Comparison of recovery from anesthesia with isoflurane, sevoflurane, or desflurane in healthy dogs

Luis A. Lopez Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, GA 30602.

Search for other papers by Luis A. Lopez in
Current site
Google Scholar
PubMed
Close
 MVZ
,
Erik H. Hofmeister Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, GA 30602.

Search for other papers by Erik H. Hofmeister in
Current site
Google Scholar
PubMed
Close
 DVM, MA
,
Juan C. Pavez Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, GA 30602.

Search for other papers by Juan C. Pavez in
Current site
Google Scholar
PubMed
Close
 MV
, and
Benjamin M. Brainard Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, GA 30602.

Search for other papers by Benjamin M. Brainard in
Current site
Google Scholar
PubMed
Close
 VMD

Abstract

Objective—To determine the quality and speed of recovery from anesthesia with isoflurane, sevoflurane, or desflurane and determine end-tidal inhalant concentration at certain events during recovery in healthy dogs.

Animals—11 healthy dogs.

Procedures—Anesthesia was induced with propofol (IV), and dogs were assigned by use of a crossover design to receive isoflurane at 2.0%, sevoflurane at 3.2%, or desflurane at 11% end-tidal concentrations. Direct blood pressure was monitored throughout the 120 minutes of anesthesia. At the end of anesthesia, the circuit was flushed with oxygen, and the time to specific events in recovery and overall quality of recovery were assessed. Blood gas concentrations were measured prior to anesthesia and after recovery.

Results—Dogs in the desflurane group had the shortest time to standing (11.7 ± 5.1 minutes), followed by dogs in the sevoflurane group (18.6 ± 7.5 minutes) and dogs in the isoflurane group (26.3 ± 7.2 minutes). There was no difference for recovery quality among groups. Arterial blood pressure was higher in the sevoflurane group than in the desflurane group at 10 and 15 minutes and in the isoflurane group at 10, 15, 30, 45, 60, 75, 105, and 120 minutes. There were no significant differences among groups with respect to blood gas concentrations.

Conclusions and Clinical Relevance—Results suggested that in dogs for which a short interval to standing is desired, desflurane is the best selection, followed by sevoflurane.

Abstract

Objective—To determine the quality and speed of recovery from anesthesia with isoflurane, sevoflurane, or desflurane and determine end-tidal inhalant concentration at certain events during recovery in healthy dogs.

Animals—11 healthy dogs.

Procedures—Anesthesia was induced with propofol (IV), and dogs were assigned by use of a crossover design to receive isoflurane at 2.0%, sevoflurane at 3.2%, or desflurane at 11% end-tidal concentrations. Direct blood pressure was monitored throughout the 120 minutes of anesthesia. At the end of anesthesia, the circuit was flushed with oxygen, and the time to specific events in recovery and overall quality of recovery were assessed. Blood gas concentrations were measured prior to anesthesia and after recovery.

Results—Dogs in the desflurane group had the shortest time to standing (11.7 ± 5.1 minutes), followed by dogs in the sevoflurane group (18.6 ± 7.5 minutes) and dogs in the isoflurane group (26.3 ± 7.2 minutes). There was no difference for recovery quality among groups. Arterial blood pressure was higher in the sevoflurane group than in the desflurane group at 10 and 15 minutes and in the isoflurane group at 10, 15, 30, 45, 60, 75, 105, and 120 minutes. There were no significant differences among groups with respect to blood gas concentrations.

Conclusions and Clinical Relevance—Results suggested that in dogs for which a short interval to standing is desired, desflurane is the best selection, followed by sevoflurane.

Inhalant anesthesia is commonly used for anesthetic maintenance in dogs.1 Isoflurane and sevoflurane are regularly used in clinical practice, and desflurane is available at many academic veterinary institutions. These 3 agents induce similar cardiovascular depression at MAC-equivalent doses.2,3 However, they differ in their blood solubility. In humans, use of agents with a lower blood-gas partition coefficient results in a more rapid induction and recovery.4,5 In humans, the blood-gas partition coefficient is 1.33 for isoflurane, 0.65 for sevoflurane, and 0.46 for desflurane.6 On the basis of the principle of solubility, it would be expected that induction and recovery would be fastest with desflurane, slower with sevoflurane, and slowest with isoflurane.

Comparisons between sevoflurane and isoflurane for induction of anesthesia in the dog have been made and generally support faster inductions with sevoflurane than with isoflurane.7,8 Four previous publications8–11 have compared isoflurane with sevoflurane for recovery times in dogs and found no difference between the 2 agents. One study10 maintained anesthesia for 60 minutes and had 6 subjects, another study8 maintained anesthesia for 30 minutes before recovery, and the other 2 studies9,11 were clinically oriented with a mean anesthesia duration of 82 and 80 minutes. The difference in recovery times between inhalants becomes more pronounced with longer anesthesia duration in humans.4 It is possible that a difference among the 3 inhalant agents may only emerge with longer anesthetic episodes. With a longer anesthetic duration, a greater amount of inhalant dissolves into vessel-poor tissues (including fat).4,12 An inhalant with low blood solubility would be expected to have little tissue accumulation, resulting in a more rapid recovery.

The events of anesthesia recovery have been correlated with the end-tidal concentration of the inhalant anesthetic in horses.13 In dogs, it has been documented that the concentration of inhalant at recovery is higher than it is in humans.14 Although the time to certain recovery events has been documented for isoflurane and sevoflurane,8,9 the end-tidal concentration at the time of specific recovery events has not been documented in dogs.

