Cardiopulmonary Effects of Laparoscopic Ovariectomy of Variable Duration in Cats

Laparoscopic versus Open Ovariectomy in Bitches: Changes in Cardiorespiratory Values, Blood Parameters, and Sevoflurane Requirements Associated with the Surgical Technique

The aim of this study was to examine the cardiorespiratory and blood changes associated with pneumoperitoneum (PNP) in laparoscopic ovariectomy (LAP Ove), as well as sevoflurane requirements, comparing them to those determined in open surgery (LPT Ove). The study was performed in 16 bitches submitted to LAP or LPT Ove. The cardiorespiratory and end-tidal sevoflurane concentration values were recorded as follows: at the beginning of surgery (T1), after the right ovary resection (T2), after the left ovary resection (T3), and after surgical closure (T4). Blood samples were taken before and after PNP. Among the cardiorespiratory parameters, no differences were observed in the values of end-tidal CO2, minute volume, and heart rate. In the LAP Ove group, a significant increase in inspiratory pressures and a decreased compliance were identified at T2 and T3. Significant higher arterial pressure values were observed in both groups at T2 and T3, with this increase especially marked at T2 in the LPT Ove group. Sevoflurane requirements were significantly higher in the LPT group during ovarian resection. Finally, in terms of the hematochemical parameters, statistical differences were recorded between pre- and post-operative assessments, but not between both surgical groups. The pathophysiological effects associated with PNP seemed to be transient and well-tolerated by healthy dogs.

Pre-surgical hand preparation in veterinary practice

The objective of this paper is to review the evidence for different methods of surgical hand preparation applicable to veterinary practice. Surgical hand preparation is an essential step in performing surgery as a veterinarian. Recommended protocols and products for surgical hand preparation have varied since its inception in the late 1800s. Many factors must be considered when assessing the efficacy, safety, and users' compliance with any available product. Traditional scrub methods employing chlorhexidine gluconate or povidone-iodine have been compared to alcohol-based rub protocols with respect to immediate and prolonged efficacy, safety, compliance, requirements for theatre furniture, cost and water usage. Although much of the comparative data has been generated in human medical facilities, extrapolation of the data to veterinary surgery is appropriate. Considerations for veterinary practice are specifically discussed. Overall, the benefits of alcohol-based rubs indicate that this should be the preferred method of pre-surgical hand preparation for veterinarians in all types of practice.

Randomized, controlled clinical trial to assess the effect of antimicrobial-impregnated suture on the incidence of surgical site infections in dogs and cats

OBJECTIVE

To evaluate the prophylactic efficacy of triclosan-coated (TC) suture in preventing surgical site infections (SSIs) in dogs and cats undergoing surgical procedures.

ANIMALS

862 animals (794 dogs and 68 cats).

PROCEDURES

Incidences of SSI of surgical wounds closed with TC suture and surgical wounds closed with non-TC suture occurring between the time of surgery and 1 month postoperatively were compared. Animals were randomly assigned to TC or non-TC suture groups. When TC suture was assigned, all suture available as TC material was used rather than non-TC suture. Presence of an SSI was determined by an owner questionnaire or direct examination.

RESULTS

Overall, 50 of 862 (5.8%) animals developed SSIs. Incidence of SSI was 6% (24/428) in the non-TC suture group and 6% (26/434) in the TC suture group. No significant difference was found in the incidence of SSI between groups. No significant difference was detected in the incidence of incisional problems (eg, redness, dehiscence, and seroma formation) between animals in which TC suture was used and those in which non-TC suture was used. On multivariable analysis, other factors were associated with increased SSI rates, including an incision length > 10 cm, surgery performed by the soft tissue surgery department, and anesthesia duration of > 240 minutes.

CONCLUSIONS AND CLINICAL RELEVANCE

No significant difference in incidence of SSI was detected between animals undergoing surgical procedures performed with non-TC versus TC suture.

