What's new in emergency medicine

The following represent additions to UpToDate from the past six months that were considered by the editors and authors to be of particular interest. The most recent What's New entries are at the top of each subsection.

ADULT RESUSCITATION

ECMO for severe hypothermia in adults (February 2023)

In patients with cardiac arrest from severe hypothermia, extracorporeal life support (eg, ECMO) provides rapid active internal rewarming and may improve survival. In a multicenter, prospective study (ICE-CRASH) that included 242 patients with severe hypothermia (mostly older adults with indoor-onset hypothermia), in the 57 patients with cardiac arrest, treatment with ECMO (24 patients) was associated with better 28-day survival (adjusted odds ratio [OR] 0.17) and favorable neurologic outcome (adjusted OR 0.22) [1]. In patients without cardiac arrest, treatment with ECMO (17 patients) was not associated with improved 28-day survival or favorable neurologic outcomes but was associated with more adverse events such as bleeding. These findings support our recommendation for using ECMO, when available, in patients with severe hypothermia and a nonperfusing cardiac rhythm. (See "Accidental hypothermia in adults", section on 'Extracorporeal life support'.)

Restrictive versus liberal fluid regimen does not impact mortality in refractory sepsis (February 2023)

The optimal approach to adults with sepsis refractory to initial fluid resuscitation is unclear. In a recent trial of over 1500 patients with sepsis-induced hypotension refractory to initial resuscitation, 90-day mortality was not significantly different between a restrictive fluid regimen (prioritizing vasopressors and lower intravenous fluid volumes) or a more "liberal" regimen (prioritizing higher volumes of intravenous fluids before vasopressor use) [2]. Vasopressors were administered earlier and for longer periods in those who received the restrictive regimen without excess adverse effects. This study suggests that fluid restriction with early initiation of vasopressors compared with more liberal fluid administration similar to current practice does not decrease mortality. (See "Evaluation and management of suspected sepsis and septic shock in adults", section on 'Volume'.)

High-flow oxygen for acute respiratory failure due to COVID-19 (January 2023)

In patients with acute hypoxemic respiratory failure due to coronavirus disease 2019 (COVID-19), high-flow oxygen delivered via nasal cannulae (HFNC) is used to lower intubation rates. In a recent randomized trial in >700 patients with respiratory failure due to COVID-19, use of HFNC resulted in lower intubation rates compared with standard low-flow oxygen (45 versus 53 percent) without an impact on mortality or ventilator-free days [3]. These results, along with outcomes from a prior trial, support our practice of switching to HFNC in adults with COVID-19 who have advanced respiratory needs rather than increasing low-flow oxygen (eg, above 6 L per minute). (See "COVID-19: Respiratory care of the nonintubated hypoxemic adult (supplemental oxygen, noninvasive ventilation, and intubation)", section on 'Noninvasive modalities'.)

Video laryngoscopy for emergency intubation in adults (December 2022)

Video laryngoscopes (VLs) are rigid devices that allow glottic visualization without a direct line of sight, and they are increasingly being used for rapid sequence intubation in the emergency department. In a meta-analysis of 222 trials in adults (most in the elective surgery setting), Macintosh-style, hyperangulated, and channelled VLs all reduced the rate of failed intubation, increased first-pass attempt success, improved the glottic view, and reduced peri-intubation hypoxia compared with a direct laryngoscope (DL) [4]. Given these findings, we suggest using a VL, if available, instead of a DL when laryngoscopy is indicated for emergency intubation. (See "Overview of advanced airway management in adults for emergency medicine and critical care", section on 'Choice of laryngoscopy technique'.)

