Search Results

You are looking at 1 - 7 of 7 items for

  • Author or Editor: Deborah V. Wilson x
  • Refine by Access: All Content x
Clear All Modify Search

Abstract

Objective—To determine the effect of morphine administered prior to anesthesia on the incidence of gastroesophageal reflux (GER) in dogs during the subsequent anesthetic episode.

Animals—90 dogs (30 dogs/group).

Procedure—The randomized prospective clinical study included healthy dogs with no history of vomiting. Dogs were scheduled to undergo elective orthopedic surgery. Food was withheld for (mean ± SD) 17.8 ± 4.1 hours prior to induction of anesthesia. The anesthetic protocol included acepromazine maleate, thiopental, and isoflurane. Dogs were randomly selected to receive morphine at various dosages (0, 0.22, or 1.10 mg/kg, IM) concurrent with acepromazine administration prior to induction of anesthesia. A sensor-tipped catheter was used to measure esophageal pH, and GER was defined as a decrease in pH to < 4 or an increase to > 7.5.

Results—40 dogs had acidic reflux, and 1 had biliary reflux. Proportions of dogs with GER were 8 of 30 (27%), 15 of 30 (50%), and 18 of 30 (60%) for morphine dosages of 0, 0.22, and 1.10 mg/kg, respectively. Mean duration of GER was 91.4 ± 56.8 minutes. There was no significant association between GER and age, weight, vomiting after preanesthetic medication, administration of antimicrobials, or start of surgery.

Conclusions and Clinical Relevance—Most healthy dogs vomit after a large dose of morphine, but vomiting does not increase the likelihood of GER during the subsequent anesthetic episode. Administration of morphine prior to anesthesia substantially increases the incidence of GER during the subsequent anesthetic episode. (Am J Vet Res 2005;66:386–390)

Full access
in American Journal of Veterinary Research
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine whether maintenance of anesthesia with halothane or sevoflurane is associated with a lower incidence of gastroesophageal reflux (GER) than the use of isoflurane in dogs undergoing orthopedic surgery.

Animals—90 dogs.

Procedures—Dogs were evaluated during elective orthopedic surgery. Dogs with a history of vomiting or that had received any drugs that would alter gastrointestinal tract function were excluded from the study. The anesthetic protocol used was standardized to include administration of acepromazine maleate and morphine prior to induction of anesthesia with thiopental. Dogs were allocated to receive halothane, isoflurane, or sevoflurane to maintain anesthesia. A sensor-tipped catheter was placed to measure esophageal pH during anesthesia. Gastroesophageal reflux was defined as an esophageal pH < 4or > 7.5.

Results—51 dogs had 1 or more episodes of acidic GER during anesthesia. Reflux was detected in 14 dogs receiving isoflurane, 19 dogs receiving halothane, and 18 dogs receiving sevoflurane. In dogs with GER, mean ± SD time from probe placement to onset of GER was 36 ± 65 minutes and esophageal pH remained < 4 for a mean of 64% of the measurement period. There was no significant association between GER and start of surgery or moving a dog on or off the surgery table. Dogs that developed GER soon after induction of anesthesia were more likely to regurgitate.

Conclusions and Clinical Relevance—Maintenance of anesthesia with any of the 3 commonly used inhalant agents is associated with a similar risk for development of GER in dogs.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To determine the effect of 2 doses of metoclopramide on the incidence of gastroesophageal reflux (GER) in anesthetized dogs.

Animals—52 healthy dogs undergoing elective orthopedic surgery.

Procedure—In this prospective clinical study, dogs were evaluated before and during orthopedic surgery. The anesthetic protocol used was standardized to include administration of acepromazine, morphine, thiopental, and isoflurane. Dogs were randomly selected to receive an infusion of saline (0.9% NaCl) solution, a low dose of metoclopramide, or a high dose of metoclopramide before and during anesthesia. Treatment groups were similar with respect to age, body weight, duration of food withholding before surgery, duration of surgery, and dose of thiopental administered. Dogs were positioned in dorsal recumbency during surgery. A sensor-tipped catheter was inserted to measure esophageal pH during anesthesia. We defined GER as a decrease in esophageal pH to < 4 or an increase to > 7.5 that lasted more than 30 seconds.

Results—The high dose of metoclopramide (bolus loading dose of 1.0 mg/kg, IV, followed by continuous infusion at a rate of 1.0 mg/kg/h) was associated with a 54% reduction in relative risk of developing GER. The low dose did not significantly affect the incidence of GER.

Conclusions and Clinical Relevance—Administration of metoclopramide by bolus and constant rate infusion at doses much higher than commonly used will reduce the incidence but not totally prevent GER in anesthetized dogs undergoing orthopedic surgery.

Full access
in American Journal of Veterinary Research
in Journal of the American Veterinary Medical Association

Abstract

Objective—To evaluate changes in serial hemograms and serum biochemical profiles in tumor-bearing dogs undergoing daily anesthesia with propofol as an induction agent for radiation therapy.

Design—Retrospective case series.

Animals—31 dogs with cutaneous or subcutaneous malignancies over the trunk or limbs.

Procedures—Radiation therapy consisted of 18 daily treatments administered Monday through Friday over a period of 24 days. Propofol was administered IV to effect for induction of anesthesia. Complete blood count and serum biochemical data were generated at the beginning, middle, and end of radiation therapy and compared to identify changes over time via either a repeated-measures ANOVA or Friedman test.

Results—Leukocyte and platelet parameters did not differ significantly over time. Calculated Hct, erythrocyte count, hemoglobin concentration, and mean corpuscular hemoglobin concentration decreased overtime, whereas mean corpuscular volume increased overtime.

Conclusions and Clinical Relevance—Dogs receiving propofol for induction of anesthesia and radiation therapy had a decrease in RBC count, although these changes were not determined to be of clinical importance in this patient population. The cause of these alterations was not immediately apparent. Propofol appeared to be a safe choice for induction of anesthesia in dogs during daily radiation therapy.

Full access
in Journal of the American Veterinary Medical Association