Multivariable analysis of anesthetic factors associated with time to extubation in dogs

Peripheral warming for prevention of hypothermia in small dogs during soft tissue surgery: A randomized controlled trial

OBJECTIVE

To evaluate the effects of wrapping the extremities of small dogs with table leg covers to prevent hypothermia during anesthesia.

STUDY DESIGN

Randomized parallel-group study.

ANIMALS

A total of 60 adult dogs with a body mass <15 kg anesthetized for soft tissue surgery.

METHODS

Dogs were randomly assigned to one of two groups. The control group received routine intraoperative thermal support, while the limb-wrapping group had their peripheral limbs covered with table leg covers up to the mid-metacarpal/metatarsal region, in addition to routine thermal support. Rectal temperature during anesthesia was recorded and compared between the two groups. Data analyses were performed using Student's t-test for rectal temperature, Fisher's exact test for hypothermia incidence and analysis of covariance for the effect of limb-wrapping while taking other factors into account.

RESULTS

Thirty dogs were included per group. Rectal temperature did not differ between the groups at the time of intubation, but it was significantly higher in the limb-wrapping group (36.7 ± 1.0 °C) than in the control group (35.9 ± 0.8 °C) at the end of surgery (p = 0.003). The mean difference was 0.81 °C (95% confidence interval of mean difference 0.33-1.29 °C). The incidence of hypothermia (<37.0 °C) was significantly lower in the limb-wrapping group than in the control group (19/30 versus 28/30 dogs, respectively; p = 0.010).

CONCLUSIONS

For dogs with body masses <15 kg, limb-wrapping with table leg covers slowed the reduction in intraoperative rectal temperature. Limb-wrapping is inexpensive and easy to perform, making it a practical method for minimizing hypothermia during anesthesia in small dogs undergoing soft tissue surgery.

CLINICAL RELEVANCE

Peripheral warming with table leg covers has the potential to reduce hypothermia during soft tissue surgery in small dogs.

The effects of general anaesthesia on body temperature of dogs subjected to ovariohysterectomy or orchiectomy performed by veterinary students in a teaching hospital

Hypothermia during anaesthesia is a significant concern in veterinary practice, as it can lead to various complications, making it essential to understand the factors that contribute to temperature regulation in animals undergoing surgical procedures. This retrospective study aimed to evaluate the change in body temperature over the course of anaesthesia in dogs undergoing elective ovariohysterectomy and orchiectomy, and determine the effect of gender, dose of premedication, weight, age and duration of anaesthesia of the change of body temperature over time. One-hundred and ten dogs (n=110) that underwent elective ovariohysterectomy (n=75) and orchiectomy (n=35) surgery performed by veterinary students at the University of Adelaide were enrolled in this study. Dogs' anaesthesia records were evaluated for change in body temperature over the course of anaesthesia, and correlated with gender, two premedication doses of acepromazine (mg/kg), body weight (kg), age (months) and anaesthesia times (minutes). The analyses were performed at TPm (temperature at premedication), T0 (induction), T15, T30, T60, T90, T120 and TRec (recovery) minutes. Statistical analysis was performed using the GenStat software and included repeated measures analysis and ANOVA. Significance was considered when p < 0.05. The data showed a significant time-by-gender interaction with female dogs experienced a greater degree of heat loss than male dogs at T60 (p<0.01), T90 (p<0.01) and T120 (p<0.01). At recovery, female average temperature was higher than in males (p<0.01). There was no significant difference in body temperature when other covariates were used in the analysis. The core body temperature of female dogs decreased significantly over time compared to males, with the most pronounced differenced during the intraoperative period. However, the study's retrospective nature and limited sample size may influence the generalizability of these findings.

Erector spinae plane block in dogs undergoing hemilaminectomy: A prospective randomized clinical trial

OBJECTIVE

To compare the perioperative cumulative opioid consumption and the incidence of cardiovascular complications in dogs undergoing hemilaminectomy in which either an erector spinae plane (ESP) block or systemic opioids were administered.

STUDY DESIGN

Prospective randomized clinical trial.

ANIMALS

A total of 60 client-owned dogs.

METHODS

Dogs were randomized to one of three groups: an ESP block (group ESP), a constant rate infusion of fentanyl (group FNT, positive control) or a single dose of methadone as premedication (group MTD, negative control). Intraoperative nociceptive response was treated with fentanyl [1 μg kg-1, intravenously (IV)] boli. Before closure of the surgical site, morphine (0.1 mg kg-1) was applied to the dura mater. The cumulative dose of opioids was recorded and compared between groups. The incidence of intraoperative bradycardia and/or hypotension and the time to extubation were compared between groups. The short form of the Glasgow Composite Pain Scale (SF-GCPS) was used to score nociception before anaesthetic induction and 1, 2, 6, 12,18 and 24 hours postoperatively. Methadone 0.2 mg kg-1 was administered IV if the SF-GCPS score was ≥ 5.

