Defining sepsis in small animals

OBJECTIVE

To discuss the definitions of sepsis in human and veterinary medicine.

DESIGN

International, multicenter position statement on the need for consensus definitions of sepsis in veterinary medicine.

SETTING

Veterinary private practice and university teaching hospitals.

ANIMALS

Dogs and cats.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Sepsis is a life-threatening condition associated with the body's response to an infection. In human medicine, sepsis has been defined by consensus on 3 occasions, most recently in 2016. In veterinary medicine, there is little uniformity in how sepsis is defined and no consensus on how to identify it clinically. Most publications rely on modified criteria derived from the 1991 and 2001 human consensus definitions. There is a divergence between the human and veterinary descriptions of sepsis and no consensus on how to diagnose the syndrome. This impedes research, hampers the translation of pathophysiology insights to the clinic, and limits our abilities to optimize patient care. It may be time to formally define sepsis in veterinary medicine to help the field move forward. In this narrative review, we present a synopsis of prior attempts to define sepsis in human and veterinary medicine, discuss developments in our understanding, and highlight some criticisms and shortcomings of existing schemes.

CONCLUSIONS

This review is intended to serve as the foundation of current efforts to establish a consensus definition for sepsis in small animals and ultimately generate evidence-based criteria for its recognition in veterinary clinical practice.

Seizures in 3 juvenile dogs after intravenous anesthetic drug withdrawal during weaning from mechanical ventilation suspected to be a sign of iatrogenic withdrawal syndrome

OBJECTIVE

To describe seizure activity in juvenile dogs successfully weaned from long-term mechanical ventilation.

CASE SERIES SUMMARY

Three juvenile dogs (all approximately 3 months old) underwent long-term mechanical ventilation with IV anesthesia for suspected noncardiogenic pulmonary edema. Within 24 hours of extubation and within 10 hours of discontinuing midazolam continuous infusions, all dogs experienced seizures, which is 1 sign of iatrogenic withdrawal syndrome. Each dog was treated with an anticonvulsant protocol, and none experienced seizures after being discharged.

NEW OR UNIQUE INFORMATION PROVIDED

Each dog received IV anesthesia, including fentanyl, dexmedetomidine, midazolam, and propofol, during mechanical ventilation and subsequently experienced seizures after successful weaning from mechanical ventilation. Juvenile dogs may be at risk for seizures after weaning from mechanical ventilation and IV anesthesia. Neurological monitoring and further research into an appropriate weaning protocol may prove beneficial in juvenile dogs requiring prolonged anesthesia.

Establishment of a reference interval for thiamine concentrations in healthy dogs and evaluation of the prevalence of absolute thiamine deficiency in critically ill dogs with and without sepsis using high-performance liquid chromatography

OBJECTIVE

To determine the normal reference interval (RI) for thiamine concentrations in healthy dogs and investigate the prevalence of thiamine deficiency in critically ill dogs with and without sepsis.

DESIGN

Prospective, observational, multicenter study, conducted between 2019 and 2021.

SETTING

Two veterinary university teaching hospitals.

ANIMALS

A total of 109 dogs were enrolled into 3 groups: 40 healthy dogs, 33 dogs with suspected or confirmed sepsis and evidence of tissue hypoperfusion (Doppler blood pressure ≤90 mm Hg or plasma lactate ≥3 mmol/L), and 36 dogs with other critical illnesses and evidence of tissue hypoperfusion.

INTERVENTIONS

For each dog, CBC, serum biochemistry, plasma lactate concentration, whole-blood thiamine concentration, blood pressure, vital parameters, Acute Patient Physiologic and Laboratory Evaluation (APPLE)fast score, and clinical outcomes were recorded, alongside basic patient parameters and dietary history. Whole-blood thiamine pyrophosphate (TPP) concentrations were measured using high-performance liquid chromatography.

MEASUREMENTS AND MAIN RESULTS

The RI for whole-blood TPP in healthy dogs was 70.9-135.3 μg/L. Median TPP concentrations were significantly lower in septic dogs compared to healthy controls (P = 0.036). No significant difference in median TPP concentrations was found between septic dogs and nonseptic critically ill dogs, or between healthy dogs and nonseptic critically ill dogs. TPP concentrations were below the normal RI in 27.3% of septic dogs, compared to 19.4% of nonseptic critically ill dogs (P = 0.57). No correlations were found between TPP concentrations and lactate concentrations, age, body condition scores, time since last meal, RBC count, serum alanine aminotransferase, APPLEfast scores, or patient outcomes.

