Anesthesia for cesarean section in the dog

The major goal in anesthesia for cesarean section (CS) is to minimize fetal effects of anesthetic drugs in order to minimize fetal respiratory, central nervous system and cardiovascular depression and deliver live, vigorous puppies. Of equal importance is to provide adequate analgesia to the dam and prevent anesthesia-related complications such as hypotension, hypoventilation, hypoxemia, hemorrhage and hypothermia, which will increase morbidity and mortality in both mother and puppies. The physiochemical properties which allow drugs to cross the blood-brain barrier also facilitate crossing of the placenta, therefore the assumption should be made (with very few exceptions) that anes- thetics, analgesics and sedatives/tranquilizers all cross the placenta. Prolonged labor prior to delivery causes maternal physiologic compromise, resulting in fetal depression due to decreased placental perfusion, hypoxemia and acidosis. Maternal and puppy mortality is significantly increased during emergent versus planned CS (1,2). Timing and preparation are extremely impor- tant for puppy survival for both elective and emergency CS, and a thorough understanding of the maternal phy- siologic changes and the potential impact of anesthetic drugs is essential to optimize outcomes for both mother and fetus (Figure 1)

Efficacy of orally administered maropitant citrate in preventing vomiting associated with hydromorphone administration in dogs

Objective—To evaluate the effectiveness of orally administered maropitant citrate in preventing vomiting after hydromorphone hydrochloride administration in dogs. Design—Randomized, blinded, prospective clinical study. Animals—40 dogs with American Society of Anesthesiologists status of I or II, \u3e 6 months of age, and weighing between 24 and 58.2 kg (52.8 and 128.04 lb). Procedures—Dogs were randomly selected to receive maropitant (2.0 to 4.0 mg/kg [0.9 to 1.8 mg/lb]) or placebo (lactose monohydrate) orally 2 hours prior to receiving hydromorphone (0.1 mg/kg [0.045 mg/lb], IM). A blinded observer recorded the occurrence of vomiting or signs of nausea (eg, salivation or lip-licking) during a 30-minute period after hydromorphone administration. Two-tailed Fisher exact tests were used to compare the incidences of vomiting and signs of nausea with or without vomiting between treatment groups. Results—Of the 20 dogs receiving maropitant, none vomited but 12 (60%) developed signs of nausea. Of the 20 dogs receiving placebo, 5 (25%) vomited and 11 (55%) developed signs of nausea; overall, 16 of 20 (80%) dogs in the placebo treatment group vomited or developed signs of nausea. Compared with the effects of placebo, maropitant significantly decreased the incidence of vomiting but not signs of nausea in dogs administered hydromorphone. Conclusions and Clinical Relevance—Among the 40 study dogs, the incidence of vomiting associated with hydromorphone administration was 25%. Oral administration of maropitant prevented vomiting but not signs of nausea associated with hydromorphone administration in dogs

Efficacy of maropitant in preventing vomiting in dogs premedicated with hydromorphone

Objective The goal of this study was to evaluate the effectiveness of maropitant (Cerenia®) in preventing vomiting after premedication with hydromorphone. Study design Randomized, blinded, prospective clinical study. Animals Eighteen dogs ASA I/II admitted for elective orthopedic surgical procedures. The dogs were a mixed population of males and females, purebreds and mixed breeds, 1.0–10.2 years of age, weighing 3–49.5 kg. Methods Dogs were admitted to the study if they were greater than 1 year of age, healthy and scheduled to undergo elective orthopedic surgery. Dogs were randomly selected to receive one of two treatments administered by subcutaneous injection. Group M received 1.0 mg kg−1 of maropitant, Group S received 0.1 mL kg−1 of saline 1 hour prior to anesthesia premedication. Dogs were premedicated with 0.1 mg kg−1 of hydromorphone intramuscularly. A blinded observer documented the presence of vomiting, retching and/or signs of nausea for 30 minutes after premedication. Results All dogs in S vomited (6/9), retched (1/9) or displayed signs of nausea (2/9). None (0/9) of the dogs in M vomited, retched or displayed signs of nausea. Dogs in M had significantly fewer incidences of vomiting (p=0.0090), vomiting and retching (p=0.0023) and vomiting, retching and nausea (p\u3c0.0001) when compared to S. Conclusion and clinical relevance Maropitant prevents vomiting, retching and nausea associated with intramuscular hydromorphone administration in dogs

Anticholinergic Drugs in Dogs

Can I use anticholinergic drugs with dexmedetomidine in dogs

Effect of dosing interval on efficacy of maropitant for prevention of hydromorphone-induced vomiting and signs of nausea in dogs

