The US military experience with THAM.

BACKGROUND: Acidosis, a part of the lethal trauma triad, occurs frequently after major combat trauma. Tris-hydroxymethyl aminomethane (THAM) has been used to effectively treat acidosis in injured casualties. No research has been conducted assessing the safety of THAM in the military combat setting. We sought to describe the US military experience with THAM administration to battlefield injury subjects. METHODS: We conducted a retrospective descriptive cohort study reviewing the trauma data from the Department of Defense Trauma Registry. US military personnel with an injury severity score greater than 15, between September 2001 and December 2014, were analyzed. Our primary outcome was the 30-day all-cause mortality among cohort treated with THAM versus those who were not. Differences between the cohort were examined using a student t-test (continuous variables), Wilcoxon Rank Sum test (ordinal variables), and chi-squared test (nominal variables). RESULTS: 4558 subjects met the inclusion criteria. 69 received THAM and 4489 did not. Casualties receiving THAM had higher mean ISS scores (33 vs. 27, p < 0.001), and required significantly higher amounts of packed red blood cells (RBCs, 37 vs. 10, p < 0.001). THAM cohort had longer ventilator and intensive care unit (ICU) days with an overall lower survival to hospital discharge. On univariable analysis, THAM was associated with lower odds of survival (OR 0.18, 95% CI 0.11-0.31) but on multivariable analysis, when controlling for confounders, THAM use was not associated with a worse odds of survival (OR 0.83, 95% CI 0.21-3.24). CONCLUSIONS: Within our combat trauma population, we were unable to detect worse 30 day mortality associated with THAM administration. Prospective investigations are needed to validate its use in critically injured combat casualties.

The THINK (Treatment of Headache with Intranasal Ketamine) Trial: A Randomized Controlled Trial Comparing Intranasal Ketamine with Intravenous Metoclopramide.

BACKGROUND: Headache is a common chief complaint in the emergency department (ED) setting. OBJECTIVES: To compare analgesia with metoclopramide and diphenhydramine vs. intranasal ketamine among ED patients with primary headache. METHODS: We enrolled a convenience sample of adults with a primary headache in a randomized, single-blind, placebo-controlled trial. We randomized patients to either a control arm (intravenous metoclopramide and diphenhydramine) or intranasal ketamine. The primary outcome was change in pain 0-100 mm visual analog scale (VAS) score measured at study start and 30 min post completion of initial medication administration. Secondary outcomes included side effects, hospital admission, and return to care within 48-72 h. RESULTS: All 53 enrolled subjects completed the study, 26 of whom were allocated to the control arm and 27 to intranasal ketamine. The mean change in pain VAS score at 30 min post intervention was 22.2 mm in the control arm vs. 29.0 in the intranasal ketamine arm (effect size difference 6.8 mm, 95% confidence interval -5.8-19.4). The incidence of reported side effects was 65.4% in the control arm vs. 66.7% in the ketamine arm. Three patients (11.5%) allocated to the control arm required admission for headache pain control vs. 1 patient (3.7%) in the intranasal ketamine arm. Three (11.5%) additional patients in the control arm returned to the ED within 48-72 h for headache pain vs. none in the ketamine arm. CONCLUSIONS: In this small randomized study, intranasal ketamine was not superior to standard therapy among ED patients with primary headache syndromes.

An uncommon cause of vision loss: Leber hereditary optic neuropathy.

Leber hereditary optic neuropathy (LHON) is a rare mitochondrial genetic disorder characterized by painless acute or subacute vision loss that develops during adolescence. Clinicians should know how to identify potential LHON and when to refer patients to a neuro-ophthalmologist for diagnosis and treatment. This case highlights the value of a thorough family history in ED patients.

Association between seatbelt sign and internal injuries in the contemporary airbag era: A retrospective cohort study.