The purposes of the study reported here were to determine the quality and time of recovery with isoflurane, sevoflurane, and desflurane in dogs after 120 minutes of anesthesia and to document the end-tidal inhalant concentration at certain recovery events by use of a fast alveolar washout of anesthetic. The hypothesis was that use of sevoflurane and desflurane would result in more rapid recoveries than would use of isoflurane.

Materials and Methods

Eleven random-source dogs were used in this study in a randomized Williams crossover design. Anesthesia was administered with isoflurane, sevoflurane, or desflurane. Each dog was anesthetized no more than once every 7 days. Nine dogs were determined as the minimum number required by a power calculation based on previous publications to achieve an α of 0.05 and β of 0.20 and to detect a 3-minute difference in time to extubation and a 0.6-point difference in recovery score.8,15 To allow for the design and possibly larger variation than previously reported, the number was increased to 11.

The protocol was approved by the University of Georgia Institutional Animal Care and Use Committee, and husbandry was provided according to established institutional guidelines. Body condition score was assessed by use of a published system.16 Dogs were deemed healthy on the basis of results of a physical examination, PCV, total protein concentration, blood glucose concentration, and BUN concentration estimated by use of a reagent strip.

Dogs were assigned by use of a Williams crossover design to 1 of 6 groups (Appendix 1). Each dog was instrumented with peripheral venous and arterial cathetersa placed after SC instillation of 0.3 mL of lidocaine 2%.b After instrumentation, the dog was placed in a kennel alone for at least 20 minutes. Anesthesia in each dog was induced with propofolc given until loss of jaw tone, to a maximum of 8 mg/kg, IV, as determined by a single observer who was unaware of treatment groups. Induction quality was scored (0 to 3) by a single observer who was unaware of treatment groups15 (Appendix 2). The dog was then orotracheally intubated, and intermittent positive-pressure ventilation was initiated by use of a volume-cycled ventilator set to deliver 12 breaths/min to achieve a target end-tidal CO2 concentration from 35 to 40 mm Hg. Intermittent positive-pressure ventilation was continued until extubation. The oxygen flow was initially delivered at 2 L/min, with the vaporizer set to achieve an end-tidal concentration of 2.0% (isofluraned), 3.2% (sevofluranee), or 11% (desfluranef) within 20 minutes of induction. These values represent 1.5 times the MAC value for the selected anesthetic.17–19 After the target concentration was achieved, the oxygen flow was decreased to 0.5 L/min for the remainder of anesthesia. End-tidal agent concentrations were measured with a calibrated gas analyzer with a sidestream sampling T located between the endotracheal tube and the Y-piece of the anesthesia circuit.g Lactated Ringer's solutionh was administered IV at 10 mL/kg/h during anesthesia. Temperature was measured continuously by use of a probe placed in the thoracic portion of the esophagusi and maintained from 36.9° to 37.8°C with a forced-air warming unit.j Direct arterial blood pressure was measured continuously with a mercury-calibrated transducer attached to a physiologic monitori and recorded at 10, 15, 30, 45, 60, 75, 90, 105, and 120 minutes after the start of inhalant anesthesia. Arterial blood samples were taken from the dorsal pedal arterial catheter with syringes containing dry lithium heparin.k Samples were taken before induction and in the recovery period and analyzed for electrolyte and blood gas values with a blood gas analyzer.l At 120 minutes after induction, the vaporizer was turned to 0%, the system was flushed with 100% oxygen, and the oxygen flow rate was increased to 4 L/min to maintain a near-zero inspired concentration of anesthetic.20 The end-tidal inhalant concentration was recorded for the following events: return of the palpebral reflex, dog resisting mechanical ventilation, first opening of the eyes, first movement, first head movement, and extubation. Each behavior was evaluated by a single blinded observer who marked the time since discontinuing administration of the anesthetic. The dog was extubated if it was actively swallowing. After extubation, the time for the dog to achieve sternal recumbency, first attempt to stand, and successful standing were recorded. The quality of recovery and ataxia while walking after recovery were scored as 0 to 315 (Appendix 2). Ataxia was scored initially after the dog stood and ambulated and every 5 minutes thereafter until the score was 0.

Normality was determined by use of the Shapiro-Wilk test. Time to recovery events, propofol induction dose, and induction quality were compared among groups by use of a paired t test for normally distributed data and the Wilcoxon signed rank test for nonnormally distributed data. Arterial blood pressure and pulse rate were compared among groups by use of a 1-way ANOVA with post hoc testing by use of a Tukey test. Baseline and recovery blood gas concentrations were compared by use of a 2-way ANOVA. Recovery and ataxia scores were compared by use of the χ2 test. Ataxia scores were summed for all time intervals for each group and compared by use of the Wilcoxon signed rank test. To correct for the effect of multiple tests, the Holm-Bonferroni method was used. Significance was set at values of P < 0.05.

Results

One dog had profound hypotension throughout anesthesia and an extremely prolonged recovery time with all 3 agents, so the dog was removed from all analyses. One dog was only anesthetized with isoflurane and sevoflurane because of time constraints, leaving 9 dogs for comparisons involving desflurane and 10 dogs for comparisons between isoflurane and sevoflurane. The dogs' mean ± SD weight was 21.3 ± 6.2 kg, and their median body condition was 5 (range, 3 to 7); these did not change over the course of the study. The mean ± SD dose of propofol was 5.9 ± 1.3 mg/kg in the isoflurane group, 6.2 ± 2.0 mg/kg in the sevoflurane group, and 5.8 ± 1.7 mg/kg in the desflurane group, and this was not significantly (P = 0.56) different among groups. The median induction quality was 0 (range, 0 to 3) in the isoflurane group, 0 (range, 0 to 2) in the sevoflurane group, and 0 (range, 0 to 2) in the desflurane group, and this was not significantly (P = 0.93) different among groups.

