Mood change after anaesthesia with remifentanil or alfentanil:

Remimazolam-remifentanil causes less postoperative nausea and vomiting than remimazolam-alfentanil during hysteroscopy: a single-centre randomized controlled trial

BACKGROUND

Although the operation time of hysteroscopy is short, the incidence of postoperative nausea and vomiting is high. The aim of this study was to compare the incidence of postoperative nausea and vomiting in hysteroscopy when remimazolam is combined with remifentanil or alfentanil.

METHODS

We conducted a randomized, controlled, double-blind trial. Patients undergoing hysteroscopy were recruited and randomly assigned to either the remimazolam-remifentanil (Group RR) or the remimazolam-alfentanil group (Group RA). All patients in the two groups were started with an induction dose of remimazolam besylate 0.2 mg/kg and then maintained with a dosage of 1.0 mg/kg/h. After induction with remimazolam besylate, in Group RR, remifentanil was infused using a target-controlled infusion system with a target concentration of 1.5 ng/ml and titrated throughout the procedure. In Group RA, infusion of alfentanil was started with an initial bolus dose of 20 µg/kg over 30 s and then maintained at an initial rate of 0.16 µg/kg/min. The primary observation outcome was the incidence rate of postoperative nausea and vomiting. The secondary observation outcomes were the time to awakening, the length of stay in the PACU, the total remimazolam dose and adverse effects, such as low SpO₂, bradycardia, hypotension and body movement.

RESULTS

A total of 204 patients were successfully included in this study. The incidence of postoperative nausea and vomiting in Group RR (2/102, 2.0%) was significantly lower than that in Group RA (12/102, 11.8%) (p < 0.05). There was no significant difference in the incidence of adverse events, such as low SpO₂, bradycardia, hypotension and body movement, between Groups RR and RA (p > 0.05).

CONCLUSIONS

Remimazolam-remifentanil causes less postoperative nausea and vomiting than remimazolam-alfentanil in hysteroscopy.

TRIAL REGISTRATION

Clinical trial registration number: ChiCTR2100044177. Full date of the first registration: 12/03/2021.

The effects of tramadol on postoperative shivering after sevoflurane and remifentanil anesthesia

BACKGROUNDS

Remifentanil has been reported to cause post-anesthetic shivering (PAS). Higher doses of remifentanil reportedly induce more intense PAS. Tramadol, a synthetic opioid that acts at multiple sites, is considered to be an effective treatment for PAS, but the evidence for its therapeutic benefit after remifentanil anesthesia is limited. We investigated the effect of tramadol on the incidence of PAS after remifentanil anesthesia.

METHODS

Sixty-three patients who had undergone upper abdominal surgery under general anesthesia were studied retrospectively. Tramadol was administered at induction of anesthesia. The patients were divided into four groups: HT(+), high dose remifentanil (1-1.5 μg/kg/min) with tramadol; HT(-), high dose remifentanil without tramadol; LT(+), low dose remifentanil (0.15-0.25 μg/kg/min) with tramadol; and LT(-), low dose remifentanil without tramadol. We recorded perioperative changes in nasopharyngeal temperature and episodes of PAS on emergence from anesthesia.

RESULTS

The incidences of PAS in both tramadol treatment groups were significantly lower than the groups that did not receive tramadol. Nasopharyngeal temperature after surgery fell significantly more from baseline in the tramadol treatment groups compared with the non-treatment groups.

CONCLUSION

Tramadol administered at induction of anesthesia appears to suppress PAS following remifentanil anesthesia.

An intraoperative small dose of ketamine prevents remifentanil-induced postanesthetic shivering

Patients undergoing gynecological laparotomy were randomized to receive either 0.5 mg/kg ketamine at induction of anesthesia followed by an infusion of 0.3 mg/kg/h until the end of surgery (ketamine group, n = 32), or an equivalent volume of normal saline (control group, n = 32). Anesthesia was maintained with IV propofol, a fixed infusion rate of remifentanil (0.25 μg/kg/min), and epidural ropivacaine. Postanesthetic shivering (PAS) was evaluated for 30 minutes after emergence. Intraoperative temperatures were similar between the 2 groups. The incidence of PAS was less frequent in the ketamine group (n = 2, 6%) compared with the control group (n = 12, 38%, P = 0.005). We conclude that, during the early recovery phase, intraoperative ketamine reduces remifentanil-induced PAS.

The mu-opioid receptor agonist remifentanil induces acute dysphoria irrespective of its analgesic properties

Mu-opioidergic agonists are believed to induce euphoria, whereas kappa-agonists are thought to lead to dysphoria. Our study investigated mood effects of remifentanil, a mu-receptor opioid agonist, in healthy male volunteers. Moreover, we examined interactions between mood and pain. Three conditions were investigated in 21 volunteers: saline, 0.05 and 0.15 microg kg(-1) min(- 1) remifentanil. Each condition was investigated during non-painful heat and during painful heat stimulation. Mood was measured with the von Zerssen's mood scale (Bf-S score) and pain intensity using a Visual Analogue Scale (VAS). High Bf-S scores are reflecting discontent and dysphoria. Changes were tested for significance using a linear mixed model approach. Remifentanil significantly increased Bf-S scores during painful heat (+91.4%), indicating a negative mood effect, although it reduced VAS scores of painful heat intensity (-49.0%). The type of sensory stimulation (non-painful versus painful) had no effect on mood. There was no interaction between remifentanil dose and type of stimulation. Our results provide evidence for negative mood effects of remifentanil. These effects occur with and without pain. Taken into account that remifentanil reduces pain, one could have expected analgesia-related amelioration of mood instead. In clinical practice, these remifentanil effects should be considered and a comedication might be advisable.

