ood of ROSC [5]. Thus, capnography may help identify which adults undergoing CPR are likely to develop a perfusing rhythm. (See "Carbon dioxide monitoring (capnography)", section on 'Return of spontaneous circulation'.)
ENVIRONMENTAL EMERGENCIES
Scoring systems for the diagnosis of acute mountain sickness (January 2018)
Acute mountain sickness (AMS) is diagnosed clinically based upon the appearance of typical symptoms in a person who lives at low altitude but has recently ascended to high altitude (generally over 2000 m). Although most experts do not routinely use scoring systems to diagnose AMS in practice, clinical studies often use them. In a systematic review of 91 studies (almost 67,000 patients), the accuracy of instruments to diagnose AMS (eg, Acute Mountain Sickness-Cerebral score, Visual Analog Scale for the Overall Feeling of Mountain Sickness, or the Clinical Functional Score [CFS]) was assessed using the Lake Louise Questionnaire Score (LLQS) (table 1) as the standard [6]. All evaluated scores had similar diagnostic accuracy when compared with a LLQS >5. In particular, the CFS was easy to administer relative to the other scores and may be a reasonable screening tool to identify potential patients with AMS in high altitude clinics or in research studies. (See "Acute mountain sickness and high altitude cerebral edema", section on 'AMS diagnosis'.)
GENERAL ADULT EMERGENCY MEDICINE
Vasopressin as a second agent in septic shock (May 2018)
In patients with distributive shock from sepsis, norepinephrine is the agent of choice, but the optimal additive agent is unknown. One recent meta-analysis of 23 trials reported that the addition of vasopressin to catecholamine agents (eg, epinephrine, norepinephrine) in such patients did not decrease mortality, but it did result in a lower rate of atrial fibrillation [7]. Although not specifically studied, the protective effect of vasopressin on arrhythmia is likely due to a reduced need for catecholamines. Despite the lack of mortality benefit, these results provide support for vasopressin as an additive agent to norepinephrine in patients with septic shock whose blood pressure does not respond to a catecholamine alone. (See "Evaluation and management of suspected sepsis and septic shock in adults", section on 'Vasopressors'.)
Intravenous thrombolysis in patients with an unknown stroke onset time (May 2018)
Standard treatment with intravenous atleplase is indicated for eligible patients with acute ischemic stroke. However, many patients do not qualify because more than 4.5 hours have passed since they were last known to be without stroke symptoms. The placebo-controlled Wake-Up Stroke trial selected 500 adults with unwitnessed stroke onset (most awoke from sleep with stroke symptoms) who had an ischemic parenchymal brain lesion on magnetic resonance imaging (MRI) diffusion-weighted imaging but no corresponding hyperintensity on fluid-attenuated inversion recovery (FLAIR) [8]. This imaging constellation correlates with a stroke onset time of 4.5 hours or less. At 90 days, a favorable outcome was more likely for patients assigned to intravenous alteplase compared with those assigned to placebo (53 versus 42 percent). However, the mortality rate and the rate of symptomatic intracranial hemorrhage were both nonsignificantly higher in the alteplase group. Although this approach seems promising, additional trials are needed to determine the efficacy and safety of intravenous alteplase for patients with unknown stroke onset time and a mismatch pattern on imaging. (See "Approach to reperfusion therapy for acute ischemic stroke", section on 'Benefit with imaging mismatch'.)
Etanercept for Stevens-Johnson syndrome/toxic epidermal necrolysis (May 2018)
Limited evidence suggests that tumor necrosis factor (TNF)-alpha inhibitors may be effective in patients with Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN). In a randomized trial including 91 patients with SJS/TEN, treatment with etanercept, an anti-TNF fusion protein, was associated with a shorter time to complete
ENVIRONMENTAL EMERGENCIES
Scoring systems for the diagnosis of acute mountain sickness (January 2018)
Acute mountain sickness (AMS) is diagnosed clinically based upon the appearance of typical symptoms in a person who lives at low altitude but has recently ascended to high altitude (generally over 2000 m). Although most experts do not routinely use scoring systems to diagnose AMS in practice, clinical studies often use them. In a systematic review of 91 studies (almost 67,000 patients), the accuracy of instruments to diagnose AMS (eg, Acute Mountain Sickness-Cerebral score, Visual Analog Scale for the Overall Feeling of Mountain Sickness, or the Clinical Functional Score [CFS]) was assessed using the Lake Louise Questionnaire Score (LLQS) (table 1) as the standard [6]. All evaluated scores had similar diagnostic accuracy when compared with a LLQS >5. In particular, the CFS was easy to administer relative to the other scores and may be a reasonable screening tool to identify potential patients with AMS in high altitude clinics or in research studies. (See "Acute mountain sickness and high altitude cerebral edema", section on 'AMS diagnosis'.)
GENERAL ADULT EMERGENCY MEDICINE
Vasopressin as a second agent in septic shock (May 2018)
In patients with distributive shock from sepsis, norepinephrine is the agent of choice, but the optimal additive agent is unknown. One recent meta-analysis of 23 trials reported that the addition of vasopressin to catecholamine agents (eg, epinephrine, norepinephrine) in such patients did not decrease mortality, but it did result in a lower rate of atrial fibrillation [7]. Although not specifically studied, the protective effect of vasopressin on arrhythmia is likely due to a reduced need for catecholamines. Despite the lack of mortality benefit, these results provide support for vasopressin as an additive agent to norepinephrine in patients with septic shock whose blood pressure does not respond to a catecholamine alone. (See "Evaluation and management of suspected sepsis and septic shock in adults", section on 'Vasopressors'.)
Intravenous thrombolysis in patients with an unknown stroke onset time (May 2018)
Standard treatment with intravenous atleplase is indicated for eligible patients with acute ischemic stroke. However, many patients do not qualify because more than 4.5 hours have passed since they were last known to be without stroke symptoms. The placebo-controlled Wake-Up Stroke trial selected 500 adults with unwitnessed stroke onset (most awoke from sleep with stroke symptoms) who had an ischemic parenchymal brain lesion on magnetic resonance imaging (MRI) diffusion-weighted imaging but no corresponding hyperintensity on fluid-attenuated inversion recovery (FLAIR) [8]. This imaging constellation correlates with a stroke onset time of 4.5 hours or less. At 90 days, a favorable outcome was more likely for patients assigned to intravenous alteplase compared with those assigned to placebo (53 versus 42 percent). However, the mortality rate and the rate of symptomatic intracranial hemorrhage were both nonsignificantly higher in the alteplase group. Although this approach seems promising, additional trials are needed to determine the efficacy and safety of intravenous alteplase for patients with unknown stroke onset time and a mismatch pattern on imaging. (See "Approach to reperfusion therapy for acute ischemic stroke", section on 'Benefit with imaging mismatch'.)
Etanercept for Stevens-Johnson syndrome/toxic epidermal necrolysis (May 2018)
Limited evidence suggests that tumor necrosis factor (TNF)-alpha inhibitors may be effective in patients with Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN). In a randomized trial including 91 patients with SJS/TEN, treatment with etanercept, an anti-TNF fusion protein, was associated with a shorter time to complete