Dogs in the desflurane group had a significantly shorter time to eye opening (P = 0.004), sternal recumbency (P < 0.001), first attempt to stand (P < 0.001), and standing (P < 0.001), compared with dogs in the isoflurane group (Table 1). Dogs in the desflurane group had a significantly shorter time to first attempt to stand (P = 0.006) and standing (P = 0.007), compared with dogs in the sevoflurane group. Dogs in the sevoflurane group had significantly (P = 0.02) shorter times to first attempt to stand and standing, compared with dogs in the isoflurane group. After 120 minutes, the mean ± SD final end-tidal inhalant concentration was 2.0 ± 0.1% for isoflurane, 3.2 ± 0.1% for sevoflurane, and 11.0 ± 0.2% for desflurane.

Table 1—

Mean ± SD (95% confidence interval) values for the duration since end of anesthetic administration (time from end of gas administration [gas off]), end-tidal agent concentration, and MAC ratio corresponding to various events associated with anesthesia with isoflurane (Iso), sevoflurane (Sevo), or desflurane (Des) in dogs.

EventTime from gas off (min)End-tidal concentration (vol/vol)MAC ratio
Palpebral
   Iso7.7 ± 5.4 (3.8–11.6)0.5 ± 0.1 (0.4–0.6)0.38
   Sevo5.7 ± 4.1 (2.8–8.6)0.64 ± 0.3 (0.4–0.9)0.30
   Des3.0 ± 1.8 (1.6–4.5)3.65 ± 0.9 (2.9–4.4)0.50
Bucking
   Iso11.1 ± 6.0 (5.6–16.7)0.4 ± 0.1 (0.4–0.5)0.30
   Sevo8.3 ± 5.0 (4.5–12.1)1.0 ± 1.1 (0.2–1.8)0.47
   Des5.3 ± 2.3 (3.4–7.3)3.6 ± 2.0 (1.9–5.3)0.50
Open eyes
   Iso15.1 ± 5.6 (11.1–19.1)0.4 ± 0.1 (0.3–0.5)0.30
   Sevo12.7 ± 8.3 (6.8–18.6)0.4 ± 0.1 (0.2–0.6)0.19
   Des5.0 ± 4.2 (1.7–8.2)*3.1 ± 0.8 (2.4–3.9)0.42
First movement
   Iso11.7 ± 4.9 (8.2–15.1)0.4 ± 0.1 (0.4–0.5)0.30*
   Sevo9.1 ± 3.8 (6.4–11.8)0.46 ± 0.1 (0.4–0.5)0.22
   Des6.2 ± 3.8 (3.2–9.1)2.7 ± 1.1 (1.8–3.6)0.37
Head movement
   Iso13.9 ± 6.5 (8.4–19.3)0.4 ± 0.1 (0.4–0.5)0.30
   Sevo9.4 ± 3.9 (6.7–12.2)0.4 ± 0.1 (0.3–0.5)0.19
   Des6.5 ± 3.7 (3.6–9.3)2.7 ± 1.2 (1.8–3.6)0.37*
Extubation
   Iso13.0 ± 5.4 (9.2–16.9)0.4 ± 0.1 (0.3–0.5)0.30*
   Sevo9.5 ± 3.9 (6.7–12.3)0.4 ± 0.1 (0.3–0.5)0.19
   Des6.7 ± 3.7 (3.8–9.5)2.6 ± 1.1 (1.7–3.5)0.35
Sternal
   Iso22.2 ± 8.8 (15.9–28.5)NANA
   Sevo14.8 ± 9.3 (8.1–21.4)
   Des8.6 ± 5.1 (4.7–12.6)
First stand
   Iso25.3 ± 7.9 (19.7–30.9)NANA
   Sevo17.5 ± 7.1 (12.5–22.6)
   Des10.1 ± 4.9 (6.3–13.9)*
Standing
   Iso26.3 ± 7.2 (21.2–31.5)NANA
   Sevo18.6 ± 7.5 (13.2–24.0)
   Des11.7 ± 5.1 (7.8–15.6)*

Significant (P < 0.05) difference from value for Sevo at this time point.

Significant (P < 0.05) difference from value for Iso at this time point.

Bucking = Resisting mechanical ventilation. NA = Not applicable.

There were 9 dogs for comparisons involving Des and 10 for comparisons between Iso and Sevo.

The end-tidal inhalant concentration-to-MAC ratio was significantly lower in the sevoflurane group for first movement (P = 0.002) and extubation (P < 0.001), compared with the isoflurane group (Table 1). There was no significant difference in the ratio for any end point between the desflurane groups.

There was no significant difference in proportion of dogs with varying ataxia scores at any time point. The cumulative ataxia score was not significantly different among groups. There was no significant difference among groups with regard to recovery score.

Dogs in the sevoflurane group had significantly higher blood pressures than dogs in the other 2 groups at 10 and 15 minutes, and dogs in the isoflurane group had significantly lower blood pressures than dogs in the other 2 groups at various time points (Table 2). Dogs in the desflurane group had significantly higher pulse rates than dogs in the sevoflurane group from 45 minutes on. There was no significant treatment effect for blood gas values, ionized calcium concentration, or ionized magnesium concentration. There was a significant (P < 0.001) effect of sampling time on pH and PaCO2, with the pH being significantly lower and the PaCO2 being significantly higher after recovery, compared with baseline (Table 3). There was no significant effect of sampling time on PaO2, HCO3 concentration, base excess, ionized calcium concentration, or ionized magnesium concentration.

