[EFFECTS OF CANNABIS EXTRACT PREMEDICATION ON ANESTHETIC DEPTH].

BACKGROUND: Cannabis is the most widely used illicit drug in the world, used by approximately 2.7-4.9% of the world's population, and 7.6-10.2% of Israel's adults. During the past few years, legal systems around the world have enacted large scale adoption of the legalization of both medical and recreational cannabis. Anesthetists should therefore be prepared to treat patients who used cannabis and are undergoing elective or emergency operations. However, the interactions between cannabinoids and general anesthetic agents and the possible implications for patient care are not yet fully understood. OBJECTIVES: The study aimed to examine how preoperative use of cannabis affects the anesthesia process, and whether this use requires special attention by the anesthesiologists during surgery. Hence, we examined the effect of preoperative administration of cannabis extract Sativex (nabiximols) on obtained BIS value relative to the concentration of anesthetic gases. METHODS: This study is a double-blind randomized controlled trial. Twenty-seven patients undergoing elective orthopedic surgery under general anesthesia were randomly allocated to one of the following regimes: high dose cannabis (6), low dose cannabis (8), active placebo (6) and placebo (7). The study drugs were administered as premedication 20 minutes before induction of general anesthesia in a double-blind fashion. Cannabis was administered in the form of nabiximols (Sativex®), which is a highly-standardized extract of cannabis plants containing known drug dosages. During the surgery, hemodynamic parameters were monitored, and the anesthesia depth was measured using a BIS monitor, which is based on brain activity analysis. RESULTS: We found a significant effect of treatment groups on bispectral index (BIS) after controlling for minimum alveolar concentration (MAC). The average BIS values, as measured during steady state anesthesia, were significantly higher in the high dose cannabis treatment group. CONCLUSIONS: This study provides the first evidence that cannabinoids may affect the BIS. We speculate that the cannabinoid-induced increase in BIS may be the result of changes in EEG activity rather than an indication of a shallower anesthetic state. However, this hypothesis should be examined in further studies. The clinical importance of this study is that with patients who use cannabis adjacent to general anesthesia induction, one cannot rely on the BIS monitoring for the purpose of determining the patient sedative state.

High Success Rates Using Ultrasound for Neuraxial Block in Obese Patients.

BACKGROUND: Successful neuraxial block performance relies on assessment and palpation of surface landmarks, potentially challenging in patients with a high body mass index (BMI). OBJECTIVES: To evaluate the use of ultrasound-assisted neuraxial bock in a non-obstetric population with BMI above versus below 30 kg/m2. METHODS: Healthy adult patients undergoing extracorporeal shock wave lithotripsy (ESWL) under neuraxial block were observed in this quality assurance study. Prior to the neuraxial block, an ultrasound examination was performed to identify the puncture site. Neuraxial anesthesia block was performed under aseptic surgical conditions with the patient in the sitting position. Following block placement, external landmarks were palpated. Our primary study outcome was the number of attempts (skin insertions with the needle) after pre-puncture ultrasound identification of the insertion point, comparing patients with BMI above versus below 30 kg/m2. Our secondary outcome was assessment by palpation of external anatomical landmarks. RESULTS: Our study group included 63 consecutive patients undergoing neuraxial block for ESWL. Data were assessed according to BMI (above versus below 30 kg/m2). An overall success rate at the first attempt of 90.5% (CI 0.8-0.95) was achieved using ultrasound-guided neuraxial block. This block placement success rate was similar for all patients, regardless of BMI above versus below 30 kg/m2. In contrast, the ease of palpation of anatomic landmarks, P = 0.001, and the ease of palpation of iliac crest, P < 0.001, differed significantly between the patients above versus below 30 kg/m2. The reported verbal pain scores (VPS) due to block insertion was similar among all patients regardless of BMI category (above versus below 30 kg/m2). CONCLUSIONS: We observed high success rates when ultrasound-assisted neuraxial block is performed, regardless of BMI above versus below 30 kg/m2, despite expected differences in surface landmark palpation.

The Effect of Medicinal Cannabis on Pain and Quality-of-Life Outcomes in Chronic Pain: A Prospective Open-label Study.

OBJECTIVES: The objective of this prospective, open-label study was to determine the long-term effect of medicinal cannabis treatment on pain and functional outcomes in participants with treatment-resistant chronic pain. PATIENTS AND METHODS: The primary outcome was the change in the pain symptom score on the S-TOPS (Treatment Outcomes in Pain Survey-Short Form) questionnaire at the 6-month follow-up in an intent-to-treat population. Secondary outcomes included the change in S-TOPS physical, social, and emotional disability scales, the pain severity, and pain interference on the Brief Pain Inventory, sleep problems, and the change in opioid consumption. RESULTS: A total of 274 participants were approved for treatment; complete baseline data were available for 206 (intent-to-treat), and complete follow-up data for 176 participants. At follow-up, the pain symptom score improved from median 83.3 (95% confidence interval [CI], 79.2-87.5) to 75.0 (95% CI, 70.8-79.2) (P<0.001). The pain severity score (7.50 [95% CI, 6.75-7.75] to 6.25 [95% CI, 5.75-6.75]) and the pain interference score (8.14 [95% CI, 7.28-8.43] to 6.71 [95% CI, 6.14-7.14]) improved (both P<0.001), together with most social and emotional disability scores. Opioid consumption at follow-up decreased by 44% (P<0.001). Serious adverse effects led to treatment discontinuation in 2 participants. DISCUSSION: The treatment of chronic pain with medicinal cannabis in this open-label, prospective cohort resulted in improved pain and functional outcomes, and a significant reduction in opioid use. Results suggest long-term benefit of cannabis treatment in this group of patients, but the study's noncontrolled nature should be considered when extrapolating the results.