Effect of pre-incisional continuous regional block on early and late postoperative conditions in tibial osteotomy and total knee arthroplasty.

BACKGROUND: Postoperative regional anesthesia hastens recovery and reduces the length of hospital stay of orthopedic surgical patients. This study was designed to assess the impact of pre-incisional continuous femoral block on postoperative conditions (POC) of tibial osteotomy and total knee arthroplasty patients. METHODS: After insertion of a femoral catheter under peripheral nerve stimulation control, 111 patients scheduled for total knee arthroplasty or tibial osteotomy were randomized to receive either pre-incisionnal (treatment) or postoperative (control) continuous femoral block. Anesthesia and postoperative management was standardized. An assessor blinded to the randomization process recorded early and late postoperative conditions (POC) which included pain scores, opioid demands, length of stay in Postoperative care unit and patients' satisfaction. RESULTS: Eleven patients were excluded from the final analysis because of catheter disconnection or malfunction. Thus 100 patients (50 in each group) were analyzed for POC. Treatment failed to influence patients overall satisfaction but significantly improved early POC. Subgroup analysis demonstrated that late POC were significantly improved in tibial osteotomy as compared to total knee arthroplasty patients. No complication occurred during the study period. CONCLUSION: Continuous femoral nerve block before surgery significantly improved early postoperative conditions in both surgery while late postoperative conditions were improved only in tibial osteotomy.

Tracheal intubation of morbidly obese patients: a randomized trial comparing performance of Macintosh and Airtraq laryngoscopes.

BACKGROUND: The Airtraq laryngoscope is designed to allow visualization of the glottis without alignment of the oral, pharyngeal, and laryngeal axes. We hypothesized that this new airway device would facilitate tracheal intubation of morbidly obese patients. We compared tracheal intubation performance of standard Macintosh laryngoscope with the Airtraq laryngoscope in morbidly obese patients. METHODS: One hundred and six consecutive ASA I-III morbidly obese patients undergoing surgery were randomized to intubation with the Macintosh laryngoscope or the Airtraq laryngoscope. Induction of anaesthesia was standardized. If tracheal intubation failed within 120 s with the Macintosh or Airtraq , laryngoscopes were switched. Success rate, SpO2, duration of tracheal intubation, and quality of airway management were evaluated and compared between the groups. RESULTS: Preoperative characteristics of the patients were similar in both groups. In the Airtraq group, tracheal intubation was successfully carried out in all patients within 120 s. In the Macintosh laryngoscope group, six patients required intubation with the Airtraq laryngoscope. The mean (SD) time taken for tracheal intubation was 24 (16) and 56 (23) s, respectively, with the Airtraq and Macintosh laryngoscopes, (P<0.001). SpO2 was better maintained in the Airtraq group than in the Macintosh laryngoscope group with one and nine patients, respectively, demonstrating drops of SpO2 to 92% or less (P<0.05). CONCLUSIONS: In this study, the Airtraq laryngoscope shortened the duration of tracheal intubation and prevented reductions in arterial oxygen saturation in morbidly obese patients.

A comparison of two techniques for inserting the Airtraq laryngoscope in morbidly obese patients.

We postulated that video-controlled tracheal intubation with the Airtraq laryngoscope using the reverse manoeuvre instead of the standard technique of insertion could facilitate the airway management of morbidly obese patients. For the reverse manoeuvre the laryngoscope is inserted 180 degrees opposite to that recommended, and once in place rotated into the conventional pharyngeal position. Eighty (40 lean and 40 morbidly obese) ASA I-III adult patients were randomly allocated to four equal groups to compare the standard technique to the reverse manoeuvre for inserting the Airtraq laryngoscope. Video-controlled and clinical tracheal intubation characteristics were recorded. The reverse manoeuvre did not influence tracheal intubation characteristics in the group of lean patients. In the group of morbidly obese patients, the standard technique of insertion was not satisfactory in 20% of cases and the reverse manoeuvre facilitated, speeded and secured tracheal intubation.

Post-tetanic count at adductor pollicis is a better indicator of early diaphragmatic recovery than train-of-four count at corrugator supercilii.