CONCLUSIONS

TPP concentrations were significantly lower in septic dogs compared to healthy controls, with an absolute thiamine deficiency found in 27.3% of septic dogs. The established TPP RI allows for further investigation of thiamine deficiency in critically ill dogs.

Neutrophil-to-lymphocyte ratio is increased in dogs with acute congestive heart failure secondary to myxomatous mitral valve disease compared to both dogs with heart murmurs and healthy controls

OBJECTIVE

To retrospectively evaluate neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) as a biomarker for severity and short-term outcomes of congestive heart failure (CHF) secondary to myxomatous mitral valve disease (MMVD) in dogs.

ANIMALS

47 dogs with CHF secondary to MMVD, 47 dogs with presumptive preclinical MMVD, and 47 control dogs.

METHODS

Medical record data (signalment, physical examination findings, medical treatments instituted, American College of Veterinary Internal Medicine MMVD stage, length of hospitalization, outcome, and hospital re-presentation due to CHF) from March 2012 through March 2022 for each dog were collected. Statistical analyses were performed with Mann-Whitney, Spearman correlation, and Fisher exact tests.

RESULTS

NLR (but not PLR) was significantly higher in dogs with CHF secondary to MMVD (6.41) compared to presumptive preclinical MMVD dogs (4.66; P < .001) and control dogs (3.95; P < .001). Dogs with higher NLR and PLR received significantly higher cumulative dosages of loop-diuretic therapy during hospitalization (ρ = 0.3, P = .04; and ρ = 0.4, P = .02, respectively). There was a positive association between NLR and duration of oxygen supplementation within the CHF group (ρ = 0.4; P = .01).

CLINICAL RELEVANCE

The increased diuretic dose and time receiving oxygen supplementation may represent increased disease severity for which NLR (and to a lesser extent PLR) may serve as a readily available marker. The data presented provide information regarding some of the systemic inflammatory changes seen in CHF secondary to MMVD in dogs. Future research should include prospective, longitudinal studies to provide insight into the long-term prognostic value of NLR and PLR in dogs with CHF.

Hepatic abscessation in dogs: A multicenter study of 56 cases (2010-2019)

OBJECTIVE

To investigate the clinical findings, treatment strategies, and outcomes in dogs with confirmed hepatic abscessation.

DESIGN

Retrospective cohort study from 2010 to 2019.

SETTING

Multicenter study.

ANIMALS

Fifty-six client-owned dogs with hepatic abscessation confirmed by culture, cytology, or histopathology.

MEASUREMENTS AND MAIN RESULTS

Dogs were presented for lethargy (39/56), hyporexia (31/56), and vomiting (26/56). Abnormal physical examination findings included increased temperature (41/56) and abdominal pain (22/54). CBCs revealed neutrophilia (31/49), toxic changes (25/49), anemia (28/49), and thrombocytopenia (23/49). Biochemical analyses revealed increased alkaline phosphatase (45/50), increased alanine aminotransferase (40/50), hypoalbuminemia (25/48), and hyperbilirubinemia (19/49). Hypoglycemia was found in 13 of 49 dogs. Hepatic abscesses ranging from 0.5 to 15 cm in diameter were identified ultrasonographically in 37 of 48 dogs; 19 of 37 had solitary abscesses, and 18 of 37 had multifocal abscessation. Escherichia coli was the most commonly cultured organism, isolated in 18 of 42 cases. Histopathology revealed underlying hepatic neoplasia in 10 of 47 dogs. Surgical management was performed in 41 of 49 dogs, and 35 of 41 survived to discharge. Medical management was performed in 8 of 49 dogs, and 5 of 8 survived to discharge. With univariate analysis, hypoglycemia and multifocal abscessation were associated with decreased odds of survival (odds ratio [OR]: 0.2, 95% confidence interval [CI]: 0.03-0.9, P = 0.04; OR: 0.07, 95% CI: 0.01-0.6, P = 0.02, respectively). With multivariate analysis, only multifocal abscessation was associated with decreased odds of survival (OR: 0.09, 95% CI: 0.01-0.87, P = 0.04).