Effect of prewarming on post-induction core temperature and the incidence of inadvertent perioperative hypothermia in patients undergoing general anaesthesia

BACKGROUND

Inadvertent perioperative hypothermia (IPH) occurs in many patients because warming techniques are insufficient to counteract thermal redistribution resulting from the ablation of thermoregulatory vasoconstriction associated with anaesthesia. We tested the efficiency of a preoperative forced-air warming (FAW) device (Bair Paws) in preventing IPH.

METHODS

Sixty-eight adult patients undergoing spinal surgery under general anaesthesia were randomized to receive either normal care or prewarming for 60 min, at 38 degrees C, using the Bair Paws system. All patients received routine FAW intraoperatively.

RESULTS

Thirty-one patients were prewarmed and 37 patients were in the control group. There was a 0.3 degrees C smaller decrease in mean core temperature in the prewarmed group at 40, 60, and 80 min post-induction (P< or =0.05). Temperature was maintained above the hypothermic threshold of 36 degrees C in 21 (68%) patients in the prewarmed group, compared with 16 (43%) patients in the control group (P<0.05).

CONCLUSIONS

Preoperative warming using the Bair Paws system results in smaller decreases in core temperature intraoperatively and less IPH in patients undergoing spinal surgery under general anaesthesia.

Remifentanil for general anaesthesia: a systematic review

We performed a quantitative systematic review of randomised, controlled trials that compared remifentanil to short-acting opioids (fentanyl, alfentanil, or sufentanil) for general anaesthesia. Eighty-five trials were identified and these included a total of 13 057 patients. Intra-operatively, remifentanil was associated with clinical signs of deeper analgesia and anaesthesia, such as fewer responses to noxious stimuli (relative risk 0.65, 95% CI 0.48-0.87), more frequent episodes of bradycardia (1.46, 1.04-2.05), more hypotension (1.68, 1.36-2.07) and less hypertension (0.60, 0.46-0.78). Postoperatively, remifentanil was associated with faster recovery (difference in extubation time of -2.03, 9.5% CI, -2.92 to -1.14 min), more frequent postoperative analgesic requirements (1.36, 1.21-1.53) and fewer respiratory events requiring naloxone (0.25, 0.14-0.47). Remifentanil had no overall impact on postoperative nausea (1.03, 0.97-1.09) or vomiting (1.06, 0.96-1.17), but was associated with twice as much shivering (2.15, 1.73-2.69). Remifentanil does not seem to offer any advantage for lengthy, major interventions, but may be useful for selected patients, e.g. when postoperative respiratory depression is a concern.

The Effect of Hippotherapy on Spasticity and on Mental Well-Being of Persons With Spinal Cord Injury

OBJECTIVES

To determine the effect of hippotherapy on spasticity and on mental well-being of persons with spinal cord injury (SCI), and to compare it with the effects of other interventions.

DESIGN

Crossover trial with 4 conditions.

SETTING

Swiss paraplegic center.

PARTICIPANTS

A volunteer sample of 12 people with spastic SCI (American Spinal Injury Association grade A or B).

INTERVENTIONS

Hippotherapy, sitting astride a Bobath roll, and sitting on a stool with rocking seat. Each session lasted 25 minutes and was conducted twice weekly for 4 weeks; the control condition was spasticity measurement without intervention.

MAIN OUTCOME MEASURES

Clinical rating by a blinded examiner of movement-provoked muscle resistance, using the Ashworth Scale; self-rating of spasticity by subjects on a visual analog scale (VAS); and mental well-being evaluated with the self-rated well-being scale Befindlichkeits-Skala of von Zerssen. Assessments were performed immediately after intervention sessions (short-term effect); data from the assessments were analyzed 3 to 4 days after the sessions to calculate the long-term effect.

RESULTS

By analyzing the clinically rated spasticity, only the effect of hippotherapy reached significance compared with the control condition (without intervention); median differences in the Ashworth scores' sum before and after hippotherapy sessions ranged between -8.0 and +0.5. There was a significant difference between the spasticity-reducing effect of hippotherapy and the other 2 interventions in self-rated spasticity by VAS; median differences of the VAS before and after hippotherapy sessions ranged between -4.6 and +0.05cm. There were no long-term effects on spasticity. Immediate improvements in the subjects' mental well-being were detected only after hippotherapy (P=.048).

CONCLUSIONS

Hippotherapy is more efficient than sitting astride a Bobath roll or on a rocking seat in reducing spasticity temporarily. Hippotherapy had a positive short-term effect on subjects' mental well-being.