ENVIRONMENTAL EMERGENCIES

Neurotoxicity after Southern Pacific rattlesnake envenomation (March 2023)

Acute neurotoxicity is uncommon after most North American snakebites. A case series of seven patients bitten by the Southern Pacific rattlesnake (Crotalus helleri) in the Los Angeles and San Diego regions described neurotoxicity such as paresthesias, truncal ataxia, dysarthria, dysphagia, weakness, and myokymia (rippling muscle movement) [5]. These patients also had local tissue and hematologic toxicity typically associated with North American rattlesnake envenomation. They were treated with antivenom and had eventual resolution in neurologic symptoms; all but one individual required repeat dosing. Neurotoxicity is a rare feature of Southern Pacific rattlesnake envenomation. When managing rattlesnake bites in its geographical range (southern California into Baja Mexico), clinicians should be aware of potential neurotoxicity, which is an indication for timely antivenom. (See "Bites by Crotalinae snakes (rattlesnakes, water moccasins [cottonmouths], or copperheads) in the United States: Clinical manifestations, evaluation, and diagnosis", section on 'Venom properties'.)

GENERAL ADULT EMERGENCY MEDICINE

Mechanical thrombectomy for large ischemic core infarcts (February 2023)

Mechanical thrombectomy (MT) for acute ischemic stroke due to a large artery occlusion in the anterior circulation has been limited to patients with a small- to moderate-sized core infarct at baseline. The exclusion of patients with large core infarcts was first challenged in 2022 by results from the RESCUE-Japan LIMIT. The recent SELECT2 and ANGEL-ASPECT trials now confirm that MT compared with medical treatment alone improves outcomes for patients with a large ischemic core infarct (defined by an Alberta Stroke Program Early CT Score [ASPECTS] <6 or a core volume ≥50 ml) [6,7]. As an example, the SELECT2 trial showed that functional independence for patients with large infarcts was more likely with MT than with medical care alone (20 versus 7 percent) [6]. Based on these results, in addition to previously defined eligible groups, we now recommend MT for patients who have a large ischemic core infarct as defined in these trials and can start treatment within 24 hours of the time last known to be well. (See "Mechanical thrombectomy for acute ischemic stroke", section on 'Benefit for large core infarcts'.)

Ultrasound in patients with suspected peritonsillar abscess (February 2023)

In patients with peritonsillar infection, physical examination may not accurately distinguish peritonsillar abscess (PTA) from peritonsillar cellulitis. In a meta-analysis of 17 studies (812 patients, mostly adults), ultrasound (US) was able to distinguish PTA from peritonsillar cellulitis with a pooled sensitivity of 86 percent and specificity of 76 percent [8]. Subgroup analysis suggested improved diagnostic characteristics for radiologist-performed US. These findings support our suggestion for US by an experienced clinician, if available, to distinguish PTA from peritonsillar cellulitis. (See "Peritonsillar cellulitis and abscess", section on 'Imaging'.)

Removal of X-waiver requirement to prescribe buprenorphine for opioid use disorder (February 2023)

Previously, in order to prescribe buprenorphine for opioid use disorder (OUD) in the United States, clinicians had to apply for a federally required DATA Waiver (X-Waiver). In January 2023, the Consolidated Appropriations Act of 2023 removed this requirement and allowed clinicians with schedule III authority on their Drug Enforcement Administration (DEA) registration to prescribe buprenorphine for OUD treatment if permitted by applicable state law [9]. We believe this change will encourage buprenorphine prescribing and thus prevent opioid overdose. (See "Acute opioid intoxication in adults", section on 'Prevention of recurrent opioid overdose'.)

Ultrasound-guided peripheral venous cannulation in adults (January 2023)

Point-of-care real-time ultrasound guidance is commonly used for peripheral intravenous (PIV) catheter placement. A meta-analysis of >2200 adults undergoing PIV placement found that ultrasound guidance, compared with the landmark technique, increased first-pass success rate and overall success rate in patients with difficult access (eg, failed access by landmark approach, no apparent or palpable veins, history of difficult PIV placement) [10]. There was no difference in pain or overall complications, but ultrasound guidance did increase the time to first-pass cannulation by two minutes and did not demonstrate a benefit in patients with easy IV access. These results support our recommendation for ultrasound-guided PIV placement in patients with anticipated difficulty or two failed attempts at the landmark technique. (See "Peripheral venous access in adults", section on 'Role of ultrasound guidance'.)