Table 2—

Hemodynamic values for dogs anesthetized with Iso, Sevo, or Des for 120 minutes.

VariableBaselineMinutes after induction
510153045607590105120
SAP (mm Hg)
   Iso173 ± 1788 ± 2469 ± 1668 ± 1879 ± 1577 ± 1581 ± 1480 ± 1181 ± 1581 ± 1582 ± 16
   Sevo164 ± 1794 ± 1988 ± 13a88 ± 13a87 ± 985 ± 885 ± 1085 ± 1188 ± 1087 ± 988 ± 10
   Des173 ± 2081 ± 2765 ± 1071 ± 1184 ± 1285 ± 1285 ± 1185 ± 1087 ± 1087 ± 990 ± 13
MAP (mm Hg)
   Iso124 ± 1258 ± 1248 ± 1046 ± 952 ± 851 ± 7a54 ± 653 ± 6a54 ± 8b55 ± 8b55 ± 8b
   Sevo119 ± 1568 ± 1462 ± 8a61 ± 8a61 ± 6c59 ± 659 ± 660 ± 661 ± 560 ± 462 ± 5
   Des121 ± 956 ± 1647 ± 750 ± 859 ± 960 ± 760 ± 860 ± 662 ± 861 ± 565 ± 11
DAP (mm Hg)
   Iso97 ± 1043 ± 837 ± 636 ± 741 ± 741 ± 6a43 ± 642 ± 543 ± 643 ± 743 ± 8
   Sevo97 ± 1654 ± 1348 ± 7a49 ± 7a49 ± 6c48 ± 547 ± 5c48 ± 5c49 ± 5c49 ± 3c50 ± 6
   Des96 ± 743 ± 1237 ± 541 ± 747 ± 749 ± 748 ± 748 ± 649 ± 848 ± 551 ± 11
HR (beats/min)
   Iso135 ± 21112 ± 23110 ± 2098 ± 1790 ± 1591 ± 1194 ± 1395 ± 1297 ± 1198 ± 1199 ± 12
   Sevo137 ± 19123 ± 19111 ± 1399 ± 1294 ± 1193 ± 1094 ± 996 ± 998 ± 1298 ± 1395 ± 16b
   Des128 ± 26120 ± 34110 ± 21103 ± 19103 ± 13105 ± 15a105 ± 10a107 ± 9a110 ± 10a115 ± 12a114 ± 71

Significant (P < 0.05) difference from other values at this time point.

Significant (P < 0.05) difference from value for Des at this time point.

Significant (P < 0.05) difference from value for Iso at this time point.

DAP = Diastolic arterial pressure. HR = Heart rate. MAP = Mean arterial pressure. SAP = Systolic arterial pressure.

Table 3—

Blood gas and ionized magnesium and calcium variables (mean ± SD) in dogs anesthetized with Iso, Sevo, or Des.

VariableIso (baseline)Iso (recovery)Sevo (baseline)Sevo (recovery)Des (baseline)Des (recovery)
pH*7.47 ± 0.037.45 ± 0.027.47 ± 0.037.45 ± 0.027.46 ± 0.027.44 ± 0.03
PaCO2 (mm Hg)*27.1 ± 2.629.3 ± 2.626.8 ± 2.229.1 ± 2.127.3 ± 2.129.4 ± 1.5
PaO2 (mm Hg)101 ± 10103 ± 11107 ± 12106 ± 9103 ± 8101 ± 7.7
HCO3 (mEq/L)19.8 ± 1.220.5 ± 1.519.7 ± 1.120.2 ± 1.119.7 ± 1.220.2 ± 1.5
BE (mEq/L)−4.2 ± 1.1−3.8 ± 1.4−4.3 ± 1.2−4.2 ± 1.1−4.4 ± 1.2−4.2 ± 1.9
Ca (mmol/L)1.12 ± 0.051.14 ± 0.071.13 ± 0.061.14 ± 0.051.13 ± 0.091.16 ± 0.08
Mg (mmol/L)0.37 ± 0.050.37 ± 0.060.36 ± 0.050.38 ± 0.040.34 ± 0.050.37 ± 0.06

Significant (P < 0.05) difference between baseline and recovery values.

BE = Base excess.

Discussion

Dogs in the desflurane group had a faster recovery, followed by dogs in the sevoflurane group and dogs in the isoflurane group. It has been documented that isoflurane and sevoflurane are associated with similar recovery times in dogs.8–11 Results of the present study indicated significantly faster time to standing in the sevoflurane group, compared with isoflurane group. In 3 of the previous studies,9–11 premedication had been administered to the dogs, which may have obscured any difference in recovery time attributable to the inhalant anesthetic. In the other study,8 the dogs were maintained with anesthesia for only 30 minutes. It is likely that the difference observed is attributable to anesthetic duration. With longer anesthetic episodes, the difference between isoflurane and sevoflurane may become even more evident. However, if this difference is obviated by the use of premedications, the clinical importance is minimal because most clinically anesthetized dogs receive premedicant sedation. There was no significant difference among groups in the time to extubation from discontinuing the anesthetic. If time to extubation is the critical end point in a clinical case, it appears that sevoflurane has no benefit over isoflurane.

