Successful cardiopulmonary resuscitation and use of short-term mechanical ventilation following inadvertent ketamine overdose in a cat

Objective: To describe the clinical manifestations and successful outcome following an inadvertent overdose of ketamine to a cat. Case summary: A 4‐year‐old neutered male domestic shorthair cat was evaluated for a urethral obstruction. Because of an inadvertent miscalculation of ketamine, 20 times the intended dose was administered intravenously, which resulted in cardiopulmonary arrest. Cardiopulmonary‐cerebral resuscitation was successful, and short‐term mechanical ventilation, fluids and intensive monitoring were utilized to achieve full recovery and subsequent discharge of the animal. New or unique information provided: Ketamine is a common anesthetic agent used in cats that is considered to have a wide therapeutic index and minimal cardiopulmonary depressant effects at recommended doses. Successful management of inadvertent ketamine overdose has been reported in children, but not in cats. Prompt CPCR and short‐term mechanical ventilation may be necessary to treat a significant ketamine overdose. In cats, yohimbine may act as a partial antagonist of ketamine.     

The prevalence and significance of hyperglycemia in hospitalized cats

Objective – To report the prevalence of hyperglycemia in cats admitted to a veterinary hospital and to determine if hyperglycemic cats had increased morbidity and mortality when compared with normoglycemic cats.
Design – Retrospective clinical study.
Setting – Community-based referral hospital.
Animals – Nondiabetic cats admitted to the hospital.
Interventions – None.
Measurements and Main Results – The medical records of nondiabetic cats admitted to the hospital over a 1-year period were reviewed. There were 182 cats that met the criteria for inclusion in the study. Information obtained included signalment, length of hospitalization, initial and highest blood glucose measurement, diagnosis, treatment, and final disposition. Sixty-three percent of cats (116/182) were hyperglycemic at the time of presentation. Total incidence of hyperglycemia at any point during hospitalization was 64% (118/182). No association was found between hyperglycemia either initially or at any point during the hospitalization and mortality. However, a significant association was documented between the presence of hyperglycemia and increased length of hospitalization (LOH) ( P =0.04). The duration of LOH was also significantly associated with the degree of hyperglycemia ( P =0.01). A number of different disease processes were represented in the study population. However, the number of cats in each disease category was small and no association could be found between any of them and blood glucose affecting mortality and morbidity.
Conclusion – The prevalence of hyperglycemia in feline patients admitted to a primary referral hospital was 64%. Cats with hyperglycemia had a longer LOH when compared with normoglycemic cats; however, presence of hyperglycemia did not impact mortality in this population of cats.     

Comparison of the neuromuscular blocking effects of cisatracurium during isoflurane or propofol anesthesia in dogs

ObjectiveTo compare the neuromuscular blocking effects of cisatracurium during isoflurane versus propofol anesthesia in dogs.Study designProspective, randomized study.AnimalsA total of 20 healthy, client-owned dogs (16 females, four males) weighing 12.5–22 kg and aged 1–8 years.MethodsDogs undergoing elective surgery were randomized in equal numbers to an isoflurane (ISO) or propofol (PPF) group. Other drugs used during anesthesia were equal between groups. Single-twitch (ST) stimulation was used to monitor neuromuscular response. After recording the baseline ST (T0), cumulative doses of cisatracurium (0.05 mg kg^–1) were administered intravenously until ST/T0 ≤5%. Effective doses 50 (ED₅₀) and 95 (ED₉₅) of cisatracurium in each group were calculated from group dose-response curves. Recovery of ST (TR) was defined as spontaneous recovery of ST to 80–120% of T0 remaining stable for 2 minutes. The ST after each dose of cisatracurium, duration 25% (time after the last dose until 25% recovery of TR), recovery index (time to recovery from 25% to 75% of TR) and duration to TR (time after the last dose until recovery of TR) were recorded.ResultsIncremental doses of cisatracurium, median (range), were 2 (1–3) in ISO and 4 (2–5) in PPF to achieve ≥95% depression of ST/T0 (p < 0.01). ED₅₀ and ED₉₅ were 20 μg kg^–1 and 117 μg kg^–1 in ISO and 128 μg kg^–1 and 167 μg kg^–1 in PPF, respectively. The duration 25%, recovery index and duration to TR, median (range), were longer in ISO [22.6 (10.3–24.3), 5.3 (3.0–7.8) and 36.1 (20.1–49.7) minutes, respectively] than in PPF [10.2 (6.8–16.5), 3.0 (2.0–3.8) and 17.7 (14.2–28.7) minutes, respectively] (p < 0.01).Conclusions and clinical relevanceCisatracurium-induced neuromuscular blockade was significantly enhanced and prolonged by isoflurane compared with propofol.     

