Knee strength retention and analgesia with continuous perineural fentanyl infusion after total knee replacement: randomized controlled trial.

PURPOSE: Despite providing adequate pain relief, a femoral nerve block can induce postoperative muscle weakness after total knee arthoplasty (TKA). Fentanyl has been shown to have peripheral effects but has not been used as a perineural infusate alone after TKA. METHODS: Sixty patients scheduled for TKA were randomized to one of three blinded groups: a continuous 24 h infusion of either fentanyl 3 µg/ml, ropivacaine 0.1%, or 0.9% normal saline through a femoral nerve sheath catheter at 10 ml/h. The main outcome was maximum voluntary isometric contraction (MVIC) in the quadriceps femoris (knee extension), measured by a handheld dynamometer (Nm/kg). Other variables assessed were preoperative and postoperative visual analog scale (VAS) scores, hamstrings MVIC (knee flexion), active range of motion of the operative knee, distance ambulated, incidence of knee buckling, supplemental morphine usage, postoperative side effects, and serum fentanyl levels. RESULTS: Quadriceps MVIC values were significantly greater in the fentanyl group compared to the group that received ropivacaine (median values, 0.08 vs. 0.03 Nm/kg; p = 0.028). The incidence of postoperative knee buckling upon ambulation was higher in the ropivacaine group compared to the fentanyl group, although not statistically significant (40% vs. 15 %, respectively; p = 0.077). VAS scores while ambulating were not significantly different between the fentanyl group and the ropivacaine group (p = 0.270). Postoperative morphine consumption, nausea and vomiting, and resting VAS scores were similar among the three groups. CONCLUSIONS: A continuous perineural infusion of fentanyl produced greater strength retention than ropivacaine post-TKA.

Bloodless surgery by a regional intraarterial tourniquet during primary and revision THA.

Primary total hip arthroplasty (THA) and revision THA are associated with blood loss that can be significant. The purpose of this retrospective study was to compare the efficacy of intra-arterial occlusive balloons in reducing blood loss during primary and revision THA. Twelve patients (Jehovah's Witnesses) scheduled for a primary (n=6) or revision (n=6) THA who refused blood transfusions were compared with 48 control-matched patients (primary THA, n=24; revision THA, n=24). All Jehovah's Witnesses received an intra-arterial balloon preoperatively, and all control patients underwent conventional surgery. Intraoperatively, balloons were periodically inflated to reduce blood loss and deflated to prevent limb ischemia. Endpoints for the study were estimated blood loss, perioperative hemoglobin, mean hospital stay, mean operative time, amount of intraoperative fluid or blood administered, and complications. None of the patients with an occlusive balloon received blood, whereas the primary THA group received an average of 0.6 units (P=.08) and the revision THA group received an average of 1.9 units (P=.02). Estimated blood loss was significantly decreased in the balloon group compared with the primary THA group (145 vs 402 mL, respectively; P<.01) and the revision THA group (333 vs 767 mL, respectively; P<.01). No complications were associated with the intra-arterial balloons. All patients showed a significant reduction in hemoglobin immediately postoperatively compared with preoperative values. No statistically significant differences existed in the amount of fluids given intraoperatively or the mean hospital stay among all groups. Temporary internal tourniquets used as an adjuvant to surgery significantly reduce intraoperative blood loss during primary and revision THA.

Intravenous acetaminophen vs. ketorolac for postoperative analgesia after ambulatory parathyroidectomy.

Background and methods Minimally invasive parathyroidectomy requires limited analgesia and short recovery times. The preferred post-operative analgesic regimen for this patient population has not been established but non-narcotic components would be quite appropriate. The aim of the study was to determine whether intravenous (IV) acetaminophen (1 g) or ketorolac (30 mg) provide better pain control after parathyroidectomy. A parallel, randomized, double blind, comparative study was completed on 180 patients scheduled for outpatient parathyroidectomy utilizing general anesthesia. Patients were randomized to a blinded administration of either intravenous acetaminophen 1 g or ketorolac 30 mg intra-operatively. Upon arrival but before premedication, baseline pain scores were assessed in all patients. A consecutive series of postoperative pain scores were collected every 15 min using a 10 cm visual analog pain scale (VAS) upon arrival to the post anesthesia care unit (PACU) until discharge by blinded study personnel. Other data collected included: anesthesia time, surgical time, time to discharge, supplemental morphine and postoperative side effects. Results Overall mean postoperative VAS scores were not significantly different between the two treatment groups (p = 0.07). However, ketorolac produced significantly lower pain scores compared with acetaminophen in the later postoperative periods (3.9 ± 1.9 vs. 4.8 ± 2.4 at 45 min, p = 0.009; 3.4 ± 1.7 vs. 4.5 ± 2.1 at 60min, p = 0.04; and 3.2 ± 2.1 vs. 4.4 ± 2.1 at 75 min, p = 0.03). Supplemental morphine was administered to 3 patients in the ketorolac group and 9 patients in the acetaminophen group but total consumption was not significantly different between groups (p = 0.13). The occurrence of nausea was significantly lower in the ketorolac group compared with the IV acetaminophen group (3.4% vs. 14.6%, respectively; p = 0.02). The overall incidence of morphine supplementation, vomiting, headache, muscular pain, dizziness, and drowsiness were not significantly different when compared between the treatment groups. Conclusions Both postoperative regimens provided adequate analgesia but patients receiving ketorolac intraoperatively had significantly lower pain scores at later recovery time points and significantly lower occurrences of nausea. Implications The large volume of patients undergoing parathyroidectomies at our facility warranted a study to develop a standardized postoperative analgesic regimen. We conclude both medications can be utilized safely in this patient population, but there is a slight advantage in pain control with the usage of ketorolac for minimally invasive parathyroidectomies.

One-lung ventilation in infants and small children: blood gas values.

PURPOSE: We investigated one-lung ventilation (OLV) in pediatric patients under 10 kg. The feasibility of OLV using either Arndt endobronchial blocker (AEB) or mainstem intubation technique is analyzed. Arterial blood gases (ABG) monitored throughout the procedures are presented. METHODS: Following IRB approval, a retrospective chart review was conducted on 9 patients ≤6 months of age and 2 patients ≥12 months of age undergoing lung resections or aortic coarctations. For right thoracotomy, a conventional, cuffed, endotracheal tube (ETT) was inserted and guided into the left mainstem bronchus with a bronchoscope and the left lung was ventilated. For left thoracotomy, an AEB was inserted into the trachea 2 cm past the vocal cords and an ETT was placed through the cords adjacent to the blockers (extraluminal). A bronchoscope was then inserted through the ETT to visualize and manipulate the blocker into the left mainstem bronchus. The blocker cuff was inflated slowly under direct vision while the ETT continued to ventilate the right, dependent lung. ABG values were collected intraoperatively in all cases. RESULTS: One-lung ventilation could be accomplished within 15 min in all cases, and lung isolation was successful in all patients. All patients were extubated within 12 h of surgery and had an uneventful recovery. ABG values revealed modest arterial acidosis and hypercarbia and mild acute ventilatory insufficiency. CONCLUSION: The use of extraluminal AEB or mainstem intubation for OLV can be successfully completed in infants weighing less than 10 kg. OLV may induce acute respiratory pathology; therefore we recommend routine intraoperative ABG monitoring for pediatric patients.