Effect of Intraoperative Sedation with Dexmedetomidine Versus Propofol on Acute Postoperative Pain Following Major Foot Surgery under Popliteal Sciatic Nerve Block: A Randomized Controlled Trial.

Intravenous (IV) dexmedetomidine is reported to prolong analgesia following peripheral nerve blocks. Popliteal sciatic nerve block provides effective postoperative analgesia, but some patients still experience severe pain during the early postoperative period. We aimed to evaluate the postoperative analgesic effects of IV dexmedetomidine versus propofol in patients undergoing foot surgeries under popliteal sciatic nerve block. Forty patients were enrolled and randomly assigned to receive either IV propofol (n = 20) or IV dexmedetomidine (n = 20) for intraoperative sedation. All the patients received continuous popliteal sciatic nerve block. The corresponding drug infusion rate was adjusted to achieve a modified observer's assessment of alertness/sedation score of 3 or 4. The primary outcome was postoperative cumulative opioid consumption during the first 24 h after surgery. Thirty-nine patients were analyzed. The median (interquartile ranges) postoperative cumulative opioid consumption during the first 24 h after surgery was significantly lower in the dexmedetomidine group (15 (7.5-16.9) mg) than in the propofol group (17.5 (15-25) mg) (p = 0.019). The time to first rescue analgesic request was significantly greater in the dexmedetomidine group than in the propofol group (11.8 ± 2.2 h vs. 10.0 ± 2.7 h, p = 0.030) without the prolonged motor blockade (p = 0.321). Intraoperative sedation with dexmedetomidine reduced postoperative opioid consumption and prolonged analgesic duration after a popliteal sciatic nerve block.

Reduced Hemidiaphragmatic Paresis With a "Corner Pocket" Technique for Supraclavicular Brachial Plexus Block: Single-Center, Observer-Blinded, Randomized Controlled Trial.

BACKGROUND AND OBJECTIVE: Hemidiaphragmatic paresis is common after supraclavicular brachial plexus block (SCBPB). In this randomized trial, we compared the incidence of hemidiaphragmatic paresis in patients who had local anesthetic injected primarily in the corner pocket (defined as the intersection of the first rib and subclavian artery) during SCBPB with that of patients who underwent injection primarily inside the neural cluster. METHODS: Thirty-six patients scheduled for right elbow, forearm, wrist, or hand surgery under SCBPB (using 12.5 mL of 0.75% ropivacaine and 12.5 mL of 2% lidocaine with 1:200,000 epinephrine) were randomly assigned to 1 of 2 groups. In group CP, local anesthetic was injected primarily in the corner pocket (20 mL) and secondarily inside the neural cluster (5 mL). In group NC, local anesthetic was deposited primarily inside the neural cluster (20 mL) and secondarily in the corner pocket (5 mL). The primary outcome was the incidence of hemidiaphragmatic paresis, as measured by M-mode ultrasonography 30 minutes after SCBPB. RESULTS: The incidence of hemidiaphragmatic paresis was significantly lower in group CP than in group NC (27.8% vs 66.7%, P = 0.019). The median decreases in forced expiratory volume at 1 second (7.5% [interquartile range, 3.3%-17.1%] vs 24.4% [interquartile range, 10.2%-31.2%]; P = 0.010) and forced vital capacity (6.4% [interquartile range, 3.3%-11.1%] vs 19.3% [interquartile range, 13.7%-33.2%]; P = 0.001) were also lower in group CP than in group NC. CONCLUSIONS: The incidence of hemidiaphragmatic paresis was effectively reduced when local anesthetic was injected primarily in the corner pocket during right-sided SCBPB. However, the 28% incidence of hemidiaphragmatic paresis associated with the corner pocket technique may still represent a prohibitive risk for patients with preexisting pulmonary compromise. CLINICAL TRIAL REGISTRATION: This study was registered at Clinical Trial Registry of Korea, identifier KCT0001769.

Carbon dioxide pneumothorax occurring during laparoscopy-assisted gastrectomy due to a congenital diaphragmatic defect: a case report.