RESULTS

Group MTD required more intraoperative rescue analgesia than groups ESP (p = 0.008) and FNT (p = 0.001). The total cumulative intraoperative dose of fentanyl was higher in groups FNT (p < 0.0001) and MTD (p = 0.002) than in group ESP. The incidence of cardiovascular complications was similar between groups. Extubation time was longer in group MTD (p = 0.03). Postoperatively, the time to first rescue analgesia was longer in group ESP than in group MTD (p = 0.03). The cumulative postoperative opioid consumption and pain scores were similar between groups.

CONCLUSIONS AND CLINICAL RELEVANCE

The ESP block resulted in a reduced intraoperative opioid consumption compared with the control positive and negative groups.

Factors Associated with Prolonged Extubation after Total Intravenous Anesthesia in Patients Undergoing Vestibular Schwannoma Resection

OBJECTIVE

To identify factors associated with prolonged tracheal extubation after vestibular schwannoma resection in patients receiving propofol-remifentanil-based total intravenous anesthesia (TIVA).

STUDY DESIGN

Single-center retrospective study of vestibular schwannoma resection performed by a single neurosurgeon between July 2018 and September 2021.

SETTING

Tertiary academic medical center.

PATIENTS

Adults receiving TIVA for vestibular schwannoma resection, classified according to extubation time: non-prolonged extubation (<15 min) and prolonged extubation (≥15 min).

MAIN OUTCOME MEASURES

Time from end of surgery to extubation, demographic parameters, intraoperative variables, and familiarity between the anesthesia provider and the neurosurgeon were analyzed. Predictors for prolonged extubation were analyzed via multivariate analysis. The primary outcome was the incidence of prolonged extubation. The secondary outcome was factors associated with prolonged tracheal extubation.

RESULTS

A total of 234 cases were analyzed. The median (interquartile range) extubation time was 9.4 minutes (7.2, 12.2 min). Extubation was prolonged in 39 patients (16.7%). Factors predicting prolonged extubation were significant blood loss (odds ratio [OR], 12.8; 95% confidence interval [CI], 2.6-61.7; p = 0.002), intraoperative neuromuscular blocking drug infusion (OR, 6.6; 95% CI, 2.8-15.7; p < 0.001), and lack of familiarity between the anesthesia provider and neurosurgeon (OR, 4.4; 95% CI, 1.5-12.3; p = 0.005).

CONCLUSION

Significant blood loss, intraoperative neuromuscular blocking drug infusion, and lack of familiarity between anesthesia provider and neurosurgeon were associated with prolonged extubation following TIVA for vestibular schwannoma resection.

Supplemental reflective blankets and wool socks help maintain body temperature in dogs undergoing celiotomy procedures: a prospective randomized controlled clinical trial

OBJECTIVE

To compare results for body (esophageal) temperature measurements obtained during celiotomy in normothermic (presurgical) canine patients receiving routine heat support versus routine heat support plus supplemental support (consisting of covering the thorax in a reflective blanket and placing reflective blankets plus wool socks on 3 limbs) in a prospective randomized controlled clinical trial.

ANIMALS

44 dogs requiring celiotomy that were presented sequentially to an emergency and specialty referral veterinary hospital.

PROCEDURES

The 44 dogs undergoing celiotomy were randomly assigned to 2 groups. The control group received routine intraoperative heat support consisting of a circulating warm water blanket and either a towel or blanket. The supplemental group received the same routine heat support plus a reflective blanket covering the cervical and thoracic regions and reflective blankets wrapped around 3 limbs and covered with wool socks from the digits to the axillary or inguinal region.

RESULTS

Mean esophageal temperature for both the control and supplemental groups dropped throughout celiotomy. Esophageal temperature measurements at several time points were significantly higher for the supplemental group than for the control group. The lowest temperature measurement for the supplemental group, adjusted for initial esophageal temperature and procedure duration, was significantly higher by 0.8 °C than that for the control group.

CLINICAL RELEVANCE

Covering the cervical and thoracic regions with a reflective blanket and wrapping limbs in reflective blankets and wool socks is an affordable adjunctive method to provide passive heat support and minimize perioperative hypothermia in canine patients undergoing celiotomy.

