A simple clinical decision rule to rule out appendicitis in patients with nondiagnostic ultrasound results.

OBJECTIVES: The objective was to identify a set of clinical features that can rule out appendicitis in patients with suspected acute appendicitis and nondiagnostic ultrasound (US) results, allowing safe discharge and next-day reevaluation without initial computed tomography (CT) or magnetic resonance imaging (MRI). METHODS: Data on clinical and US evaluation, including a number of prespecified variables potentially associated with acute appendicitis, were prospectively collected in two diagnostic accuracy studies of imaging. These studies included patients with suspected appendicitis seen in the emergency department (ED). For development and validation of the clinical decision rule (CDR), only patients with inconclusive or negative US results were included. There were 199 (of 422) patients in the development cohorts and 120 (of 211) patients in the validation cohort. Logistic regression analysis was used for data from patients with inconclusive or negative US results, and profiles were created of all possible combinations of predictors retained in the multivariable model. A final diagnosis was assigned by an expert panel based on perioperative data, histopathology, and clinical follow-up of at least 3 months. RESULTS: The CDR selected patients after negative or inconclusive US for discharge and next-day reevaluation without initial CT or MRI if fewer than two of the following predictors were present: male sex, migration of pain to the right lower quadrant, vomiting, and white blood cell (WBC) count higher than 12.0 × 10(9) /L. Applying the CDR in the development set selected 126 of 199 (63%) patients with negative or inconclusive US results for discharge without further imaging. This rule reduced the probability of appendicitis from 26% (51 of 199) in the total group of patients with negative or inconclusive US results to 12% (15 of 126) in the group that would be discharged based on the rule (p = 0.001). In the validation set (n = 120), the decision rule selected 72 (60%) patients for discharge and next-day reevaluation and reduced the probability of appendicitis from 20% (24 of 120) in the total group to 6% (4 of 72) in the patients selected on the rule (p = 0.001). The negative predictive value of the decision rule in the validation set was 94% (95% confidence interval [CI] = 87% to 98%). In comparison, the negative predictive value of CT in the same group was 99% (95% CI = 93% to 100%, p = 0.14), and that of MRI was 99% (95% CI = 94% to 100%, p = 0.12). Alternative decision rules based on combinations of the present decision rule with C-reactive protein (CRP) results did not improve selection. CONCLUSIONS: This newly developed CDR significantly reduces the probability of appendicitis in a large subgroup of patients with negative or inconclusive US results. These patients can be safely discharged for outpatient reevaluation without further initial imaging if proper follow-up is available. This could assist in lowering the number of ED imaging investigations in patients with suspected appendicitis.

Safety and efficacy of procedural sedation with propofol in a country with a young emergency medicine training program.

OBJECTIVES: To evaluate the safety and effectiveness of procedural sedation with propofol by newly trained Dutch emergency physicians. METHODS: A prospective observational cohort study of patients in emergency department undergoing procedural sedation at two teaching hospitals. Primary outcomes were serious adverse events, sedation events, and efficacy. A standardized protocol and data collection form was used at both sites. RESULTS: Three hundred and eighty-six patients were enrolled over 18 months. The median age was 57 years (range 6-94, interquartile range 38-70), 55% were male patients. All had an American Society of Anesthesiologists class score of 3 or less. Indications for procedural sedation were reduction of dislocations (51%), electrocardioversion (32%), fracture reduction (8%), and abscess/wound treatment (6%). The median propofol dose was 1.0 mg/kg (0.70-1.5) and 45% received fentanyl in addition; median dose was 1 mcg/kg (0.6-1.3). Most had a Ramsay sedation score of 4 or 5. The procedural success rate was 99.5%. No serious adverse events were reported. Sedation events included; hypoventilation (11%), desaturation (5%), hypotension (3%), and bradycardia (1%), all of which resolved with simple supportive interventions. One patient vomited without aspirating. Increased age (>60 years) (P=0.001) and high Ramsay score (>3) (P=0.024) were the only significant predictors of events. Sex, weight, total dose of propofol, use of fentanyl, and type of procedure were not independent risk factors for any event. CONCLUSION: Newly trained Dutch emergency physicians can perform procedural sedation with propofol safely and effectively. Increased age and high Ramsay scores were the only risk factors for sedation events. All events were minor and responded to simple interventions.