Effect of combined intraoperative use of the Nociception Level (NOL) and bispectral (BIS) indexes on desflurane administration.

BACKGROUND: Currently, nociception monitors are not part of standard anaesthesia care. We investigated whether combined intraoperative nociception (NOL index) and anaesthesia (BIS index) monitoring during general anaesthesia would reduce anaesthetics consumption and enhance intraoperative safety and postoperative recovery when compared to standard of care monitoring (SOC). METHODS: In this randomised study, we included 60 patients undergoing colonic surgery under desflurane/remifentanil anaesthesia and epidural analgesia. Patients received either standard monitoring or combined BIS + NOL index monitoring. In the monitored group, remifentanil infusion was titrated to achieve a NOL index below 20. Desflurane was adjusted to BIS values (45-55). In the SOC group, remifentanil and desflurane were titrated on vital signs and MAC. The primary outcome was intraoperative desflurane consumption. RESULTS: Fifty-five patients were analysed. Desflurane administration was reduced in the monitored group from 0.25 ± 0.05 to 0.20 ± 0.06 mL kg-1 h-1 (p < 0.001). The cumulative time with a BIS under 40 was significantly higher in the SOC group with a median time of 12.6 min (95% CI: 0.6-80.0) versus 2.0 min (95% CI: 0.3-5.83) (p = 0.023). Time for extubation was significantly shorter in the monitored group: 4.4 min (95% CI: 2.4-4.9) versus 6.28 min (95% IC: 5.0-8.2) (p = 0.003). We observed no differences in remifentanil or phenylephrine requirements during anaesthesia or in postoperative outcome measures, such as postoperative pain, opioid consumption, neurocognitive recovery. CONCLUSION: Combined intraoperative monitoring of anaesthesia and nociception during colonic surgery resulted in less desflurane consumption and quicker extubation time compared to standard clinical care monitoring.

Host perspective on academic supervision, health care provision and institutional partnership during short-term electives in global health.

CONTEXT: Studies about the impact of global health electives on host institutions are scarce and often made from the perspective of institutions that send students. The present research examined the impact of short-term electives in global health (STEGHs) from the under-represented perspective of host institutions in Benin. METHODS: The authors conducted 30 semi-structured interviews from a convenience sample of Beninese health care professionals who had hosted Canadian medical students. Interviewees had previously supervised STEGHs in one of the five different institutions. A subsequent qualitative thematic analysis methodology was used to compilate codes and generate themes. RESULTS: Hosting STEGH students motivated respondents to increase their medical knowledge through self-driven learning. They perceived an improvement in the quality of their care and felt a negligible impact on patient safety. They negatively commented on the lack of clear pedagogic objectives that they could rely on. Interviewees think current STEGH partnerships do not advantage them because institutions that send students offer little support during the electives. Furthermore, sending institutions do not offer the same opportunity for local medical students or professionals to take part in such electives outside of Benin. CONCLUSIONS: Although host health care professionals evaluated global health electives positively overall, specific improvements could mitigate their negative impacts and help create a more balanced partnership between sending and host institutions. Sending institutions could involve host institutions in curriculum planning. They could invest in building reciprocal elective programmes to receive students from elsewhere. Meanwhile they can maximise the transfer of relevant medical knowledge, and provide expertise, resources and support during the electives.

Impact of intravenous phenylephrine bolus administration on the nociceptive level index (NOL).

