Impact of a preoperative conversational hypnotic session on propofol consumption using closed-loop anesthetic induction guided by the bispectral index: A randomized controlled trial

Conversational hypnosis versus standard of care to reduce anxiety in patients undergoing marker placement under radiographic control prior to breast cancer surgery: A randomized, multicenter trial

BACKGROUND

Surgery is a cornerstone of breast cancer management. Prior to surgery, a wire marker is placed at the site of the tumor, to enable the surgeon to accurately localize the lesion during later surgery. This procedure can generate considerable anxiety for many patients. We investigated the value of conversational hypnosis (CH) in reducing anxiety in patients undergoing preoperative wire placement under radiographic control.

METHODS

Randomized, multicentre study in 7 centers in France. Inclusion criteria were patients aged >18 years with an Eastern Cooperative Oncology Group performance status ≤2, scheduled to undergo preoperative wire placement in one or several breast lesions. Patients were randomized in a 1:1 ratio, stratified by center to undergo preoperative wire placement with or without the use of CH by a radiological technician trained in the CH technique. The primary endpoint was the percentage of patients with an anxiety score ≥ 6 on a visual analog scale ranging from 0 (absence of anxiety) to 10 (maximal anxiety). Secondary endpoints were pain score, perceived duration reported by the patient, technician satisfaction with their relationship with the patient, and ease of marker insertion reported by the radiologist. Semi-structured interviews were performed with patients to assess their perception of the marker placement procedure.

RESULTS

The trial was prematurely interrupted for futility after a planned interim analysis after accrual of 167 patients, i.e., half the planned sample size. Prior to marker placement, 29.3% (n = 24) of patients in the control group had an anxiety score ≥ 6, versus 42.3% (n = 33) in the CH group (p = 0.08). After marker placement, the change of anxiety score was not significantly different between groups (11.0% (n = 9) versus 14.3% (n = 11), p = 0.615). There was no significant difference in any of the secondary endpoints. In the interviews, patients from both groups frequently spoke of a feeling of trust.

CONCLUSION

This study failed to show a benefit of conversational hypnosis on anxiety in patients undergoing marker placement prior to surgery for breast cancer. The fact that some caregivers had learned this personalized therapeutic communication technique may have had a positive impact on the whole caregiving team.

TRIAL REGISTRATION

The study was registered with ClinicalTrials.gov (NCT02867644).

The Effect of Low-Dose Intraoperative Ketamine on Closed-Loop-Controlled General Anesthesia: A Randomized Controlled Equivalence Trial

BACKGROUND

Closed-loop control of propofol-remifentanil anesthesia using the processed electroencephalography depth-of-hypnosis index provided by the NeuroSENSE monitor (WAVCNS) has been previously described. The purpose of this placebo-controlled study was to evaluate the performance (percentage time within ±10 units of the setpoint during the maintenance of anesthesia) of a closed-loop propofol-remifentanil controller during induction and maintenance of anesthesia in the presence of a low dose of ketamine.

METHODS

Following ethical approval and informed consent, American Society of Anesthesiologist (ASA) physical status I-II patients aged 19-54 years, scheduled for elective orthopedic surgery requiring general anesthesia for >60 minutes duration, were enrolled in a double-blind randomized, placebo-controlled, 2-group equivalence trial. Immediately before induction of anesthesia, participants in the ketamine group received a 0.25 mg·kg-1 bolus of intravenous ketamine over 60 seconds followed by a continuous 5 µg·kg-1·min-1 infusion for up to 45 minutes. Participants in the control group received an equivalent volume of normal saline. After the initial study drug bolus, closed-loop induction of anesthesia was initiated; propofol and remifentanil remained under closed-loop control until the anesthetic was tapered and turned off at the anesthesiologist's discretion. An equivalence range of ±8.99% was assumed for comparing controller performance.

RESULTS

Sixty patients participated: 41 males, 54 ASA physical status I, with a median (interquartile range [IQR]) age of 29 [23, 38] years and weight of 82 [71, 93] kg. Complete data were available from 29 cases in the ketamine group and 27 in the control group. Percentage time within ±10 units of the WAVCNS setpoint was median [IQR] 86.6% [79.7, 90.2] in the ketamine group and 86.4% [76.5, 89.8] in the control group (median difference, 1.0%; 95% confidence interval [CI] -3.6 to 5.0). Mean propofol dose during maintenance of anesthesia for the ketamine group was higher than for the control group (median difference, 24.9 µg·kg-1·min-1; 95% CI, 6.5-43.1; P = .005).

CONCLUSIONS

Because the 95% CI of the difference in controller performance lies entirely within the a priori equivalence range, we infer that this analgesic dose of ketamine did not alter controller performance. Further study is required to confirm the finding that mean propofol dosing was higher in the ketamine group, and to investigate the implication that this dose of ketamine may have affected the WAVCNS.

Nociceptive stimulation during Macintosh direct laryngoscopy compared with McGrath Mac videolaryngoscopy: A randomized trial using indirect evaluation using an automated administration of propofol and remifentanil

BACKGROUND

Decrease of the nociceptive stimulation induced by laryngoscopy could be an advantage for patients without risk of difficult intubation. The present study aimed to compare the difference in nociceptive stimulation between the use of a conventional laryngoscope or of a videolaryngoscope. Amount of nociception was assessed indirectly using the peak remifentanil concentration determined by a closed-loop administration of propofol and remifentanil with bispectral index (BIS) as the input signal (target 50).

METHODS

A prospective single-center randomized study was performed including surgical patients without predictable risk of difficult mask ventilation or of difficult tracheal intubation. Forty consecutive surgery patients were randomly assigned to CL group (conventional laryngoscope) or VL group (McGrath Mac videolaryngoscope). Induction of anesthesia was performed automatically using the closed-loop system and myorelaxation with atracurium. The allocation was revealed just before tracheal intubation. The primary outcome was the peak plasma remifentanil concentration observed during the 5-minute period which followed intubation.

RESULTS

Sixteen patients in the CL group and 11 in the VL group were analyzed. Plasmatic remifentanil and propofol concentrations were similar in both groups either before tracheal intubation or during the 5 minutes following intubation. There was a nonsignificant between-group difference (P = .09) for the peak concentration of remifentanil. A comparable result was observed for other outcomes except for the heart rate which increased in the CL group.

CONCLUSION

Use of the videolaryngoscope McGrath Mac did not reduce the nociceptive stimulation induced during intubation as evaluated by the automatically administered remifentanil concentration.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02245789.