- Email: [email protected]
Anesthesia effects on laryngeal motion
Advances
Page 8
Procedure Six large breed healthy dogs with no previous history of respiratory dysfunction were randomly assigned to a different injectable anesthetic protocol once weekly for 6 weeks. All dogs were anesthetized with isoflurane in the 7th week. Videolaryngoscopy was begun immediately after induction and continued until recovery when dogs could no longer be safely restrained for endoscopy. The video was digitized and 3 still images of maximal inspiration and expiration from the first 15 seconds of induction and the last 15 seconds of recovery were captured for an analysis by an image software program. The height and area of the laryngeal ostium were measured.
Surgery (Soft Tissue) Anesthesia Effects on Laryngeal Motion Background Laryngeal paralysis is a common respiratory disease in mid-aged to older-aged large and giant breed dogs. A congenital form has been reported in young Siberian Huskies and Bouvier Des Flandres. Clinical signs of laryngeal paralysis include inspiratory stridor, exercise intolerance, voice change, coughing, gagging, retching, and vomiting. Severe cases may develop cyanosis and collapse. Diagnosis is confirmed by laryngoscopy with the patient in a light plane of anesthesia. Misdiagnosis of laryngeal paralysis during laryngoscopy can be avoided by selecting the anesthetic regimens with the least effect on arytenoid motion. Objectives To evaluate the effects of various drugs and drug combinations conventionally used for anesthesia on arytenoid cartilage motion during laryngoscopy in normal dogs.
Results Laryngeal motion at induction was not significantly different from laryngeal motion measured at recovery within any protocol. No significant differences occurred in arytenoid motion immediately after induction when anesthetic protocols were compared. Arytenoid motion before recovery was significantly greater with thiopental when compared with propofol, ketamine plus diazepam, acepromazine plus thiopental, and acepromazine plus propofol. No significant differences in arytenoid motion was seen immediately after induction or before recovery when acepromazine plus butorphanol plus isoflurane and thiopental were compared. Author Conclusion 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. Inclusions Two tables, 14 references Editor Annotation Evaluation of laryngeal motion is subjective, being influenced by the evaluator’s expertise, drugs used, and depth of anesthesia. The evaluator must be familiar with the drugs used and their effects on laryngeal function for accurate assessment because laryngeal reflexes are influenced by many anesthetic agents.
Earn CE Credits Online by Reading Advances!! Each issue of Advances in Small Animal Medicine and Surgery is accompanied by an online only Continuing Education module. Each module consists of a single exam with several multiple choice questions followed by a brief post-test evaluation. Upon successful completion of each test, you will qualify to receive one (1) contact hour of Continuing Education credit by the University of Missouri Extension and the College of Veterinary Medicine. Take the CE test online at: http://www.journals.elsevierhealth .com/periodicals/ynasa Access is free and open to subscribers of the journal. There is no obligation to register or pay for a test unless you wish to receive CE credits. If you wish to receive CE credit, the cost per exam credit is US $10 payable by credit card. Subscribers who wish to apply this credit to fulfill state relicensure requirements should consult their respective state authorities regarding the applicability of this program.
Thiopental, a drug used by many for years, has often been replaced by propofol for laryngoscopy. Animals recover rapidly from propofol effects. However, this article warns against using propofol. When normal laryngeal function is questioned during laryngoscopy, it is wise to administer doxapram hydrochloride (2-5 mg/kg, intravenously) which will stimulate short, vigorous respiratory motion to help rule in or rule out adequate laryngeal abduction. (CSH) Jackson Am, Tobias K, Long C, et al. Effects of various anesthetic agents on laryngeal motion during laryngoscopy in normal dogs. Vet Surg 2004;33:102-106.
Page 8
Procedure Six large breed healthy dogs with no previous history of respiratory dysfunction were randomly assigned to a different injectable anesthetic protocol once weekly for 6 weeks. All dogs were anesthetized with isoflurane in the 7th week. Videolaryngoscopy was begun immediately after induction and continued until recovery when dogs could no longer be safely restrained for endoscopy. The video was digitized and 3 still images of maximal inspiration and expiration from the first 15 seconds of induction and the last 15 seconds of recovery were captured for an analysis by an image software program. The height and area of the laryngeal ostium were measured.
Surgery (Soft Tissue) Anesthesia Effects on Laryngeal Motion Background Laryngeal paralysis is a common respiratory disease in mid-aged to older-aged large and giant breed dogs. A congenital form has been reported in young Siberian Huskies and Bouvier Des Flandres. Clinical signs of laryngeal paralysis include inspiratory stridor, exercise intolerance, voice change, coughing, gagging, retching, and vomiting. Severe cases may develop cyanosis and collapse. Diagnosis is confirmed by laryngoscopy with the patient in a light plane of anesthesia. Misdiagnosis of laryngeal paralysis during laryngoscopy can be avoided by selecting the anesthetic regimens with the least effect on arytenoid motion. Objectives To evaluate the effects of various drugs and drug combinations conventionally used for anesthesia on arytenoid cartilage motion during laryngoscopy in normal dogs.
Results Laryngeal motion at induction was not significantly different from laryngeal motion measured at recovery within any protocol. No significant differences occurred in arytenoid motion immediately after induction when anesthetic protocols were compared. Arytenoid motion before recovery was significantly greater with thiopental when compared with propofol, ketamine plus diazepam, acepromazine plus thiopental, and acepromazine plus propofol. No significant differences in arytenoid motion was seen immediately after induction or before recovery when acepromazine plus butorphanol plus isoflurane and thiopental were compared. Author Conclusion 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. Inclusions Two tables, 14 references Editor Annotation Evaluation of laryngeal motion is subjective, being influenced by the evaluator’s expertise, drugs used, and depth of anesthesia. The evaluator must be familiar with the drugs used and their effects on laryngeal function for accurate assessment because laryngeal reflexes are influenced by many anesthetic agents.
Earn CE Credits Online by Reading Advances!! Each issue of Advances in Small Animal Medicine and Surgery is accompanied by an online only Continuing Education module. Each module consists of a single exam with several multiple choice questions followed by a brief post-test evaluation. Upon successful completion of each test, you will qualify to receive one (1) contact hour of Continuing Education credit by the University of Missouri Extension and the College of Veterinary Medicine. Take the CE test online at: http://www.journals.elsevierhealth .com/periodicals/ynasa Access is free and open to subscribers of the journal. There is no obligation to register or pay for a test unless you wish to receive CE credits. If you wish to receive CE credit, the cost per exam credit is US $10 payable by credit card. Subscribers who wish to apply this credit to fulfill state relicensure requirements should consult their respective state authorities regarding the applicability of this program.
Thiopental, a drug used by many for years, has often been replaced by propofol for laryngoscopy. Animals recover rapidly from propofol effects. However, this article warns against using propofol. When normal laryngeal function is questioned during laryngoscopy, it is wise to administer doxapram hydrochloride (2-5 mg/kg, intravenously) which will stimulate short, vigorous respiratory motion to help rule in or rule out adequate laryngeal abduction. (CSH) Jackson Am, Tobias K, Long C, et al. Effects of various anesthetic agents on laryngeal motion during laryngoscopy in normal dogs. Vet Surg 2004;33:102-106.