CDC updates opioid prescribing guidelines (November 2022)

The United States Centers for Disease Control and Prevention (CDC) has published a new guideline for prescribing opioids for acute, subacute, and chronic pain, updating their 2016 guideline (table 1). The guideline is intended for clinicians who prescribe opioids to outpatients ≥18 years of age and does not apply to pain related to sickle cell disease, cancer, palliative care, or end of life care [11]. (See "Use of opioids in the management of chronic non-cancer pain", section on 'Opioid therapy in the context of the opioid epidemic'.)

Complications of physician burnout (September 2022)

Physician burnout appears to adversely affect career engagement and patient care. A meta-analysis that included 170 observational studies with >230,000 physician participants found that physicians with burnout were more than three times as likely to be dissatisfied with their career, regret their career choice, and think about leaving their job [12]. In addition, physicians with burnout were twice as likely to be involved in patient safety incidents, have low professionalism, and to receive low patient satisfaction ratings. Interventions to mitigate burnout should be implemented. (See "Unipolar depression in adults: Assessment and diagnosis", section on 'Burnout'.)

GENERAL PEDIATRIC EMERGENCY MEDICINE

HFNC oxygen therapy for mild to moderate acute hypoxemic respiratory failure in children (February 2023)

Evidence is limited regarding the role of high-flow nasal cannula (HFNC) oxygen therapy for children with mild to moderate acute hypoxemic respiratory failure (AHRF). In the multicenter PARIS-2 trial, over 1500 children hospitalized with AHRF defined as increased work of breathing, respiratory rate ≥35 per minute, and oxygen requirement to maintain pulse oximetry over 90 to 92 percent were randomized to HFNC or standard oxygen therapy; wheezing was present in approximately three-quarters of patients. Patients assigned to HFNC oxygen therapy, compared with standard oxygen therapy, had longer length of stay (1.77 versus 1.50 days) and more ICU admissions (12.5 versus 6.9 percent) [13]. Adverse events were low in both groups. These findings do not support the routine use of oxygen delivery by HFNC in young children with mild to moderate AHRF. (See "High-flow nasal cannula oxygen therapy in children", section on 'Indications'.)

Revised CDC MIS-C case definition (February 2023)

The case definition for multisystem inflammatory syndrome in children (MIS-C) that was revised by the United States Council of State and Territorial Epidemiologists/Centers for Disease Control (CSTE/CDC) and implemented in 2023 aligns closely with the World Health Organization (WHO) MIS-C criteria [14-16]. Both definitions require fever, elevated inflammatory markers, at least two signs of multisystem involvement, evidence of SARS-CoV-2 infection or exposure, and exclusion of other potential causes. One important change is that the CTSE/CDC MIS-C case definition designates Kawasaki disease (KD) as an alternative diagnosis that should trigger reporting to the CDC KD passive surveillance system. (See "COVID-19: Multisystem inflammatory syndrome in children (MIS-C) clinical features, evaluation, and diagnosis", section on 'CDC and WHO case definitions'.)

Pediatric early warning scores in hospitalized children (January 2023)

Pediatric early warning scores (PEWS) are used to identify hospitalized children whose condition may be worsening and to prompt rapid assessment and specific intervention. The effect of PEWS was reviewed as part of the 2022 International Liaison Committee on Resuscitation (ILCOR) consensus recommendations [17]. In the single randomized trial of PEWS in 21 pediatric hospitals, fewer clinical deterioration events (eg, endotracheal intubation, fluid resuscitation, or CPR) occurred in hospitals using PEWS compared with those that did not, and there was a nonsignificant trend towards lower mortality. Meta-analysis of nine cohort studies found similar results, with nonsignificant differences in mortality and other endpoints favoring use of PEWS. Although the overall quality of the evidence is low, we agree with the ILCOR consensus and suggest use of PEWS in all hospitalized children. (See "Pediatric advanced life support (PALS)", section on 'Pediatric early warning scores'.)