Desflurane has been used for several investigations in dogs,21–24 but has not been evaluated in a side-by-side fashion with other inhalant anesthetics. In 3 studies from 1 laboratory, the times to standing were 3.9 minutes, 7.5 minutes with premedication with romifidine (40 μg/kg, IV), or 3.8 minutes with premedication with medetomidine (1 μg/kg, IV).22 These values are substantially lower than the time to standing of 11.7 minutes reported in the present study. The dogs in those studies were anesthetized for 90 minutes, which is comparable to the 120 minutes in this study. The dogs in those studies were maintained at approximately 7.5% end-tidal desflurane concentration (approx the MAC for desflurane), whereas the dogs in our study were maintained at 11% end-tidal concentration (1.5 times the MAC). Another study,24 in which dogs were maintained with approximately 8% desflurane and fentanyl, found a time to standing of approximately 13 minutes. It is possible that frequent fentanyl administration prolonged recovery in those dogs relative to what would be expected with an end-tidal concentration of 8%. The concentration of inhalant affects time to first positive eyelid reflex and extubation in dogs anesthetized with 1.5 or 2 times the MAC of halothane, isoflurane, or sevoflurane.10 Therefore, it is possible that the difference between previous studies and the results reported here was attributable to the difference in maintenance anesthetic concentration.

The end-tidal concentration-to-MAC ratio at first movement and extubation was significantly smaller in the sevoflurane group, compared with the isoflurane and desflurane groups. In a previous publication,14 it was determined that the MACawake-to-MAC ratio was significantly smaller for dogs anesthetized with sevoflurane, compared with isoflurane. The findings published here confirm those results, which suggest that dogs anesthetized with sevoflurane require a lower concentration of inhalant relative to the MAC value to suppress behavioral responses associated with a light plane of anesthesia. Similar differences in behavioral responses to different inhalants have been documented in horses13 and humans.25 If the extubation concentration is taken as the MACawake, the values reported here are substantially lower than previously reported.14 This may be attributed to the fast alveolar washout used in the present study as compared with a step-down protocol used previously.26 A fast alveolar washout does not allow for effect-site equilibrium between the endtidal concentration and the CNS concentration of an anesthetic gas. Hence, the values resulting from a fast alveolar washout are not likely to represent effect-site concentration.

There was no significant difference in recovery quality or ataxia scores for any of the groups in this study. In 1 study8 comparing isoflurane and sevoflurane quality, no significant difference was found. In a recent publication,9 an improvement in quality with sevoflurane, compared with isoflurane, was documented. Johnson et al8 used a categorical scoring system for recovery, similar to the system used in this report, as compared to a visual analog scale used by Love et al.9 It is possible that the visual analog scale is a more sensitive scale for recovery quality and could detect more subtle differences than a categorical scale. In the study9 that detected a significant difference in recovery quality between isoflurane and sevoflurane, data collection for the ataxia score was done at 30 minutes and 60 minutes after administration of the inhalant was discontinued. It is possible that the ataxia at these times was caused by the acepromazine that was used as a premedication and not caused by the inhalant anesthetic. It is possible that dogs in the desflurane or sevoflurane groups in our study had faster return of cognitive function but did not have a similarly rapid return of psychomotor function, resulting in a more rapid recovery but no improvement in recovery quality.

The sequence of recovery events for dogs in the isoflurane and sevoflurane groups was palpebral reflex, dog resisting mechanical ventilation, first movement, movement of the head, open eyes, and extubation. In dogs in the desflurane group, eye opening was the second event. This may have occurred because dogs in the desflurane group regained cognitive function more quickly. In a systematic review of anesthetized humans, it was found that early recovery, characterized by opening eyes and obeying commands, was significantly different but only marginally quicker with desflurane and sevoflurane, compared with isoflurane.27 The conclusion was that the specific anesthetic appears to play a minor role in outcome after surgery. The minor effect of the anesthetic agent in those studies may have occurred because clinical cases were used and the anesthetic protocols included adjuvant drugs such as opioids and muscle relaxants, which may have affected recovery scores, as seems to be true in dogs.9–11

The mean arterial blood pressures observed in the dogs of the present study were at the low end of an acceptable range (60 mm Hg) and were less than that value in the isoflurane group. Inhalant anesthetics induced a dose-dependent cardiovascular depression,28 and single-agent anesthesia is typically not advocated because of that effect. Our findings suggested that a single-agent protocol involving only isoflurane, sevoflurane, or desflurane is suboptimal from a cardiovascular perspective, and a balanced anesthetic technique should be used to reduce the dose of inhalant and thus reduce cardiovascular depression in clinical patients. It is possible that, if the patients had been stimulated, such as by surgery, the blood pressures would have been more acceptable. The higher pulse rate observed in the desflurane group from 45 minutes on was consistent with previous findings, which have determined that this is a result of vagal blockade.29

Arterial blood gas analysis revealed significant differences between baseline and recovery time values for pH and the PaCO2. At recovery time, PaCO2 was greater than the baseline value and pH was less than the baseline value, although the baseline and recovery PaCO2 were low, indicating hyperventilation. The hyperventilation may have been caused by the introduction of the dogs to a strange environment and unfamiliar procedures. The relatively higher PaCO2 in recovery may have been caused by the lack of restraint in recovery, compared with baseline values; residual respiratory depression from the inhalant anesthesia; or residual sedation preventing the dogs from becoming anxious and hyperventilating. Regardless, the values were not significantly different among the 3 groups, indicating that there was no effect of the treatment group assignment on blood gas values.