During laparoscopic surgery, carbon dioxide (CO2) pneumothorax can develop due to a congenital defect in the diaphragm. We present a case of a spontaneous massive left-sided pneumothorax that occurred during laparoscopy-assisted gastrectomy, because of an escape of intraperitoneal CO2 gas, under pressure, into the pleural cavity through a congenital defect in the esophageal hiatus of the left diaphragm. This was confirmed on intraoperative chest radiography and laparoscopic inspection. This CO2 pneumothorax caused tolerable hemodynamic and respiratory consequences, and was rapidly reversible after release of the pneumoperitoneum. Thus, a conservative approach was adopted, and the remainder of the surgery was completed, laparoscopically. Due to the high solubility of CO2 gas and the extra-pulmonary mechanism, CO2 pneumothorax with otherwise hemodynamically stable conditions can be managed by conservative modalities, avoiding unnecessary chest tube insertion or conversion to an open procedure.

What influence does intermittent pneumatic compression of the lower limbs intraoperatively have on core hypothermia?

BACKGROUND: Intermittent pneumatic compression (IPC) devices have been widely used for thrombosis prophylaxis in laparoscopic colorectal surgery. However, periodic compression using an IPC device may inject augmented boluses of cool blood from the lower limbs into the central circulation repetitively, thereby causing a reduction in core temperature. The authors therefore conducted a prospective, randomized, double-blind, controlled study to compare the effects of intraoperative IPC on core temperature in patients undergoing laparoscopic colorectal surgery. METHODS: For this study, 56 patients ages 18-60 years and scheduled to undergo laparoscopic resection for colorectal cancer under general anesthesia were randomly assigned to receive either no IPC (control group) or calf-thigh-length IPC in both legs using the SCD Express (IPC group). Anesthetic, thermal, and pneumoperitoneum management were standardized. Esophageal temperature, as an indicator of core temperature, was measured at 15-min intervals for 2 h after induction of anesthesia. RESULTS: A total of 47 subjects (23 control and 24 IPC subjects) were included in the analysis. The core temperature drop in the IPC group was significantly greater than in the control group, starting from 45 min after induction of anesthesia (P < 0.05). As a result, the total temperature drop during the 2-h study period was significantly greater in the IPC group (1.2 ± 0.3 °C) than in the control group (0.9 ± 0.3 °C) (P = 0.004). CONCLUSIONS: Because intraoperative application of IPC carries an increased risk of a core temperature drop, appropriate temperature monitoring and active thermal management are required for surgical patients receiving IPC.

Risk factors for an intraoperative arrhythmia during esophagectomy.

PURPOSE: Arrhythmias after an esophagectomy (most commonly atrial fibrillation) are a significant contributing factor to patient morbidity. However, the significance of an intraoperative arrhythmia is not completely understood. The aim of this retrospective study was to determine the occurrence and risk factors for developing intraoperative arrhythmias in patients undergoing an esophagectomy. MATERIALS AND METHODS: We reviewed the records of 427 patients who underwent a transthoracic esophagectomy between 2001 and 2005. Variables such as age, sex, hypertension, diabetes, cardiac disease, preoperative pulmonary function test (PFT) results, cancer level, combined radiochemotherapy, intrathoracic cavity adhesions and anastomosis site, hemoglobin, central venous pressure (CVP), fluid balance, serum potassium level, dose of vasopressors, temperature, and combined general and epidural anesthesia were analyzed as risk factors for the occurrence of an arrhythmia. We defined this arrhythmia as one not originating from the sinus node. RESULTS: The incidence of intraoperative arrhythmia in this subset of patients was 17.1%, with a 37.2% reoccurrence rate during the first three postoperative days. Univariate and multivariate analysis revealed the presence of heart disease, poor PFTs, cervical anastomosis, elevated CVP, and higher ephedrine doses to be independent predictors of the development of an intraoperative arrhythmia. CONCLUSION: The incidence of intraoperative arrhythmia during esophagectomy was 17.1% with a 37.2% of reoccurrence rate.