Analgesic effect of bupivacaine eluting porcine small intestinal submucosa (SIS) in ferrets undergoing acute abdominal hernia defect surgery.

BACKGROUND: Porcine small intestinal submucosa (SIS) is used as a biological implant for abdominal wall hernia repair to facilitate wound healing and augment local tissue strength. This prospective, randomized, blinded study evaluated local pain control provided by bupivacaine adsorbed to SIS for repair of acutely created abdominal wall full thickness muscle/fascial defects in ferrets. MATERIALS AND METHODS: Eighteen healthy ferrets were randomly and equally assigned to three groups: (1) SIS with bupivacaine subjected to surgery, (2) SIS with no bupivacaine subjected to surgery, and (3) anesthesia only control group. Ferrets in groups 1 and 2 were anesthetized with butorphanol and sevoflurane for the surgery. Control ferrets were anesthetized in the same fashion for the same duration without surgery. Behavior and pain were evaluated in all ferrets by behavioral observation, algometer, and palpometer measurements, and heart and respiratory rates each obtained before surgery and at various intervals for 96 h after surgery. When pain reached a predetermined threshold, buprenorphine was used as a rescue analgesic. The serum and combined tissue concentrations of bupivacaine were analyzed. RESULTS: Overall, the palpometer testing was better tolerated in the bupivacaine treated SIS group than by the untreated SIS group (P = 0.04). There was an observed physiologically significant difference in algometer and other palpometer readings as well as heart and respiratory rates. All ferrets in the untreated SIS group were rescued while 33% of the SIS-bupivacaine groups were rescued (P < 0.01). Peak serum concentrations of bupivacaine were in the range of 0.7 µg/mL with tissue level below detection levels and no clinical signs of toxicity were observed. CONCLUSIONS: Bupivacaine adsorbed to SIS provided some degree of pain relief over 2-4 days with no clinical adverse effects observed in the ferrets.

Efficacy of oral transmucosal and intravenous administration of buprenorphine before surgery for postoperative analgesia in dogs undergoing ovariohysterectomy.

OBJECTIVE: To compare the efficacy of preoperative administration of buprenorphine (via oral transmucosal [OTM] and IV routes) for postoperative analgesia in dogs undergoing ovariohysterectomy. DESIGN: Prospective, randomized, blinded study. ANIMALS: 18 dogs undergoing routine ovariohysterectomy. PROCEDURES: Dogs were allocated to 3 groups (6 dogs/group) and were assigned to receive buprenorphine (20 µg/kg [9.09 µg/lb], IV; a low dose [20 µg/kg] via OTM administration [LOTM]; or a high dose [120 µg/kg [54.54 µg/lb] via OTM administration [HOTM]) immediately before anesthetic induction with propofol and maintenance with isoflurane for ovariohysterectomy. Postoperative pain was assessed by use of a dynamic interactive pain scale. Dogs were provided rescue analgesia when postoperative pain exceeded a predetermined threshold. Blood samples were collected, and liquid chromatography-electrospray ionization-tandem mass spectrometry was used to determine plasma concentrations of buprenorphine and its metabolites. Data were analyzed with an ANOVA. RESULTS: Body weight, surgical duration, propofol dose, isoflurane concentration, and cardiorespiratory variables did not differ significantly among treatment groups. Number of dogs requiring rescue analgesia did not differ significantly for the HOTM (1/6), IV (3/6), and LOTM (5/6) treatments. Similarly, mean ± SEM duration of analgesia did not differ significantly for the HOTM (20.3 ± 3.7 hours), IV (16.0 ± 3.8 hours), and LOTM (7.3 ± 3.3 hours) treatments. Plasma buprenorphine concentration was ≤ 0.60 ng/mL in 7 of 9 dogs requiring rescue analgesia. CONCLUSIONS AND CLINICAL RELEVANCE: Buprenorphine (HOTM) given immediately before anesthetic induction can be an alternative for postoperative pain management in dogs undergoing ovariohysterectomy.