CONCLUSIONS

Hepatic abscessation, although rare, should remain a differential diagnosis for dogs presenting with nonspecific clinical signs and increase liver enzyme activities, especially with concurrent increased temperature and neutrophilia. Rate of survival to discharge for dogs in this study was consistent with previously reported survival rates, with 40 of 56 (71%) of the total population surviving to discharge. No variables assessed were able to predict survival to discharge; however, hypoglycemia and multifocal abscessation should be assessed in larger populations to determine prognostic significance.

Reassessment Campaign on Veterinary Resuscitation (RECOVER) Initiative small animal CPR registry report 2016-2021

OBJECTIVE

To introduce the Reassessment Campaign on Veterinary Resuscitation (RECOVER) CPR registry and report cardiopulmonary arrest (CPA) and CPR event data collected to date.

DESIGN

International, multi-institutional veterinary CPR registry data report.

SETTING

Veterinary private practice and university teaching hospitals.

ANIMALS

Data from 514 dogs and 195 cats undergoing CPR entered in the RECOVER CPR registry between February 2016 and November 2021.

INTERVENTIONS

The RECOVER CPR registry is an online medical database created for standardized collection of hospital, animal, arrest, and outcome information on dogs and cats undergoing CPR. Data were collected according to the veterinary Utstein-style guidelines for standardized reporting of in-hospital CPR in dogs and cats. Case records were downloaded, duplicate and incomplete cases were removed, and summary descriptive data were reported.

MEASUREMENTS AND MAIN RESULTS

Sixteen hospitals in the United States, Europe, and Australia contributed data on 709 CPR events to the registry. One hundred and forty-two (28%) dogs and 58 (30%) cats attained return of spontaneous circulation (ROSC), 62 (12%) dogs and 25 (13%) cats had ROSC >20 minutes, and 14 (3%) dogs and 4 (2%) cats survived to hospital discharge. The reason for CPR discontinuation was reported as owner choice in 321 cases (63%). The most common suspected causes for CPA were respiratory failure (n = 142, 20%), heart failure (n = 86, 12%), and hemorrhage (n = 76, 11%).

CONCLUSION

The RECOVER CPR registry contains the first multicenter data set on small animal CPR. It confirms poor outcomes associated with CPA, emphasizing the need for large-sized studies to gain adequate information on characteristics associated with favorable outcomes.

Comparison of a viscoelastic point-of-care coagulation monitor with thromboelastography in sick dogs with hemostatic abnormalities

BACKGROUND

Viscoelastic coagulation monitor (VCM-Vet) is a point-of-care device that has been used to characterize hemostatic abnormalities in sick pets but has not been validated in veterinary patients.

OBJECTIVES

We aimed to compare VCM-Vet and thromboelastography (TEG) in sick dogs with suspected disorders of hemostasis.

METHODS

Duplicate VCM-Vet tests using untreated native blood performed concurrently on two VCM-Vet machines, and simultaneous TEG tests were performed (one citrated native (CN), and one activated with tissue factor (TF) at a 1:3600 dilution). Each VCM-Vet result was compared with both TF-activated and CN TEG.

RESULTS

Fifty-three dogs were enrolled. Eleven cases displayed apparent hyperfibrinolysis. Spearman correlation coefficients for individual VCM-Vet devices and CN and TF TEG were obtained between R and CT values and ranged from 0.21 to 0.27, CFT and K (r = 0.60-0.67), angles (r = 0.51-0.62), and MCF and MA (r = 0.85-0.87). Comparison of the two VCM-Vet devices displayed positive correlations for all clot formation parameters with Lin's concordance correlation coefficients of 0.75-0.95. Variable lysis parameter agreement existed between the VCM-Vet devices and VCM-Vet and TEG. When samples were classified as hypercoagulable or coagulopathic, VCM-Vet had a low positive predictive value (17-33%) for the detection of hypercoagulable states and a moderate negative predictive value (64-74%) for the detection of coagulopathy as defined by TEG.

CONCLUSIONS

VCM-Vet and TEG had variable correlations in clot formation values and a strong correlation for final clot strength. More information is needed to make conclusions about the lysis parameters. Artifact in the fibrinolysis portion of the test can confound the interpretation of VCM-Vet results.

Evaluation of the neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios in critically ill dogs

OBJECTIVE

To evaluate whether the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are accurate prognostic indicators and correlate with illness severity scores in critically ill dogs.

DESIGN

Prospective observational study from December 2016 to May 2017.

SETTING

ICU at a veterinary teaching hospital.