Comparison of ultrasonic Doppler flow monitor,oscillometric, and direct arterial blood pressure measurements in ill dogs

Objective – To compare blood pressure measurements obtained via ultrasonic Doppler flow monitor (DOP) and 2 oscillometric noninvasive blood pressure monitors (CAR and PAS) to invasive blood pressure (IBP) in hospitalized, conscious dogs with a range of blood pressures. Design – Prospective clinical study. Setting – University teaching hospital. Animals – Eleven client‐owned dogs aged between 4 months and 11.5 years (median 6 y), and weighing between 5.8 and 37.5 kg (median 30.2 kg). Interventions – Blood pressure measurement. Measurements and Main Results – Three consecutive measurements of systolic, diastolic, and mean arterial pressure (MAP) were recorded for each of the 3 indirect devices (only systolic for DOP), along with concurrent IBP measurements. The data were categorized into 3 groups: hypotensive (direct MAP<80 mm Hg), normotensive (80 mm Hg≤direct MAP≥100 mm Hg), and hypertensive (direct MAP>100 mm Hg). Each indirect method was compared with the corresponding direct arterial pressure using the Bland‐Altman method. Within the hypotensive group, each indirect method overestimated the corresponding IBP. Within the normotensive group all indirect systolic measurements and the PAS diastolic measurements underestimated the corresponding IBP. The remaining indirect measurements overestimated the corresponding IBP. Within the hypertensive group, DOP and CAR systolic measurements underestimated the corresponding IBP, and the remaining indirect measurements overestimated the corresponding IBP. In hypertensive dogs oscillometric systolic measurements were more accurate than MAP. In hypotensive dogs MAP measurements were more accurate than systolic measurements. All indirect measurements were most accurate in hypertensive dogs. Conclusions – The noninvasive blood pressure monitors in our study did not meet the validation standards set in human medicine. However, CAR diastolic and MAP measurements within the normotensive group, CAR MAP measurements within the hypertensive group, and PAS diastolic measurements in all groups were close to these standards. All indirect measurements showed greater bias during hypotension. Precision was poorer for all indirect systolic measurements than for MAP.     

Lithium dilution cardiac output and oxygen delivery in conscious dogs with systemic inflammatory response syndrome

Objective: Compare cardiac index (CI) and oxygen delivery index (DO₂I) in conscious, critically ill dogs to control dogs; evaluate the association of CI and DO₂I with outcome. Design: Prospective non‐randomized clinical study. Setting: Veterinary teaching hospital. Animals: Eighteen client‐owned dogs with systemic inflammatory response syndrome (SIRS) and 8 healthy control dogs. Measurements and Main Results: CI of dogs with SIRS was measured using lithium dilution at times 0, 4, 8, 16, and 24 hours. Data collected included physical exam, arterial blood gas (ABG) and hemoximetry. CI of control dogs was measured 3 times with 1 measurement of ABG. Mean CI ± SE in SIRS patients was 3.32 ± 0.95 L/min/m²; lower than controls at 4.18 ± 0.22 L/min/m² (P<0.001). Mean DO₂I ± SE in SIRS patients was 412.91 ± 156.67 mL O₂/min/m²; lower than controls at 785.24 ± 45.99 mL O₂/min/m² (P<0.001). There was no difference in CI (P=0.49) or DO₂I (P=0.51) for dogs that survived to discharge versus those that did not. There was no difference in mean CI (P=0.97) or DO₂I (P=0.50) of survivors versus non‐survivors for 28‐day survival. Survivors had lower blood glucose (P=0.03) and serum lactate concentrations (P=0.04) than non‐survivors. Conclusions: CI and DO₂I in conscious dogs with SIRS were lower than control dogs, which differs from theories that dogs with SIRS are in a high cardiac output state. CI and DO₂I were not significantly different between survivors and non‐survivors. Similar to previous studies, lactate and glucose concentrations of survivors were lower than non‐survivors.     

