Sevoflurane preserves regional cerebral oxygen saturation better than propofol: Randomized controlled trial

STUDY OBJECTIVE

To investigate possible effects of volatile induction and maintenance anesthesia with sevoflurane (VIMA) and total intravenous anesthesia with propofol (TIVA) on regional cerebral oxygen saturation (rcSo₂) during laparoscopic cholecystectomy.

DESIGN

Randomized, prospective and single-blinded study.

SETTING

Academic hospital.

PATIENTS

ASA physical status of I and II surgical patients, scheduled for elective laparoscopic cholecystectomy from March 2013 to October 2014.

MEASUREMENTS

Changes of regional cerebral oxygen saturation were measured by near-infrared spectroscopy on the left and right sides of forehead at different time points: before anesthesia induction (Tbas), immediately after induction (Tind), after applaying a pneumoperitoneum (TCo₂), 10 minutes after positioning the patient into reverse Trendelenburg's position (TrtCo₂), immediately after desufflation of gas (Tpost) and 30 (Trec30) and 60 (Trec60) minutes after emergence from anesthesia.

MAIN RESULTS

Study population included 124 patients, 62 in each group. There was no significant difference between these groups according to demographic characteristics, surgery and anesthesia times as well as in the basal rcSo₂ values. Statistically higher rSco₂ values were noted in the VIMA group when compared to the TIVA group in all time points Tind, TCo₂, TrtCo₂, Tpost, Trec30 and Trec60 and incidence of critical rcSo₂ decreases was statistically lower in VIMA group (P<.05). There were no serious perioperative complications.

CONCLUSIONS

VIMA technique provides significantly (4%-11%) higher rcSO₂ values during general anesthesia for laparoscopic cholecystectomy, when compared with TIVA and also provides significantly less number of critical rcSO₂ decreases.

Factors associated with difficult neuraxial blockade

Spinal and epidural blocks are common practice in anesthesia and are usually used for various surgical or endoscopic procedures. Correct identification and puncture of the epidural or subarachnoid space determine the success or failure of the technique. Multiple attempts and difficult access to the epidural or subarachnoid space is a frequent problem in operating theaters and may be hazardous due to a number of possible acute or long-term complications. In addition, multiple punctures are associated with increased pain and patient discomfort. The aim of this study was to determine the factors associated with a difficult spinal or epidural block, dependent on the patient (age, gender, height, weight, body mass index, and quality of anatomical landmarks), the technique (type of blockade, needle gauge, and patient positioning), and the provider (level of experience). The study was conducted at the Department of Anesthesiology, Resuscitation, and Intensive Care Unit of University Hospital Osijek (Osijek, Croatia) and it included 316 patients who underwent a range of different surgical procedures in neuraxial blocks. There were 219 cases of first puncture success, while the overall success of neuraxial blocks was 97.5%. Five patients (1.6%) were submitted to the alternative technique, ie, general anesthesia. In three patients (0.9%), neuraxial block was partial so they required supplementation of intravenous anesthetics and analgesics. Furthermore, it was found that first puncture success was associated with younger age (P=0.007), lower weight (P=0.032), and body mass index (P=0.020). Spine deformity (P=0.015), poor identification of interspinous space (P=0.005), recumbent patient position during the puncture (P=0.001), and use of a paramedian approach were associated with first puncture failure. Adequate preoperative prediction of difficulties can help to reduce the incidence of multiple attempts, rendering the technique more acceptable and less risky to the patient, and consequently leading to improvement of medical care quality. The attending anesthesiologist should consider an alternative technique (general anesthesia or peripheral nerve block) for a patient if certain difficulties can be predicted.