Risk of meningitis in febrile young infants with a positive urinalysis (October 2022)

Existing American Academy of Pediatrics guidelines suggest that cerebrospinal fluid (CSF) studies be obtained in otherwise low-risk febrile young infants (29 to 60 days old) with elevated blood inflammatory markers (IMs) (table 2), independent of urinalysis (UA) results. However, prior studies have found that for these infants, the risk of meningitis is low. In a secondary analysis of a prospective cohort study of nearly 700 well-appearing, previously healthy, febrile young infants (29 to 60 days old) with a positive UA, none had bacterial meningitis, including the 204 individuals with elevated procalcitonin or absolute neutrophil count [18]. Based on these findings, for otherwise low-risk febrile young infants 29 to 60 days old with elevated IMs and a positive UA, we no longer suggest obtaining CSF studies. Our practice is unchanged with regard to febrile infants in this age group who have elevated IMs and a negative UA (CSF recommended) or normal IMs and a positive UA (CSF not recommended). (See "The febrile infant (29 to 90 days of age): Outpatient evaluation", section on '29 to 60 days old'.)

PEDIATRIC RESUSCITATION

Calcium administration during CPR in children with heart disease (November 2022)

According to the American Heart Association (AHA) guidelines, the use of calcium during pediatric cardiopulmonary resuscitation (CPR) is limited to specific indications (ie, hypocalcemia, hyperkalemia, hypermagnesemia, or calcium channel blocker overdose). However, calcium administration remains common during CPR in children with heart disease. In a retrospective study of the AHA resuscitation registry that included over 4500 children with heart disease and in-hospital cardiac arrest, 44 percent of patients received calcium [19]. In a propensity-matched cohort of over 1300 patients, calcium administration versus no calcium administration was associated with lower survival to hospital discharge (39.4 versus 45.6 percent) and lower survival to hospital discharge with favorable neurologic outcome (27.8 versus 34. 2 percent). These findings confirm prior observational studies regarding the detrimental effects of calcium during CPR. For children with cardiac arrest and heart disease, calcium administration should be confined to indications recommended by the AHA. (See "Primary drugs in pediatric resuscitation", section on 'Calcium'.)

Sodium bicarbonate administration during pediatric CPR (October 2022)

According to the American Heart Association guidelines, the use of sodium bicarbonate during pediatric cardiopulmonary resuscitation (CPR) is limited to specific indications (ie, hyperkalemia, hypermagnesemia, and overdose with prolonged QRS duration or tachyarrhythmias). In a propensity-matched cohort study of infants and children (1100 children, median age 0.6 years) who received CPR in a pediatric intensive care unit, sodium bicarbonate was given to 528 individuals who had no approved indications and was associated with lower survival to hospital discharge with favorable neurologic outcome compared with matched controls (adjusted odds ratio 0.69) [20]. These findings confirm prior observational studies. For children with cardiac arrest who do not have the above conditions, the routine use of sodium bicarbonate is not recommended. (See "Primary drugs in pediatric resuscitation", section on 'Sodium bicarbonate'.)

Administration of vasoactive therapy by peripheral IV in children with shock (October 2022)

For children with shock who require vasoactive therapy, central venous access is preferred. However, delivery of vasoactive therapy by peripheral intravenous (PIV) access may be used during initial resuscitation while central venous access is obtained. In a recent retrospective cohort study of over 750 critically ill children receiving vasoactive infusions for shock, of 231 children who initially received vasoactive therapy by PIV (93 patients with septic shock), extravasation occurred in 4 patients (1.7 percent, all hand vein sites) with no long-term complications; 46 percent of these patients ultimately did not require central venous access and had full recovery [21]. These findings confirm prior data that the delivery of dilute vasoactive medications by the most proximal peripheral vein in selected children with shock is safe. The decision and timing of central venous catheter placement depends on the expected severity and trajectory of shock, as well as other clinical needs that may require central venous access. (See "Septic shock in children: Rapid recognition and initial resuscitation (first hour)", section on 'Indications for vasoactive agents'.)

