Total Anesthesia Time Research Articles

Patterns of Sevoflurane use in a Children's Hospital: The Effects of a Simple Educational Intervention

We conducted a prospective observational study of sevoflurane use over a four-week period at our tertiary referral children's hospital. Sevoflurane vaporisers were weighed before and after all general anaesthesia sessions and anaesthesia time intervals recorded. Midway through the audit, the initial findings were presented to the department with a brief reminder of ways to reduce sevoflurane use. These included recommendations for fresh gas flows and use of alternative agents during maintenance. Sevoflurane use then continued to be audited over a further two-week period. Anaesthesia in induction rooms accounted for 60% of total sevoflurane use but involved only 15% of total general anaesthetic time. Thus sevoflurane was used eight times faster in the induction rooms when compared to operating theatres. There was a 53% reduction in the rate of use of sevoflurane after the educational intervention, with an 87% reduction in in-theatre use and a 31% reduction in induction room use. This represents a potential saving of $108,120 per annum in our institution. Workloads before and after the educational intervention were comparable. A more complete cost benefit analysis of this initiative would include the costs of alternative agents and any clinical disadvantages incurred and would be seen in the context of the overall health budget. This was beyond the scope of this project. Clinicians can be relatively complacent about financial accountability. In this study, a simple educational reminder halved sevoflurane use in the short term. This study suggests that specific reminders or recommendations about anaesthetic technique in the induction rooms may be indicated.

The effect of inotropic and/or vasopressor support on postoperative survival following equine colic surgery

ObjectiveTo determine the effects of dobutamine and phenylephrine on intra- and postoperative survival in horses undergoing emergency abdominal surgery. Study designRetrospective case analysis. AnimalsA total of 637 client-owned horses undergoing colic surgery. MethodsClinical details of horses admitted for colic surgery were recorded on a computer database. Information collected included history, clinical variables observed before surgery, anaesthesia and surgical details, and postoperative survival and morbidity rates. Details of specific importance for this study were those recorded during anaesthesia, in particular the duration of dobutamine and phenylephrine administration, separately and combined, and total anaesthesia time. Two outcomes were considered: 1) intra-operative death, i.e. death between time of pre-anaesthetic medication and recovery from anaesthesia (defined as horse walking from recovery box); and 2) all deaths, i.e. death at any time after induction of anaesthesia. The definition of ‘death’ included euthanasia. Univariable and multivariable statistical analyses were performed to evaluate the associations between dobutamine and/or phenylephrine use and these two outcomes. ResultsResults from univariable analyses suggested that dobutamine administration was not significantly associated with increased intra- or postoperative mortality. Phenylephrine administration showed univariable association with intra- and postoperative death. However, in multivariable models adjusted for the effects of heart rate and packed cell volume at admission, the phenylephrine effect was not significantly associated with intra-operative, or other types of death. ConclusionThis study provides no evidence to suggest that dobutamine or phenylephrine administration is associated with altered survival rates during or after colic surgery. Clinical relevanceOur study supports previous work, suggesting that pre-existing cardiovascular status is an important prognostic determinant in equine colic cases. It provides no evidence that dobutamine or phenylephrine administration is associated with survival.