Objective—To evaluate the effect of dosing interval on the efficacy of maropitant for prevention of opioid-induced vomiting and signs of nausea in dogs. Design—Randomized prospective clinical study. Animals—50 client-owned dogs that underwent an elective surgical procedure. Procedures—Dogs were randomly assigned to receive maropitant (1 mg/kg [0.45 mg/lb], SC), then hydromorphone (0.1 mg/kg [0.045 mg/lb], IM) at 0 (simultaneously; group 0; n = 10), 15 (group 15; 10), 30 (group 30; 10), 45 (group 45; 10), or 60 (group 60; 10) minutes later. Dogs were monitored for vomiting and signs of nausea for 30 minutes after hydromorphone administration. A historical control group of similar dogs (n = 9) that were administered hydromorphone (0.1 mg/kg, IM) but not maropitant served as the referent for comparison purposes. Results—Vomiting was recorded for 6 dogs in group 0 and 2 dogs in group 15. Signs of nausea were recorded for 10 dogs in group 0, 9 dogs in group 15, 8 dogs in group 30, 6 dogs in group 45, and 1 dog in group 60. Compared with dogs in the historical control group, vomiting was significantly decreased and prevented when maropitant was administered 15 and 30 minutes, respectively, before hydromorphone; signs of nausea were significantly decreased only when maropitant was administered 60 minutes before hydromorphone. Conclusions and Clinical Relevance—Results indicated that vomiting was significantly decreased and then prevented when maropitant was administered to dogs 15 and 30 minutes before hydromorphone. However, signs of nausea were significantly decreased only when the dosing interval was 60 minutes

Spotlight on the perioperative use of maropitant citrate

Neurokinin-1 (NK-1) receptors are present in both the central nervous system and peripheral tissues. Substance P (SP) is the major ligand and is involved in multiple processes including pain transmission, vasodilation, modulation of the inflammatory response, as well as the sensory neuronal transmission involved in stress, anxiety, and emesis. The involvement of NK-1 and SP in the vomiting reflex has led to the development of NK-1 antagonists to prevent and treat vomiting in human and veterinary medicine. Maropitant is a potent, selective neurokinin (NK-1) receptor antagonist that blocks the pharmacologic action of SP in the central nervous system. Maropitant is available in both an injectable and tablet formulation and approved for use in dogs and cats for the treatment and prevention of vomiting from a variety of clinical causes and motion sickness. When administered prior to anesthetic premedication, maropitant prevents or significantly decreases the incidence of opioid-induced vomiting and signs of nausea in dogs and cats. Maropitant has also been shown to improve postoperative return to feeding and food intake in dogs. The minimum alveolar concentration of sevoflurage is decreased in both dogs and cats by maropitant, indicating a potential role as an adjunct analgesic, especially for visceral pain. This article will review the background information and literature, including clinical recommendations with respect to the perioperative use of maropitant in canine and feline veterinary patients

Assessment of Dog Owner Concern Regarding Peri-operative Nausea and Vomiting and Willingness to Pay for Anti-emetic Treatment

Objective: The objective of this study was to assess dog owners\u27 concern regarding peri-operative nausea and vomiting, and their willingness to pay for treatment. Design: Descriptive survey. Sample: A survey was administered to 104 dog owning clients with non-emergent surgical (52) or non-surgical (52) appointments at a University teaching hospital. Procedure: Descriptive statistics were calculated. A Mann-Whitney U test was used to detect differences between clients expecting their pet to undergo elective general anesthesia and those that did not. A Spearman\u27s Rank Co-efficient was used to correlate predictive data. Results: Ninety-seven (93%) dog owners had at least some worry regarding their dog experiencing nausea associated with opioid analgesics and anesthesia, with 39/104 (37.5%) moderately to very worried. Forty-one owners (39%) would definitely and 59/104 (56.7%) would likely choose treatment to decrease or prevent signs of nausea. Ninety-four owners (90.4%) had at least some worry regarding vomiting, and 48/104 (46%) indicated they were moderately to very worried. Fifty-three owners (51.4%) would definitely and 49/103 (47.6%) would likely choose treatment to prevent vomiting. The median and mean amount owners were willing to pay was 50 and 76.47 USD, respectively. Ninety-five (91.3%) were likely or very likely to opt for treatment if required to arrive 1 h earlier for their appointment. There was no correlation between age, income, or owner\u27s PONV experience with likelihood of choosing treatment but there was a significant positive correlation with the owner\u27s level of education. Conclusion: Canine owners are concerned with their pets experiencing nausea and vomiting in relation to opioid analgesics and anesthesia and are willing to pay and stay the required time for effective treatment

