ABSTRACT
In the gluteal and thigh region, the arteria comitans accompanies the sciatic nerve for a short distance, then penetrates the nerve and runs to the lower part of the thigh. There is no study that recognizes this artery as a guide to the location of the sciatic nerve. In this report, we describe a series of 6 knee arthroplasty patients in whom ultrasound-guided sciatic nerve block was successfully performed using color Doppler and pulsed wave Doppler to visualize the arteria comitans as a guide to the location of the sciatic nerve. We have found that detecting the arteria comitans as a landmark is novel and may offer an additional tool with the existing methods for sciatic nerve block.
Subject(s)
Arteries/diagnostic imaging , Arthroplasty, Replacement, Knee/adverse effects , Buttocks/blood supply , Nerve Block/methods , Pain, Postoperative/prevention & control , Sciatic Nerve/diagnostic imaging , Ultrasonography, Doppler, Color , Ultrasonography, Doppler, Pulsed , Ultrasonography, Interventional , Anatomic Landmarks , Female , Humans , Male , Middle Aged , Pain, Postoperative/diagnosis , Pain, Postoperative/etiology , Pain, Postoperative/physiopathology , Treatment OutcomeABSTRACT
PURPOSE: Trendelenburg positioning is commonly used to temporarily treat intraoperative hypotension. The Trendelenburg position improves cardiac output in normovolemic or anesthetized patients, but not hypovolemic or non-anesthetized patients. Therefore, the response to Trendelenburg positioning may vary depending on patient population or hemodynamic conditions. We thus tested the hypothesis that the effectiveness of the Trendelenburg position, as indicated by an increase in cardiac output, improves after replacement of a stenotic aortic valve. Secondarily, we evaluated whether measurements of left ventricular preload, systolic function, or afterload were associated with the response to Trendelenburg positioning. METHODS: This study is a secondary analysis of a clinical trial which included patients having aortic valve replacement (AVR) who were monitored with pulmonary artery catheters (NCT01187329). We examined changes in thermodilution cardiac output with Trendelenburg positioning before and after AVR. We also examined whether echocardiographic and hemodynamic measurements of preload, afterload, and systolic function were associated with changes in cardiac output during Trendelenburg positioning. RESULTS: Thirty-seven patients were included. The median [IQR] cardiac output change with Trendelenburg positioning was -3% [-10%, 5%] before AVR versus +4% [-4%, 15%] after AVR. Estimated median difference in cardiac output with Trendelenburg was 5% (95% CI 1, 15%, P = 0.04) greater after AVR. The response to Trendelenburg positioning was largely independent of hemodynamic conditions. CONCLUSION: The response to Trendelenburg positioning improved following AVR, but by a clinically unimportant amount. The response to Trendelenburg positioning was independent of hemodynamic conditions.
Subject(s)
Aortic Valve Stenosis/surgery , Head-Down Tilt , Heart Valve Prosthesis Implantation/methods , Aged , Aortic Valve/surgery , Cardiac Output/physiology , Echocardiography , Female , Hemodynamics/physiology , Humans , Hypovolemia , Male , Middle Aged , Patient Positioning , Systole , Thermodilution , Ventricular Function, LeftABSTRACT
BACKGROUND: Whether intraoperative use of hydroxyethyl starch impairs kidney function remains unknown. The authors thus tested the primary hypothesis that Hextend promotes renal injury in surgical patients. Secondarily, the authors evaluated the dose-outcome relationship, in-hospital and 90-day mortality, and whether the relationship between colloid use and acute kidney injury (AKI) depends on baseline risk for AKI. METHODS: The authors evaluated the data of 44,176 adults without preexisting kidney failure who had inpatient noncardiac surgery from 2005 to 2012. Patients given a combination of colloid and crystalloid were propensity matched on morphometric, and baseline characteristics to patients given only crystalloid. The primary analysis was a proportional odds logistic regression with AKI as an ordinal outcome based on the Acute Kidney Injury Network classification. RESULTS: The authors matched 14,680 patients receiving colloids with 14,680 patients receiving noncolloids for a total of 29,360 patients. After controlling for potential confounding variables, the odds of developing a more serious level of AKI with Hextend was 21% (6 to 38%) greater than with crystalloid only (P = 0.001). AKI risk increased as a function of colloid volume (P < 0.001). In contrast, the relationship between colloid use and AKI did not differ on baseline AKI risk (P = 0.84). There was no association between colloid use and risk of in-hospital (P = 0.81) or 90-day (P = 0.02) mortality. CONCLUSION: Dose-dependent renal toxicity associated with Hextend in patients having noncardiac surgery is consistent with randomized trials in critical care patients.