Comparison of isoflurane and sevoflurane for short-term anesthesia in piglets

ObjectivesTo compare isoflurane (ISO) and sevoflurane (SEVO) short-term anesthesia in piglets during castration. Study designProspective, randomized study. AnimalsA total of 114 male piglets aged 6–10 days, body weight 1.3–5.0 kg. MethodsPiglets were randomly selected from multiple litters and randomly assigned to being anesthetized with ISO or SEVO prior to castration. To calculate appropriate doses for induction and maintenance of anesthesia, a square root of time model was used, with calculations based on metabolic size and attainment of 1.3× minimum alveolar concentration. The equipotent target alveolar concentration of ISO was 1.82% and for SEVO 4.03%. After doses were calculated, a table listing piglet weights and agent requirements was produced. Anesthetics were delivered via liquid anesthetic injection into a previously developed rebreathing inhaler that was filled with oxygen prior to use. Piglets were anesthetized, castrated and allowed to recover prior to return to the sow. Times for induction, recovery and total time to standing were recorded, and end-tidal carbon dioxide (Pe′CO2) tensions were measured by capnography immediately after mask removal. Each response variable was analyzed in sas using the Proc Mixed procedure, with piglet weight and days of age as covariates. Castration problems and mortality were assessed relative to unanesthetized littermates. ResultsThere were no statistically significant differences in age, weight or total anesthetic time between the anesthetics. Induction time was shorter, recovery time longer, and Pe′CO2 lower with ISO. No morbidity or mortality was associated with either group. Conclusion and clinical relevanceIsoflurane and SEVO, delivered in a novel inhaler, provided economical, safe, rapid anesthetic induction and maintenance. Optimal conditions were provided for castration and recoveries were brief and smooth. Statistically significant differences in times would be of minor clinical importance. The cost of anesthesia was much less with ISO than with SEVO.

Minimally invasive endoscopic port‐access™ intracardiac surgery with one lung ventilation: impact on gas exchange and anaesthesia resources

Minimally invasive endoscopic intracardiac surgery including one lung ventilation has been proposed to decrease surgical trauma but its impact on oxygenation and resource consumption has not been reported. We compared effects on gas exchange, induction, total anaesthesia time, staffing costs, and complications in 42 consecutive patients to a matched group undergoing similar surgery conventionally. Use of endoscopic compared to conventional surgery evoked a decrease in the P(a)o(2)/F(I)o(2) ratio (mean (SD) 24.1 (14.9) vs 48.9 (14) kPa, p < 0.05) following termination of bypass with one lung ventilation (10 patients showed a P(a)o(2)/F(i)o(2) below 13.3 kPa (100 mmHg)). There was also an increase of anaesthesia induction time (47 (13) vs 31 (9) min, p < 0.05), and an increase by 156 min of total anaesthesia time (474 (89) vs 321 (69) min, p < 0.05). Anaesthetist staffing costs increased by 300%. Thus, minimally invasive endoscopic intracardiac surgery consumes many more anaesthesia resources than conventional surgery and can result in hypoxaemia, but overall can be considered feasible provided that extensive continuous monitoring is employed.

Differences in need for hemodynamic support in horses anesthetized with sevoflurane as compared to isoflurane

Objective To study whether hemodynamic function in horses, particularly mean arterial blood pressure (MAP), is better maintained with sevoflurane than isoflurane, thus requiring less pharmacological support.Study design Prospective randomized clinical investigation.Animals Thirty-nine racehorses undergoing arthroscopy in lateral recumbency.Methods Horses were assigned to receive either isoflurane (n = 20) or sevoflurane (n = 19) at 0.9–1.0 minimum alveolar concentration (MAC) for maintenance of anesthesia. Besides routine clinical monitoring, cardiac output (CO) was measured by lithium dilution. Hemodynamic support was prescribed as follows: when MAP decreased to <70 mmHg, patients were to receive infusion of 0.1% dobutamine, which was to be discontinued at MAP >85 mmHg or heart rate >60 beats minute−1. Statistical analysis of results, given as mean ± SD, included a clustered regression approach.Results Average inhalant anesthetic time [91 ± 35 (isoflurane group) versus 97 ± 26 minutes (sevoflurane group)] and dose (in MAC multiples), volume of crystalloid solution infused, and cardiopulmonary parameters including CO were similar in the two groups, except heart rate was 8% higher in isoflurane than sevoflurane horses (p < 0.05). To maintain MAP >70 mmHg, isoflurane horses received dobutamine over a significantly longer period (55 ± 26 versus 28 ± 21% of total anesthetic time, p < 0.01) and at a 51% higher dose than sevoflurane horses (41 ± 19 versus 27 ± 23 μg kg−1 MAC hour−1; p = 0.058), with 14/20 isoflurane animals and only 9/19 sevoflurane horses being infused with dobutamine at >30 μg kg−1 MAC hour−1 (p < 0.05). Dobutamine infusion rates were consistently lower in the sevoflurane as compared to the isoflurane group, with differences reaching significance level during the 0–30 minutes (p < 0.01) and 61–90 minutes periods (p < 0.05).Conclusions and clinical relevance Horses under sevoflurane anesthesia may require less pharmacological support in the form of dobutamine than isoflurane-anesthetized horses. This could be due to less suppression of vasomotor tone.

