Acetazolamide fails to decrease pulmonary artery pressure at high altitude in partially acclimatized humans.

In this randomized, double-blind placebo controlled trial our objectives were to determine if acetazolamide is capable of preventing high altitude pulmonary edema (HAPE) in trekkers traveling between 4250 m (Pheriche)\4350 m (Dingboche) and 5000 m (Lobuje) in Nepal; to determine if acetazolamide decreases pulmonary artery systolic pressures (PASP) at high altitude; and to determine if there is an association with PASP and signs and symptoms of HAPE. Participants received either acetazolamide 250 mg PO BID or placebo at Pheriche\Dingboche and were reassessed in Lobuje. The Lake Louise Consensus Criteria were used for the diagnosis of HAPE, and cardiac ultrasonography was used to measure the velocity of tricuspid regurgitation and estimate PASP. Complete measurements were performed on 339 of the 364 subjects (164 in the placebo group, 175 in the acetazolamide group). No cases of HAPE were observed in either study group nor were differences in the signs and symptoms of HAPE found between the two groups. Mean PASP values did not differ significantly between the acetazolamide and placebo groups (31.3 and 32.6 mmHg, respectively). An increasing number of signs and symptoms of HAPE was associated with elevated PASP (p < 0.01). The efficacy of acetazolamide against acute mountain sickness, however, was significant with a 21.9% incidence in the placebo group compared to 10.2 % in the acetazolamide group (p < 0.01). Given the lack of cases of HAPE in either group, we can draw no conclusions about the efficacy of acetazolamide in preventing HAPE, but the absence of effect on PASP suggests that any effect may be minor possibly owing to partial acclimatization during the trek up to 4200 m.

Bench-to-bedside review: outcome predictions for critically ill patients in the emergency department.

The escalating number of emergency department (ED) visits, length of stay, and hospital overcrowding have been associated with an increasing number of critically ill patients cared for in the ED. Existing physiologic scoring systems have traditionally been used for outcome prediction, clinical research, quality of care analysis, and benchmarking in the intensive care unit (ICU) environment. However, there is limited experience with scoring systems in the ED, while early and aggressive intervention in critically ill patients in the ED is becoming increasingly important. Development and implementation of physiologic scoring systems specific to this setting is potentially useful in the early recognition and prognostication of illness severity. A few existing ICU physiologic scoring systems have been applied in the ED, with some success. Other ED specific scoring systems have been developed for various applications: recognition of patients at risk for infection; prediction of mortality after critical care transport; prediction of in-hospital mortality after admission; assessment of prehospital therapeutic efficacy; screening for severe acute respiratory syndrome; and prediction of pediatric hospital admission. Further efforts at developing unique physiologic assessment methodologies for use in the ED will improve quality of patient care, aid in resource allocation, improve prognostic accuracy, and objectively measure the impact of early intervention in the ED.

Deferral of the rectal examination in blunt trauma patients: a clinical decision rule.

OBJECTIVES: To develop a clinical decision rule that would allow for the safe deferral of the digital rectal examination (DRE) in blunt trauma patients. METHODS: The authors reviewed the medical records of all adult blunt trauma patients meeting trauma team activation criteria over a 14-month period. The results of the DRE and six predictor variables-abnormal neurologic examination, abdominal tenderness, pelvic stability, blood at the urethral meatus, blood pressure < 90 mm Hg, and age over 65 years-were recorded. Patients with abnormal DREs had their discharge summaries reviewed for specific criteria to determine if the abnormal DRE was a true- or false-positive examination. Predictor variables were entered into a classification and regression tree (CART) analysis designed to predict true-positive abnormal DREs. RESULTS: Of the 579 patients, 53 had abnormal DREs, 34 of which were true positives. CART analysis retained three predictors, abnormal neurologic examination, blood at the urethral meatus, and age over 65 years, and accurately classified all patients with a true-positive abnormal DRE. The probability of a true-positive abnormal DRE in a patient with a normal neurologic examination, no blood at the urethral meatus, and age less than 65 years is between 0% and 0.8%. CONCLUSIONS: Adult patients with blunt trauma and a normal neurologic examination, with no blood at the urethral meatus, and who are less than 65 years old have an exceedingly low likelihood of a true-positive abnormal DRE. If validated, patients who meet these three criteria may have the DRE safely deferred.

Intramuscular ketamine to facilitate pediatric central vascular access.

OBJECTIVES: Obtaining prompt vascular access in young children presenting to the emergency department (ED) is frequently both necessary and technically challenging. The objective of our study was to describe our experience using intramuscular (IM) ketamine to facilitate the placement of central venous catheters in children presenting to our ED needing vascular access in a timely fashion. METHODS: We performed a retrospective medical record review of all pediatric patients <18 years of age who presented to our tertiary care pediatric ED between May 1, 1998, and August 7, 2003, and underwent the placement of a central venous catheter facilitated by the use of IM ketamine. RESULTS: Eleven children met our inclusion criteria. Most of the children were young and medically complicated. The children ranged in age from 6 months to 8 years. The only complication identified was vomiting experienced by an 8-year-old boy. Emergency physicians successfully obtained central venous access in all subjects in the case series. CONCLUSIONS: The use of IM ketamine to facilitate the placement of central venous catheters in children who do not have peripheral venous access appears to be helpful. Emergency physicians may find it useful to be familiar with this use of IM ketamine.