Design and performance of a pilot-scale constructed wetland treatment system for natural gas storage produced water.

To test the hypothesis that water produced from natural gas storage wells could be treated effectively by constructed wetland treatment systems, a modular pilot-scale system was designed, built, and used for treating gas storage produced waters. Four simulated waters representing the range of contaminant concentrations typical of actual produced waters were treated, and the system's performance was monitored. Freshwater wetland cells planted with Schoenoplectus californicus and Typha latifolia were used to treat fresh and brackish waters. Saline and hypersaline waters were treated by saltwater wetland cells planted with Spartina alterniflora and by reverse osmosis. Effective removal of cadmium, copper, lead, and zinc was achieved by the pilot-scale system. Results suggest that use of specifically designed constructed wetland treatment systems provides a flexible and effective approach for treating gas storage produced waters over a wide range of compositions.

Effect of orally administered tramadol alone or with an intravenously administered opioid on minimum alveolar concentration of sevoflurane in cats.

OBJECTIVE-To compare the effect of oral administration of tramadol alone and with IV administration of butorphanol or hydromorphone on the minimum alveolar concentration (MAC) of sevoflurane in cats. DESIGN-Crossover study. ANIMALS-8 Healthy 3-year-old cats. PROCEDURES-Cats were anesthetized with sevoflurane in 100% oxygen. A standard tail clamp method was used to determine the MAC of sevoflurane following administration of tramadol (8.6 to 11.6 mg/kg [3.6 to 5.3 mg/lb], PO, 5 minutes before induction of anesthesia), butorphanol (0.4 mg/kg [0.18 mg/lb], IV, 30 minutes after induction), hydromorphone (0.1 mg/kg [0.04 mg/lb], IV, 30 minutes after induction), saline (0.9% NaCl) solution (0.05 mL/kg [0.023 mL/lb], IV, 30 minutes after induction), or tramadol with butorphanol or with hydromorphone (same doses and routes of administration). Naloxone (0.02 mg/kg [0.009 mg/lb], IV) was used to reverse the effects of treatments, and MACs were redetermined. RESULTS-Mean +/- SEM MACs for sevoflurane after administration of tramadol (1.48 +/- 0.20%), butorphanol (1.20 +/- 0.16%), hydromorphone (1.76 +/- 0.15%), tramadol and butorphanol (1.48 +/- 0.20%), and tramadol and hydromorphone (1.85 +/- 0.20%) were significantly less than those after administration of saline solution (2.45 +/- 0.22%). Naloxone reversed the reductions in MACs. CONCLUSIONS AND CLINICAL RELEVANCE-Administration of tramadol, butorphanol, or hydromorphone reduced the MAC of sevoflurane in cats, compared with that in cats treated with saline solution. The reductions detected were likely mediated by effects of the drugs on opioid receptors. An additional reduction in MAC was not detected when tramadol was administered with butorphanol or hydromorphone.

Pharmacokinetics of buprenorphine following intravenous and oral transmucosal administration in dogs.

Pharmacokinetic analysis of buprenorphine administered to six healthy dogs via the oral transmucosal (OTM) route at doses of 20 and 120 microg/kg was conducted using liquid chromatography-electrospray ionization-tandem mass spectroscopy (LC-ESI-MS/MS). Bioavailability was 38% plus or minus 12% for the 20 microg/kg dose and 47%+/-16% for the 120 microg/kg dose. Maximum plasma concentrations were similar for buprenorphine doses of 20 microg/kg IV and 120 microg/kg OTM. Sedation and salivation were common side effects, but no bradycardia, apnea, or cardiorespiratory depressive effects were seen. When the two OTM dosing rates were normalized to dose, LC-ESI-MS/MS analysis of buprenorphine and its metabolites detected no significant difference (P>.05), indicating dose proportionality. The results of this study suggest that OTM buprenorphine may be an alternative for pain management in dogs.