R7 Theatre time trials: an efficiency study of paediatric dentistry lists

Objective: To determine usage of theatre time during Paediatric Dentistry operating lists.Design: Prospective cross‐sectional study.Setting: Operating theatres, Sheffield Children's Hospital.Sample and methods: A standard data collection sheet was employed to record the following information: session (am/pm); type and time of anaesthetic induction; medical status of patient; dental procedures undertaken and total operating time; start and finish time of list and reason for any delays. Each session allocation was 210 minutes.Results: Data were collected for 36 consecutive Paediatric Dentistry lists over a 4‐month period, involving 95 patients. A further eight patients were cancelled on admission. Only one list started on time, the remaining lists had a mean delay of 16 minutes (SD = 12.9; range = 1–51). Delays were mainly attributed to porter shortages, ward delays and late arrival of the anaesthetist. The mean time taken to anaesthetise a patient was 18 minutes (SD = 7.7; range = 5–42) with no significant differences according to type of intubation or patient's medical status (P &gt; 0.05, ANOVA). Mean operating time was 32 minutes (SD = 19.6; range = 5–128) with significant time differences according to procedures undertaken and the patient's medical condition (P &lt; 0.05, ANOVA). Six lists ran overtime by a mean 28.7 minutes (SD = 30.2; range = 3–85) and 25 lists finished early by a mean 56.4 minutes (SD = 41.2; range = 1–170). Overall, a mean 60 minutes (SD = 42.0; range = 1–184) are ‘wasted’ during every theatre list, with total anaesthetic and operating time accounting for only 71% of the actual session allocation.Conclusions: This study has revealed significant inefficiencies within hospital systems, which may adversely affect productivity.

Infraclavicular Brachial Plexus Block Versus Humeral Approach: Comparison of Anesthetic Time and Efficacy

Most upper arm regional anesthesia techniques are successful and differences in efficacy should not dictate the choice of technique. In the present study, we compared humeral block (HB) and infraclavicular brachial plexus block (ICB) using anesthetic time (i.e., duration of the procedure + onset time) as the primary outcome measure. The block was successful when a complete sensory block was obtained in the four major nerves of the arm, and the time to complete block was recorded. Patients undergoing orthopedic surgery of the upper limb were included in a prospective randomized study and received ICB (group I, n = 60 patients) or HB (group H, n = 60 patients). Total anesthetic time was 19.5 min (95% confidence interval [CI], 17.4-21.6 min) for ICB and 20.8 min (95% CI, 18.7--22.9 min) for HB (not significant). Time to perform the block was 4.5 min (95% CI, 4-5 min) for ICB and 9.8 min (95% CI, 8.9--10.7 min) for HB (P < 0.05). The onset time was 15 min (95% CI, 13-17 min) for ICB and 11 min (95% CI, 9--13 min) for HB (P < 0.05). The success rate was 92% for ICB and 95% for HB (not significant). One self-limited vascular puncture was made in each group. HB had a faster onset time but ICB using a double-stimulation technique was faster to perform. Anesthetic time was similar with the two techniques. We have compared infraclavicular brachial plexus block (ICB) with humeral block. Efficacy and anesthetic time were not significantly different, although time to perform the block was shorter with the ICB.