Pressure-Volume Curve during Capnoperitoneum in Cats

Laparoscopy is a growing field in veterinary medicine, although guidelines are lacking. The objective of this study was to evaluate the pressure-volume curve during capnoperitoneum in cats. A total of 59 female cats were scheduled for routine laparoscopy. Pressure and volume data were recorded and processed, and the yield point of the curve was calculated using a method based on a capacitor discharging function. For the remaining 40 cats, a linear-like pressure-volume curve was observed until a yield point with a mean cutoff pressure (COP) of 6.44 ± 1.7 mmHg (SD) (range, 2.72-13.00 mmHg) and a mean cutoff volume (COV) of 387 ± 144.35 mL (SD) (range, 178.84-968.43 mL) was reached. The mean mL/kg CO₂ value in cats was 208 ± 34.69 mL/kg (range, 100.00-288.46 mL/kg). The COV correlated with COP and body weight but not with body condition score (BCS). COP correlated only with the COV. This study suggests that feline patients have a pressure-volume curve similar to that of canine patients, and the same pressure limit recommendations can be used for both species. After a yield point of 6.44 mmHg is reached, the increment in volume decreases exponentially as the intra-abdominal pressure (IAP) increases.

Adverse events and outcomes in dogs with appendicular osteosarcoma treated with limb amputation and a single subcutaneous infusion of carboplatin

OBJECTIVE

To evaluate adverse events and outcomes in dogs with appendicular osteosarcoma treated with limb amputation followed by a single SC infusion of carboplatin.

ANIMALS

45 client-owned dogs with appendicular osteosarcoma treated with limb amputation and SC infusion of carboplatin between January 1, 2006, and January 15, 2017.

PROCEDURES

Medical records were reviewed, and data collected included signalment, tumor location, treatment, results of clinicopathologic analyses and diagnostic imaging, adverse effects of chemotherapy, metastasis-free interval, survival time, and communications with owners and referring veterinarians. Findings were evaluated with the Kaplan-Meier survival analysis and Mantel-Haenszel log-rank test.

RESULTS

45 dogs were identified that met the inclusion criteria (12 of the 45 dogs had been reported in a previous case series). No dogs had pulmonary metastases detectable by CT or radiography before treatment. All dogs completed the protocol as planned. Median survival time (MST) was 196 days; metastasis-free interval was 197 days. Three of the 45 (7%) dogs required hospitalization for gastrointestinal signs related to chemotherapy. There were no chemotherapy-related deaths.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that although treatment with SC infusion of carboplatin was well tolerated, the MST for dogs in the present study was similar to reported MSTs in dogs with appendicular osteosarcoma treated with limb amputation alone and was in the lower range of historically reported survival times for dogs receiving IV adjunctive chemotherapy. Therefore, we could not recommend this protocol of SC infusion of carboplatin but recommended that protocols with IV administration of carboplatin be used instead.

Investigation of the in vitro antimicrobial activity of triclosan-coated suture material on bacteria commonly isolated from wounds in dogs

OBJECTIVE

To investigate in vitro effects of triclosan coating of suture materials on the growth of clinically relevant bacteria isolated from wounds in dogs.

SAMPLE

6 types of suture material and 10 isolates each of methicillin-susceptible Staphylococcus pseudintermedius, methicillin-resistant S pseudintermedius, Escherichia coli, and AmpC β-lactamase and extended-spectrum β-lactamase-producing E coli from clinical wound infections.

PROCEDURES

Isolates were cultured on Mueller-Hinton agar with 3 types of triclosan-coated suture, uncoated counterparts of the same suture types, and positive and negative controls. Zones of inhibition (ZOIs) were measured after overnight incubation. Sustained antimicrobial activity assays were performed with susceptible isolates. The ZOI measurements and durations of sustained antimicrobial activity were compared among suture types and isolates by statistical methods. Suture surface characteristics and bacterial adherence were evaluated qualitatively with scanning electron microscopy.

RESULTS

ZOIs were generated only by triclosan-coated materials; triclosan-coated suture had sustained antimicrobial activity (inhibition) for 3 to 29 days against all tested pathogens. The ZOIs around triclosan-coated suture were significantly greater for S pseudintermedius isolates than for E coli isolates. Bacterial adherence to uncoated polyglactin-910 was greatest, followed by triclosan-coated polyglactin-910, and then uncoated monofilament sutures, with least adherence to coated monofilament sutures.

CONCLUSIONS AND CLINICAL RELEVANCE

Surface characteristics of suture materials may be as important or more important than triclosan coating for microbial inhibition; however, triclosan coating appeared to affect bacterial adherence for multifilament sutures. Triclosan-coated, particularly monofilament, sutures inhibited pathogens commonly isolated from wounds of dogs, including multidrug-resistant bacteria. Further studies are required to assess clinical efficacy of triclosan-coated suture materials in vivo.

