Effect of premedication with butorphanol or methadone on ease of endoscopic duodenal intubation in dogs

The effective dose of butorphanol tartrate in patients of different ages undergoing painless gastroscopy

OBJECTIVE

This study evaluated the 50% effective dose (ED50) and 95% effective dose (ED95) of butorphanol tartrate in patients undergoing painless gastroscopy.

METHODS

Patients who underwent painless gastroscopy at Binzhou Medical University Hospital were divided into the youth, middle-aged, and older groups. The ED50 and ED95 required for successful sedation using butorphanol tartrate were measured using the Dixon up-and-down method in patients in the different age groups. Patients in each group were administered intravenous butorphanol 5 minutes before gastroscopy. Each patient was administered 2 mg/kg propofol. The ED50 and ED95 of butorphanol were calculated using probit analysis.

RESULTS

In total, 95 patients were included. The ED50s of butorphanol in the youth, middle-aged, and older groups were 7.384, 6.657, and 6.364 μg/kg, respectively. The ED95s of butorphanol doses in these groups were 9.108, 8.419, and 7.348 μg/kg, respectively.

CONCLUSIONS

The ED50 and ED95 varied among the age groups, indicating that the effective dose decreases with age.

Effect of butorphanol on visceral pain in patients undergoing gastrointestinal endoscopy: a randomized controlled trial

BACKGROUND

Butorphanol slightly influences the respiratory and circulatory systems, has a better effect on relieving the discomfort caused by mechanical traction, and has a low incidence of postoperative nausea and vomiting (PONV). Combined butorphanol and propofol may suppress postoperative visceral pain, which is avoidable in gastrointestinal endoscopy. Thus, we hypothesized that butorphanol could decrease the incidence of postoperative visceral pain in patients undergoing gastroscopy and colonoscopy.

METHODS

This was a randomized, placebo-controlled, and double-blinded trial. Patients undergoing gastrointestinal endoscopy were randomized to intravenously receive either butorphanol (Group I) or normal saline (Group II). The primary outcome was visceral pain after the procedure 10 min after recovery. The secondary outcomes included the rate of safety outcomes and adverse events. Postoperative visceral pain was defined as a visual analog scale (VAS) score ≥ 1.

RESULTS

A total of 206 patients were enrolled in the trial. Ultimately, 203 patients were randomly assigned to Group I (n = 102) or Group II (n = 101). In total, 194 patients were included in the analysis: 95 in Group I and 99 in Group II. The incidence of visceral pain at 10 min after recovery was found to be statistically lower with butorphanol than with the placebo (31.5% vs. 68.5%, respectively; RR: 2.738, 95% CI [1.409-5.319], P = 0.002), and the notable difference was in pain level or distribution of visceral pain (P = 0.006).

CONCLUSIONS

The trial indicated that adding butorphanol to propofol results in a lower incidence of visceral pain after surgery without noticeable fluctuations in circulatory and respiratory functions for gastrointestinal endoscopy patients.

TRIAL REGISTRATION

Clinicaltrials.gov NCT04477733 (PI: Ruquan Han; date of registration: 20/07/2020).

Effect of anaesthetic maintenance with isoflurane or propofol on ease of endoscopic duodenal intubation in dogs

OBJECTIVE

To compare the ease of endoscopic duodenal intubation (EDI) in dogs during maintenance of general anaesthesia with isoflurane or propofol infusion.

STUDY DESIGN

Prospective, randomized, partially blinded clinical trial.

ANIMALS

A total of 22 dogs undergoing upper gastrointestinal tract endoscopy to include EDI were recruited.