Causes of cardiopulmonary arrest, resuscitation management, and functional outcome in dogs and cats surviving cardiopulmonary arrest

Objective: To describe the functional outcome of canine and feline survivors of cardiopulmonary arrest (CPA) and the clinical characteristics surrounding their resuscitation. Design: Retrospective study. Setting: Veterinary teaching hospital. Animals: Client‐owned dogs (15) and cats (3) with CPA. Interventions: None. Measurements and main results: Eighteen animals were identified to have survived to discharge following CPA. Cardiopulmonary arrest was associated with anesthesia with or without pre‐existing disease in 10 animals, cardiovascular collapse in 5 animals, and chronic disease with an imposed stress in 3 animals. All CPAs were witnessed in the hospital. The most common initial rhythm at CPA was asystole (72%). Return of spontaneous circulation (ROSC) was achieved in less than 15 minutes from the onset of cardiopulmonary cerebral resuscitation (CPCR) in all animals. No animals had a recurrence of CPA after the initial CPA. Animals were of a wide range of ages (0.5–16 years) and breeds. Two animals were neurologically abnormal at discharge, one of which was normal at 2 months following CPA. Conclusions: A good functional recovery after CPCR was documented in the small number of CPA survivors presented in this study. This may be due to the reversible nature of their inciting cause of CPA, early detections of CPA (‘witnessed’), and/or the animal's underlying normal health status.     

Original Study: Determination of normal intra‐abdominal pressure using urinary bladder catheterization in clinically healthy cats

Objective – To establish a reference interval for intra‐abdominal pressure (IAP) measured by urinary bladder catheterization in normal cats and determine if IAP is affected by observer variation, volume of saline instillation before measurement, or subject variables of gender, positioning, body condition score, and sedation. Design – Prospective experimental study. Setting – Private referral center. Animals – Twenty healthy adult cats. Interventions – Sedation with butorphanol, midazolam, and propofol for catheterization of the urinary bladder and measurement of IAP. Measurements and Main Results – A 5‐Fr red rubber urinary catheter was placed under sedation, and IAP was determined using a water manometer with the cats in right lateral and sternal recumbency. Three readings were taken in each position by 2 observers. The cats were allowed to recover with the urinary catheter in place, and IAP was measured in each cat while they were awake in right lateral and sternal recumbency. Conclusions – In this population of clinically healthy cats, median (interquartile range) IAP taken over all measurements was 7.00 cm H₂O (5.23–8.83 cm H₂O). There was no statistical difference between observers or subject gender. Factors associated with a statistically significant increase in IAP were right lateral compared with sternal recumbency (P=0.002), being awake compared with sedated (P<0.001), having a higher body condition score (P=0.01 and 0.001), instillation of a higher volume of saline into the bladder for measurement (P<0.001), and struggling during awake measurements (P<0.001).     

A comparison of total calcium,corrected calcium,and ionized calcium concentrations as indicators of calcium homeostasis among hypoalbuminemic dogs requiring intensive care

Objective – (1) To evaluate whether total calcium (tCa) correlates with ionized calcium (iCa) in hypoalbuminemic dogs; (2) to evaluate whether calcium adjusted for albumin (Alb), or total protein (TP), or both accurately predict iCa concentrations and hence can be used to monitor calcium homeostasis in critically ill hypoalbuminemic dogs; and (3) to evaluate factors associated with any potential discrepancy in calcium classification between corrected total and ionized values. Design – Prospective observational clinical study. Setting – Small animal intensive care unit in a veterinary medical teaching hospital. Animals – Twenty‐eight client‐owned dogs with hypoalbuminemia. Interventions – None. Measurements and Main Results – iCa was determined using ion‐specific electrode methodology, on heparinized plasma. The tCa concentration was adjusted for Alb and TP using published equations. In total 29% (8/28) of the hypoalbuminemic, critically ill dogs in this study were hypocalcemic at intensive care unit admission, as determined by iCa measurement. Corrected calcium values failed to accurately classify calcium status in 67.9% and 64.3% of cases, according to whether the Alb‐adjusted or TP‐adjusted values, respectively, were used. The sensitivity and specificity of the tCa to evaluate hypocalcemia was 100% and 47%, respectively. The sensitivity and specificity of the correction formulae were 37.5% and 79% for the Alb‐adjusted values and 37.5% and 74% for TP‐adjusted values. tCa overestimated the presence of hypocalcemia and underestimated the presence of normocalcemia, while corrected calcium values overestimated the presence of normocalcemia and underestimated the presence of hypocalcemia. Conclusions – Calcium homeostasis in hypoalbuminemic critically ill dogs should be evaluated by iCa concentrations rather than tCa or calcium adjusted for Alb or TP. Given that tCa has 100% sensitivity for detecting hypocalcemia in this population it is recommended that all hypoalbuminemic and critically ill patients with low tCa should be evaluated with an iCa measurement.     

