General Anesthesia With and Without Remifentanil for Flexible and Rigid Bronchoscopy: A Retrospective Case-Matched Study.

Prior research suggests general anesthesia (GA) with remifentanil is superior to GA without remifentanil regarding perioperative outcomes, including the postanesthesia care unit (PACU) length of stay (LOS). The objective of this study was to compare the intraoperative management and PACU LOS in patients who underwent GA with or without remifentanil for bronchoscopy. The study included 5,763 adult patients who underwent flexible bronchoscopy and received GA with or without remifentanil or who underwent rigid bronchoscopy and received GA with or without remifentanil. Despite prolonged procedural length in both the flexible and rigid bronchoscopy groups and greater ASA score in the flexible bronchoscopy group, no difference in the adjusted PACU LOS or time to extubation was found. Remifentanil was associated with hemodynamic perturbations and desaturation events. Remifentanil was associated with a significant reduction in nonremifentanil opioid requirements. Although both groups receiving remifentanil were associated with a less favorable intraoperative hemodynamic profile, remifentanil did not increase the incidence of postoperative complications despite that group having a greater ASA score and procedural duration.

An Analysis of Substandard Propofol Detected in Use in Zambian Anesthesia.

BACKGROUND: In early 2015, clinicians throughout Zambia noted a range of unpredictable adverse events after the administration of propofol, including urticaria, bronchospasm, profound hypotension, and most predictably an inadequate depth of anesthesia. Suspecting that the propofol itself may have been substandard, samples were procured and sent for testing. METHODS: Three vials from 2 different batches were analyzed using gas chromatography-mass spectrometry methods at the John L. Holmes Mass Spectrometry Facility. RESULTS: Laboratory gas chromatography-mass spectrometry analysis determined that, although all vials contained propofol, its concentration differed between samples and in all cases was well below the stated quantity. Two vials from 1 batch contained only 44% ± 11% and 54% ± 12% of the stated quantity, whereas the third vial from a second batch contained only 57% ± 9%. The analysis found that there were no hexane-soluble impurities in the samples. CONCLUSIONS: None of the analyzed vials contained the stated amount of propofol; however, our analysis did not detect additional contaminants that would explain the adverse events reported by clinicians. Our results confirm the presence of substandard propofol in Zambia; however, anecdotal accounts of substandard anesthetic medicines in other countries abound and warrant further investigation to provide estimates of the prevalence and scope of this global problem.

The Role of Pharmacogenomics in Anesthesia Pharmacology.

The field of pharmacogenomics seeks to identify the impact of genetic variants on drug dosing, response, metabolism, and safety outcomes. The narrow therapeutic indices for anesthesia drugs, variability of patient responses to anesthesia, and the risks associated with surgery make anesthetics and the perioperative period prime targets for pharmacogenetic research. Anesthesia providers strive to optimize anesthesia delivery and patient outcomes and to specifically reduce anesthesia-related risks and negative outcomes. Despite pharmacogenomics emerging from the field of anesthesia, the most significant advances to date in the understanding and application of genetics to pharmacology have occurred outside of anesthesiology. This chapter provides an overview of genetic concepts fundamental to understanding the pharmacogenetics of anesthesia practice and presents the current state of the science with respect to the genetic influence on the response to volatile and intravenous anesthetic agents and opioid receptor agonists commonly used in anesthesia practice. In addition, the chapter delineates U.S. Food and Drug Administration labeling tenets for pharmacogenetics, discusses clinical implications of pharmacogenomics for family members, and highlights the potential for future paradigm shifts in pharmacogenomics of anesthesia practice.

Investigating the impact of clinical anaesthetic practice on bacterial contamination of intravenous fluids and drugs.

Syringes (N = 426), ventilator machine swabs (N = 202) and intravenous (IV) fluid administration sets (N = 47) from 101 surgical cases were evaluated for bacterial contamination. Cultures from the external surface of syringe tips and syringe contents were positive in 46% and 15% of cases, respectively. The same bacterial species was cultured from both ventilator and syringe in 13% of cases, and was also detected in the IV fluid administration set in two cases. A significant association was found between emergency cases and contaminated syringes (odds ratio 4.5, 95% confidence interval 1.37-14.8; P = 0.01). Other risk factors included not using gloves and failure to cap syringes.