Duration, complications, stress, and pain of open ovariohysterectomy versus a simple method of laparoscopic-assisted ovariohysterectomy in dogs

To describe a simple method of laparoscopic-assisted ovariohysterectomy (LAOHE) and compare duration of surgery, complications, measures of surgical stress, and postoperative pain with open ovariohysterectomy (OHE) in dogs. Randomized, prospective clinical trial. 20 healthy sexually intact female dogs weighing >10 kg (22 lb). Dogs were randomly allocated to receive conventional OHE or LAOHE. Intraoperative complications, anesthetic complications, total anesthesia time, and total surgery time were recorded. Serum cortisol and glucose concentrations, temperature, heart rate, and respiratory rate were measured preoperatively and 1, 2, 4, 6, 12, and 24 hours postoperatively. Pain scores were assigned by a nonblinded observer at 1, 2, 4, 6, 12, and 24 hours postoperatively. Duration of surgery, pain scores, objective measures of surgical stress, anesthetic complications, and surgical complications were compared between OHE and LAOHE. Age, weight, PCV, and duration of surgery did not differ between treatment groups. Nine of 10 dogs in the OHE group required additional pain medication on the basis of pain scores, whereas none of the dogs in the LAOHE group did. Blood glucose concentrations were significantly increased from preoperative concentrations in the OHE group at 1, 2, 4, and 6 hours postoperatively and at 1 hour postoperatively in the LAOHE group. Cortisol concentrations were significantly increased at 1 and 2 hours postoperatively in the OHE group. LAOHE caused less pain and surgical stress than OHE and may be more appropriate for an outpatient setting.

Development and Validation of a Perioperative Satisfaction Questionnaire

Satisfaction is considered a valuable measure of outcome of healthcare processes. Only a few anesthesia-related validated questionnaires are reported. Because their scope is restricted to specific clinical contexts, their use remains limited. The objective of the current study was to develop and validate a self-reported questionnaire, Evaluation du Vecu de l'Anesthesie Generale (EVAN-G), assessing the satisfaction of the perioperative period surrounding general anesthesia. Development of the EVAN-G questionnaire comprised a phase of item generation and a phase of psychometric validation. The patient sample was generated to be proportionally matched to the population of patients undergoing general anesthesia in France. The structure of the questionnaire was identified studying interitem, item-dimension, and interdimension correlations and factor analyses. Data were concurrently gathered to assess external validity. The discriminant validity was determined by comparison of scores across well known patient groups. Reliability was assessed by computation of Cronbach alpha coefficients and by test-retest. Eight hundred seventy-four patients were recruited in eight anesthesia departments. The EVAN-G includes 26 items; six specific scores and one global index score are available. Correlations between EVAN-G scores and other concurrent measures supported convergent validity. The EVAN-G correlated poorly with age, American Society of Anesthesiologists physical status, total anesthesia time, and number of previous anesthesias. Significantly higher satisfaction was reported by patients older than 65 yr, belonging to the laryngeal mask group. Reliability and reproducibility were shown. The EVAN-G adds important information oriented toward patients' perceptions. The authors' approach provides a novel, valid, and reliable tool that may be used in anesthesia practice.

A Randomized Study Comparing Combined Spinal Epidural or General Anesthesia for Renal Transplant Surgery

Introduction The appropriate anesthesia for renal transplantation requires minimal toxicity for patients and for the transplanted organ, as well as sufficient pain relief and maintenance of vital functions. The aim of this study was to determine how the anesthetic technique influences the outcome in patients after renal transplantation in terms of preoperative and intraoperative hemodynamic changes and blood gas changes. Methods Fifty adult patients undergoing renal transplantation were randomly divided into two groups receiving standardized general anesthesia or combined spinal and epidural anesthesia. Results Demographically both groups were similar. Total anesthesia time (202 ± 53 vs 186 ± 37 minutes) and surgical time (191 ± 52 vs 162 ± 31 minutes) did not differ between the groups. The heart rate and systolic blood pressure values of the groups as measured before induction and 5, 15, 20, 30, as well as 60 minutes thereafter did not differ between the groups. Neither the frequency of bradycardia (four vs two) nor of hypotension (six vs four) during anesthesia differed between regional versus general anesthesia groups. Conclusion Regional is an important alternative to general anesthesia during renal transplantation surgery in adult patients.

