Newer diagnostic and surgical techniques and their impact on anesthesia

Comparison of cardiopulmonary responses during sedation with epidural and local anesthesia for laparoscopic-assisted jejunostomy feeding tube placement with cardiopulmonary responses during general anesthesia for laparoscopic-assisted or open surgical jejunostomy feeding tube placement in healthy dogs

OBJECTIVE

To evaluate the use of laparoscopic-assisted jejunostomy feeding tube (J-tube) placement in healthy dogs under sedation with epidural and local anesthesia and compare cardiopulmonary responses during this epidural anesthetic protocol with cardiopulmonary responses during general anesthesia for laparoscopic-assisted or open surgical J-tube placement.

ANIMALS

15 healthy mixed-breed dogs.

PROCEDURES

Dogs were randomly assigned to receive open surgical J-tube placement under general anesthesia (n = 5 dogs; group 1), laparoscopic-assisted J-tube placement under general anesthesia (5; group 2), or laparoscopic-assisted J-tube placement under sedation with epidural and local anesthesia (5; group 3). Cardiopulmonary responses were measured at baseline (time 0), every 5 minutes during the procedure (times 5 to 30 minutes), and after the procedure (after desufflation [groups 2 and 3] or at the start of abdominal closure [group 1]). Stroke volume, cardiac index, and O(2) delivery were calculated.

RESULTS

All group 3 dogs tolerated laparoscopic-assisted J-tube placement under sedation with epidural and local anesthesia. Comparison of cardiovascular parameters revealed a significantly higher cardiac index, mean arterial pressure, and O(2) delivery in group 3 dogs, compared with group 1 and 2 dogs. Minimal differences in hemodynamic parameters were found between groups undergoing laparoscopic-assisted and open surgical J-tube placement under general anesthesia (ie, groups 1 and 2); these differences were not considered to be clinically important in healthy research dogs.

CONCLUSIONS AND CLINICAL RELEVANCE

Sedation with epidural and local anesthesia provided satisfactory conditions for laparoscopic-assisted J-tube placement in healthy dogs; this anesthetic protocol caused less cardiopulmonary depression than general anesthesia and may represent a better choice for J-tube placement in critically ill patients.

Anesthetic management of an orangutan (Pongo abelii/pygmaeus) undergoing laparoscopic tubal ligation

An adult hybrid orangutan (Pongo abelii/pygmaeus) was presented to a veterinary teaching hospital for laparoscopic tubal ligation. The orangutan was immobilized with the use of injectable anesthetic agents, then orotracheally intubated. Anesthesia was maintained with the use of isoflurane in oxygen, and positive-pressure ventilation was used to ensure adequate gas exchange. Parameters monitored included arterial blood pressure, ECG, capnometry, and arterial blood gases. Anesthesia was uneventful, and recovery was smooth.

Evaluation of laparoscopic-assisted placement of jejunostomy feeding tubes in dogs

OBJECTIVE

To evaluate feasibility of performing laparoscopic-assisted placement of a jejunostomy feeding tube (J-tube) and compare complications associated with placement, short-term feedings, and medium-term healing with surgically placed tubes in dogs.

DESIGN

Prospective study.

ANIMALS

15 healthy mixed-breed dogs.

PROCEDURES

Dogs were randomly allocated to undergo open surgical or laparoscopic-assisted J-tube placement. Required nutrients were administered by a combination of enteric and oral feeding while monitoring for complications. Radiographic contrast studies documented tube direction and location, altered motility, or evidence of stricture.

RESULTS

Jejunostomy tubes were successfully placed in the correct location and direction in all dogs. In the laparoscopic group, the ileum was initially selected in 2 dogs, 2 dogs developed moderate hemorrhage at a portal site, and 2 J-tubes kinked during placement but were successfully readjusted postoperatively. All dogs tolerated postoperative feedings. All dogs developed minor ostomy site inflammation, and 1 dog developed bile-induced dermatitis at the ostomy site. Despite mild, transient neutrophilia, no significant difference was noted in WBC counts between groups. No dog had altered gastric motility or evidence of stricture, although the jejunopexy site remained identifiable in several dogs at 30 days.

