The impact of bolus versus continuous infusion of intravenous ketamine on bispectral index variations and desflurane administration during major surgery: The KETABIS study.

BACKGROUND: Although ketamine, a NMDA-receptor antagonist, tends to increase the bispectral index (BIS), it remains a widely used analgesic whenever administered in low doses during major surgery. OBJECTIVE: The objective of this study was to compare the impact of intravenous ketamine (given either as a continuous infusion or as a bolus) on BIS and to compare desflurane administration and postoperative outcomes between the groups. DESIGN: Prospective, randomised, parallel-group, open-label study. SETTING: University hospital, operating room. PARTICIPANTS: Fifty patients, scheduled for major abdominal surgery. INTERVENTIONS AND MAIN OUTCOMES MEASURES: Patients were randomised into two groups: ketamine by intravenous continuous infusion - group (KI) and ketamine by i.v. bolus - group (KB). In the KI group, ketamine at a rate of 0.25 mg kg-1 h-1 was commenced at skin incision (T0) and maintained at this rate for the duration of surgery. In group KB, a ketamine bolus of 0.25 mg kg-1was administered at T0 and repeated every hour. The difference in BIS between the groups was compared from T0 onwards. The amount of desflurane administered to keep BIS within the usual recommended range (40-60) was compared, as were the doses of phenylephrine and remifentanil. Postoperative pain and recovery outcomes were also assessed. RESULTS: After T0, the BIS increased significantly from baseline in group KB compared with group KI: the rise in BIS was 20 ±â€Š8 vs. 11 ±â€Š6, respectively (P = 0.0001). The between-group mean difference (95% confidence interval (CI), was 9 (5 to 13). In group KB, desflurane administration significantly increased for the first 15 min after T0: 6.3 ±â€Š1.8 vs. 3.8 ±â€Š1.3 ml (P < 0.0001) with a mean intergroup group difference (95% CI) of 2.4 (1.5 to 3.4) ml. There was no difference in desflurane administration when considering the full hour from T0 to T60 min: 16 ±â€Š9 vs. 15 ±â€Š5 ml (P = 0.63) with a mean intergroup difference (95% CI) of 1 (-3 to 5) ml. After surgery, pain scores, opioid consumption, incidence of nausea and vomiting and recovery scores were similar between groups. CONCLUSION: Compared with a continuous ketamine infusion, a ketamine bolus significantly increased the BIS after T0. In order to keep the BIS below 60, significantly more desflurane was administered from T0 to T15 min in group KB. To prevent such higher desflurane administration and its related atmospheric pollution, our results suggest administering intra-operative intravenous ketamine as an infusion rather than a bolus. TRIAL REGISTRATION: Clinicaltrials.gov registration identifier: NCT03781635.

Prognostic factors associated with six month mortality of critically ill elderly patients admitted to the intensive care unit with severe acute cholangitis.

BACKGROUND: Little is known about the outcomes of elderly patients admitted to the intensive care unit (ICU) with severe acute cholangitis (SAC). The objectives were to describe the 6-month mortality in patients with SAC ≥75 years and to identify factors associated with this mortality. METHODS: Bi-center retrospective study of critically ill elderly patients with SAC conducted between 2013 and 2017. Demographic and clinical variables of ICU and hospital stays with a 6-month follow-up were analyzed. RESULTS: 85 patients, with a median [Q1-Q3] age of 83 [80-89] years were enrolled of whom 51 (60%) were men. SAC was due to choledocholithiasis in 72 (85%) patients. Median [Q1-Q3] ICU length of stay was 3 [2-6] days. Median [Q1-Q3] admission SAPS II was 50 [42-70]. The ICU and 6-month mortality rates were 18% and 48% respectively. Multivariate analysis showed that malnutrition (OR = 34.5, 95% CI [1.4-817.9]) and a decrease in SOFA score at 48 h (OR by unit 0.7, 95% CI [0.5-0.9]) were associated with higher 6-month mortality. CONCLUSION: In their decision-making process, ICU physicians and hepato-pancreato-biliary surgeons could use these data to estimate the probability of survival of an elderly patient presenting with SAC and to offer time-limited trials of intensive care. TRIAL REGISTRATION: NCT03831529.

"Impact of Nociception Level (NOL) index intraoperative guidance of fentanyl administration on opioid consumption, postoperative pain scores and recovery in patients undergoing gynecological laparoscopic surgery. A randomized controlled trial".

STUDY OBJECTIVE: The Nociception Level (NOL) index uses a multiparametric approach to measure the balance between sympathetic and parasympathetic systems activity. Recently, a strong correlation between the NOL index response to nociceptive stimuli and the level of opioid analgesia during surgery was reported. Others observed that intraoperative doses of remifentanil and sufentanil were reduced when the NOL index was used. So far, no study has evaluated the impact of NOL-guided fentanyl antinociception in laparoscopic gynecological surgery. The primary hypothesis of this present study was to evaluate whether intraoperative NOL-guided fentanyl administration would reduce intra-operative opioid consumption. Secondary hypotheses were to assess whether this would lead to lower postoperative opioid consumption and pain scores, as well as improved postoperative outcomes. SETTING: University hospital, operating room. PATIENTS: 70 adult patients, ASA 1-3, scheduled for total laparoscopic hysterectomy. INTERVENTIONS: Patients were randomized into 2 groups: SOC (standardization of care) and NOL (using the NOL index to guide the administration of fentanyl). The depth of anesthesia was monitored with BIS™. Intraoperative fentanyl boluses were administered based on heart rate and mean arterial pressure variations in the SOC group, and NOL index for the NOL group. MEASUREMENTS: Fentanyl total intraoperative dose administered was collected and also averaged per hour. Pain scores and hydromorphone consumption were assessed in the post-anesthesia care unit and up to 24 h. MAIN RESULTS: Sixty-six patients completed the study, 33 in each group. Total intraoperative fentanyl administration was not different between the two groups (217 (70) in the NOL group vs 280 (210) in the SOC group (P = 0.11)). Nevertheless, intraoperative fentanyl administration per hour was reduced by 25% in the NOL-guided group compared to the SOC group: 81 (24) vs 108 (66) µg.h-1, respectively (P = 0.03). Hydromorphone consumption and pain scores in the post-anesthesia care unit and at 24 h were not significantly different between the two groups. CONCLUSION: NOL-guided analgesia allowed for a 22% reduction of the total amount of intraoperative fentanyl which was not significant. Nevertheless, results reported a significant reduction by 25% in the doses of fentanyl averaged per hour of surgery and administered in the NOL-guided group compared with the standardized practice in laparoscopic gynecological surgery. The pain measured postoperatively was similar in the two groups while the average postoperative consumption of opioids to achieve the same level of pain scores in post-anesthesia care unit and at 24 h was not significantly reduced. Further larger multicenter studies centered towards postoperative outcomes are needed.