Two distinct application habits for propofol: an observational study.

BACKGROUND AND OBJECTIVES: In total intravenous anaesthesia, two different application modes for propofol are widely used: infusion by means of manually controlled infusion pumps, and infusion by means of microprocessor-controlled infusion pumps operating according to pharmacokinetic algorithms (target controlled infusion, TCI). The parallel use of these two methods in our department by various anaesthetists offered the opportunity to retrospectively compare both application patterns regarding clinical effects and drug consumption. METHODS: Ninety-six anaesthesia records from general anaesthesias with propofol and opioids from gynaecological laparoscopic operations were retrospectively evaluated. Forty-eight records were derived from six anaesthetists using manual propofol infusion (retrospective allocation to group C) and 48 other records from six anaesthetists using TCI infusion (retrospective allocation to group M). We assessed the intraoperative haemodynamic course, drug consumption, awakening time and postoperative side effects. RESULTS: The awakening time after TCI was significantly shorter than after manual propofol infusion (M: 4.9 +/- 3.1 min vs. C: 9.9 +/- 5.7 min). We observed a nonsignificantly rarer occurrence of postoperative side effects such as postoperative nausea and vomiting and pain. Only insignificant differences in drug consumption could be found. CONCLUSION: Both observed application patterns for propofol showed similar clinical profiles. Using TCI, awakening time was 5 min earlier than with manual infusion mode, thus showing a potential pharmaco-economical advantage in anaesthesias for gynaecological laparoscopy. The detected differences did not have a statistically significant influence on the early postoperative outcome.

Detomidine-butorphanol-propofol for carotid artery translocation and castration or ovariectomy in goats.

OBJECTIVE: To determine the safety and efficacy of propofol, after detomidine-butorphanol premedication, for induction and anesthetic maintenance for carotid artery translocation and castration or ovariectomy in goats. STUDY DESIGN: Case series. ANIMALS: Nine 4-month-old Spanish goats (17.1 +/- 2.6 kg) were used to evaluate propofol anesthesia for carotid artery translocation and castration or ovariectomy. METHODS: Goats were premedicated with detomidine (10 micrograms/kg intramuscularly [i.m.]) and butorphanol (0.1 mg/kg i.m.) and induced with an initial bolus of propofol (3 to 4 mg/kg intravenously [i.v.]). If necessary for intubation, additional propofol was given in 5-mg (i.v.) increments. Propofol infusion (0.3 mg/kg/min i.v.) was used to maintain anesthesia, and oxygen was insufflated (5 L/min). The infusion rate was adjusted to maintain an acceptable anesthetic plane as determined by movement, muscle relaxation, ocular signs, response to surgery, and cardiopulmonary responses. Systolic (SAP), mean (MAP) and diastolic (DAP) arterial pressures, heart rate (HR), ECG, respiratory rate (RR), SpO2, and rectal temperature (T) were recorded every 5 minutes postinduction; arterial blood gas samples were collected every 15 minutes. Normally distributed data are represented as mean +/- SD; other data are medians (range). RESULTS: Propofol (4.3 +/- 0.9 mg/kg/min i.v.) produced smooth, rapid (15.2 +/- 6 sec) sternal recumbency. Propofol infusion (0.52 +/- 0.11 mg/kg/min i.v.) maintained anesthesia. Mean anesthesia time was 83 +/- 15 minutes. Muscle relaxation was good; eye signs indicated surgical anesthesia; two goats moved before surgery began; one goat moved twice during laparotomy. Means are reported over the course of the data collection period. Means during the anesthesia for pHa (arterial PH), PaCO2, PaO2, HCO3-, and BE (base excess) ranged from 7.233 +/- 0.067 to 7.319 +/- 0.026, 54.1 +/- 4.6 to 65.3 +/- 12.0 mm Hg, 133.1 +/- 45.4 to 183.8 +/- 75.1 mm Hg, 26.9 +/- 2.6 to 28.2 +/- 2.1 mEq/L, and -0.8 +/- 2.9 to 1.4 +/- 2.2 mEq/L. Means over time for MAP were 53 +/- 12 to 85 +/- 21 mm Hg. Mean HR varied over time from 81 +/- 6 to 91 +/- 11 beats/minute; mean RR, from 9 +/- 8 to 15 +/- 5 breaths/minute; SpO2 from 97 +/- 3% to 98 +/- 3%; mean T, from 36.0 +/- 0.6 degrees C to 39.1 +/- 0.7 degrees C. Over time, SpO2 and SaO2 did not change significantly; HR, RR, T, and PaCO2 decreased significantly; SAP, DAP, MAP, pHa, PaO2, and BE increased significantly. HCO3- concentrations increased significantly, peaking at 45 minutes. Recoveries were smooth and rapid; the time from the end of propofol infusion to extubation was 7.3 +/- 3 minutes, to sternal was 9.2 +/- 5 minutes, and to standing was 17.7 +/- 4 minutes. Median number of attempts to stand was two (range of one to four). Postoperative pain was mild to moderate. CONCLUSIONS: Detomidine-butorphanol-propofol provided good anesthesia for carotid artery translocation and neutering in goats. CLINICAL RELEVANCE: Detomidine-butorphanol-propofol anesthesia with oxygen insufflation may be safely used for surgical intervention in healthy goats.