Desflurane anesthesia in dogs resulted in faster recoveries than sevoflurane anesthesia, which resulted in faster recoveries than isoflurane after 120 minutes of anesthesia. Recovery scores, however, were not significantly different among groups. In dogs in which a rapid time to standing is desired, desflurane appears to be the best selection, followed by sevoflurane.

ABBREVIATION

MAC

Minimum alveolar concentration

a.

Surflo 20G × 1”, Terumo Medical Corp, Somerset, NJ.

b.

Lidocaine 2%, Hospira Inc, Lake Forest, Ill.

c.

Propoflo, Abbott Animal Health, North Chicago, Ill.

d.

Isoflo, Abbott Animal Health, North Chicago, Ill.

e.

Sevoflo, Abbott Animal Health, North Chicago, Ill.

f.

Suprane, Baxter Health Care Corp, Deerfield, Ill.

g.

Ohmeda 5250 RGM, BOC Health Care Co Division, Louisville, Colo.

h.

Lactated Ringer's, Hospira Inc, Lake Forest, Ill.

i.

Surgivet Advisor, Smiths Medical PM, Waukesha, Wis.

j.

TC3000 Thermacare convective warming system, Gaymar Industries, Orchard Park, NY.

k.

Portex arterial blood sample syringe, Smiths Medical ASD, Keene, NH.

l.

Critical Care Xpress, Nova Biomedical, Waltham, Mass.

References

  • 1.

    Steffey EP. Overview of veterinary anesthesia. In: Thurmon JC, Tranquilli WJ, Benson GJ, eds. Lumb & Jones' veterinary anesthesia. 3rd ed. Philadelphia: Lippincott Williams & Wilkins, 1996;298.

    • Search Google Scholar
    • Export Citation
  • 2.

    Preckel B, Mullenheim J, Hoff J, et al. Haemodynamic changes during halothane, sevoflurane, and desflurane anaesthesia in dogs before and after induction of severe heart failure. Eur J Anaesthesiol 2004;21:797806.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 3.

    Gare M, Schwabe DA, Hettrick DA, et al. Desflurane, sevoflurane, and isoflurane affect left atrial active and passive mechanical properties and impair left atrial-left ventricular coupling in vivo: analysis using pressure-volume relations. Anesthesiology 2001;95:689698.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 4.

    Eger EI II, Gong D, Koblin DD, et al. The effect of anesthetic duration on kinetic and recovery characteristics of desflurane versus sevoflurane, and on the kinetic characteristics of Compound A, in volunteers. Anesth Analg 1998;86:414421.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 5.

    Robinson BJ, Uhrich TD, Ebert TJ. A review of recovery from sevoflurane anesthesia: comparisons with isoflurane and propofol including meta-analysis. Acta Anaesthesiol Scand 1999;43:185190.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 6.

    Yang NC, Wang HF, Hwang KL, et al. A novel method for determining the blood/gas partition coefficients of inhalation anesthetics to calculate the percentage of loss at different temperatures. J Anal Toxicol 2004;28:122127.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 7.

    Mutoh T, Kojima K, Takao K, et al. Comparison of sevoflurane with isoflurane for rapid mask induction in midazolam and butorphanol-sedated dogs. J Vet Med A Physiol Pathol Clin Med 2001;48:223230.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 8.

    Johnson RA, Striler E, Sawyer DC, et al. Comparison of isoflurane with sevoflurane for anesthesia induction and recovery in adult dogs. Am J Vet Res 1998;59:478481.

    • Search Google Scholar
    • Export Citation
  • 9.

    Love EJ, Holt PE, Murison PJ. Recovery characteristics following maintenance of anesthesia with sevoflurane or isoflurane in dogs premedicated with acepromazine. Vet Rec 2007;161:217221.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 10.

    Polis I, Gasthuys F, Van Ham L, et al. Recovery times and evaluation of clinical hemodynamic parameters of sevoflurane, isoflurane and halothane anaesthesia in mongrel dogs. J Vet Med A Physiol Pathol Clin Med 2001;48:401411.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 11.

    Bennett RC, Fancy SPJ, Walsh CM, et al. Comparison of sevoflurane and isoflurane in dogs anaesthetised for clinical surgical or diagnostic procedures. J Small Anim Pract 2008;49:392397.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 12.

    Nordmann GR, Read JA, Sale SM, et al. Emergence and recovery in children after desflurane and isoflurane anesthesia: effect of anesthesia duration. Br J Anaesth 2006;96:779785.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 13.

    Whitehair KJ, Steffey EP, Willits NH, et al. Recovery of horses from inhalation anesthesia. Am J Vet Res 1993;54:16931702.

  • 14.

    Hofmeister EH, Brainard BM, Sams LM, et al. Evaluation of induction characteristics and hypnotic potency of isoflurane and sevoflurane in healthy dogs. Am J Vet Res 2008;69:451456.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 15.

    Sams L, Braun C, Allman D, et al. A comparison of the effects of propofol and etomidate on the induction of anesthesia and on cardiopulmonary parameters in dogs. Vet Anaesth Analg 2008;35:488494.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 16.

    Lund EM, Armstrong PJ, Kirk CA, et al. Health status and population characteristics of dogs and cats examined at private veterinary practices in the United States. J Am Vet Med Assoc 1999;214:13361341.

    • Search Google Scholar
    • Export Citation
  • 17.

    Valverde A, Morey TE, Hernández J, et al. Validation of several types of noxious stimuli for use in determining the minimum alveolar concentration for inhalation anesthetics in dogs and rabbits. Am J Vet Res 2003;64:957962.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 18.

