Head multidetector computed tomography: emergency medicine physicians overestimate the pretest probability and legal risk of significant findings.

OBJECTIVES: This study focuses on clinically assigned prospective estimated pretest probability and pretest perception of legal risk as independent variables in the ordering of multidetector computed tomographic (MDCT) head scans. Our primary aim is to measure the association between pretest probability of a significant finding and pretest perception of legal risk. Secondarily, we measure the percentage of MDCT scans that physicians would not order if there was no legal risk. METHODS: This study is a prospective, cross-sectional, descriptive analysis of patients 18 years and older for whom emergency medicine physicians ordered a head MDCT. RESULTS: We collected a sample of 138 patients subjected to head MDCT scans. The prevalence of a significant finding in our population was 6%, yet the pretest probability expectation of a significant finding was 33%. The legal risk presumed was even more dramatic at 54%. These data support the hypothesis that physicians presume the legal risk to be significantly higher than the risk of a significant finding. A total of 21% or 15% patients (95% confidence interval, ±5.9%) would not have been subjected to MDCT if there was no legal risk. CONCLUSIONS: Physicians overestimated the probability that the computed tomographic scan would yield a significant result and indicated an even greater perceived medicolegal risk if the scan was not obtained. Physician test-ordering behavior is complex, and our study queries pertinent aspects of MDCT testing. The magnification of legal risk vs the pretest probability of a significant finding is demonstrated. Physicians significantly overestimated pretest probability of a significant finding on head MDCT scans and presumed legal risk.

Morbidly obese patients receive delayed ED care: body mass index greater than 40 kg/m2 have longer disposition times.

OBJECTIVES: Our study compares treatment times of morbidly obese patients (body mass index [BMI]>40 kg/m2) with patients having BMI less than 35 kg/m2. METHODS: We used an institutional review board-approved, retrospective, sequential, cohort, data analysis of emergency department (ED) medical records from our county teaching hospital (January 2010). Our data set of 102 morbidly obese patients (World Health Organization class 3 [BMI>40 kg/m2]) was compared with that of 195 normal or mildly obese patients (World Health Organization class 0 or 1 [BMI<35 kg/m2]). Inclusion was limited to patients of Emergency Severity Index level 2 and 3 who presented for triage. The primary outcome variable was total length of stay for patients discharged home from the ED. RESULTS: Morbidly obese patients take significantly longer to disposition than normal or mildly obese patients (difference, 101 minutes [95% CI, 55-146]; P<.0001). The mean length of stay for patients with BMI less than 35 kg/m2 was 287 minutes in contrast to 388 minutes for patients with BMI greater than 40 kg/m2. Computed tomography use was significantly less likely in the BMI class 0 and 1 groups compared with the BMI class 3 group (0.41 [79/195] vs 0.56 [57/102]; difference, 0.15 [95% CI, 0.03-0.27]; P=.012). CONCLUSIONS: In our institution, morbidly obese patients take significantly longer to disposition home than patients of more normal weight.

Towards evidence based emergency medicine: Best BETs from the Manchester Royal Infirmary. BET 4: Is magnetic resonance imaging useful for suspected appendicitis in pregnant patients?

In the case of a pregnant patient with suspected appendicitis, MRI is a valuable tool.