The Effect of Vibration on Pain During Intravenous Injection of Propofol: A Randomized Controlled Trial.

PURPOSE: Pain is a common side effect of intravenous injection of propofol. We conducted a randomized, prospective, single-blinded controlled trial to assess the efficacy of vibration analgesia on pain during propofol infusion in ambulatory surgery. METHODS: After institutional review board approval, 100 patients undergoing elective ambulatory surgery with general anesthesia were randomized into 2 groups. A control group (n = 50) consisted of patients who received infusion of propofol without vibration analgesia. A treatment group (n = 50) consisted of patients who received infusion of propofol with vibration analgesia using the Buzzy device. Pain was assessed using a 4-point pain manifestation scale scored by 2 independent, blinded observers. RESULTS: Participants in the treatment group with vibration analgesia were 0.47 times less likely (95% confidence interval, 0.24-0.94; P = 0.03) to experience any pain than the control group. The median summative pain score in the treatment group was significantly less than that of the control group [1 (interquartile range, 1-2) vs 2 (interquartile range, 2-4); P < 0.01] among participants who experienced any pain. Agreement between the 2 blinded observers regarding pain scores was excellent with κw = 0.82 (P < 0.001). Age, sex, body mass index, needle location or size, and medication doses did not differ significantly between the 2 groups. CONCLUSION: Vibration analgesia is an effective, low-risk modality that reduces the pain of intravenous propofol injection in general anesthesia.

Respiratory gas exchange during robotic-assisted laparoscopic radical prostatectomy.

STUDY OBJECTIVE: Robotic-assisted laparoscopic prostatectomy requires patients to be secured in a steep Trendelenburg position for several hours. Added to the CO2 pneumoperitoneum that is created, this positioning invariably restricts diaphragmatic and chest wall excursion, which can adversely affect respiratory gas exchange. This study sought to measure the extent of respiratory gas change during this procedure. DESIGN: Retrospective, institutional review board approved. SETTING: Operating room. PATIENTS: N = 186 males, American Society of Anesthesiologists 2-3, with prostatic carcinoma undergoing robotic-assisted laparoscopic radical prostatectomy. INTERVENTIONS: Arterial blood gases and noninvasive respiratory measurements were recorded for those patients (n = 32) in whom a radial arterial catheter had been inserted intraoperatively, specifically timed to different phases of the procedure: supine lithotomy, steep Trendelenburg, and return to supine. Ventilatory parameters were standardized. MEASUREMENTS: Systemic blood pressure, heart rate, respiratory rate, Pao2, Paco2, oxygen saturation as measured by pulse oximetry, and end-tidal carbon dioxide pressure. MAIN RESULTS: Although no patients developed perioperative respiratory complications, the Pao2 invariably fell (395 vs 316 mm Hg; P = .001) while the patients were in steep Trendelenburg, and the Paco2-end-tidal carbon dioxide pressure rose (10.0 vs 13.4 mm Hg; P < .0001). Upon return to supine, patients' respiratory measurements promptly returned to within 15% of baseline. Subgroup analysis for high-BMI vs low-BMI patients as well as for patients with pulmonary disease and/or a smoking history showed similar individual effects and only small, although significant, respiratory gas exchange aberrations. CONCLUSIONS: Positioning patients with a CO2 pneumoperitoneum in steep Trendelenburg for several hours imposes restriction of diaphragmatic and chest wall movement sufficient for respiratory gas exchange to be adversely affected. Return of function to within 15% of baseline occurred within minutes after return to supine and release of the CO2 pneumoperitoneum. No patients during the study period developed pulmonary complications that required alteration in their level of care.

A comparison of the effect of aprotinin and ε-aminocaproic acid on renal function in children undergoing cardiac surgery.

OBJECTIVE: To assess the incidence of renal injury among pediatric patients who received aprotinin while undergoing cardiac surgery compared with those who received ε-aminocaproic acid (EACA). DESIGN: A retrospective observational study. SETTING: A single academic center. PARTICIPANTS: Pediatric cardiac patients who had cardiopulmonary bypass and received aprotinin or EACA. INTERVENTION: Patients undergoing pediatric cardiac surgery received aprotinin from 2005 to 2007 and EACA from 2008 to 2009. MEASUREMENTS AND MAIN RESULTS: The primary outcome was acute kidney injury (AKI) defined as serum Cr elevation at discharge more than 1.5 times the baseline value. Secondary outcomes included bleeding, blood transfusion, and the volume of chest tube drainage in the first 24 hours postoperatively. One hundred seventy-eight patients met inclusion criteria; 120 patients received aprotinin, and 58 patients received EACA. These 2 groups did not differ significantly in age, weight, or duration of cardiac bypass. Logistic regression analysis, adjusted for confounding variables (ie, baseline Cr, sex, age, CPB time, inotropic support and vasopressors), showed a higher odds of suffering AKI at discharge with the usage of aprotinin (odds ratio = 4.7; 95% confidence interval, 1.1-19.5; p = 0.03). The volume of the first 24 hours of chest tube drainage was not significantly different between groups, as well as packed red blood cells and cryoprecipitate units. However, fresh frozen plasma and platelets showed statistically significant differences with more transfusion in the EACA group. CONCLUSION: In this retrospective study, the authors observed a higher odds of AKI for aprotinin usage compared with EACA, suggesting that the known concern for adults with adverse kidney effects with aprotinin is also appropriate for pediatric patients.