    Galloway DS, Ko JC, Reaugh HF, et al. Anesthetic indices of sevoflurane and isoflurane in unpremedicated dogs. J Am Vet Med Assoc 2004;225:700704.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 19.

    Doorley BM, Waters SJ, Terrell RC, et al. MAC of I-653 in beagles dogs and New Zealand white rabbits. Anesthesiology 1988;69:8991.

  • 20.

    Gauman DM, Mustaki JP, Tassonyi E. MAC-awake of isoflurane, enflurane and halothane evaluated by slow and fast alveolar washout. Br J Anaesth 1992;68:8184.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 21.

    Gomez-Villamandos RJ, Palacios C, Benitez A, et al. Effect of medetomidine infusion on the anaesthetic requirements of desflurane in dogs. Res Vet Sci 2008;84:6873.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 22.

    Gomez-Villamandos RJ, Redondo JI, Martin EM, et al. Cardiorespiratory effects of desflurane in dogs given romifidine or medetomidine before induction of anesthesia with propofol. Can J Vet Res 2006;70:308312.

    • Search Google Scholar
    • Export Citation
  • 23.

    Gomez-Villamandos RJ, Palacios C, Benitez A, et al. Dexmedetomidine or medetomidine premedication before propofol-desflurane anaesthesia in dogs. J Vet Pharmacol Ther 2006;29:157163.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 24.

    Martin MF, Lima JR, Ezquerra LJ, et al. Prolonged anesthesia with desflurane and fentanyl in dogs during conventional and laparoscopic surgery. J Am Vet Med Assoc 2001;219:941945.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 25.

    Goto T, Nakata Y, Ishiguro Y, et al. Minimum alveolar concentration-awake of xenon alone and in combination with isoflurane or sevoflurane. Anesthesiology 2000;93:11881193.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 26.

    Katoh T, Suguro Y, Kimura T, et al. Cerebral awakening concentration of sevoflurane and isoflurane predicted during slow and fast alveolar washout. Anesth Analg 1993;77:10121017.

    • Search Google Scholar
    • Export Citation
  • 27.

    Gupta A, Stierer T, Zuckerman R, et al. Comparison of recovery profile after ambulatory anesthesia with propofol, isoflurane, sevoflurane and desflurane: a systematic review. Anesth Analg 2004;98:632641.

    • Search Google Scholar
    • Export Citation
  • 28.

    Mutoh T, Nishimura R, Kim HY, et al. Cardiopulmonary effects of sevoflurane, compared with halothane, enflurane, and isoflurane, in dogs. Am J Vet Res 1997;58:885890.

    • Search Google Scholar
    • Export Citation
  • 29.

    Picker O, Schwarte LA, Schindler AW, et al. Desflurane increases heart rate independent of sympathetic activity in dogs. Eur J Anaesthesiol 2003;20:945951.

    • Crossref
    • Search Google Scholar
    • Export Citation

Appendix 1

Assignment of dogs to treatment groups for a study of recovery from anesthesia with isoflurane, sevoflurane, or desflurane.

GroupWeek 1Week 2Week 3
1IsofluraneSevofluraneDesflurane
2IsofluraneDesfluraneSevoflurane
3SevofluraneDesfluraneIsoflurane
4SevofluraneIsofluraneDesflurane
5DesfluraneIsofluraneSevoflurane
6DesfluraneSevofluraneIsoflurane

Appendix 2

Ataxia, induction, and recovery quality scores in a study of recovery from anesthesia with isoflurane, sevoflurane, or desflurane in healthy dogs.

ScoreDescriptorAtaxiaInductionRecovery
0PerfectWalking without ataxiaSmooth uncomplicated inductionSmooth uncomplicated recovery
1GoodWalking with minimal ataxiaInduction uncomplicatedRecovery uncomplicated
2AdequateWalking with moderate ataxiaInduction difficultRecovery difficult
3PoorWalking with substantial ataxia or crawlingInduction poorRecovery poor
  • 1.

    Steffey EP. Overview of veterinary anesthesia. In: Thurmon JC, Tranquilli WJ, Benson GJ, eds. Lumb & Jones' veterinary anesthesia. 3rd ed. Philadelphia: Lippincott Williams & Wilkins, 1996;298.

    • Search Google Scholar
    • Export Citation
  • 2.

    Preckel B, Mullenheim J, Hoff J, et al. Haemodynamic changes during halothane, sevoflurane, and desflurane anaesthesia in dogs before and after induction of severe heart failure. Eur J Anaesthesiol 2004;21:797806.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 3.

    Gare M, Schwabe DA, Hettrick DA, et al. Desflurane, sevoflurane, and isoflurane affect left atrial active and passive mechanical properties and impair left atrial-left ventricular coupling in vivo: analysis using pressure-volume relations. Anesthesiology 2001;95:689698.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 4.

    Eger EI II, Gong D, Koblin DD, et al. The effect of anesthetic duration on kinetic and recovery characteristics of desflurane versus sevoflurane, and on the kinetic characteristics of Compound A, in volunteers. Anesth Analg 1998;86:414421.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 5.

    Robinson BJ, Uhrich TD, Ebert TJ. A review of recovery from sevoflurane anesthesia: comparisons with isoflurane and propofol including meta-analysis. Acta Anaesthesiol Scand 1999;43:185190.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 6.

    Yang NC, Wang HF, Hwang KL, et al. A novel method for determining the blood/gas partition coefficients of inhalation anesthetics to calculate the percentage of loss at different temperatures. J Anal Toxicol 2004;28:122127.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 7.