CONCLUSIONS AND CLINICAL RELEVANCE

Requirements for successful J-tube placement were met by use of a laparoscopic-assisted technique, and postoperative complications were mild and comparable to those seen with surgical placement. Laparoscopic-assisted J-tube placement compares favorably to surgical placement in healthy dogs and should be considered as an option for dogs requiring enterostomy feeding but not requiring a celiotomy for other reasons.

Effects of Various Anesthetic Agents on Laryngeal Motion During Laryngoscopy in Normal Dogs

OBJECTIVE

To evaluate the effects of various drugs and drug combinations conventionally used for anesthesia on arytenoid cartilage motion during laryngoscopy in normal dogs.

STUDY DESIGN

Experimental study.

ANIMALS

Six large breed healthy dogs with no previous history of respiratory dysfunction.

METHODS

Each dog was randomly assigned to a different injectable anesthetic protocol once weekly for 6 weeks, then in the 7th week all dogs were anesthetized with isoflurane. Videolaryngoscopy was performed and recorded starting immediately after induction until dogs could no longer be safely restrained for endoscopy. Video was digitized and 3 still images of maximal inspiration and expiration from the first 15 seconds (induction) and the last 15 seconds (recovery) were captured and imported into an image analysis software program. The height and area of the laryngeal ostium were measured in pixels. Normalization of the glottal gap area was performed using the formula (normalized glottal gap area (NGGA)=area in pixels/height(2)). ANOVA was performed on the NGGA of images collected at inspiration and expiration during induction and recovery. Fischer's exact test was performed when significance (P<.05) was found.

RESULTS

Within each protocol, laryngeal motion (defined as change in NGGA) at induction was not significantly different from laryngeal motion measured at recovery. Additionally, no significant differences were found in arytenoid motion immediately after induction when anesthetic protocols were compared. Arytenoid motion before recovery was significantly greater with thiopental when compared with propofol (P=.046), ketamine+diazepam (P=.0098), acepromazine+thiopental (P=.0021), and acepromazine+propofol (P=.0065). No significant difference in arytenoid motion was seen immediately after induction or before recovery when acepromazine+butorphanol+ isoflurane and thiopental were compared.

CONCLUSION

We concluded that intravenous thiopental given to effect is the best choice for assessing laryngeal function in dogs. Dogs premedicated with acepromazine with or without opioids that require further anesthetic restraint for laryngoscopy should be anesthetized with isoflurane administered by mask.

CLINICAL RELEVANCE

Misdiagnosis of laryngeal paralysis during laryngoscopy can be avoided by selecting the anesthetic regimens with the least effect on arytenoid motion.

Laser use and research in gastroenterology, gynecology, and general surgery: a status report

OBJECTIVE AND BACKGROUND DATA

Despite the burgeoning growth of laser applications in dermatology and plastic surgery, applications in other specialties have declined. Laser use in gastroenterology, general surgery, and gynecology was examined over the past 3 years. Future trends and opportunities are discussed.

METHODS

The MEDLINE database was scanned for scholarly publications between January 1, 1997, and January 1, 2000, and the number of publications in these specialties was determined. A questionnaire was distributed to 362 general surgeons from the American Society for Laser Medicine and Surgery (ASLMS) to assess current use and future needs. These results were compared to the actual cases performed at a laser center over the same period.

RESULTS

Of 3,331 publications, 21 (0.6%) covered gastroenterology (GE), general surgery (GS), gynecology (GYN), or laparoscopy (LAP). Keyword citations were 2 GS, 3 GYN, 7 GE, and 12 LAP. Questionnaire results and actual utilization were well correlated.

CONCLUSIONS

Lasers are being used in these specialties despite slow development of novel uses. Opportunities exist for future applications.