Topical ethyl chloride to reduce pain associated with venous catheterization: a randomized crossover trial.

OBJECTIVE: To compare pain associated with venous catheterization after administration of topical ethyl chloride vs placebo among emergency department health care providers. METHODS: We conducted a randomized, double-blind, placebo-controlled, crossover trial among a convenience sample of health care provider volunteers in a tertiary care urban emergency department. We randomly allocated subjects to initial treatment (ethyl chloride vs sterile water aerosol spray) and catheterization site (left or right antecubital fossa). After venous catheterization placement and discontinuation, subjects underwent a 5-minute washout period. All subjects then underwent venous catheterization in the contralateral antecubital fossa after administration of the alternative agent. We measured all outcomes after discontinuation of the second catheter. The primary outcome was difference in pain verbal numeric rating scale score (0-10) between the 2 agents. Secondary outcomes included preferred agent (binary) and future willingness to use agent on patients (5-point Likert scale). RESULTS: Thirty-eight health care providers were recruited; all completed the study. Median pain verbal numeric rating scale scores were 4 (interquartile range, 2-5) for placebo vs 2 (1-4) for ethyl chloride. The effect size for pain reduction with ethyl chloride compared with placebo was 2 (95% confidence interval, 0.5-2; P = .001). Most subjects (68.4%) preferred ethyl chloride to placebo. Five-point Likert scale scores measuring willingness to use preferred product on future patients were higher by 2 (95% confidence interval, 1-3) among subjects preferring ethyl chloride vs placebo. CONCLUSIONS: We found that topical ethyl chloride yields a greater reduction in pain associated with venous catheterization compared with topical placebo.

A sinister cause of anterograde amnesia: painless aortic dissection.

Aortic dissection is a frequently devastating diagnosis classically associated with severe chest pain.We present a case of painless aortic dissection with anterograde amnesia. An 84-year-old man was brought to the emergency department by ambulance, when his wife noted that he developed acute onset complete loss of short-term memory. Medical history was notable for a 4.5-cm fusiform thoracic aortic root aneurysm. On arrival,he denied pain or syncope.On examination, he was mildly hypotensive(110/59 mm Hg); and there were no murmurs, pulse deficits, or focal neurologic deficits. During his stay, he developed left flank pain. Chest radiography demonstrated subtle mediastinal widening and obscuration of the aortic knob compared with previous films. Computed tomography revealed an extensive intimal flap consistent with an aortic dissection involving the sinus of Valsalva and left renal artery. The patient subsequently developed acute onset chest pain after which he became unresponsive. Echocardiography demonstrated tamponade physiology.The family decided to transition to comfort care measures, and the patient died soon after.We identified 7 other cases in the literature of aortic dissection cases with presentations consistent with transient global amnesia,5 of which without neurologic deficits and 3 of which without pain. This case highlights the imperative of a thorough history and high index of suspicion for this catastrophic diagnosis in patients with transient global amnesia who otherwise might be expected to have an excellent prognosis and little need for diagnostic work-up.