Differences in Disaster Preparedness Among Dog and Other Pet Owners in Oporto, Portugal

OBJECTIVES

The aim of this study was to assess the knowledge and practices related to disaster preparedness among pet owners in North Portugal. The present research provides an evaluation of differences among pet owners regarding preparedness in the event of disasters.

METHODS

A cross-sectional study was conducted among a convenience sample of 155 pet owners between September and November 2018. Subjects were interviewed using a structured questionnaire with items addressing sociodemographic characteristics and questions related to owners' emergency preparedness and practices.

RESULTS

In this study, 53.5% of the respondents thought about the possibility of a disaster. Only 21.3% of respondents reported having knowledge on the existence of a disaster kit for pets in case of an emergency. The majority (94.8%) of respondents said they were not aware of the preparedness county-level organization plans. Knowledge and preparedness were found to be significantly higher among dog owners compared with owners of other pet species.

CONCLUSIONS

The results suggest that Portuguese pet owners have inadequate knowledge on how to prepare for inclusion of their pets in a disaster.

Anesthetic risk during subsequent anesthetic events in brachycephalic dogs that have undergone corrective airway surgery: 45 cases (2007-2019)

OBJECTIVE

To determine whether previous corrective upper airway surgery in brachycephalic dogs would decrease perianesthetic complications in subsequent anesthetic events.

ANIMALS

45 client-owned dogs.

PROCEDURES

Brachycephalic dogs undergoing any combination of staphylectomy, nasal alaplasty, or laryngeal sacculectomy that were anesthetized at a later date for additional surgical procedures or imaging from August 2, 2007, to February 8, 2019, had their medical records reviewed during both anesthetic events for signalment, American Society of Anesthesiologists status, perianesthetic drug administration, anesthetic duration, presence and total time of positive-pressure ventilation, procedure invasiveness, and perianesthetic complications such as bradycardia, hypothermia, hypotension, cardiac arrhythmias, hypertension, vomiting or regurgitation, dysphoria, respiratory distress, hypoxemia, reintubation, and prolonged periods of recovery.

RESULTS

The odds of having complications during the postanesthetic period following subsequent anesthetic events were decreased by 79% in dogs having previous surgical intervention to correct clinical signs of brachycephalic airway syndrome. Intra-anesthetic bradycardia increased the odds of developing a postanesthetic complication by 4.56 times. Every 15-minute increase in anesthetic duration increased the odds of having a postanesthetic complication by 12% and having an intra-anesthetic complication by 11%.

CONCLUSIONS AND CLINICAL RELEVANCE

Previous corrective upper airway surgery decreased odds of postanesthetic complications in brachycephalic dogs that underwent subsequent anesthetic events. Findings in this study indicated that corrective upper airway surgery for brachycephalic dogs may reduce postanesthetic complications following subsequent anesthetic events, which may reduce perianesthetic morbidity in patients undergoing multiple surgical or diagnostic imaging procedures.

Intraoperative anaesthetic complications in dogs undergoing general anaesthesia for thoracolumbar hemilaminectomy: a retrospective analysis

OBJECTIVE

To establish the incidence of intraoperative anaesthetic complications in dogs undergoing general anaesthesia (GA) for thoracolumbar hemilaminectomy (TH), to determine whether GA duration affects incidence of intraoperative complications and to identify associations between intraoperative complications.

STUDY DESIGN

Retrospective observational study.

ANIMALS

A total of 224 client-owned dogs of various breeds undergoing TH for intervertebral disc extrusion.

METHODS

Anaesthetic records of dogs undergoing TH at a university teaching hospital between 2010 and 2016 were analysed. Data recorded included breed, sex, body weight, GA duration, magnetic resonance imaging (MRI) under the same GA, pharmacological intervention to increase heart rate (PIHR), hypotension (mean arterial blood pressure < 60 mmHg for ≥ 10 minutes), mechanical ventilation (MV) for inadequate ventilation, hypothermia (oesophageal temperature < 37 °C), oesophageal temperature ≥ 39 °C (T ≥ 39 °C), temperature trend, regurgitation and use of alpha-2 adrenoreceptor agonists, acepromazine, ketamine or lidocaine. Multivariate logistic regression models were fitted for hypothermia, T ≥ 39 °C, hypotension and PIHR with forced inclusion of GA duration.