The effects of spontaneous and mechanical ventilation on central cardiovascular function and peripheral perfusion during isoflurane anaesthesia in horses

ObjectiveTo compare the effects of spontaneous breathing and mechanical ventilation on haemodynamic variables, including muscle and skin perfusion measured with laser Doppler flowmetery, in horses anaesthetized with isoflurane. Study designProspective controlled study. AnimalsTen warm-blood trotter horses (five males, five females). Mean mass was 492 kg (range 420–584 kg) and mean age was 5 years (range 4–8 years). Materials and methodsAfter pre-anaesthetic medication with detomidine (10 μg kg−1) anaesthesia was induced with intravenous (IV) guaifenesin and thiopental (4–5 mg kg−1 IV) and maintained using isoflurane in oxygen. The horses were positioned in dorsal recumbency. In five animals breathing was initially spontaneous (SB) while the lungs of the other five were ventilated mechanically using intermittent positive pressure ventilation (IPPV). Total anaesthesia time was 4 hours with the ventilatory mode changed after 2 hours. During anaesthesia, heart rate (HR) cardiac output ( Q˙t) stroke volume (SV) systemic arterial blood pressures (sAP), and pulmonary arterial pressure (pAP) were recorded. Peripheral perfusion was measured in the semimembranosus and gluteal muscles and on the tail skin using laser Doppler flowmetry. Arterial (a) and mixed venous ( v¯) blood gases, pH, haemoglobin concentration [Hb], haematocrit (Hct), plasma lactate concentration and muscle temperature were measured. Oxygen content, venous admixture ( Q˙s/ Q˙t) oxygen delivery (DO2) and oxygen consumption ( V˙O2) were calculated. ResultsDuring mechanical ventilation, HR, sAP, pAP, Q˙t, SV, Q˙s/ Q˙t and PaCO2 were lower and PaO2 was higher compared with spontaneous breathing. There were no differences between the modes of ventilation in the level of perfusion, DO2, V˙O2, [Hb], (Hct), or plasma lactate concentration. After the change from IPPV to SB, left semimembranosus muscle and skin perfusion improved, while muscle perfusion tended to decrease when SB was changed to IPPV. Low-frequency flow motion was seen twice as frequently during IPPV compared with SB. ConclusionsMechanical ventilation impaired cardiovascular function compared with SB in horses during isoflurane anaesthesia. Muscle and skin perfusion changes occurred with ventilation, although further studies are needed to elucidate the underlying mechanisms.

Postoperative Alopecia in Five Patients after Treatment of Aneurysm Rupture with a Guglielmi Detachable Coil: Pressure Alopecia, Radiation Induced, or Both?

Postoperative pressure alopecia is an uncommon complication of long anesthetic surgical procedures, typically affecting the occiput and resulting from pressure-induced tissue hypoxia. Generally, it develops after procedures of long duration, of more than four hours. Most alopecia is transient, but a few cases are permanent. Guglielmi detachable coil (GDC) coiling is a procedure guided by fluoroscopy that fills an intracranial aneurysm. Our cases were characterized by an unusual distribution of alopecia, short duration of procedure, and radiation exposure. The alopecic lesions of our patients were located on the temporal scalp as well as the occipital scalp. The total time of anesthesia was relatively short, two to three hours. During the procedure, these patients were exposed to ionizing radiation (over 2Gy). These cases are different from previous reports in that the duration of the procedure was short, the temporal scalp was affected in addition to the occipital scalp, and the pathology occurred after GDC coiling.