ANIMALS

Seventy-two client-owned dogs admitted to the ICU with CBCs and abbreviated and complete acute patient physiologic and laboratory evaluation (APPLE_fast and APPLE_full ) scores were enrolled.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The NLR, PLR, APPLE_fast , and APPLE_full scores were calculated for each patient on the day of admission. Patients were followed from admission to discharge, and diagnosis, survival, and length of hospitalization were recorded. The patient population was assessed as a whole and as subcategories of patients with neoplastic disease, infectious disease, sepsis, and severe hemorrhage. Dogs with nonseptic disease processes (n = 52) that died had a significantly higher median PLR (P = 0.04) of 441 (range: 106-986) compared to those that survived with a median PLR of 217 (range: 28.4-3225). The PLR was strongly predictive of ICU length of stay in dogs with severe hemorrhage (P = 0.03, Spearman's rho = 0.84). The NLR had a poor positive correlation with APPLE_full score (P = 0.04, Spearman's rho = 0.24), and PLR had a poor negative correlation with APPLE_fast score (P = 0.02, Spearman's rho = -0.27).

CONCLUSIONS

The PLR correlated with ICU length of stay for patients with severe hemorrhage and with survival for patients with nonseptic disease processes. The PLR and NLR correlated with illness severity as measured by APPLE scores. Future studies with larger sample sizes are warranted to further determine the merit of NLR and PLR as indicators of morbidity, mortality, and illness severity.

Use of vasopressors for treatment of vasodilatory hypotension in dogs and cats by Diplomates of the American College of Veterinary Emergency and Critical Care

OBJECTIVE

To identify the most common practices of Diplomates of the American College of Veterinary Emergency and Critical Care (DACVECCs) as they relate to the recognition and treatment of hypotension in dogs and cats, particularly concerning the use of vasopressors in vasodilatory shock states.

DESIGN

A survey regarding vasopressor use was sent to all active DACVECCs using the Veterinary Information Network. Questions focused on respondent characteristics, method of recognition of hypotension, triggers for initiation of vasopressor therapy, first- and second-line vasopressor choice, and methods of determining response to therapy.

SUBJECTS

A total of 734 DACVECCs were invited to participate, and 203 Diplomates (27.7%) completed the survey.

RESULTS

For both dogs and cats, the most common first-line vasopressor was norepinephrine (87.9% in dogs and 83.1% in cats). The most common second-choice vasopressor was vasopressin (44.2% in dogs and 39.0% in cats). Cutoff values for initiating vasopressor therapy varied between species and modality used for blood pressure measurement. In general, most DACVECCs chose to initiate vasopressor therapy at a Doppler blood pressure <90 mm Hg or a mean arterial pressure of <60 or <65 mm Hg when using oscillometric or direct arterial blood pressure measurements in dogs and cats.

CONCLUSIONS

Most DACVECCs adhere to published human guidelines when choosing a first-line vasopressor. However, there is significant variability in blood pressure measurement technique, cutoffs for initiation of vasopressor use, and choice of second-line vasopressors.

Assessment of changes in intra-abdominal pressure and abdominal perfusion pressure in late-term pregnant queens undergoing elective ovariohysterectomy

OBJECTIVE

Compare changes in intra-abdominal pressure (IAP), abdominal perfusion pressure (APP), hemodynamics, and clinicopathological variables in nonpregnant and late-term pregnant queens undergoing elective ovariohysterectomy (OHE) and evaluate the effect of patient positioning on IAP and APP measurements.

ANIMALS

18 late-term pregnant queens and 25 nonpregnant controls.

PROCEDURES

Temperature, heart rate (HR), Doppler blood pressure (DBP), IAP (dorsal and right lateral), PCV, total protein (TP), and lactate were recorded preoperatively, at abdominal wall closure (dorsal IAP only), and postoperatively under general anesthesia. Uterine weight, blood loss, and surgical duration were recorded. Abdominal perfusion pressure was calculated as DBP minus IAP.

RESULTS

Pre- and postoperatively, pregnant queens had lower DBP, APP, and PCV compared to controls (P < 0.001). IAP was higher in pregnant queens preoperatively (P < 0.001). Controls had a decrease in HR and increase in IAP, while both groups had a decrease in body temperature, DBP, APP, and lactate over time (P < 0.05). Pregnant queens had a decrease (P = 0.029), and controls had an increase in TP (P = 0.001). Blood loss and surgical time were greater for pregnant queens (P < 0.001). Dorsal IAP and APP were higher and lower than right lateral measurements (P < 0.001), respectively, and correlation was strong.

