accurate TBSA estimation: Getting TBSA right matters because fluid estimates hinge on it; when using the palm method, use the patient’s palm, and we get into practical estimation pitfalls in the episode. Burn shock physiology: Severe burns create persistent capillary leak, hypovolemia, and reduced cardiac output from a massive inflammatory response, so the core task is preserving perfusion without causing fluid overload. Lactated Ringer first line: Lactated Ringer is the preferred initial fluid because it is relatively iso-osmotic and less likely to create electrolyte problems than other crystalloids in early burn resuscitation. No set-and-forget fluids: Initial formulas are only a starting point; the hourly rate should be tapered or increased based on response rather than left unchanged through the first phase of care. Monitoring, Adjustment, and Special Situations Urine output endpoint: Urine output is the primary bedside marker of tissue perfusion, with adult resuscitation targeting more than 30 mL per hour and pediatric care aiming for more than 1 mL/kg/hr. Escalation for poor response: If urine output stays low, increase the hourly fluid rate in small stepwise adjustments; hypotension despite adequate resuscitation may justify a 500 mL LR bolus, and we walk through that distinction in the episode. Avoid diuretic correction: Diuretics are not used to force urine output in burn shock because they obscure the endpoint and can worsen under-resuscitation when the problem is inadequate circulating volume. Higher-than-expected fluid needs: Electrical injury, inhalation injury, delayed presentation, dehydration, substance use, and very deep burns can all push patients beyond formula-based estimates and require more aggressive reassessment. Pediatric maintenance caveat: Children have higher fluid needs per body mass, and those under 30 kg also need dextrose-containing maintenance fluid because their glycogen stores are limited. Burn center referral triggers: American Burn Association referral criteria include more than 10% partial-thickness burns, full-thickness injury, special locations, chemical or electrical burns, inhalation injury, and complex psychosocial factors.

Lit Matters 1: Ankle Immobilization and VTE Risk

Ankle fracture immobilization raises venous thromboembolism risk even when the absolute event rate stays low. In ED patients discharged with lower-limb immobilization, VTE risk is several-fold higher than matched upper-extremity injury controls, making risk stratification and prophylaxis conversations clinically relevant. Ankle Immobilization and VTE Risk Ninety-day event rate: The 90-day incidence of venous thromboembolism after ED discharge with an immobilized ankle fracture was 1.3%, a low absolute risk that still matters because a third of DVTs progress to PE. Relative risk signal: Lower-extremity fracture plus immobilization carried a 5- to 6-fold higher hazard of VTE than matched controls with finger wounds or wrist fractures, a useful framing point for bedside counseling. Highest-risk patient profile: Prior VTE or superficial venous thrombosis was the strongest predictor, with older age, recent hospitalization, recent non-ankle fracture surgery, and later ankle surgery also increasing risk. Routine prophylaxis limits: Empiric anticoagulation for every immobilized ankle fracture is hard to justify; a large POT-CAST trial found no significant VTE reduction with prophylactic LMWH during casting. Selective chemoprophylaxis strategy: The practical move is targeted prophylaxis discussion for higher-risk patients, balancing bleeding risk against clot risk and reviewing warning symptoms we get into in the episode.