This Month in Anesthesiology

This Month in Anesthesiology

Percutaneous repair of abdominal aortic aneurysm

Objective Percutaneous treatment of an abdominal aortic aneurysm (AAA) is feasible, but is associated with a unique set of risks. A comparison of Excluder endograft deployment with femoral artery cutdown (FAC) versus percutaneous femoral access (PFA) for treatment of infrarenal AAA was undertaken. Methods A single-institution, controlled, retrospective review was carried out in patients who underwent either bilateral FAC or bilateral PFA for endovascular repair of infrarenal AAA with the Gore bifurcated Excluder endograft between March 1999 and November 2003. To November 2000, 35 patients underwent bilateral FAC; since then, 47 patients have undergone bilateral PFA. All have been followed up for at least 30 days. Results Mean AAA size was 5.7 cm in the FAC group and 6.0 cm in the PFA group. During hospitalization there were six access-related complications in the FAC group; three required early surgical intervention. In the PFA group nine perioperative access-related complications occurred, all consisting of either hemorrhage or arterial occlusion; seven required additional intervention, and were recognized and ameliorated while the patient was still in the operating room. At 30-day follow-up there were no additional access-related complications in the PFA group. There were eight other access-related complications in eight additional patients who underwent FAC. In patients undergoing bilateral PFA total operative time was shorter (PFA 139 minutes vs FAC 169 minutes; P = .002), total in-room anesthesia time was less (PFA 201 minutes vs FAC 225 minutes; P < .008), and use of general anesthesia was reduced ( P < .001). No significant differences were observed between groups with respect to estimated blood loss (PFA 459 mL vs FAC 389 mL; P = .851). Conclusion Complete percutaneous treatment of AAA may have some advantages over open femoral artery access, but it is not free from risk. Percutaneous treatment of AAA can be completed successfully in most patients, but should be performed at an institution where conversion to an open procedure can be completed expeditiously if necessary.

The potential for bronchoscopic lung volume reduction using bronchial prostheses. A pilot study

The potential for bronchoscopic lung volume reduction using bronchial prostheses. A pilot study

Laparoscopic versus Open Appendectomy: Analysis of Systemic Acute-Phase Responses in a Prospective Randomized Study

Background: The aim of this randomized study was to assess the postoperative acute-phase response of laparoscopic appendectomy and to compare its results with those of open appendectomy. Methods: 81 patients admitted to our emergency service with acute appendicitis were randomized to laparoscopic and open appendectomy groups. Preoperative and postoperative values for acute-phase reactants of white blood-cell count, erythrocyte sedimentation rate, C-reactive protein, and fibrinogen in blood samples were recorded. We also collected data concerning age and gender, total anesthesia time, operation time, time of oral intake, and hospital stay time of the study groups. Results: Although total anesthesia time was significantly longer in the laparoscopic group than in the open group (p < 0.05), there was no significant difference in operation time between both groups (p > 0.05). We found oral intake and hospital stay time to be significantly lower in the laparoscopic appendectomy group than in the open appendectomy group (p < 0.05). The acute-phase reactant levels were significantly lower in the laparoscopic appendectomy group than in the open appendectomy group (p < 0.05). Conclusion: Laparoscopic appendectomy causes relatively less trauma and less tissue damage than the open procedure and appears to have distinct advantages over open appendectomy.

A comparison of a triple-injection axillary brachial plexus block with the humeral approach

Background and Objectives: This prospective, randomized, and single-blind study compared effectiveness, performance, onset, and total anesthetic time and complications of the multiple axillary block (median, radial, and musculocutaneous nerves) with the humeral approach. Methods: One hundred patients were randomly assigned to 2 groups. In group A (axillary) median, radial, and musculocutaneus nerves were located by a nerve stimulator and injections were made. In group H (humeral) all 4 terminal nerves of the brachial plexus were located and injections were made. A total of 40 mL mepivacaine of 1% was used. Results: Complete sensory block of all 6 peripheral nerves occurred in 94% and 79% of patients in groups A and H, respectively ( P < .05). The time to perform the block was shorter in group A (8 ± 4 minutes v 11 ± 4 minutes; P < .001); onset time was shorter in group A (16 ± 8 minutes v 21 ± 9 minutes; P < .05); total anesthetic time was shorter in group A (24 ± 8 minutes v 33 ± 10 minutes; P < .0001). Complete motor block was greater in group A (88% v 66%; P < .05). More vascular punctures occurred in group A (22% v 8%, P < .05). Conclusion: The triple-injection axillary block was more effective than the humeral approach as it was associated with more cases of sensory and complete motor block and gave shorter performance and onset times.

Epidemiologic evaluation of postoperative wound infection in clean-contaminated wounds: A retrospective study of 239 dogs and cats.