A comparison of the effects of carbon dioxide and medical air for abdominal insufflation on respiratory parameters in xylazine-sedated sheep undergoing laparoscopic artificial insemination

AIMS: To determine if abdominal insufflation with medical air will improve oxygenation and ventilation parameters when compared to insufflation with CO2 in xylazine-sedated sheep undergoing laparoscopic artificial insemination (AI). METHODS: Forty-seven sheep underwent oestrus synchronisation and were fasted for 24 hours prior to laparoscopic AI. Each animal was randomised to receive either CO2 or medical air for abdominal insufflation. An auricular arterial catheter was placed and utilised for serial blood sampling. Respiratory rates (RR) and arterial blood samples were collected at baseline, after xylazine (0.1 mg/kg I/V) sedation, 2 minutes after Trendelenburg positioning, 5 minutes after abdominal insufflation, and 10 minutes after being returned to a standing position. Blood samples were collected in heparinised syringes, stored on ice, and analysed for arterial pH, partial pressure of arterial O2 (PaO2), and CO2 (PaCO2). The number of ewes conceiving to AI was also determined. RESULTS: Repeated measures ANOVA demonstrated temporal effects on RR, PaO2, PaCO2 and arterial pH during the laparoscopic AI procedure (p0.01). No sheep experienced hypercapnia (PaCO2\u3e50 mmHg) or acidaemia (pH CONCLUSIONS AND CLINICAL RELEVANCE: There were no statistical or clinical differences in RR, PaO2, PaCO2, pH, or conception to AI when comparing the effects of CO2 and medical air as abdominal insufflation gases. None of the sheep experienced hypercapnia or acidaemic, yet 42% (19/45) of sheep developed clinical hypoxaemia, with a higher percentage of ewes in the CO2 group developing hypoxaemia than in the medical air group. Based on the overall analysis, medical air could be utilised as a comparable alternative for abdominal insufflation during laparoscopic AI procedures

The effect of intravenous maropitant on blood pressure in healthy awake and anesthetized dogs

Objective To evaluate the effects of intravenous maropitant on arterial blood pressure in healthy dogs while awake and under general anesthesia. Design Experimental crossover study. Animals Eight healthy adult Beagle dogs. Procedure All dogs received maropitant (1 mg kg-1) intravenously under the following conditions: 1) awake with non-invasive blood pressure monitoring (AwNIBP), 2) awake with invasive blood pressure monitoring (AwIBP), 3) premedication with acepromazine (0.005 mg kg-1) and butorphanol (0.2 mg kg-1) intramuscularly followed by propofol induction and isoflurane anesthesia (GaAB), and 4) premedication with dexmedetomidine (0.005 mg kg-1) and butorphanol (0.2 mg kg-1) intramuscularly followed by propofol induction and isoflurane anesthesia (GaDB). Heart rate (HR), systolic (SAP), diastolic (DAP), and mean blood pressures (MAP) were recorded before injection of maropitant (baseline), during the first 60 seconds of injection, during the second 60 seconds of injection, at the completion of injection and every 2 minutes post injection for 18 minutes. The data were compared over time using a Generalized Linear Model with mixed effects and then with simple effect comparison with Bonferroni adjustments (p \u3c0.05). Results There were significant decreases from baseline in SAP in the GaAB group (p \u3c 0.01) and in MAP and DAP in the AwIBP and GaAB (p \u3c 0.001) groups during injection. A significant decrease in SAP (p \u3c 0.05), DAP (p \u3c 0.05), and MAP (p \u3c 0.05) occurred at 16 minutes post injection in GaDB group. There was also a significant increase in HR in the AwIBP group (p \u3c 0.01) during injection. Clinically significant hypotension occurred in the GaAB group with a mean MAP at 54 ± 6 mmHg during injection. Conclusion Intravenous maropitant administration significantly decreases arterial blood pressure during inhalant anesthesia. Patients premedicated with acepromazine prior to isoflurane anesthesia may develop clinically significant hypotension

Quantum Mechanics of Successive Measurements with Arbitrary Meter Coupling

We study successive measurements of two observables using von Neumann's measurement model. The two-pointer correlation for arbitrary coupling strength allows retrieving the initial system state. We recover Luders rule, the Wigner formula and the Kirkwood-Dirac distribution in the appropriate limits of the coupling strength