Outpatient COVID Management, Spring 2022

Early outpatient COVID treatment is mainly about identifying who is at risk for progression and starting the right antiviral within the symptom window. Vaccination remains the most effective intervention, while routine steroids, antibiotics, anticoagulants, and ivermectin do not belong in most ambulatory cases. Outpatient COVID Antiviral Strategy High-risk patient profile: Highest priority goes to patients who are unvaccinated, older, immunocompromised, or carrying major comorbidities, because outpatient antivirals matter most when progression risk is real. Paxlovid first-line role: Nirmatrelvir ritonavir is the preferred outpatient therapy for eligible high-risk patients when started within 5 days of symptom onset, with an approximate 88% reduction in hospitalization or death. Renal and hepatic limits: Paxlovid needs renal dose reduction in moderate CKD and should be avoided with eGFR below 30 mL/min or severe hepatic impairment, a distinction we walk through in the episode. Drug interaction burden: Ritonavir is there to boost nirmatrelvir, but that CYP interaction profile creates major problems with agents like warfarin, anticonvulsants, and antiarrhythmics. Remdesivir backup option: IV remdesivir is the second-choice antiviral and remains useful when started within 7 days of symptoms, with efficacy that closely tracks Paxlovid in high-risk outpatients. Fallback oral alternative: Molnupiravir is a lower-efficacy backup option for early disease when preferred agents are unavailable or contraindicated, and it is not recommended during pregnancy. Supportive Care And What Not To Do Universal symptom treatment: Most outpatients need pragmatic supportive care: acetaminophen or ibuprofen for fever and pain, fluids for evaporative losses, rest, and simple measures like honey for cough. Cough remedy reality: Over-the-counter and prescription antitussives have limited supporting evidence in COVID cough, so expectations should stay modest even when patients are eager for a prescription. Steroid exception only: Dexamethasone belongs in outpatients only when they are being discharged on home oxygen; otherwise routine steroid use is not recommended. We get into that boundary in the chapter. Antibiotics usually unnecessary: Bacterial superinfection is uncommon in routine outpatient COVID, so empiric antibiotics are generally not indicated unless the presentation suggests a separate bacterial process. Ineffective outpatient therapies: Hydroxychloroquine and ivermectin do not improve meaningful outcomes in ambulatory COVID, and routine outpatient anticoagulants or antiplatelet agents are not recommended. Vaccination still matters most: Even in the antiviral era, vaccination remains the single most effective intervention for preventing severe COVID outcomes across outpatient populations. Alternative Agents When Preferred Drugs Fail Bebtelovimab contingency role: Bebtelovimab was a reasonable monoclonal fallback when Paxlovid or remdesivir could not be used, especially early in illness before variant activity changed the landscape. Variant-dependent antibody limits: Monoclonal antibody utility can disappear as circulating variants shift, as seen with sotrovimab losing activity against BA.2 and falling out of NIH recommendations. Treatment window discipline: Outpatient COVID therapeutics are time-sensitive, and the key decision is anchored to symptom onset rather than the test date in most patients. We cover the practical timing nuances on the show. Observation after infusion: IV outpatient therapies like remdesivir and monoclonal antibodies require post-administration observation, an operational detail that often determines whether a treatment is realistically feasible.

Lit Matters 2: The EPIC trial (Electrode Position In Cardioverting AF)

Biphasic synchronized cardioversion for atrial fibrillation works better with anterior-lateral pad placement than anterior-posterior placement. In the EPIC trial, anterior-lateral positioning improved first-shock conversion, achieved higher overall success, and did not increase arrhythmias, skin injury, or procedural pain. Pad Position for AF Cardioversion Anterior-lateral first-shock advantage: Anterior-lateral pad placement converted more patients on the first 100 J synchronized biphasic shock than anterior-posterior placement, with 54% versus 33% reaching sinus rhythm. Higher overall conversion success: Across up to four escalating shocks, anterior-lateral positioning still outperformed anterior-posterior, achieving 93% overall cardioversion versus 85%. No safety tradeoff detected: Arrhythmias, skin redness, and patient-reported periprocedural pain were similar between positions, so the efficacy edge for anterior-lateral did not come with a measurable safety penalty. Lower cumulative energy exposure: Anterior-lateral placement reached success with much less delivered energy, with a median total of 100 J versus 450 J for anterior-posterior. Shock vector rationale: Anterior-lateral positioning likely captures a larger mass of myocardium with the biphasic shock vector, a mechanistic clue that helps explain why it beats the left-atrium-targeted anterior-posterior approach. We get into the practice implications in the episode. Practical takeaway for ED practice: For synchronized biphasic cardioversion of atrial fibrillation, the best default pad position is anterior-lateral rather than anterior-posterior, though first-pass success still lands near only half of cases.