PROCEDURES

Video laryngoscopy for emergency endotracheal intubation in children (January 2023)

Laryngeal exposure with visualization of the glottis is a key determinant of success or failure for emergency endotracheal intubation (ETI) in children. In a prospective cohort study of over 1400 children undergoing ETI in pediatric emergency departments, use of video laryngoscopy (VL) with standard geometry blades, when compared with traditional direct laryngoscopy (DL), was associated with higher odds of first-attempt success and decreased odds of severe adverse airway outcomes such as aspiration, severe hypoxia, unrecognized esophageal intubation, hypotension, or cardiac arrest [22]. Based on these and other data, we suggest routine use of VL, if readily available, for emergency intubation in children. However, some experienced clinicians continue to prefer DL based upon their expertise. (See "Emergency endotracheal intubation in children", section on 'Laryngoscopy'.)

Role of wound packing after drainage of perianal and perirectal abscess (September 2022)

After incision and drainage of a perianal or perirectal abscess, it is common practice to pack the wound, under the assumption that this will facilitate further drainage by wicking and prevent premature skin closure. In the PPAC2 trial of 443 patients with a primary perianal abscess, nonpacking, compared with packing, resulted in similar rates of fistula formation (11 versus 15 percent) and abscess recurrence (6 versus 3 percent), differences that were not statistically significant [23]. However, the nonpacking group had lower average pain scores (28 versus 38 on a 100-point visual analog scale). Given these and similar findings from two earlier small trials, we now suggest not packing the wound after drainage of perianal or perirectal abscess. (See "Perianal and perirectal abscess", section on 'Role of wound packing'.)

TOXICOLOGY

Toxicity with combined acetaminophen/opioid products (March 2023)

Patients taking combined acetaminophen/opioid formulations are at risk for unintentional acetaminophen overdose and hepatotoxicity. As a consequence, in 2011 the US Food and Drug Administration announced a mandate (effective in 2014) limiting acetaminophen to 325 mg in combined opioid formulations. An interrupted time-series analysis of a large hospitalization database and multicenter liver failure study group (nearly 40,000 and 465 cases of combined acetaminophen/opioid toxicity, respectively) found that since 2011 there has been a significant decrease in hospitalizations and percentage of acute liver failure cases caused by combined acetaminophen/opioid products [24]. In patients taking medications containing acetaminophen and in those who present with unexplained liver injury, it is important to review the total daily acetaminophen dose to prevent hepatoxicity and to investigate a cause for hepatoxicity, respectively. (See "Acetaminophen (paracetamol) poisoning in adults: Pathophysiology, presentation, and evaluation", section on 'Epidemiology'.)

Isotonitazene, a potent synthetic opioid, identified in opioid overdose outbreak (March 2023)

Isotonitazene is a synthetic opioid that is more potent than fentanyl and was first reported several years ago after entering the illicit drug market. In a case report from the United Kingdom, isotonitazene was identified in 2 individuals out of a 23-patient cluster of acute opioid poisoning that presented to the same London emergency department with coma, miosis, and depressed respirations over the course of a month [25]. Both patients had reversal of toxicity after naloxone administration, but one patient needed repeat doses. Isotonitazene has also been identified as causing opioid poisoning in several regions of the United States by the Drug Enforcement Agency. Isotonitazene is structurally different from fentanyl and is not detected by hospital-based rapid drug screens for opioids. It should be suspected in any patient with clinical features of opioid poisoning and may require multiple doses of naloxone to reverse toxicity. (See "Acute opioid intoxication in adults", section on 'Isotonitazene and other benzimidazoles'.)