To evaluate risk factors for development of postoperative wound infections in clean-contaminated wounds. Retrospective clinical study. Two hundred thirty-nine dogs and cats that had clean-contaminated surgical procedures. Records of animals that had a clean-contaminated surgical procedure and were prospectively monitored for development of postoperative wound infection were reviewed. Prospective data included signalment, nutritional status, body weight, duration of surgery, surgical procedures, wound classification, surgical site clip time before surgery, hypotension during surgery, the presence of an active distant infection, endocrinopathy, administration of an immunosuppressive agent, administration of antibiotics, and the type of antibiotic used. Additional retrieved data included total anesthesia time, temperature variables, blood loss, and suture material used. Intact males (P =.008) and animals with concurrent endocrinopathy (P =.008) were at a higher risk of development of postoperative wound infection. Total surgery time (P =.02) and total anesthesia time (P =.04) were longer in animals that developed postoperative wound infection. No other factors were statistically significant. Intact males and animals with a concurrent endocrinopathy were at higher risk of postoperative wound infection after clean-contaminated surgical procedures. Time under anesthesia and duration of surgery should be minimized to reduce the risk of wound infection in clean-contaminated surgical procedures.

Use of a hydro-pool system to recover horses after general anesthesia: 60 cases.

To report complications observed using a hydro-pool recovery system after general anesthesia in horses. Retrospective study. Sixty horses. Retrospective review of the medical records and quality of recovery from anesthesia of 60 horses that had surgical or diagnostic procedures under general anesthesia. Mean total anesthesia time was 182 minutes (range, 25 to 390 minutes). Mean time in the hydro-pool was 108 minutes (range, 20 to 270 minutes). One horse that had bilateral rear limb extensor weakness while recovering in a padded recovery stall was moved to the hydro-pool and maintained for 12 hours. Ten horses developed some pulmonary edema; in 3 horses, the signs of pulmonary edema were severe; and 1 horse died from related complications. One horse developed septic arthritis of an operated stifle joint, and 2 horses developed incisional infections. Two horses incurred multiple skin abrasions on the distal aspect of their limbs during violent attempts to leave the pool. A hydro-pool system was useful for recovering horses from general anesthesia when difficult recoveries were anticipated because of the horse's injury, size, demeanor, duration of anesthesia, or risk of further injury. Recovery using the hydro-pool was more time and labor intensive than a standard stall recovery. Pulmonary edema that required treatment was a serious complication that occurred in 17% of the horses. Careful closure of the skin with cyanoacrylate glue and pressure from bandages were used to prevent postoperative incisional infections. A hydro-pool system is a useful method for recovering horses from general anesthesia when difficult recoveries are anticipated.

A comparison of thromboembolic prophylaxis in gynecologic oncology patients

The objective of this study was to compare two methods of thromboembolic prophylaxis: sequential compression devices alone (SCDs) vs. SCDs with subcutaneous low-dose unfractionated heparin (UH). A retrospective cohort study was conducted of 168 patients who had undergone surgery for suspected gynecological malignancies. These patients were examined for associated risk factors, method of prophylaxis, and incidence of clinically significant thromboembolic events. Of these patients, 94 (56%) received perioperative and postoperative sequential compression devices alone, while 74 (44%) received both SCDs and subcutaneous low-dose UH. The postoperative course of these patients, while in the hospital and after discharge, was followed for clinically evident thromboembolic complications. Univariate and multivariate analyses were performed. The two groups were comparable in terms of most risk factors, including age, stage, height, weight, body surface area, estimated blood loss, total anesthesia time, and nodal disease. Six of 94 patients (6.4%) in the SCDs group suffered from venous thromboembolism, while four of 74 patients (5.4%) who received both SCDs and low-dose UH had a thromboembolic event (χ2P= 0.79). There was no difference in postoperative changes in platelet counts between the two groups. Heparin added additional cost, 105 extra minutes of nursing time per patient per admission, and additional pain for the patient. In conclusion, the addition of subcutaneous low-dose unfractionated heparin to SCDs for prophylaxis against deep venous thrombosis in women undergoing surgery for gynecologic malignancies does not improve the outcome. Adding heparin was more expensive, time consuming, and painful. Heparin should not be used with SCDs unless an additional benefit can be demonstrated in a randomized controlled trial.