CLINICAL RELEVANCE

Hemodynamics and APP are impaired in late-term pregnant queens undergoing OHE, and increased monitoring is warranted. Although strongly correlated, feline IAP and APP measurements in dorsal and right lateral recumbency are not interchangeable.

Comparison of Mean Arterial Blood Pressure and Heart Rate Changes in Response to Three Different Randomized Isotonic Crystalloid Boluses in Hypotensive Anesthetized Dogs

The aim of this prospective, randomized, nonblinded, controlled clinical trial was to compare mean arterial blood pressure (MAP) and heart rate (HR) during an intravenous bolus of three different balanced isotonic crystalloid solutions in euvolemic, anesthetized dogs with hypotension. Thirty healthy dogs (American Society of Anesthesiologists Physical Status I–II) weighing at least 15 kg that presented for elective orthopedic or dental surgical procedures at the Ryan Veterinary Hospital for Small Animals of the University of Pennsylvania were included in this study. Anesthetized hypotensive patients (defined as a MAP ≤ 65 mmHg), were administered an infusion of Lactated Ringer’s solution (LRS), Plasma-Lyte (PLYTE) or Canadian Plasma-Lyte (PLYTECA), selected at random. The infusion was administered over 15 min via a volumetric fluid pump. Differences in oscillometric MAP and HR between time points and across treatments were evaluated by mANOVA. Intravenous isotonic crystalloid infusions over 15 min did not significantly change MAP or HR in hypotensive dogs under general anesthesia. Neither LRS, PLYTE nor PLYTECA exacerbated hypotension or caused tachycardia.

Clinical application of the StatSensor and StatSensor Xpress point-of-care creatinine measurement devices in dogs

BACKGROUND

Creatinine is a universally important blood parameter used to detect and monitor acute and chronic kidney disease. Reliable measurements at the bedside remain a challenge in human and veterinary medicine. Despite its potential, a trustworthy point-of-care creatinine biosensor has yet to be established.

OBJECTIVES

We aimed to determine the precision and accuracy of the StatSensor (SS) and StatSensor Xpress (SSX) handheld creatinine measurement devices in dogs.

METHODS

Paired creatinine samples from dogs with normal (creatinine ≤159 μmol/L), moderate (159-354 μmol/L), and marked (>354 μmol/L) azotemia were compared with a commercial enzymatic analyzer. Within-day precision and linearity studies were performed prior to method comparison studies. Method comparison was evaluated using Bland-Altman, concordance correlation coefficient, Deming, and Passing-Bablok regression analysis.

RESULTS

Seventy-eight dogs were enrolled in the study, including 28 (35%), 25 (32%), and 26 (33%) with normal, moderate, and marked azotemia. Total error surpassed recommendations for all devices, and linearity deviated from identity for the SS1 and SS2. The concordance correlation coefficients of the SS1, SS2, SSXI, and SSX2, were 0.69, 0.59, 0.82, and 0.44, respectively. Bland-Altman analyses showed a high variation in the differences, and relationships showed high heteroskedasticity with negative systemic bias among high creatinine concentrations.

CONCLUSIONS

Neither the SS and SSX are considered acceptable for clinical applications in dogs. Further research is indicated for the development of a reliable, cost-effective, point-of-care creatinine analyzer to improve the rapid detection and monitoring human and veterinary patients.

Retrospective evaluation of carboxyhemoglobin and methemoglobin levels in dogs and cats with respiratory disease

OBJECTIVE

To evaluate carboxyhemoglobin (COHb) and methemoglobin (MetHb) levels in dogs and cats with respiratory disease in the ICU.

DESIGN

Retrospective study.

SETTING

University veterinary teaching hospital.

ANIMALS

The ICU census was searched for dogs (n = 466) and cats (n = 97) hospitalized within the ICU between January 2016 and January 2019 in whom blood gas with co-oximetry was performed. Dogs and cats were stratified into those with primary respiratory and nonrespiratory categories; the underlying cause of the disease was also noted. Venous blood gas, co-oximeter, PaO₂ /FiO₂ (PF ratio), physical examination findings, and outcome were recorded.