Hyperbaric oxygen for hydrogen peroxide poisoning (February 2023)

Ingestion of concentrated hydrogen peroxide (H₂O₂, >10% solution) or high-volume ingestion of lower concentrations of H₂O₂ (eg, 3% antiseptic) can cause air-gas embolism with life-threatening toxicity. Hyperbaric oxygen (HBO) may reduce embolism size and enhance reabsorption, but the efficacy and optimal timing are unclear. In a systematic review of 126 patients with H₂O₂ poisoning, 78 developed air-gas emboli, and 54 received HBO [26]. None of 30 patients with portal venous gas treated with HBO developed systemic air-gas emboli versus 8 of 33 who did not. Full recovery occurred in 13 of 23 who received HBO for air-gas emboli, compared with 23 of 55 who did not. Patients with a full recovery may have received HBO several hours earlier. These findings suggest that HBO may prevent systemic air-gas emboli if performed for HNone of 30 patients with portal venous gas treated with HBO developed systemic air-gas emboli versus 8 of 33 who did not. Full recovery occurred in 13 of 23 who received HBO for air-gas emboli, compared with 23 of 55 who did not. Patients with a full recovery may have received HBO several hours earlier. These findings suggest that HBO may prevent systemic air-gas emboli if performed for HOOpoisoning complicated by portal venous gas and facilitate recovery if embolism develops. (See "Hyperbaric oxygen therapy", section on 'Hydrogen peroxide exposure'.)

Nitrous oxide misuse and venous thromboembolism (February 2023)

Nitrous oxide misuse has been associated with venous thromboembolism (VTE), such as ischemic stroke, myocardial infarction, and pulmonary embolism. Nitrous oxide can also increase plasma homocysteine concentrations, which has been associated with an increased risk of VTE. A single-center, retrospective study of patients with recreational nitrous oxide misuse (326 patients) identified 17 patients, mostly young, with a VTE event [27]. In 9 patients with measured homocysteine concentrations, 8 had an elevation in homocysteine concentrations (7 considered moderate-severe). In a young patient with a VTE and no risk factors, the clinician should ask about nitrous oxide misuse. Hyperhomocysteinemia may be a contributing mechanism to VTE in these patients. (See "Inhalant misuse in children and adolescents", section on 'Nitrous oxide'.)

Serotonin syndrome after serotonin reuptake inhibitor overdose (February 2023)

The serotonin syndrome is a clinical diagnosis (algorithm 1) that may occur after administration or overdose of serotonergic agents (table 3). In a retrospective cohort of over 2200 patients admitted to a regional toxicology service for an overdose of a serotonin selective reuptake inhibitor (SSRI) or serotonin-norepinephrine reuptake inhibitor (SNRI), 269 (14 percent) developed serotonin syndrome [28]. The incidence of serotonin syndrome was slightly higher in patients who ingested an SNRI (desvenlafaxine, venlafaxine) compared with an SSRI. However, coingestion of the monoamine oxidase inhibitor (MAOI) moclobemide was associated with a fivefold increased risk of serotonin syndrome. In patients who have ingested an SNRI or SSRI, coingestion of an MAOI markedly increases the probability that they will develop serotonin syndrome. (See "Serotonin syndrome (serotonin toxicity)", section on 'Epidemiology'.)

Home monitoring of exploratory pediatric second-generation sulfonylurea ingestions (January 2023)

Sulfonylurea ingestion can cause delayed and prolonged hypoglycemia in young children, although the risk appears to be lower after ingestion of a second-generation sulfonylurea (eg, glyburide, gliclazide, glipizide, or glimepiride). In a retrospective case series from a single poison control center, 115 children (≤5 years old) ingested no more than one nonextended-release, second-generation sulfonylurea and were monitored at home. Five patients had asymptomatic hypoglycemia after referral to a health care facility and none had severe adverse effects [29]. Although this study provides some support for home monitoring of selected children with second-generation sulfonylurea ingestion, more evidence is needed to establish the safety of this approach, especially for children with ready access to an acute care facility or who would require home monitoring overnight. In these situations, we recommend in-hospital observation for 12 to 24 hours. (See "Sulfonylurea agent poisoning", section on 'Pediatric considerations'.)