Recently, the nociceptive level index (NOL) was shown to more specifically and sensitively detect noxious stimuli during anesthesia, in comparison to previous methods that relied on such parameters as heart rate (HR) and mean blood pressure (MAP). An ongoing study (NCT#03410485) evaluates the intraoperative combination of both NOL and bispectral (BIS) indices to improve quality of recovery after colorectal surgery. Our ethical committee (REB approval #CER15083) initially agreed on an interim analysis of the data from the first 30 patients. More specifically, this present report analyzed all the intravenous phenylephrine (PE) boluses administered during anesthesia as part of our study protocol to see whether they had a significant impact on NOL values as well as other parameters: HR, MAP, BIS index. For this trial, remifentanil and phenylephrine were given in both groups based on a specific algorithm. All study parameters were recorded electronically. Our analysis for the present specific outcome evaluated NOL index for 30 s before the intravenous PE bolus (1 µg kg-1) was given and until 5 min afterwards. The average NOL values after PE bolus, as well as MAP, HR and BIS indices, were recorded and analyzed. A total of 178 events of PE boluses were identified for 28 patients (two were excluded). Median baseline NOL was 3 (1.8-8.3) CI 95% 5.7-8.7; post-PE bolus: 5.3 (2.7-9.9) (95% CI 6.6-8.9; Wilcoxon matched-pairs signed rank test (WMPSRT), P = 0.0003). When analyzing delta NOL (difference between pre- and post-PE bolus in NOL values) for each patient, the median delta NOL was 2.9 (1.2-6.1) (95% CI 3.6-5.5) with 95% of the subjects keeping a delta NOL under 10. MAP and HR values showed expected significant variations after PE bolus: a slight increase and slight decrease, respectively. BIS index values did not change after PE bolus. Our present results demonstrate that intravenous phenylephrine boluses of 1 µg kg-1 had the expected impact on hemodynamic parameters: a significant but very slight increase in MAP and decrease in HR, which might lack clinical relevance. Our report also demonstrates that these same phenylephrine boluses induce a statistically significant increase of the NOL index which does not seem to have much of a clinical relevance for the novel NOL index used to monitor intraoperative nociception as well as for the more classical BIS index for depth of anesthesia. Nevertheless, doses of intravenous PE bolus used in the present study (1 µg kg-1) might be regarded as smaller than more conventional ones (100-200 µg per bolus). Further studies need to be done with the latter doses.

Correlation between incremental remifentanil doses and the Nociception Level (NOL) index response after intraoperative noxious stimuli.

BACKGROUND: The Pain Monitoring Device (PMD) monitor (Medasense Biometrics Ltd., Ramat Gan, Israel) uses the Nociception Level (NOL) index, a multiple parameter-derived index that has recently shown a good sensitivity and specificity to detect noxious stimuli. The aim of this study was to assess the latest version of the device (PMD200TM) on variations of the NOL response after standardized tetanic stimuli to study the correlation between remifentanil doses and NOL. METHODS: Data from 26 patients undergoing midline laparotomy and receiving a desflurane-remifentanil-based anesthetic coupled with low thoracic epidural analgesia were analyzed. A standardized tetanic stimulus was applied to the forearm of the patients at different remifentanil infusion rates. The primary aim was to evaluate the correlation between post-tetanic stimulation NOL values from the PMD200 and remifentanil doses. The NOL index variations after experimental and clinical stimuli were also compared with heart rate (HR), mean arterial pressure (MAP), and Bispectral Index™ (BIS). RESULTS: A correlation between post-tetanic stimulation NOL values and remifentanil doses was found (r = -0.56; 95% confidence interval [CI], -0.70 to -0.44; P < 0.001). The NOL discriminated noxious from non-noxious states with the maximal Youden's index value of the NOL receiver operating characteristic (ROC) curve showing a specificity of 88% (95% CI, 69.0 to 100) and sensitivity of 79.1% (95% CI, 56.2 to 95.5). The area under the NOL ROC curve (AUC, 0.9; 95% CI, 0.84 to 0.95) was significantly different from the other variables (P < 0.001 vs HR; P < 0.001 vs MAP; P < 0.001 vs BIS). CONCLUSIONS: The NOL value after noxious stimulus decreased with incremental remifentanil doses, showing a significant inverse correlation between the NOL index and opioid doses. The sensitivity and specificity of NOL to discriminate between noxious and non-noxious stimuli suggests its interesting potential as a monitor of nociception intensity during anesthesia. TRIAL REGISTRATION: www.clinicaltrials.gov (NCT02884778); 27 July, 2016.