Noradrenergic activity in anticipatory nausea

Prevention and treatment of anticipatory chemotherapy-induced nausea and vomiting in pediatric cancer patients and hematopoietic stem cell recipients: Clinical practice guideline update

This 2021 clinical practice guideline update provides recommendations for preventing anticipatory chemotherapy-induced nausea and vomiting (CINV) in pediatric patients. Recommendations are based on systematic reviews that identified (1) if a history of acute or delayed CINV is a risk factor for anticipatory CINV, and (2) interventions for anticipatory CINV prevention and treatment. A strong recommendation to optimize acute and delayed CINV control in order to prevent anticipatory CINV is made. Conditional recommendations are made for hypnosis, systematic desensitization, relaxation techniques, and lorazepam for the secondary prevention of anticipatory CINV. No recommendation for the treatment of anticipatory CINV can be made.

Effects of overshadowing on conditioned nausea in cancer patients: an experimental study

The infusion of cytotoxic drugs in cancer patients is often accompanied by posttreatment nausea (PN). In addition, patients complain about nausea prior to an infusion [i.e., anticipatory nausea (AN)]. AN is mainly explained by classical conditioning, with the infusion as the unconditioned stimulus (US) and with the stimuli signaling the infusion as conditioned stimuli (CS). Despite this conditioning etiology, a specifically derived therapy to attenuate the CS-US contingency is missing. The purpose of this study is to develop and to test an overshadowing procedure for prevention of AN, and also for the modification of PN intensity. Sixteen cancer patients were assigned to one of two groups: Overshadowing+ (OV+) and Overshadowing- (OV-). At the start of all infusions of two consecutive chemotherapy cycles A and B (acquisition), OV+ subjects drank a saliently tasting beverage (the overshadowing CS), whereas group OV- drank water. All patients received water in cycle C (test). Self-reported symptoms and heart rates were recorded. As expected, in cycle C (test), no patient of group OV+ showed AN, whereas two patients of group OV- developed AN. There was a tendency for a reduction of the intensity of PN, in terms of duration and latency after overshadowing, in cycle C: OV+ patients tended to show a shorter duration and a longer latency between end of infusion and PN onset. In OV-, there was a significantly larger heart rate deceleration in both measurement periods, in the anticipatory and the posttreatment measurement period. Data suggest to apply overshadowing for prevention of AN and modification of PN. Physiological markers of conditioned nausea are revealed. After its procedural implementation, the technique can be used in larger samples now.

Oral clonidine reduces postoperative PCA morphine requirements

PURPOSE

The purpose of this study was to evaluate the effect of perioperative oral clonidine on postoperative analgesia and PCA morphine requirements in adult patients after major orthopaedic knee surgery.

METHODS

In this prospective, double blind, placebo-controlled study 44 patients undergoing either total knee replacement or hemiarthroplasty of the knee were randomly assigned to receive oral placebo or clonidine (5 micrograms . kg-1) 1.5 hr before surgery, and at 12 hr, and 24 hr after the initial dose. Five patients were subsequently withdrawn from study. No other preoperative drugs were given. Preoperative sedation score was recorded. A standardized general anaesthetic was administered to all patients. Postoperative blood pressure, heart rate, PCA morphine use, visual analogue score (VAS) for pain, sedation, nausea, and pruritus were recorded for 36 hr postoperatively.

RESULTS

The cumulative PCA morphine used was 37% lower after clonidine 57.3 +/- 26.8 mg (mean +/- SD) compared with placebo 91 +/- 31.6 mg (P = 0.031). There was no difference in pain or sedation scores postoperatively but patients who received clonidine were more sedated preoperatively (P < 0.001) and had a lower mean arterial blood pressure throughout the period of study by 10 to 26 mmHg (P < 0.0001). Clonidine reduced the incidence of postoperative nausea (25% vs 74%) (P < 0.01) and vomiting compared with placebo (10% vs 53%) (P < 0.01) and required less antiemetic (dimenhydrinate 37.5 +/- 20.9 mg vs 82.1 +/- 49.4 mg) but not statistically significant (P = 0.065).

CONCLUSIONS

Oral clonidine is a useful component to postoperative balanced analgesia as it decreases PCA morphine requirements and decreases the incidence of nausea and vomiting.