METHODS

Dogs were randomly assigned isoflurane (ISO; n = 10) or propofol (PROP; n = 11) for maintenance of general anaesthesia. Following anaesthetic premedication with intramuscular medetomidine (0.005 mg kg^-1) and butorphanol (0.2 mg kg^-1), general anaesthesia was induced with propofol, to effect, maintained with 1.5% (vaporizer setting) isoflurane in 100% oxygen or 0.2 mg kg^-1 minute^-1 propofol. The dose of both agents was adjusted to maintain general anaesthesia adequate for the procedure. Degree of sedation 20 minutes post-anaesthetic premedication, propofol induction dose, anaesthetist and endoscopist training grade, animal's response to endoscopy, presence of gastro-oesophageal and duodenal-gastric reflux, spontaneous opening of the lower oesophageal and pyloric sphincters, antral movement and time to achieve EDI were recorded. EDI was scored 1 (immediate entry with minimal manoeuvring) to 4 (no entry after 120 seconds) by the endoscopist, blinded to the agent in use. Data were tested for normality (Shapiro-Wilk test) and differences between groups analysed using independent t test, Mann-Whitney U test and Fisher's exact test as appropriate.

RESULTS

There were no significant differences between groups for EDI score [median (interquartile range): 2 (3) ISO, 2 (3) PROP] or time to achieve EDI [mean ± standard deviation: 52.50 ± 107.00 seconds (ISO), 70.00 ± 196.00 seconds (PROP)]. Significantly more dogs responded to passage of the endoscope into the oesophagus in group PROP compared with group ISO (p = 0.01).

CONCLUSIONS AND CLINICAL RELEVANCE

Maintenance of general anaesthesia with either isoflurane or propofol did not affect EDI score or time to achieve EDI.

The Effect of Premedication on the Incidence of Gastroesophageal Reflux in 270 Dogs Undergoing General Anesthesia

The aim of this prospective, non-randomized study was to evaluate the effect of nine different premedication medications on the incidence of gastroesophageal reflux (GOR) in anesthetized dogs. Two hundred and seventy dogs undergoing non-intrathoracic, non-intrabdominal elective surgeries or invasive diagnostic procedures were included in the study, and were allocated into nine groups (30 dogs/group) defined by the type of premedication administered. Premedication consisted of dexmedetomidine with either morphine, pethidine or butorphanol, acepromazine with either one of the three opioids or midazolam with one of the above-mentioned opioids. Anesthesia was induced with propofol and maintained with isoflurane in oxygen. Esophageal pH was measured with the use of a pH-meter electrode and a pH-value less than 4 and over 7.5 was considered to be GOR. The study revealed that 119/270 (44.1%) dogs experienced a reflux episode during anesthesia. The incidence of reflux did not differ among groups (p = 0.117). In group AB the dogs refluxed within 10 min of the beginning of pH-measurements, in comparison with group DB in which dogs refluxed within 30 min (p = 0.029). Invasive diagnostic procedures had a lower incidence of GOR in comparison to castrations (p = 0.09). The outcome of the study suggests that none of the opioids used increased the incidence of GOR in anesthetized dogs.

Anesthetic effect of different doses of butorphanol in patients undergoing gastroscopy and colonoscopy

Background

This study aimed to investigate the anesthetic effect of butorphanol with different doses in patients undergoing gastroscopy and colonoscopy.

Methods

480 patients undergoing gastroscopy and colonoscopy were recruited and randomly divided into four groups to receive different doses of butorphanol (Group A = 2.5 μg/kg, Group B = 5 μg/kg, Group C = 7.5 μg/kg and Group D = 10 μg/kg). Butorphanol was administered 5 min before propofol infusion. The primary outcome was the incidence of body movement. Secondary outcomes were postoperative recovery time, length of stay in the Post-Anesthesia Care Unit (PACU), the total dose of propofol, and the incidence of intraoperative hypoxemia, propofol injection pain, cough, postoperative nausea and vomiting, drowsiness, and dizziness.

Results

The incidence of body movement and the dose of propofol in Group C and D were lower than those in Group A and B (P < 0.05). The incidence and intensity of propofol injection pain and the incidence of cough in Group B, C, and D were lower than those in Group A (P < 0.05). The length of stay in PACU and the incidence of postoperative drowsiness and dizziness were higher in Group D than in Group A, B, and C (P < 0.05).