BACKGROUND: Literature predating routine availability of airbags reported an association between seatbelt signs and internal injuries. We measured this association among patients involved in motor vehicle crashes (MVCs) with airbag deployment. METHODS: We conducted a retrospective cohort study by chart review of all MVC patients presenting to our Emergency Department (ED) during 1 January 2008-30 September 2015. We included all adult MVC patients in the driver or front passenger seats with both shoulder and lap seatbelts and airbag deployment. Two trained chart abstractors recorded data regarding restraints and airbag deployment. We obtained all other data via electronic medical record abstraction including demographics, injuries, and survival. We compared the prevalence of cervicothoracic and intra-abdominopelvic injuries between patients with a documented seatbelt sign versus no seatbelt sign using a logistic regression model. RESULTS: Of 1379 MVC patients, 350 met inclusion criteria. Of these, 138 (39.4%) had a seatbelt sign. The prevalence of cervicothoracic injury was higher among subjects with a documented seatbelt sign (54.3% versus 42.9%, p=0.036) Seatbelt sign predicted cervicothoracic injury with a positive likelihood ratio of 1.3 (95% CI 1.0-1.7) and negative likelihood ratio of 0.8 (95% CI 0.7-1.0). The odds ratio of cervicothoracic injury among patients with a seatbelt sign versus no seatbelt sign was 1.58 (95% confidence interval 1.02-2.46) in the logistic regression model. There was no association between seatbelt sign and intra-abdominopelvic injury (p=0.418). CONCLUSIONS: In the setting of airbag deployment, there is an association between seatbelt sign and cervicothoracic injury but not intra-abdominopelvic injury.

Single Rescuer Ventilation Using a Bag Valve Mask with Removable External Handle: A Randomized Crossover Trial.

Introduction Ventilation with a bag valve mask (BVM) is a challenging but critical skill for airway management in the prehospital setting. Hypothesis Tidal volumes received during single rescuer ventilation with a modified BVM with supplemental external handle will be higher than those delivered using a standard BVM among health care volunteers in a manikin model. METHODS: This study was a randomized crossover trial of adult health care providers performing ventilation on a manikin. Investigators randomized participants to perform single rescuer ventilation, first using either a BVM modified by addition of a supplemental external handle or a standard unmodified BVM (Spur II BVM device; Ambu; Ballerup, Denmark). Participants performed mask placement and delivery of 10 breaths per minute for three minutes, as guided by a metronome. After a three-minute rest period, they performed ventilation using the alternative device. The primary outcome measure was mean received tidal volume as measured by the manikin (IngMar RespiTrainer model; IngMar Medical; Pittsburgh, Pennsylvania USA). Secondary outcomes included subject device preference. RESULTS: Of 70 recruited participants, all completed the study. The difference in mean received tidal volume between ventilations performed using the modified BVM with external handle versus standard BVM was 20 ml (95% CI, -16 to 56 ml; P=.28). There were no significant differences in mean received tidal volume based on the order of study arm allocation. The proportion of participants preferring the modified BVM over the standard BVM was 47.1% (95% CI, 35.7 to 58.6%). CONCLUSIONS: The modified BVM with added external handle did not result in greater mean received tidal volume compared to standard BVM during single rescuer ventilation in a manikin model. Reed P , Zobrist B , Casmaer M , Schauer SG , Kester N , April MD . Single rescuer ventilation using a bag valve mask with removable external handle: a randomized crossover trial. Prehosp Disaster Med. 2017;32(6):625-630.

Single rescuer ventilation using a bag-valve mask with internal handle: a randomized crossover trial.

OBJECTIVE: To compare tidal volume received during single rescuer ventilation with a modified bag-valve mask (BVM) with integrated internal handle vs standard BVM among healthy volunteers using a manikin model. METHODS: This study was a randomized crossover trial of adult healthcare provider volunteers performing ventilation on a manikin. We randomized participants to perform single rescuer ventilation first using either a modified BVM with integrated internal handle or a standard unmodified BVM. Participants were responsible for mask placement and delivery of 10 breaths per minute for 3 minutes as guided by a metronome. After a 3-minute rest period, they performed ventilation using the alternative device. The primary outcome measure was mean received tidal volume as measured by the manikin (IngMar RespiTrainer model). Secondary outcomes included participant reported device preference. RESULTS: Of 70 recruited participants, all completed the study. Mean received tidal volume was higher using the modified BVM with integrated internal handle vs standard BVM by 90 mL (95% confidence interval, 60-120 mL; P< .0001). There were no significant differences in mean received tidal volume based on the order of study arm allocation. Eighty percent of participants reported preference for the modified BVM over the standard BVM (95% confidence interval, 70.0%-80.0%). CONCLUSIONS: The modified BVM with integrated internal handle results in greater mean received tidal volume compared with standard BVM during single rescuer ventilation in a manikin model. This modified BVM design may prove a useful airway adjunct for ventilation.