Comparison of whole blood and plasma colloid osmotic pressure in healthy dogs

Objective – To determine the difference between colloid osmotic pressure (COP) values determined from plasma versus those determined from whole blood. Design – Prospective observational study. Settings – University veterinary teaching hospital. Animals – Fifty‐three healthy dogs. Interventions – None. Measurements and Main Results – Whole blood and plasma COP, CBC, plasma biochemistry. In all dogs, plasma COP values were significantly lower (P=0.02) than whole blood COP, with a mean of difference of 0.5 mm Hg. The mean and median whole blood COP was 21.75 and 21.4 mm Hg, respectively, with a range of 17.9–27.1 mm Hg. The mean and median plasma COP was 21.2 and 20.9 mm Hg with a range of 16.7–28.9 mm Hg. Conclusions – While significant difference exists between plasma and whole blood COP, the individual values are within expected reference intervals for dogs (21–25 mm Hg). Using either sample appears to provide the same information in clinically healthy dog; however, it is recommended that clinicians utilize the same sample type for comparison in an individual patient.     

Epidemiology,clinical management,and outcomes of dogs involved in road traffic accidents in the United Kingdom (2009–2014)

Objective

To estimate the prevalence and risk factors for road traffic accidents (RTA) in dogs and describe the management and outcome of these dogs attending primary‐care veterinary practices in the United Kingdom.

Design

Retrospective cross‐sectional study.

Setting

Primary‐care veterinary practices in the United Kingdom.

Animals

The study population included 199,464 dogs attending 115 primary‐care clinics across the United Kingdom.

Measurements and main results

Electronic patient records of dogs attending practices participating in the VetCompass Programme were assessed against selection criteria used to define RTA cases. Cases identified as RTAs were identified and manually verified to calculate prevalence. Univariable and multivariable logistic regression methods were used to evaluate associations between risk factors and RTA. The prevalence of RTA was 0.41%. Of the RTA cases, 615 (74.9%) were purebred, 322 (39.2%) were female, and 285 (54.8%) were insured. The median age at RTA was 2.5 years. After accounting for the effects of other factors, younger dogs had increased odds of an RTA event: dogs aged under 3 years showed 2.9 times the odds and dogs aged between 6–9 years showed 1.8 times the odds of an RTA event compared with dogs aged over 14 years. Males had 1.4 times the odds of an RTA event compared with females. Overall, 22.9% of cases died from a cause associated with RTA. Of dogs with information available, 34.0% underwent diagnostic imaging, 29.4% received intravenous fluid‐therapy, 71.1% received pain relief, 46.0% were hospitalized, and 15.6% had surgery performed under general anesthetic.

Conclusions

This study identified important demographic factors associated with RTA in dogs, notably being young and male.

     

A comparison of epidural morphine with low dose bupivacaine versus epidural morphine alone on motor and respiratory function in dogs following splenectomy

ObjectiveTo compare post-operative motor function in dogs that received epidural morphine and low dose bupivacaine versus epidural morphine alone following splenectomy.Study designProspective, randomized study.Animals16 client owned dogs undergoing routine splenectomy.MethodsFollowing splenectomy dogs were randomly allocated into one of two groups. The morphine group (MOR) was administered epidural morphine (0.1 mg kg^?1); the morphine-bupivacaine group (MORB) received epidural morphine (0.1 mg kg^?1) and low dose bupivacaine [0.25 mg kg^?1, (0.167%)]. The adjusted final volume was 0.15 mL kg^?1 in both groups. Motor function and pain assessment were performed at pre-determined times using a simple numerical motor score and the University of Melbourne Pain Scale (UMPS) respectively. An arterial blood gas was performed 2 hours following epidural administration to check for respiratory compromise. If patients scored >7 on the UMPS or were deemed painful by the observer they were administered hydromorphone intravenously and dose and time of rescue analgesia were recorded.ResultsThere were no statistically significant differences in motor scores, pain scores, amount of rescue analgesia administered or PaCO₂ between treatment groups. No dogs demonstrated respiratory depression or profound motor dysfunction at any time point during the study. 9/16 (56%) dogs did not require rescue analgesia during the first 18 hours following splenectomy.Conclusions and clinical relevanceThe combination of low dose bupivacaine (0.25 mg kg^?1) and morphine (0.1 mg kg^?1) when administered epidurally has little effect on post-operative motor function. This combination can be used without concern of motor paralysis in healthy animals.     

