OBJECTIVE To evaluate agreement between observers with different training and experience for assessment of postoperative pain and sedation in cats by use of a dynamic and interactive visual analog scale (DIVAS) and for assessment of postoperative pain in the same cats with a multidimensional composite pain scale (MCPS).
PROCEDURES Cats received 1 of 3 preoperative treatments: bupivacaine, IP; meloxicam, SC with saline (0.9% NaCl) solution, IP, (positive control); or saline solution only, IP (negative control). All cats received premedication with buprenorphine prior to general anesthesia. An experienced observer (observer 1; male; native language, Spanish) used scales in English, and an inexperienced observer (observer 2; female; native language, French) used scales in French to assess signs of sedation and pain. Rescue analgesia was administered according to MCPS scoring by observer 1. Mean pain and sedation scores per treatment and time point, proportions of cats in each group with MCPS scores necessitating rescue analgesia, and mean MCPS scores assigned at the time of rescue analgesia were compared between observers. Agreement was assessed by intraclass correlation coefficient determination. Percentage disagreement between observers on the need for rescue analgesia was calculated.
RESULTS Interobserver agreements for pain scores were good, and that for sedation scores was fair. On the basis of observer 1's MCPS scores, a greater proportion of cats in the negative control group received rescue analgesia than in the bupivacaine or positive control groups. Scores from observer 2 indicated a greater proportion of cats in the negative control group than in the positive control group required rescue analgesia but identified no significant difference between the negative control and bupivacaine groups for this variable. Overall, disagreement regarding need for rescue analgesia was identified for 22 of 360 (6.1%) paired observations.
CONCLUSIONS AND CLINICAL RELEVANCE Interobserver differences in assessing pain can lead to different conclusions regarding treatment effectiveness.
OBJECTIVE To evaluate pharmacokinetics of bupivacaine after IP administration to cats undergoing ovariohysterectomy.
ANIMALS 8 healthy cats.
PROCEDURES Anesthesia was induced with propofol and maintained with isoflurane. Buprenorphine (0.02 mg/kg, IV) and meloxicam (0.2 mg/kg, SC) were administered. A 20-gauge catheter was inserted into a jugular vein for blood sample collection. A ventral midline incision was made, and a solution of 0.5% bupivacaine (2 mg/kg) diluted with an equal volume of saline (0.9% NaCl) solution (final concentration, 0.25% bupivacaine) was injected into the peritoneal space over the right and left ovarian pedicles and caudal aspect of the uterus before ovariohysterectomy. Cats were monitored for signs of bupivacaine toxicosis. Venous blood samples (2 mL) were collected before (time 0) and 2, 5, 10, 15, 20, 30, 60, 120, and 240 minutes after bupivacaine administration. Plasma bupivacaine concentrations were determined with a liquid chromatography–tandem mass spectrometry method. Pharmacokinetic parameters were determined by data plotting followed by analysis with a noncompartmental model.
RESULTS No signs of bupivacaine toxicosis were observed. Maximum bupivacaine plasma concentration was 1,030 ± 497.5 ng/mL at a mean ± SD value of 30 ± 24 minutes after administration. Mean elimination half-life was 4.79 ± 2.7 hours. Mean clearance indexed by bioavailability and volume of distribution indexed by bioavailability were 0.35 ± 0.18 L•h/kg and 2.10 ± 0.84 L/kg, respectively.
CONCLUSIONS AND CLINICAL RELEVANCE Intraperitoneal administration of bupivacaine resulted in concentrations that did not cause observable toxicosis. Studies to investigate analgesic effects for this technique in cats are warranted.
To assess the feasibility of a canister-free negative-pressure wound therapy (NPWT) device (PICO™ 1.6, Smith & Nephew Medical Ltd) and evaluate its effect on early phases of wound healing in canine experimental cutaneous wounds.
5 adult spayed female research Beagles.
In a pilot experimental study, 1 full-thickness 2-cm X 2-cm cutaneous wound was surgically created on each hemithorax in each dog. Wounds were treated with either NPWT or a conventional wound dressing for 14 days. Bandage changes and wound evaluations were done at 7 time points. First macroscopic appearance of granulation tissue, smoothness of granulation tissue, and percentages of wound contraction and epithelialization were compared between treatments. Wounds were sampled at 3 time points for histopathologic analyses and semiquantitative scoring.
NPWT dressings were well tolerated by all dogs. Complete seal of the dressing required the application of adhesive spray, and maintenance of the vacuum lessened over time. Self-limiting skin irritations appeared in all dogs and hampered the attainment of negative pressure. Granulation tissue developed faster and was more abundant in control wounds. Wound contraction, epithelialization, and fibroblast proliferation were greater in control wounds at the end of the study.
This canister-free NPWT device is feasible but problematic in maintaining a vacuum, requiring frequent revisions of the dressing. Further studies are necessary to evaluate the effect of this device on early phases of wound healing. Its benefits in wound healing remain unknown.