High Risk/Low Prevalence: Spinal Epidural Abscess

Spinal epidural abscess is rare, increasingly encountered, and easy to miss until permanent neurologic injury has occurred. The diagnosis hinges on pretest probability from back-pain risk factors and exam, then selective use of inflammatory markers to decide who needs whole-spine MRI with contrast. Recognizing Spinal Epidural Abscess Rising but missed diagnosis: SEA incidence is increasing, yet 75-90% of cases are initially misdiagnosed and the median patient has 2 ED visits before diagnosis, a delay tightly linked to residual neurologic deficit. High-stakes neurologic harm: The morbidity is severe: irreversible paraplegia occurs in 4-22% of cases, fewer than half return to baseline neurologic function, and mortality still ranges from 2-20%. Typical spread patterns: SEA usually arises from hematogenous spread, contiguous infection, or direct inoculation, with Staphylococcus aureus causing 60-90% of cases and posterior thoracic involvement especially common. Classic triad limitation: Fever, back pain, and neurologic deficit occur together in under 8% of patients, so the classic triad is highly specific when present but far too insensitive to rule out disease. Risk factor framing: IV drug use and diabetes are major clues, but up to half of patients have no identified source, so a rough pretest probability has to integrate history, exam, and neurologic findings. We get into that bedside framing in the episode. Diagnostic Workup and Imaging Strategy Inflammatory marker triage: ESR and CRP help sort higher-risk back-pain patients, with ESR above 20 mm/h present in about 95% of cases while a normal white count does not exclude SEA. MRI as gold standard: Whole-spine MRI with and without gadolinium is the diagnostic study of choice, with sensitivity and specificity above 90% and the added advantage of finding noncontiguous skip lesions. Skip lesion warning: Noncontiguous abscesses occur in roughly 15% of cases, which is why focused MRI can miss disease that extends across multiple vertebral levels. Alternative imaging caution: CT with IV contrast is less sensitive than MRI and may miss early infection, while CT myelogram is invasive and risks contaminating the subarachnoid space. Decision tool option: The SIRCH score combines 4 clinical variables to inform MRI decisions and, at the studied threshold, achieved very high sensitivity while reducing unnecessary scans. We walk through where it fits in the chapter. Lumbar puncture pitfall: LP is not recommended when SEA is on the differential because dural puncture may spread infection into the subarachnoid space. Emergency Treatment Priorities Early specialist involvement: Source control matters early, so infectious disease and spine surgery consultation should happen up front when SEA is suspected or confirmed. Antibiotic timing nuance: Patients with septic shock or neurologic symptoms should receive antibiotics as soon as possible, while stable non-toxic patients can wait until after blood cultures are obtained. Empiric coverage targets: Initial therapy should cover MRSA, streptococci, and gram-negative bacilli; vancomycin plus ceftriaxone is a common starting regimen, with antipseudomonal escalation in the right host. Surgery usually required: Most patients ultimately need surgery, and decompression within 24 hours is associated with the best outcomes, especially with worsening deficits or hemodynamic instability. Medical management exceptions: A minority of patients can be managed with antibiotics alone, but failures occur in about 17% and there are important neurologic and microbiologic caveats we cover in the episode.

EEM Rewind: Crashing Aortic Dissection

Acute type A aortic dissection that suddenly decompensates is usually declaring a complication, not a medication problem. Bedside ultrasound rapidly separates tamponade from aortic root dilation with severe aortic insufficiency, and that distinction changes what you do before the OR. Crashing Aortic Dissection Approach It’s not the drip: Sudden hypotension in a dissecting patient is far more likely to reflect tamponade or cardiogenic shock than over-titrated antihypertensives, so reflexively backing off the infusion is rarely the fix. Ultrasound-first deterioration check: Use bedside ultrasound early and liberally when the pressure falls; the high-yield search is for pericardial fluid, RV collapse, or a dilated aortic root. We walk through that scan sequence in the episode. Tamponade before intubation: Hemodynamically unstable dissection plus tamponade is a peri-intubation arrest setup, so evaluate for fluid in the sac and RV collapse before reaching for RSI. Resuscitate before intubate: RBI is the governing principle here: stabilize hemodynamics first, using a shock index goal of 0.7 or less rather than pushing ahead with an unstable airway plan. Controlled pericardial drainage: Early pericardiocentesis can be lifesaving in tamponade, but the key is controlled drainage with small aliquots only—enough to restore perfusion without suddenly increasing the leak pressure. Aortic insufficiency physiology: Aortic root dilation causing acute aortic regurgitation often declares itself with refractory tachycardia; management priority is blood pressure support and control, not aggressive heart-rate chasing.

Lit Matters 3: Moderate HEART Scores With/Without CAD

Moderate HEART scores do not all carry the same ACS risk. In possible acute coronary syndrome, a patient with HEAR 4 or higher, negative serial troponins, a nonischemic ECG, and no prior coronary artery disease had a low 30-day MACE rate in this study. Moderate HEART Score Risk Stratification Prior CAD as discriminator: Known coronary artery disease meaningfully changes post-test risk: among moderate-risk patients, 30-day MACE was 7.1% with prior CAD versus 1.4% without it. True moderate-risk definition: The study’s moderate-risk group was not troponin-positive ACS; it was HEAR score 4 or higher with negative 0- and 3-hour troponins and a nonischemic ECG. Objective testing rethink: Moderate-risk patients without prior CAD may not need routine objective coronary testing after ED evaluation, a disposition nuance we get into in the episode. Negative likelihood ratio signal: In moderate-risk patients without prior CAD, the negative likelihood ratio for 30-day MACE was 0.08, a rule-out signal strong enough to support discharge conversations. Missed-event context matters: Several adverse events in the no-CAD group were tied to protocol violations, noncardiac death, or revascularization without MI, an important caveat behind the headline reassurance.