BACKGROUND: Because the intensity of neuromuscular block at the diaphragm (DIA) is indirectly assessed, the electromyographic measurements of the DIA (DIA(EMG)) from surface electrodes were related to information provided by visual estimation of neuromuscular transmission at the adductor pollicis (AP) and the corrugator supercilii (CSC) during recovery from vecuronium block. METHODS: Twelve adult patients were studied during balanced anaesthesia. After induction of anaesthesia and tracheal intubation without neuromuscular blocking agent, supramaximal stimulations were applied to phrenic, ulnar and facial nerves. During recovery from vecuronium 0.1 mg kg(-1) an independent observer blinded to DIA(EMG) counted visually detectable train-of-four (TOF) at CSC (TOF(CSC)) and post-tetanic AP (PTC(AP)) responses. Times to recovery of PTC(AP) = 1, 10, and TOF(CSC) = 1-4 responses were related to DIA(EMG). Values are means (sd). RESULTS: Reappearance of the first response to PTC(AP) occurred significantly (P < 0.05) earlier and for a lower recovery of DIA(EMG) than that of TOF(CSC) [24 (8) min vs 33 (9) min, and 10 (10)% vs 25 (8)%, respectively]. With PTC(AP)

TOF count at corrugator supercilii reflects abdominal muscles relaxation better than at adductor pollicis.

BACKGROUND: A recovery profile from neuromuscular block similar to that of abdominal (AB) muscles, but different to that of the adductor pollicis (AP) muscle, has been demonstrated at the corrugator supercilii (CSC) muscle. We hypothesized that neuromuscular transmission (NMT) monitoring of CSC might provide useful information on AB relaxation compared with AP. We compared the visual estimation of NMT at CSC and AP with electromyographic measurements of AB during recovery from a vecuronium block. METHODS: Ten adult patients were studied during balanced anaesthesia. After induction of anaesthesia and tracheal intubation without neuromuscular blocking agents, supramaximal stimulations were applied to three nerves: left 10th intercostal, ulnar, and facial. Electromyographic activity (EMG) of AB was measured (ABemg). After a bolus dose of vecuronium 0.1 mg kg-1, an independent observer blinded to the EMG measurements counted visually detectable train-of-four (TOF) responses at CSC and AP. Values of ABemg associated with 1 to 4 TOF responses at CSC and AP were compared. Values are means (sd). RESULTS: Reappearance of the first and second TOF responses at CSC occurred significantly (P<0.05) earlier and at lower ABemg recovery than that of AP [35 (8) and 41 (9) min vs 51 (10) and 56 (12) min; and 17 (8) and 26 (9)% vs 56 (10) and 75 (11)%, respectively]. CONCLUSIONS: We demonstrated that the TOF response count at the CSC, compared with the AP, allowed a better quantification of the degree of AB muscle relaxation during recovery from vecuronium block.

Tracheal intubation of morbidly obese patients: LMA CTrach vs direct laryngoscopy.

BACKGROUND: LMA CTrach (CT), a modified version of the intubating LMA Fastrach, allows continuous video-endoscopy of the tracheal intubation procedure. We tested the hypothesis that the CT is efficient for tracheal intubation of morbidly obese patients who are at risk of a difficult airway. METHODS: After Ethics' Committee approval, 104 morbidly obese patients (BMI >35 kg m(-2)) scheduled for bariatric surgery were included in this prospective study. Patients were randomly assigned in two groups: tracheal intubation using direct laryngoscopy (DL) or the CT. Induction of anaesthesia was standardized using sufentanil, propofol and succinylcholine. Characteristics and consequences of airway management were evaluated. RESULTS: Preoperative characteristics of patients and consequences of anaesthesia induction on physiological variables were similar in both groups. Difficulty in facemask ventilation was similar in both groups. Tracheal intubation was successfully carried out with DL and CT. Forty-nine per cent of the patients from the CT group required laryngeal mask manipulation (ventilation and view optimization) resulting in increased duration of tracheal intubation by 57 s as compared with DL. Oxygenation was of better quality in the patients managed with CT than with DL. Blind tracheal intubation was mandatory in eight (17%) patients of the DL group, while tracheal intubation was seen in all patients of the CT group. CONCLUSION: We demonstrated that the CT was an efficient airway device for ventilation and tracheal intubation in case of a difficult airway in morbidly obese patients.