Review of hypocalcemia in septic patients

Objective: To review the occurrence and etiologies of hypocalcemia in septic human and veterinary patients. Data sources: A thorough search was conducted using CAB abstracts and MEDLINE and the keywords hypocalcemia, ionized calcium, sepsis, and procalcitonin (proCT). Human data synthesis: Ionized hypocalcemia (iHCa) is a common finding in septic human patients. The cause is unknown but is likely multifactorial. Low ionized calcium (iCa²⁺) concentrations coincide with increased severity of illness and increased mortality. Recent studies show that iHCa has a strong correlation with elevated calcitonin precursor concentrations. Veterinary data synthesis: There is a paucity of publications in the veterinary literature pertaining to iHCa in septic animals. Experimental models of sepsis indicate that iHCa exists in animals. iHCa has also been investigated in horses with enterocolitis and endotoxemia. Prospective studies are needed to determine the prevalence of iHCa among septic small animals, and to determine whether iHCa correlates with increased mortality and severity of disease. Indications for the treatment of iHCa in septic small animals also need to be investigated. Conclusions: iHCa is well documented in septic human patients, but little is known about iHCa in septic veterinary patients. Future veterinary studies should focus on documenting the presence of iHCa in septic patients and steps should be taken to determine the cause. proCT concentrations may show promise for predicting sepsis and mortality in critically ill veterinary patients.     

Comparison of two questionnaires to assess gastrointestinal toxicity in dogs and cats treated with chemotherapy*

Questionnaires completed by pet owners are widely used instruments to monitor adverse gastrointestinal (GI) effects in the owners' animals undergoing chemotherapy and for reporting toxicoses in clinical trials; however, no questionnaires have been formally evaluated. This study compares two questionnaire-based evaluations of adverse GI events: a basic, open-ended questionnaire and a detailed questionnaire modelled after the grading in the Veterinary Co-operative Oncology Group-Common Terminology Criteria for Adverse Events (VCOG-CTCAE). Owners completed both questionnaires after their dog or cat received moderately emetogenic chemotherapy. Results were used to derive toxicity grades for anorexia, vomiting and diarrhoea. We evaluated 123 pairs of questionnaires. Disagreement in grade of anorexia, vomiting and diarrhoea was found in 24, 7 and 13% of paired questionnaires, respectively (κ = 0.63, 0.83 and 0.71, respectively). Although 'good' to 'very good' agreement was found, the potential for only 'fair' agreement between questionnaire methods is of concern and suggests a need to adopt a standardized form.     

A comparison of four methods of analgesia in cats following ovariohysterectomy

OBJECTIVE: To evaluate the effectiveness of preoperative administration of oral carprofen, subcutaneous ketoprofen, and local nerve block with bupivacaine in preventing postoperative pain-associated behavior in cats after ovariohysterectomy. ANIMALS: Fifty-two female intact cats. Materials and methods Cats received butorphanol (0.44 mg kg(-1) IM), carprofen (2.2 mg kg(-1) PO), ketoprofen (2.2 mg kg(-1) SQ), or bupivacaine infiltration block (1.1 mg kg(-1) SQ) before surgery. Cortisol and drug concentrations and visual analog scale (VAS) and interactive visual analog scale (IVAS) pain-associated behavior scores were measured 2 hours before and 0, 1, 2, 4, 8, 12, and 24 hours after ovariohysterectomy. RESULTS: Cats receiving butorphanol had significantly increased IVAS scores 2 hours after surgery compared with baseline measurements. Cats receiving carprofen, ketoprofen, and bupivacaine had significant increases from baseline in VAS and IVAS scores 1 and 2 hours after surgery. VAS and IVAS scores for cats receiving bupivacaine were significantly greater 1 and 2 hours after surgery than for cats that received butorphanol. Cats receiving carprofen had significant increases in cortisol 1 hour after surgery and significant decreases 24 hours after surgery compared with baseline measurements. CONCLUSIONS AND CLINICAL RELEVANCE: Preoperative carprofen and ketoprofen have effects on pain-associated behavior similar to butorphanol in cats undergoing ovariohysterectomy. Cats receiving bupivacaine blocks may require additional analgesics immediately after surgery.     

Development of a questionnaire assessing health-related quality-of-life in dogs and cats with cancer

Health-related quality-of-life (HRQoL) has been studied extensively in human medicine. There is currently no standard HRQoL evaluation for veterinary oncology patients. The aim of this study was to assess the practicality, usefulness and robustness, from a pet owner and clinician perspective, of a questionnaire for the assessment of HRQoL in canine and feline cancer patients. A HRQoL assessment entitled 'Cancer Treatment Form' and two questionnaires entitled 'Owner Minitest' and 'Clinician Minitest' were designed. The first and second were completed by owners of patients presenting to a veterinary oncology referral service and the third by attending clinicians. The 'Cancer Treatment Form' was well received by owners and clinicians and provided a valuable assessment of HRQoL with 98% (82/84) of owners reporting an accurate reflection of their pet's quality-of-life. Following this, minor improvements to the form could be suggested prior to regular use in evaluation of clinical oncology patients.