MEASUREMENTS AND MAIN RESULTS

The median COHb and MetHb in dogs hospitalized in the ICU were 2.6% (0.1%-5.6%) and 1.1% (0.1%-2.9%), respectively. The median COHb and MetHb in cats hospitalized in the ICU were 2.2% (0.1%-5.4%) and 1.0% (0%-2.1%), respectively. Dogs with respiratory disease had a higher COHb than dogs without respiratory disease (median, 2.7% [range, 0.3%-5.0%] vs. 2.5% [0.1%-5.6%]; P = 0.0148). COHb was positively associated with survival in cats (median, 2.2% [range, 0.1%-5.4%] vs. 1.9% [0.1%-3.9%]; P = 0.0433). Both COHb and MetHb were higher in septic dogs than in nonseptic dogs (median COHb, 2.8% [range 0.3%-4.5%] vs. 2.6% [0.1%-5.6%]; P = 0.02 and median MetHb, 1.1% [0.1%-2.9%] vs. 1.1% [0.1%-2.4%]; P = 0.01, respectively).

CONCLUSIONS

There may be a positive association between COHb and respiratory disease in dogs; prospective studies are needed to evaluate this further. No association between COHb and respiratory disease in cats or MetHb and respiratory disease in either species was detected. Additional prospective studies are needed to determine whether COHb and MetHb are biomarkers for sepsis in dogs and whether COHb is an indicator of mortality in cats.

Owner experiences with and perceptions of owner-witnessed CPR in veterinary medicine

OBJECTIVE

To examine owner experiences with and perceptions of owner-witnessed resuscitation (OWR) in veterinary medicine and to determine if previous experience with family-witnessed resuscitation (FWR) influenced perceptions.

DESIGN

Multicenter survey.

SETTING

Two academic and 2 private practice referral hospitals in the United States.

SUBJECTS

Four hundred and seven clients presenting their small animal or exotic pet to the emergency service, or owners of patients hospitalized in the small animal ICU, April 1 to May 15, 2019.

INTERVENTIONS

None MEASUREMENTS AND MAIN RESULTS: Anonymous, online survey. Demographic variables, familiarity with CPR, previous experience with FWR or OWR, and open-ended questions and 4-point Likert items assessing level of agreement with statements on OWR were included. Scores equal or greater than 2 represented positive agreement. An overall OWR mean score was calculated from Likert items. Seventy-nine (19.4%; 95% confidence interval [CI], 15.7%-23.7%) participants reported having been involved with FWR, and 13 (3.2%; 95% CI, 1.8%-5.5%) reported having witnessed CPR on their pet. Owners were significantly more likely to participate in OWR if they had been present for FWR (P = 0.0004). Ninety-two percent of respondents who had been present for OWR would elect to be present again (95% CI, 62.1%-99.6%). Whether present for OWR or not, owners believed there may be benefits from witnessing CPR and had overall positive feelings toward the practice (OWR mean score, 2.87, SD 0.45 and 2.68, SD 0.54, respectively). Most respondents (78.6%; 95% CI, 74.2%-82.4%) felt that owners should be offered the opportunity to witness CPR on their pets.

CONCLUSIONS

Owners expressed overall positive experiences with and attitudes toward OWR and believe the option for presence should be provided. As pet owners become more aware of FWR in human medicine, veterinarians may need to be prepared to entertain the possibility of OWR and owners' wishes to remain with their pet during CPR.

Effectiveness of orally administered maropitant and ondansetron in preventing preoperative emesis and nausea in healthy dogs premedicated with a combination of hydromorphone, acepromazine, and glycopyrrolate

OBJECTIVE

To compare effectiveness of maropitant and ondansetron in preventing preoperative vomiting and nausea in healthy dogs premedicated with a combination of hydromorphone, acepromazine, and glycopyrrolate.

ANIMALS

88 dogs owned by rescue organizations.

PROCEDURES

Dogs received maropitant (n = 29) or ondansetron (28) PO 2 hours prior to premedication or did not receive an antiemetic (31; control). Dogs were evaluated for vomiting, nausea, and severity of nausea (scored for 6 signs) for 15 minutes following premedication with hydromorphone, acepromazine, and glycopyrrolate.

RESULTS

A significantly lower percentage of dogs vomited after receiving maropitant (3/29 [10%]), compared with control dogs (19/31 [62%]) and dogs that received ondansetron (15/28 [54%]). A significantly lower percentage of dogs appeared nauseated after receiving maropitant (3/29 [10%]), compared with control dogs (27/31 [87%]) and dogs that received ondansetron (14/28 [50%]), and a significantly lower percentage of dogs appeared nauseated after receiving ondansetron, compared with control dogs. Nausea severity scores for hypersalivation, lip licking, hard swallowing, and hunched posture were significantly lower for dogs that received maropitant than for control dogs, and scores for hypersalivation, lip licking, and hard swallowing were significantly lower for dogs that received ondansetron than for control dogs.