Conclusion

Intravenous pre-injection of 7.5 μg/kg butorphanol with propofol can be the optimal dosage for patients undergoing gastroscopy and colonoscopy.

Trial registration: Trial registration: Chinese Clinical Trial Registry, ChiCTR2000031506. Registered 3 April 2020—Retrospectively registered, http://www.medresman.org.cn.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12893-021-01262-8.

Incidence of Gastroesophageal Reflux in Dogs Undergoing Orthopaedic Surgery or Endoscopic Evaluation of the Upper Gastrointestinal Tract

Gastroesophageal reflux (GER) is a common event during general anaesthesia but is often underdiagnosed in veterinary medicine. The oesophageal pH in anaesthetised dogs undergoing endoscopic evaluation of the upper gastrointestinal tract (END group; n = 12) or orthopaedic surgery (ORT group; n = 12) was measured using an oesophageal probe. The dogs were sedated with acepromazine or with methadone or butorphanol, and anaesthesia was induced with propofol and maintained with isoflurane. Of the 24 dogs in this study, 21 (87.5%) had an episode of GER during anaesthesia. The incidence of GER, as well as the first, the minimum, and the maximum pH values, did not differ significantly between the groups. The mean maximum difference versus the first pH value was higher for dogs in the END group (−2.6 ± 3.5) as compared with those in the ORT group (−0.7 ± 2.5), although they were not statistically significant (p = 0.25). The administration of methadone or butorphanol had no significant effect on the development of acidic reflux or biliary reflux. In the acepromazine-sedated dogs, the incidence of GER did not differ significantly between patients undergoing an endoscopic procedure and those undergoing orthopaedic surgery; however, during endoscopy, fluctuations in the oesophageal pH can be expected, even without any clinical signs of GER.

Comparison of the effects of methadone and butorphanol combined with acepromazine for canine gastroduodenoscopy

OBJECTIVE

To evaluate the feasibility of gastroduodenoscopy in dogs premedicated with acepromazine in combination with butorphanol or methadone.

STUDY DESIGN

Prospective, randomized, double-blinded clinical trial.

ANIMALS

A group of 40 client-owned dogs.

METHODS

Dogs were randomly allocated to one of two groups and give intramuscular acepromazine 0.02 mg kg^-1 combined with either butorphanol 0.3 mg kg^-1 (group ACEBUT) or methadone 0.2 mg kg^-1 (group ACEMET). General anaesthesia was induced with propofol and ketamine and maintained with sevoflurane (2.3%) in oxygen. Cardiopulmonary variables were recorded at 5 minute intervals during anaesthesia. Feasibility of the entire gastroduodenoscopy was evaluated with a visual analogue scale (VAS) from 0 (best) to 100 (worst) (primary outcome of the study). Lower oesophageal sphincter dilatation and duodenal intubation were scored. Pylorus diameter was measured with standard endoscopic inflatable balloons. Overall cardiovascular stability was assessed during anaesthesia, using a VAS (0-100), as was the presence of fluid in the oesophagus, regurgitation, need for mechanical ventilation, and intraoperative and postoperative rescue analgesia (secondary outcomes of the study). Differences between treatments were analysed with Mann-Whitney U, Student t test, Fisher exact test or mixed model analysis of variance as appropriate. Subsequently, feasibility VAS of the gastroduodenoscopy was assessed for noninferiority between groups. The noninferiority margin was set as -10.

RESULTS

All gastroduodenoscopies were successfully completed in both groups using an endoscope tip diameter of 12.8 mm in all but one dog. Feasibility of gastroduodenoscopy was evaluated as 2.9 ± 5.6 in group ACEBUT and 5.1 ± 5.8 in group ACEMET. No significant differences between groups were detected in any measured or assessed variables, and noninferiority was confirmed.

CONCLUSION AND CLINICAL RELEVANCE

In our study population, the effects of methadone and butorphanol when combined with acepromazine were comparable.