RESULTS

Hypothermia was the most common complication (63.8% incidence), followed by MV implementation (63.4%), hypotension (33.9%), PIHR (24.6%), T ≥ 39 °C (20.5%) and regurgitation (4.9%). Multivariate models revealed that MRI and hypotension were associated with an increased risk of hypothermia, whilst increasing body weight, alpha-2 adrenoreceptor agonists and MV were associated with a reduced risk. Alpha-2 adrenoreceptor agonists and GA duration were associated with an increased risk of T ≥ 39 °C, whilst hypotension was associated with a reduced risk. Hypothermia and PIHR were associated with an increased risk of hypotension, whereas increased body weight was associated with a reduced risk. MV and hypothermia were associated with an increased risk of PIHR, whereas increased body weight was associated with a reduced risk.

CONCLUSIONS AND CLINICAL RELEVANCE

Increasing GA duration was associated with increased risk of T ≥ 39 °C, but not any other intraoperative complications.

Effects of hyaluronidase on ropivacaine or bupivacaine regional anaesthesia of the canine pelvic limb

OBJECTIVE

To determine the effect of hyaluronidase on time to onset and offset of anaesthesia in ropivacaine or bupivacaine femoral-ischiatic nerve blocks.

STUDY DESIGN

Blinded randomized crossover trial.

ANIMALS

Eight dogs.

METHODS

Each dog underwent four treatments separated into two blocks - initially, the ropivacaine treatment block: RS (ropivacaine 0.5% plus saline 0.9%) and RH (ropivacaine 0.5% plus hyaluronidase 100 IU mL^-1), followed 3 weeks later by the bupivacaine treatment block: BS (bupivacaine 0.5% plus saline) and BH (bupivacaine 0.5% plus hyaluronidase). The local anaesthetics were administered at 0.1 mL kg^-1 per site. Hyaluronidase and saline were administered at 0.02 mL kg^-1 per site. Performance of femoral-ischiatic blocks was aided by a combined ultrasound-electrolocation technique. The mechanical nociceptive threshold was measured, until offset or 360 minutes, using an algometer to ascertain baseline, onset and offset of anaesthesia. Onset and offset of anaesthesia were defined as a 25% increase above and as a return to <25% above baseline nociceptive threshold readings, respectively.

RESULTS

The median (range) onset of anaesthesia for RS and RH was 21 (3-60) and 12 (3-21) minutes, respectively (p = 0.141), and offset was 270 (90-360) and 180 (30-300) minutes, respectively (p = 0.361). By contrast, the median (range) onset of anaesthesia for BS and BH was 24 (3-60) and 9 (3-27) minutes, respectively (p = 0.394), and offset was 360 (240-360) and 330 (210-360) minutes, respectively (p = 0.456).

CONCLUSION AND CLINICAL RELEVANCE

Hyaluronidase had no effect on the onset and offset times of ropivacaine and bupivacaine femoral-ischiatic nerve blocks in dogs compared with saline. The onset and offset times were highly variable in all treatments. Clinically, the high variability of the onset and offset times of the regional anaesthesia of these local anaesthetic drugs means that clinicians must monitor the animal's response and, if required, provide additional analgesic drugs.

Planning for operating room efficiency and faster anesthesia wake-up time in open major upper abdominal surgery

Reducing anesthesia-controlled time (ACT) may improve operation room (OR) efficiency result from different anesthetic techniques. However, the information about the difference in ACT between desflurane (DES) anesthesia and propofol-based total intravenous anesthesia (TIVA) techniques for open major upper abdominal surgery under general anesthesia (GA) is not available in the literature.This retrospective study uses our hospital database to analyze the ACT of open major upper abdominal surgery without liver resection after either desflurane/fentanyl-based anesthesia or TIVA via target-controlled infusion with fentanyl/propofol from January 2010 to December 2011. The various time intervals including waiting for anesthesia time, anesthesia time, surgical time, extubation time, exit from OR after extubation, total OR time, and postanesthetic care unit (PACU) stay time and percentage of prolonged extubation (≥15 minutes) were compared between these 2 anesthetic techniques.We included data from 343 patients, with 159 patients receiving TIVA and 184 patients receiving DES. The only significant difference is extubation time, TIVA was faster than the DES group (8.5 ± 3.8 vs 9.4 ± 3.7 minutes; P = 0.04). The factors contributed to prolonged extubation were age, gender, body mass index, DES anesthesia, and anesthesia time.In our hospital, propofol-based TIVA by target-controlled infusion provides faster emergence compared with DES anesthesia; however, it did not improve OR efficiency in open major abdominal surgery. Older, male gender, higher body mass index, DES anesthesia, and lengthy anesthesia time were factors that contribute to extubation time.