CONCLUSIONS AND CLINICAL RELEVANCE

Oral administration of maropitant 2 hours prior to premedication with hydromorphone reduced the incidence of vomiting and the incidence and severity of nausea in healthy dogs. Oral administration of ondansetron reduced the incidence and severity of nausea but not the incidence of vomiting.

Indications and outcomes for puppies undergoing mechanical ventilation: 59 cases (2006 to 2020)

The medical records of 59 puppies from 6 hospitals undergoing mechanical ventilation (MV) between 2006 and 2020 were reviewed to describe the signalment, underlying disease, duration of ventilation, and outcome. The most common underlying diseases were pneumonia (n = 18), non-cardiogenic pulmonary edema (n = 16), and trauma (n = 8). Twenty-six (44%) puppies were weaned from the ventilator. The overall survival rate was 39% (23/59) including 19 non-brachycephalic dogs and 4 brachycephalics. Median duration of mechanical ventilation was 27 hours (range: 4 to 144 hours). Brachycephalic dogs were less likely to survive than nonbrachycephalic dogs (P = 0.032). English bulldogs were over-represented with pneumonia. No association between age and survival to discharge (P = 0.716) or outcome (P = 0.579) was detected. The survival rate, and underlying disease process and severity for mechanically ventilated puppies was similar to previous studies in adult dogs.

Standardized capillary refill time and relation to clinical parameters in hospitalized dogs

OBJECTIVE

To assess the relationship between various physical and clinicopathologic parameters and the capillary refill time (CRT) using a standard method; to evaluate the influence of emergency room (ER) versus ICU hospital location on CRT; and to identify latent subgroups among the CRT distribution.

DESIGN

Prospective, observational study.

SETTING

University teaching hospital.

ANIMALS

Client-owned dogs in the ER (n = 40) and ICU (n = 71).

INTERVENTIONS

The CRT was defined as the duration required for the oral mucosa of the upper lip to return to its original color after blanching for 4 seconds. The CRT was recorded in seconds to the 10ths place by a single observer using an automated recording device.

MEASUREMENTS AND MAIN RESULTS

Median CRT for all dogs was 1.1 seconds (ER, 1.2 s; ICU, 1.1 s; P = 1.000). The CRT was significantly associated with rectal temperature (P = 0.004), systolic blood pressure (P = 0.028), body weight (P = 0.031), mucous membrane color (P = 0.007), skin turgor (P = 0.039), and acute patient physiologic and laboratory evaluation mentation score (P = 0.019) for all dogs. The CRT was related to a greater number of variables in the ER than in the ICU patient population. In general, the total population of dogs had CRTs belonging to 1 of 2 groups: either ≤1.2 or ≥1.7 seconds. A statistically significant association was found between body weight CRT ≥1.3 seconds (P = 0.02).

CONCLUSIONS

A CRT following blanching for 4 seconds may provide insight into the hydration status and hemodynamic stability of canine patients. Further research into its clinical application is warranted.

Utility of the Sonoclot analyzer to assess hyperfibrinolysis in dogs

BACKGROUND

Coagulation abnormalities, including hyperfibrinolysis, have been documented in sick veterinary patients. Viscoelastic tests, including the Sonoclot Coagulation and Platelet Function Analyzer, are useful in detecting hyperfibrinolysis. Tissue plasminogen activator (tPA) assays have been used to quantify fibrinolysis using thromboelastography.

OBJECTIVES

We aimed to document and evaluate changes in the whole blood of healthy dogs exposed to in vitro tPA at varying concentrations using the Sonoclot analyzer.

METHODS

Ten milliliters of blood was collected from healthy adult dogs. Sonoclot tests were run in duplicate and included a control sample and five tPA concentrations: 50, 75, 100, 150, and 200 IU/mL of blood.

RESULTS

Eleven dogs were enrolled in the study. Based on standard Sonoclot Signature changes, a numeric value fibrinolysis time (FTi) was derived to aid in the quantification of hyperfibrinolysis. Activated clotting time and clot rate Sonoclot values were not significantly affected by any tPA concentration. There was a significant decrease in platelet function (PF) at tPA concentrations equal to and above 75 IU/mL on channel 1 and tPA concentrations of 150 IU/mL and higher on channel 2. There was a progressive decrease in FTi at increasing tPA concentrations.