Use of propofol-isoflurane as an anesthetic regimen for cesarean section in dogs.

OBJECTIVE: To evaluate use of propofol-isoflurane as an anesthetic regimen for cesarean section in dogs and to compare this protocol with epidural analgesia and anesthesia induced with thiopental sodium. DESIGN: Prospective study. ANIMALS: 141 bitches admitted for cesarean section. PROCEDURE: General anesthesia was induced with propofol in 141 dogs undergoing cesarean section. After intubation, anesthesia was maintained by means of inhalation of isoflurane (0.5 to 2.0%), administered in a 65:35 mixture of oxygen:nitrous oxide. After induction, 20 minutes were allowed to elapse before delivery of puppies was begun. Viability of neonates was ascertained immediately after surgery. Owners were interviewed by telephone to determine survival of puppies during the postoperative period. Survival rates from this study were compared with those from cesarean section performed on dogs under epidural analgesia or under general anesthesia induced with thiopental sodium. RESULTS: Induction, maintenance, and recovery were problem free in all bitches. Of 412 puppies delivered by cesarean section, 293 (71%) survived, 13 (3%) were born alive but died within 20 minutes of delivery, and 106 (26%) were stillborn. Survival rate for puppies from dams induced with propofol-isoflurane was similar to that for puppies from dams receiving epidural analgesia. Survival rate for puppies delivered by cesarean section performed on dams under general anesthesia was higher for dams induced with propofol than for dams induced with thiopental sodium. CLINICAL IMPLICATIONS: General anesthesia induced with propofol and maintained with isoflurane is acceptable for performing cesarean section in dogs.

Comparison of two techniques of narcotic-induced anesthesia for use during recording of magnetic motor evoked potentials in dogs.

OBJECTIVE: To compare 2 types of narcotic-induced anesthesia for recording of transcranial magnetic motor evoked potentials (TMMEP) in dogs. DESIGN: The effect of different doses of sufentanil and midazolam and of sufentanil and nitrous oxide on onset latencies and peak-to-peak, amplitudes of TMMEP was evaluated and compared. ANIMALS: 18 neurologically normal dogs. PROCEDURE: Premedication with droperidol and fentanyl. Induction and maintenance of anesthesia either with sufentanil and midazolam or with sufentanil and nitrous oxide. Recording of TMMEP from the extensor carpi radialis muscle of the forelimb and from the cranial tibial muscle of the hind limb. RESULTS: Both types of narcotic anesthesia induced dose-dependent suppression of TMMEP; compared with baseline recordings, latencies increased, amplitudes decreased, and reproducibility became poorer with increasing dose of the anesthetics. Using surgical-depth doses of the anesthetics, TMMEP could still be recorded in all dogs with sufentanil and nitrous oxide, but not with sufentanil and midazolam anesthesia. CONCLUSIONS: Sufentanil and nitrous oxide anesthesia was superior to sufentanil and midazolam anesthesia for TMMEP recording. CLINICAL RELEVANCE: In small animal medicine, and in dogs in particular, spinal cord diseases are among the most frequently encountered neurologic disorders. The development of techniques for recording TMMEP in anesthetized dogs allows noninvasive evaluation of transmission along descending motor pathways of the spinal cord.