Xylazine adulteration of illicit drugs (December 2022)

Xylazine is an alpha-2 agonist and a chemical analogue of clonidine that is used in veterinary medicine for sedation and analgesia. In humans, xylazine overdose has caused major toxicity consisting of coma, apnea, bradycardia, and hypotension as well as severe, necrotic skin ulcerations after repeated parenteral use. Xylazine is increasingly found as an adulterant in illicit drugs, especially heroin and fentanyl, with rising reports of serious side effects. As a result, the US Food and Drug Administration has issued an alert to health care professionals and a letter to stakeholders [30]. Xylazine poisoning is on the differential diagnosis for patients with suspected opioid overdose that does not respond to naloxone administration. Treatment consists of supportive care. There is no rapid diagnostic testing for xylazine poisoning or safe antidote. (See "Clonidine and related imidazoline poisoning", section on 'Imidazoline agents'.)

Severe complications of button battery ingestion in children (October 2022)

Button battery (BB) ingestion with esophageal impaction in children is a true emergency that can cause life-threatening complications. In a systematic review of 361 pediatric cases of BB ingestion resulting in severe complications (95 percent with esophageal impaction), death occurred in 19 percent of patients [31]. Hemorrhage from vascular injuries, primarily aortoesophageal fistulae, was the most common cause of death. Among patients with vascular injuries, those who died had a longer duration of impaction than those who survived (median 144 versus 11 hours, respectively). These findings highlight the importance of timely recognition of BB ingestion with esophageal impaction and emergency BB removal. (See "Button and cylindrical battery ingestion: Clinical features, diagnosis, and initial management", section on 'Complications'.)

TRAUMA

No additional benefit of 4F-PCC during massive transfusion of trauma patients (March 2023)

The benefit of empiric administration of 4-factor prothrombin complex concentrate (4F-PCC) to trauma patients with severe hemorrhage is unclear. The PROCOAG trial randomized 324 adults at risk for massive transfusion to either 4F-PCC or placebo in addition to a fixed ratio of packed red blood cells and fresh frozen plasma. Blood products consumed over 24 hours and mortality were similar in the two groups, but individuals assigned to 4F-PCC had a higher rate of thromboembolic events (35 versus 24 percent) [32]. These results support our practice of not empirically administering 4F-PCC to trauma patients with severe hemorrhage unless they are anticoagulated. (See "Initial management of moderate to severe hemorrhage in the adult trauma patient", section on 'Severe ongoing hemorrhage'.)

NEXUS Chest criteria for imaging in adult blunt trauma patients (March 2023)

Most adults with blunt thoracic trauma are routinely evaluated with a chest radiograph or chest computed tomography scan. The NEXUS Chest rule (algorithm 1) has been derived and validated to help determine which patients can safely forego chest imaging but is not used universally. In a meta-analysis of five prospective studies (nearly 21,000 patients), the NEXUS Chest criteria had high sensitivity (99 percent) but low specificity (32 percent) for the detection of chest injuries [33]. For patients who had none of the NEXUS Chest criteria, the likelihood of having a chest injury was very low. These findings support our recommendation to not obtain chest imaging in a hemodynamically stable adult (14 years old) with blunt trauma who meets none of the NEXUS Chest criteria. (See "Initial evaluation and management of blunt thoracic trauma in adults", section on 'When CXR is not needed (NEXUS)'.)

Aspirin for venous thromboembolism prophylaxis in multiple-trauma patients (January 2023)

Aspirin is an effective alternative for venous thromboembolism (VTE) prophylaxis in patients undergoing elective orthopedic surgery, but it’s role in trauma-related orthopedic surgery is not well-defined. The PREVENT CLOT trial has now evaluated aspirin in trauma patients with fractures and undergoing surgical fracture fixation [34]. In this trial, which randomized over 12,000 patients, aspirin was noninferior to low molecular weight heparin. Differences in rates of death, pulmonary embolism, deep venous thrombosis, bleeding, and other complications were not clinically significant. This trial supports a role for aspirin for VTE prophylaxis in multiple-trauma patients with orthopedic injuries, but more evidence is needed to determine the optimal timing (initiation) and duration of aspirin therapy before its use can become routine. (See "Venous thromboembolism risk and prevention in the severely injured trauma patient", section on 'Aspirin'.)