    Mutoh T, Kojima K, Takao K, et al. Comparison of sevoflurane with isoflurane for rapid mask induction in midazolam and butorphanol-sedated dogs. J Vet Med A Physiol Pathol Clin Med 2001;48:223230.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 8.

    Johnson RA, Striler E, Sawyer DC, et al. Comparison of isoflurane with sevoflurane for anesthesia induction and recovery in adult dogs. Am J Vet Res 1998;59:478481.

    • Search Google Scholar
    • Export Citation
  • 9.

    Love EJ, Holt PE, Murison PJ. Recovery characteristics following maintenance of anesthesia with sevoflurane or isoflurane in dogs premedicated with acepromazine. Vet Rec 2007;161:217221.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 10.

    Polis I, Gasthuys F, Van Ham L, et al. Recovery times and evaluation of clinical hemodynamic parameters of sevoflurane, isoflurane and halothane anaesthesia in mongrel dogs. J Vet Med A Physiol Pathol Clin Med 2001;48:401411.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 11.

    Bennett RC, Fancy SPJ, Walsh CM, et al. Comparison of sevoflurane and isoflurane in dogs anaesthetised for clinical surgical or diagnostic procedures. J Small Anim Pract 2008;49:392397.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 12.

    Nordmann GR, Read JA, Sale SM, et al. Emergence and recovery in children after desflurane and isoflurane anesthesia: effect of anesthesia duration. Br J Anaesth 2006;96:779785.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 13.

    Whitehair KJ, Steffey EP, Willits NH, et al. Recovery of horses from inhalation anesthesia. Am J Vet Res 1993;54:16931702.

  • 14.

    Hofmeister EH, Brainard BM, Sams LM, et al. Evaluation of induction characteristics and hypnotic potency of isoflurane and sevoflurane in healthy dogs. Am J Vet Res 2008;69:451456.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 15.

    Sams L, Braun C, Allman D, et al. A comparison of the effects of propofol and etomidate on the induction of anesthesia and on cardiopulmonary parameters in dogs. Vet Anaesth Analg 2008;35:488494.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 16.

    Lund EM, Armstrong PJ, Kirk CA, et al. Health status and population characteristics of dogs and cats examined at private veterinary practices in the United States. J Am Vet Med Assoc 1999;214:13361341.

    • Search Google Scholar
    • Export Citation
  • 17.

    Valverde A, Morey TE, Hernández J, et al. Validation of several types of noxious stimuli for use in determining the minimum alveolar concentration for inhalation anesthetics in dogs and rabbits. Am J Vet Res 2003;64:957962.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 18.

    Galloway DS, Ko JC, Reaugh HF, et al. Anesthetic indices of sevoflurane and isoflurane in unpremedicated dogs. J Am Vet Med Assoc 2004;225:700704.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 19.

    Doorley BM, Waters SJ, Terrell RC, et al. MAC of I-653 in beagles dogs and New Zealand white rabbits. Anesthesiology 1988;69:8991.

  • 20.

    Gauman DM, Mustaki JP, Tassonyi E. MAC-awake of isoflurane, enflurane and halothane evaluated by slow and fast alveolar washout. Br J Anaesth 1992;68:8184.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 21.

    Gomez-Villamandos RJ, Palacios C, Benitez A, et al. Effect of medetomidine infusion on the anaesthetic requirements of desflurane in dogs. Res Vet Sci 2008;84:6873.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 22.

    Gomez-Villamandos RJ, Redondo JI, Martin EM, et al. Cardiorespiratory effects of desflurane in dogs given romifidine or medetomidine before induction of anesthesia with propofol. Can J Vet Res 2006;70:308312.

    • Search Google Scholar
    • Export Citation
  • 23.

    Gomez-Villamandos RJ, Palacios C, Benitez A, et al. Dexmedetomidine or medetomidine premedication before propofol-desflurane anaesthesia in dogs. J Vet Pharmacol Ther 2006;29:157163.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 24.

    Martin MF, Lima JR, Ezquerra LJ, et al. Prolonged anesthesia with desflurane and fentanyl in dogs during conventional and laparoscopic surgery. J Am Vet Med Assoc 2001;219:941945.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 25.

    Goto T, Nakata Y, Ishiguro Y, et al. Minimum alveolar concentration-awake of xenon alone and in combination with isoflurane or sevoflurane. Anesthesiology 2000;93:11881193.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 26.

    Katoh T, Suguro Y, Kimura T, et al. Cerebral awakening concentration of sevoflurane and isoflurane predicted during slow and fast alveolar washout. Anesth Analg 1993;77:10121017.

    • Search Google Scholar
    • Export Citation
  • 27.

    Gupta A, Stierer T, Zuckerman R, et al. Comparison of recovery profile after ambulatory anesthesia with propofol, isoflurane, sevoflurane and desflurane: a systematic review. Anesth Analg 2004;98:632641.

    • Search Google Scholar
    • Export Citation
  • 28.

    Mutoh T, Nishimura R, Kim HY, et al. Cardiopulmonary effects of sevoflurane, compared with halothane, enflurane, and isoflurane, in dogs. Am J Vet Res 1997;58:885890.

    • Search Google Scholar
    • Export Citation
  • 29.

    Picker O, Schwarte LA, Schindler AW, et al. Desflurane increases heart rate independent of sympathetic activity in dogs. Eur J Anaesthesiol 2003;20:945951.

    • Crossref
    • Search Google Scholar
    • Export Citation

Advertisement