Pneumoperitoneum in Veterinary Laparoscopy: A Review

Objective: To review the effects of carbon dioxide pneumoperitoneum during laparoscopy, evaluate alternative techniques to establishing a working space and compare this to current recommendations in veterinary surgery. Study Design: Literature review. Sample Population: 92 peer-reviewed articles. Methods: An electronic database search identified human and veterinary literature on the effects of pneumoperitoneum (carbon dioxide insufflation for laparoscopy) and alternatives with a focus on adaptation to the veterinary field. Results: Laparoscopy is the preferred surgical approach for many human and several veterinary procedures due to the lower morbidity associated with minimally invasive surgery, compared to laparotomy. The establishment of a pneumoperitoneum with a gas most commonly facilitates a working space. Carbon dioxide is the preferred gas for insufflation as it is inert, inexpensive, noncombustible, colorless, excreted by the lungs and highly soluble in water. Detrimental side effects such as acidosis, hypercapnia, reduction in cardiac output, decreased pulmonary compliance, hypothermia and post-operative pain have been associated with a pneumoperitoneum established with CO2 insufflation. As such alternatives have been suggested such as helium, nitrous oxide, warmed and humidified carbon dioxide and gasless laparoscopy. None of these alternatives have found a consistent benefit over standard carbon dioxide insufflation. Conclusions: The physiologic alterations seen with CO2 insufflation at the current recommended intra-abdominal pressures are mild and of transient duration. Clinical Significance: The current recommendations in veterinary laparoscopy for a pneumoperitoneum using carbon dioxide appear to be safe and effective.

Cardiopulmonary changes induced by retroperitoneal insufflation in healthy dogs in sternal recumbency with the abdomen unsupported

This study assessed the effects of retroperitoneal carbon dioxide (CO₂) insufflation on cardiopulmonary variables and intra-abdominal pressure (IAP) in mechanically ventilated dogs in sternal recumbency with the abdomen unsupported, following placement of a positioning kit and towels under the pectoral and pelvic regions. General anesthesia was induced in eight healthy adult male Beagles. A Swan-Ganz catheter was placed in the pulmonary artery via the jugular vein for cardiac output measurements. A Foley urethral catheter was placed to monitor transvesical IAP. A 10 mm balloon blunt-tip trocar was inserted into the retroperitoneal space. With a fixed respiratory rate and tidal volume by mechanical ventilation, insufflation pressure was sequentially increased from 0 to 10 mmHg in 5 mmHg increments, followed by desufflation. All variables were measured before insufflation, 5 min after the establishment of each insufflation pressure, and after desufflation. At 10 mmHg, the IAP was nearly equal to insufflation pressure. Cardiopulmonary function was not compromised at any point, although the cardiac index (CI), heart rate, mean arterial pressure (MAP), and mean pulmonary arterial pressure increased within normal ranges. End-tidal CO₂ concentration, arterial CO₂ partial pressure, and oxygen delivery index (DO₂I) increased, whereas pH decreased, at 10 mmHg. CI, MAP, and DO₂I did not recover to baseline after decompression. Thus, retroperitoneal CO₂ insufflation up to 10 mmHg is well tolerated by mechanically ventilated dogs positioned in sternal recumbency with the abdomen unsupported, although sympathetic changes may occur with an insufflation pressure increase.

Scalpel blade contamination and risk of postoperative surgical site infection following abdominal incisions in dogs

Objective

This prospective observation sought to determine if scalpel blades used for abdominal skin incisions in dogs are a significant source of bacterial contamination, and if these blades should be changed prior to use in deeper dissection.

Results

Scalpel blades were swabbed for culture prior to skin incision as a control, and then again following ventral midline abdominal skin incision in a total of 75 dogs. Culture and sensitivity results were compared with review of medical records for any evidence of pre- or postoperative incisional surgical site infection/inflammation (SSI). Of the 75 blades swabbed after skin incision, only 2 (2.7%) had positive culture results. Of the 69 patients that survived to suture removal, there was evidence of SSI in 6 patients (8.7%), only one of which had a positive scalpel blade culture (16.7%). Neither the use of postoperative antibiotics nor positive scalpel blade culture results were good predictors of whether a patient would develop a SSI. Results of this pilot study suggest that there is no bacteriological evidence to support the use of a separate blade for deep dissection in routine surgical procedures.

Electronic supplementary material

The online version of this article (10.1186/s13104-019-4494-7) contains supplementary material, which is available to authorized users.

