Lack of added predictive value of portable chest radiography in diagnosing ventilator-associated pulmonary infection.

INTRODUCTION: The accurate diagnosis of ventilator-associated pulmonary infection (VAPI) poses an ongoing challenge. At our institution, patients in whom VAPI is strongly suspected on the basis of the Clinical Pulmonary Infection Score (CPIS) undergo diagnostic mini-bronchoalveolar lavage (mBAL) with quantitative cultures, followed by empiric antibiotic therapy in our surgical intensive care unit (sICU). We sought to determine the role of portable chest X-radiography (pCXR) in the diagnosis of VAPI. METHODS: We conducted a retrospective analysis of mechanically ventilated adult (>18 y of age) patients with suspected VAPI undergoing concomitant pCXR and diagnostic mBAL in a combined tertiary-care unit for trauma and surgical intensive care. Portable chest X-radiographs were evaluated in a blinded manner by surgical intensivists, critical care fellows, general surgical residents, and radiologists, and were rated as: (0) Not suspicious for pneumonia, (1) possible pneumonia, or (2) likely pneumonia. These results were compared with the microbiologic results of mBAL culture. Demographic and clinical characteristics including age, gender, white blood cell count (WBC), temperature, purulence of secretions, blood and urine culture results, and length of hospitalization were correlated with the results of mBAL. RESULTS: Regardless of interpreter specialty or level of training, pCXR had no predictive value for VAPI. The overall sensitivity and specificity of pCXR were 77% and 74%, respectively, and its positive predictive value, negative predictive value, and receiver-operating characteristic (ROC) curve areas all had values below 50%. The inter-rater agreement (ρ) was 0.965, showing little discrepancy between raters. The degree of purulence on mBAL, concurrent blood stream infection, and increase in the number of days of hospitalization before diagnostic testing were correlated with an increased frequency of VAPI. The three CPIS criteria of febrile response, leukocytosis/leukopenia, and arterial oxygenation correlated poorly with the results of mBAL culture. CONCLUSION: Portable chest X-radiography has no added predictive value in identifying patients who should be evaluated further for VAPI. This supports the elimination of findings on chest X-radiography as defining characteristics of VAP, which accords with the U.S. Centers for Disease Control and Prevention's recent definition of VAP as but one of a number of types of ventilator-associated pulmonary infection (VAPI).

Porcine wet lab improves surgical skills in third year medical students.

BACKGROUND: Medical students desire to become proficient in surgical techniques and believe their acquisition is important. However, the operating room is a challenging learning environment. Small group procedural workshops can improve confidence, participation, and performance. The use of fresh animal tissues has been rated highly among students and improves their surgical technique. Greater exposure to surgical procedures and staff could positively influence students' interest in surgical careers. We hypothesized that a porcine "wet lab" course for third year medical students would improve their surgical skills. METHODS: Two skills labs were conducted for third year medical students during surgery clerkships in the fall of 2011. The students' surgical skills were first evaluated in the operating room across nine dimensions. Next, the students performed the following procedures during the skills lab: (1) laparotomy; (2) small bowel resection; (3) splenectomy; (4) partial hepatectomy; (5) cholecystectomy; (6) interrupted abdominal wall closure; (7) running abdominal wall closure; and (8) skin closure. After the skills lab, the students were re-evaluated in the operating room across the same nine dimensions. Student feedback was also recorded. Fifty-one participants provided pre- and post-lab data for use in the final analysis. RESULTS: The mean scores for all nine surgical skills improved significantly after participation in the skills lab (P ≤ 0.002). Cumulative post-test scores also showed significant improvement (P = 0.002). Finally, the student feedback was largely positive. CONCLUSIONS: The surgical skills of third year medical students improved significantly after participation in a porcine wet lab, and the students rated the experience as highly educational. Integration into the surgery clerkship curriculum would promote surgical skill proficiency and could elicit interest in surgical careers.