A comparison of anesthetic and cardiorespiratory effects of tiletamine-zolazepam-butorphanol and tiletamine-zolazepam-butorphanol- medetomidine in cats.

Using a randomized crossover design, this study compared the anesthetic and cardiorespiratory effects of three intramuscular anesthetic combinations in seven 2-year-old cats: tiletamine-zolazepam (8 mg/kg) and butorphanol (0.2 mg/kg) (TT); tiletamine-zolazepam (3 mg/kg), butorphanol (0.15 mg/kg), and medetomidine (15 microg/kg) (TTD); or the TTD protocol plus atipamezole (75 microg/kg IM) given 20 minutes later to reverse medetomidine. Analgesia was assessed using algometry and needle pricking. All three combinations effectively induced anesthesia suitable for orotracheal intubation within 5 minutes after injection. Hemoglobin oxygen saturation was lower than 90% at least once in all three groups between 5 and 15 minutes after drug administration. Blood pressure and heart and respiratory rates were within normal ranges. Both TT and TTD appeared to be effective injectable anesthetic combinations. TTD provided significantly better analgesia with a longer duration than did TT. Atipamezole administration shortened the duration of analgesia and decreased blood pressure but did not shorten total recovery time.

Campus parking lot stormwater runoff: physicochemical analyses and toxicity tests using Ceriodaphnia dubia and Pimephales promelas.

Campus parking lot stormwater (CPLSW) runoff can mobilize a variety of constituents from vehicular and atmospheric deposition that may pose risks to receiving aquatic systems. The objective of this study was to characterize CPLSW and to discern potential constituents of concern that may affect aquatic biota in receiving systems. Characterization of CPLSW included analyses of metals, oil and grease, and general water chemistry. Toxicity tests were performed using two sentinel species, Ceriodaphniadubia Richard and Pimephales promelas Rafinesque. Metals measured (at their maximum) in CPLSW included 4756microg Al L(-1), 53microg Cu L(-1), 130microg Pb L(-1), and 908microg Zn L(-1). Although CPLSW varied widely in composition and toxicity, constituents of concern included: pH, alkalinity, total suspended solids, biological oxygen demand, chemical oxygen demand, metals, and oil and grease. Fish (P. promelas) were more sensitive to CPLSW than C. dubia with decreased survival in 92% and 15% of the samples (n=13), respectively.

Effects of cyclooxygenase inhibitor treatment on the renal toxicity of cisplatin in rats.

PURPOSE: The purpose of this study was to determine the effects of a nonselective cyclooxygenase (cox) inhibitor and of a selective cox-2 inhibitor on the renal toxicity of cisplatin. METHODS: Cisplatin with or without a cox-1 inhibitor (SC560), a cox-2 inhibitor (SC236), or a nonselective cox inhibitor (piroxicam) was administered to Sprague-Dawley rats. Renal toxicity was assessed by serum creatinine concentration (SCR), urine specific gravity (USG), and histopathologic lesion score (HLS). RESULTS: Acutely, the SCR was significantly higher in rats receiving cisplatin/SC560 (1.62+/-0.34 mg/dl) or cisplatin/piroxicam (2.0+/-0.41 mg/dl) than in rats receiving cisplatin alone (1.09+/-0.40 mg/dl). The apparent increase in SCR in the rats receiving cisplatin/SC236 (1.58+/-0.31) was not significantly different from that of rats receiving cisplatin alone (1.09+/-0.40 mg/dl). No significant differences in USG or HLSs were noted between rats receiving cisplatin alone and cisplatin combined with any cox inhibitor. In a chronic study, no differences in renal toxicity were found between rats treated with cisplatin alone and cisplatin/SC236 or cisplatin/piroxicam. CONCLUSIONS: The acute rise in SCR following cisplatin treatment can be worsened by the addition of cox inhibitors, especially those that inhibit cox-1.