Effect of pneumoperitoneum with warmed humidified or standard-temperature carbon dioxide during laparoscopy on core body temperature, cardiorespiratory and thromboelastography variables, systemic inflammation, peritoneal response, and signs of postoperative pain in healthy mature dogs

OBJECTIVE To evaluate effects of pneumoperitoneum created with warmed humidified CO₂ (WHCO₂) during laparoscopy on core body temperature, cardiorespiratory and thromboelastography variables, systemic inflammation, peritoneal response, and signs of postoperative pain in healthy mature dogs. ANIMALS 6 mature purpose-bred dogs. PROCEDURES In a randomized crossover study, each dog was anesthetized twice, and pneumoperitoneum was created with standard-temperature CO₂ (STCO₂; 22°C and 0% relative humidity) and WHCO₂ (37°C and 98% relative humidity). Data were collected during each procedure, including core body temperature, cardiorespiratory and thromboelastography variables, and inflammatory biomarkers. Peritoneal biopsy specimens were collected and evaluated with scanning electron microscopy. Dogs were assessed for signs of postoperative pain. RESULTS Mean core body temperature was significantly lower (35.2°C; 95% confidence interval, 34.5° to 35.8°C) with WHCO₂ than with STCO₂ (35.9°C; 95% confidence interval, 35.3° to 36.6°C) across all time points. Cardiac index increased during the procedure for both treatments but was not significantly different between treatments. Thromboelastography variables did not differ significantly between treatments as indicated by the coagulation index. Subjective evaluation of peritoneal biopsy specimens revealed mesothelial cell loss with STCO₂. There was no significant difference in circulating C-reactive protein or interleukin-6 concentrations. There was a significant increase in the number of postoperative pain scores > 0 for the WHCO₂ treatment versus the STCO₂ treatment. CONCLUSIONS AND CLINICAL RELEVANCE Analysis of these data suggested that effects on evaluated variables attributable to the use of WHCO₂ for creating pneumoperitoneum in healthy mature dogs undergoing laparoscopy did not differ from effects for the use of STCO₂.

Postoperative pain and short-term complications after two elective sterilization techniques: ovariohysterectomy or ovariectomy in cats

BACKGROUND

Surgical sterilization of cats is one of the most commonly performed procedures in veterinary practice and it can be accomplished by two different techniques: ovariohysterectomy (OVH) or ovariectomy (OVE). Although there is an apparent preference for OVH in United States and Canada, OVE seems to be the standard of care in many European countries due to its advantages, such as a smaller surgical incision and potentially less complications associated with surgical manipulation of the uterus. The aim of this randomized, blind, prospective study was to compare postoperative pain and short-term complications in cats undergoing ovariohysterectomy or ovariectomy.

METHODS

Twenty female cats were randomly assigned into two groups (OVH, n = 10 and OVE, n = 10). Pain was assessed prior to surgery (baseline) and 1, 2, 4, 8 12 and 24 h after the procedure using pain and sedation scales, physiologic parameters and blood glucose levels. Short-term complications were evaluated in the early postoperative period and reassessed at day 7 and day 10.

RESULTS

Changes in cardiovascular parameters were not clinically relevant, however cats in OVH group had higher heart rates at T1 h compared with baseline (p = 0.0184). Blood glucose levels in OVH group were also higher at T1 h compared with baseline (p = 0.0135) and with OVE group (p = 0.0218). Surgical time was higher in OVH group (p = 0.0115). Even though no significant differences in pain scores were observed between groups or time points, cats in OVH group had greater need for rescue analgesia compared with OVE (2/10 and 0/10, respectively). Complications were not observed in any cat during surgery, at days 7 and 10 postoperatively or at discharge.

CONCLUSIONS

Both surgical techniques promoted similar intensity of postoperative pain in cats and there were no short-term complications throughout the study's evaluation period. Therefore, both techniques may be indicated for surgical sterilization of cats, according to the surgeon's preference and expertise. Cats that underwent ovariectomy did not require rescue analgesia and surgical time was shorter in that group.

