Guidelines on muscle relaxants and reversal in anaesthesia.

OBJECTIVES: To provide an update to the 1999 French guidelines on "Muscle relaxants and reversal in anaesthesia", a consensus committee of sixteen experts was convened. A formal policy of declaration and monitoring of conflicts of interest (COI) was developed at the outset of the process and enforced throughout. The entire guidelines process was conducted independently of any industrial funding (i.e. pharmaceutical, medical devices). The authors were required to follow the rules of the Grading of Recommendations, Assessment, Development and Evaluation (GRADE®) system to assess the quality of the evidence on which the recommendations were based. The potential drawbacks of making strong recommendations based on low-quality evidence were stressed. Few of the recommendations remained ungraded. METHODS: The panel focused on eight questions: (1) In the absence of difficult mask ventilation criteria, is it necessary to check the possibility of ventilation via a facemask before muscle relaxant injection? Is it necessary to use muscle relaxants to facilitate facemask ventilation? (2) Is the use of muscle relaxants necessary to facilitate tracheal intubation? (3) Is the use of muscle relaxants necessary to facilitate the insertion of a supraglottic device and management of related complications? (4) Is it necessary to monitor neuromuscular blockade for airway management? (5) Is the use of muscle relaxants necessary to facilitate interventional procedures, and if so, which procedures? (6) Is intraoperative monitoring of neuromuscular blockade necessary? (7) What are the strategies for preventing and treating residual neuromuscular blockade? (8) What are the indications and precautions for use of both muscle relaxants and reversal agents in special populations (e.g. electroconvulsive therapy, obese patients, children, neuromuscular diseases, renal/hepatic failure, elderly patients)? All questions were formulated using the Population, Intervention, Comparison and Outcome (PICO) model for clinical questions and evidence profiles were generated. The results of the literature analysis and the recommendations were then assessed using the GRADE® system. RESULTS: The summaries prepared by the SFAR Guideline panel resulted in thirty-one recommendations on muscle relaxants and reversal agents in anaesthesia. Of these recommendations, eleven have a high level of evidence (GRADE 1±) while twenty have a low level of evidence (GRADE 2±). No recommendations could be provided using the GRADE® system for five of the questions, and for two of these questions expert opinions were given. After two rounds of discussion and an amendment, a strong agreement was reached for all the recommendations. CONCLUSION: Substantial agreement exists among experts regarding many strong recommendations for the improvement of practice concerning the use of muscle relaxants and reversal agents during anaesthesia. In particular, the French Society of Anaesthesia and Intensive Care (SFAR) recommends the use of a device to monitor neuromuscular blockade throughout anaesthesia.

Postoperative pain scores and opioid consumption in opioid-dependent patients with cancer after intraoperative remifentanil analgesia: A prospective case-controlled study.

BACKGROUND: Opioid dependency is becoming increasingly common among surgical patients with cancer, and can lead to inadequate pain relief during the initial postoperative period. No guidelines are currently available for the management of perioperative and postoperative morphine administration in these patients. As a first approach, the authors assessed the opioid requirements of these patients during the early postoperative period. METHODS: A group of 35 consecutive surgical patients with cancer on opioid therapy (opioid-dependent group) for cancer pain were compared to a matched group of 44 surgical opioid-naive patients (control group). All patients underwent major head and neck or abdominal surgery. The following parameters were recorded and compared: preoperative and postoperative morphine consumption, patient-controlled analgesia records and Visual Analog Scale scores, intraoperative remifentanil and desflurane consumption, Bispectral Index monitoring values, heart rate, and blood pressure. RESULTS: Remifentanil requirements were significantly higher (1.4-fold) in the opioid-dependent group compared to the control group (p < 0.05). On postoperative day 1, morphine requirements were significantly higher in the opioid-dependent group (2.3-fold) compared to the control group (p < 0.05). Baseline heart rate was significantly higher in the opioid-dependent group and this difference remained significant during surgery, no significant difference in blood pressure was observed between the two groups. CONCLUSION: This study shows a 40 percent increase of intraoperative remifentanil requirements in opioid-dependent patients during cancer surgery. Morphine requirements during the postoperative period were increased by up to 140 percent.