Comparison of culture methodology for the detection of methicillin-resistant Staphylococcus pseudintermedius in clinical specimens collected from dogs

Methicillin-resistant Staphylococcus pseudintermedius (MRSP) has emerged as a major pathogen in dogs and has been implicated as a hospital-acquired pathogen in veterinary hospitals. We attempted to determine if selective culture methods will detect more MRSP when compared to the traditional culture methods in clinical samples from dogs in Atlantic Canada with a high risk for MRSP infection. Each sample was tested using 4 culture methods: traditional culture; mannitol salt agar with 2 μg/mL of oxacillin (MSAox); enrichment broth (EB) with MSAox; and EB with traditional culture. Detection of penicillin-binding protein 2', via latex agglutination, was used as a confirmatory test for oxacillin resistance. We analyzed 741 samples from 556 dogs between February 2013 and April 2014. The prevalence of MRSP in samples detected by any method was estimated at 13.4% (95% CI: 11.1-16.0%). When the prevalence of MRSP was determined according to culture method, EB with MSAox detected the highest prevalence (11.2% [9.1-13.7%]), followed by EB with traditional (10.8% [8.8-13.2%]), traditional (10.1% [8.1-12.5%]), and MSAox (8.9% [7.1-11.2%]). The prevalence using the traditional culture method did not differ significantly from any of the 3 selective culture methods. Culture with MSAox detected significantly fewer MRSP than either of the EB methods. The addition of EB to current methodology is recommended, particularly for patients considered at high risk for MRSP infection.

Taurolidine susceptibility of methicillin-resistant Staphylococcus pseudintermedius isolates

Infections caused by methicillin-resistant Staphylococcus pseudintermedius (MRSP) can be challenging to treat because they are often resistant to many other antimicrobial agents. We assessed the susceptibility of 29 MRSP isolates from dogs to taurolidine in vitro. There was no growth at 0.12% taurolidine and light growth at 0.06% for all isolates. Taurolidine was reliable at inhibiting growth of MRSP at a concentration of 1,200 µg/mL.

Direct Repeat Unit (dru) Typing of Methicillin-Resistant Staphylococcus pseudintermedius from Dogs and Cats

Methicillin-resistant Staphylococcus pseudintermedius (MRSP) has emerged in a remarkable manner as an important problem in dogs and cats. However, limited molecular epidemiological information is available. The aims of this study were to apply direct repeat unit (dru) typing in a large collection of well-characterized MRSP isolates and to use dru typing to analyze a collection of previously uncharacterized MRSP isolates. Two collections of MRSP isolates from dogs and cats were included in this study. The first collection comprised 115 well-characterized MRSP isolates from North America and Europe. The data for these isolates included multilocus sequence typing (MLST) and staphylococcal protein A gene (spa) typing results as well as SmaI macrorestriction patterns after pulsed-field gel electrophoresis (PFGE). The second collection was a convenience sample of 360 isolates from North America. The dru region was amplified by PCR, sequenced, and analyzed. For the first collection, the discriminatory indices of the typing methods were calculated. All isolates were successfully dru typed. The discriminatory power for dru typing (D = 0.423) was comparable to that of spa typing (D = 0.445) and of MLST (D = 0.417) in the first collection. Occasionally, dru typing was able to further discriminate between isolates that shared the same spa type. Among all 475 isolates, 26 different dru types were identified, with 2 predominant types (dt9a and dt11a) among 349 (73.4%) isolates. The results of this study underline that dru typing is a useful tool for MRSP typing, being an objective, standardized, sequence-based method that is relatively cost-efficient and easy to perform.

Perioperative risk factors for surgical site infection in tibial tuberosity advancement: 224 stifles

OBJECTIVE

To examine perioperative factors affecting surgical site infection (SSI) rate following tibial tuberosity advancement (TTA).

STUDY DESIGN

Retrospective case series.

SAMPLE POPULATION

224 stifles in 186 dogs.

METHODS

Medical records of dogs that underwent TTA in a single institution were reviewed. Information on signalment, anaesthetic and surgical parameters, as well as occurrence of SSI was recorded. Dogs were followed for a minimum of three months postoperatively. The association between perioperative factors and SSI was assessed using Chi-squared tests and binary logistic regression.

RESULTS

The prevalence of SSI was 5.3% (12/224 TTA). Surgical time (p = 0.02) and anaesthesia time (p = 0.03) were significantly associated with SSI. For every minute increase in surgical time and anaesthesia time, the likelihood of developing SSI increased by seven percent and four percent respectively. The use of postoperative antimicrobial therapy was not significantly associated with lower SSI (p = 0.719). Implants were removed in 1.3% of cases (3/224 TTA).

CONCLUSIONS

The findings of this study suggest that increased surgical and anaesthesia times are significant risk factors for SSI in TTA, and that there is no evidence that postoperative prophylactic antimicrobial therapy is associated with SSI rate.