Pupillary Reflex for Evaluation of Thoracic Paravertebral Block: A Prospective Observational Feasibility Study.

BACKGROUND: Although thoracic paravertebral block (TPVB) is recommended in major breast surgery, there is no gold standard to assess the success of TPVB. Pupillary dilation reflex (PDR) is the variation of the pupillary diameter after a noxious stimulus. The objective was to evaluate the feasibility of recording the PDR to assess analgesia in an anesthetized thoracic dermatome after TPVB. METHODS: This prospective, observational, single-center study included 32 patients requiring breast surgery under general anesthesia and TPVB. TPVB was performed before surgery under ultrasound guidance with 20 mL of 0.75% ropivacaine. At the end of the surgery, remifentanil was stopped and the PDR was recorded after a 5-second tetanic stimulation (60 mA, 100 Hz) applied to the anterior chest wall. The PDR was defined as the maximal increase in pupil diameter after a standardized noxious stimulus, expressed as a percentage of the initial pupil diameter. The PDR was recorded twice in the same eye for each patient after a stimulus on both the TPVB and the control sides. Postoperative pain scores were recorded in a postanesthesia care unit. The primary outcome was the difference between the PDR on the TPVB and the control sides. RESULTS: The median (interquartile range) PDR was 9% (4%-13%) on the TPVB side and 41% (27%-66%) on the control side. There was a significant difference in the PDR between the TPVB and the control sides with a Hodges-Lehmann estimate of absolute difference of 37% points (95% confidence interval, 25-52, P < .001). Median postoperative pain scores (interquartile range) in the postanesthesia care unit were 1 (0-3) at rest and 1 (0-3) during mobilization, respectively. There was a linear correlation between maximal postoperative pain scores and the PDR on the TPVB side with a Pearson's correlation coefficient r = 0.40 (95% confidence interval, 0.06-0.66, P = .02). No correlation was found between the number of blocked dermatomes and maximal postoperative pain scores (P = .06) or between the number of blocked dermatomes and the PDR on the TPVB side (P = .15). CONCLUSIONS: This proof-of-concept trial suggests that the effect of TPVB could be monitored by measuring the PDR after anterior chest wall stimulation in the dermatome of interest.

Decreased Risk of Ventilator-Associated Pneumonia in Sepsis Due to Intra-Abdominal Infection.

RATIONALE: Experimental studies suggest that intra-abdominal infection (IAI) induces biological alterations that may affect the risk of lung infection. OBJECTIVES: To investigate the potential effect of IAI at ICU admission on the subsequent occurrence of ventilator-associated pneumonia (VAP). METHODS: We used data entered into the French prospective multicenter Outcomerea database in 1997-2011. Consecutive patients who had severe sepsis and/or septic shock at ICU admission and required mechanical ventilation for more than 3 days were included. Patients with acute pancreatitis were not included. MEASUREMENTS AND MAIN RESULTS: Of 2623 database patients meeting the inclusion criteria, 290 (11.1%) had IAI and 2333 (88.9%) had other infections. The IAI group had fewer patients with VAP (56 [19.3%] vs. 806 [34.5%], P<0.01) and longer time to VAP (5.0 vs.10.5 days; P<0.01). After adjustment on independent risk factors for VAP and previous antimicrobial use, IAI was associated with a decreased risk of VAP (hazard ratio, 0.62; 95% confidence interval, 0.46-0.83; P<0.0017). The pathogens responsible for VAP were not different between the groups with and without IAI (Pseudomonas aeruginosa, 345 [42.8%] and 24 [42.8%]; Enterobacteriaceae, 264 [32.8%] and 19 [34.0%]; and Staphylococcus aureus, 215 [26.7%] and 17 [30.4%], respectively). Crude ICU mortality was not different between the groups with and without IAI (81 [27.9%] and 747 [32.0%], P = 0.16). CONCLUSIONS: In our observational study of mechanically ventilated ICU patients with severe sepsis and/or septic shock, VAP occurred less often and later in the group with IAIs compared to the group with infections at other sites.