CONCLUSIONS

The Sonoclot analyzer can be used to evaluate hyperfibrinolysis. Predictable changes were seen in the Sonoclot Signature and a decrease in PF and FTi was found with increasing tPA concentrations. The Sonoclot assay with a tPA concentration of 100 IU/mL is suggested a baseline measure of hyperfibrinolysis and has a resultant median FTi of 42 minutes, which is a practical time for clinical applications.

Effectiveness of intravenous fluid resuscitation in hypotensive cats: 82 cases (2012-2019)

OBJECTIVE

To evaluate the effectiveness of intravenous fluid resuscitation in hypotensive cats in an emergency room setting. Secondary objectives were to investigate changes in heart rate (HR) and body temperature (BT) in response to fluid resuscitation, and the association of these changes with patient survival.

DESIGN

Retrospective study.

SETTING

University teaching hospital.

ANIMALS

Eighty-two cats with confirmed hypotension.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Medical records from 2012 to 2019 were searched for cats that had documented systemic arterial hypotension (blood pressure measured using a Doppler ultrasonic flow probe [DBP] < 90 mm Hg) on presentation to the emergency room. Data collected included patient characteristics and DBP, HR, and BT before and after fluid resuscitation, type and volume of fluids administered, and outcome. The median DBP before and after resuscitative fluid therapy in all cats was 65 mm Hg (range, 20-85 mm Hg) and 80 mm Hg (range, 20-128 mm Hg), respectively (P < 0.001). However, only 30 cats (37%) were classified as responders to fluid resuscitation (DBP ≥ 90 mm Hg following bolus therapy). The mean HR and median BT before resuscitative fluid therapy was 159/min and 36.7°C. Following fluid resuscitation, where measured, the mean HR and median BT was 154/min (P = 1.00) and 35.9°C (P = 1.00). No significant differences in HR and BT were identified between responders and non-responders. Cats had a low survival rate of 7%. All survivors (n = 5) were initially bradycardic (HR < 160/min), compared to only 45% of non-survivors (P = 0.4).

CONCLUSIONS

Bolus fluid resuscitation effectively increases blood pressure in hypotensive cats; however, it does not result in normalization of blood pressure, HR, or BT in the majority of cases.

Fluid Therapy and the Microcirculation in Health and Critical Illness

Fluid selection and administration during shock is typically guided by consideration of macrovascular abnormalities and resuscitative targets (perfusion parameters, heart rate, blood pressure, cardiac output). However, the microcirculatory unit (comprised of arterioles, true capillaries, and venules) is vital for the effective delivery of oxygen and nutrients to cells and removal of waste products from the tissue beds. Given that the microcirculation is subject to both systemic and local control, there is potential for functional changes and impacts on tissue perfusion that are not reflected by macrocirculatory parameters. This chapter will present an overview of the structure, function and regulation of the microcirculation and endothelial surface layer in health and shock states such as trauma, hemorrhage and sepsis. This will set the stage for consideration of how these microcirculatory characteristics, and the potential disconnect between micro- and macrovascular perfusion, may affect decisions related to acute fluid therapy (fluid type, amount, and rate) and monitoring of resuscitative efforts. Available evidence for the impact of various fluids and resuscitative strategies on the microcirculation will also be reviewed.

Establishment of normal reference intervals in dogs using a viscoelastic point-of-care coagulation monitor and its comparison with thromboelastography

BACKGROUND

Viscoelastic coagulation devices are a useful adjunct to the evaluation of hemostasis in veterinary patients. VCM Vet is a point-of-care device that is simple in operation and could be used to diagnose and trend hemostatic abnormalities in sick patients. VCM Vet does not use activators.

OBJECTIVES

We aimed to establish reference intervals (RIs) for VCM Vet in a healthy adult canine population and concurrently perform thromboelastographic (TEG) analysis on these samples with and without tissue factor (TF) activation for RI comparisons.

METHODS

Duplicate VCM Vet tests were performed immediately upon sample collection. Two concurrent TEG tests were performed on the remaining blood, one citrated, untreated (CU), and one activated with TF at a 1:3600 dilution.

RESULTS

Fifty-two dogs were enrolled in the study. The following RIs were generated for VCM Vet machine 1 and 2, respectively: clot time (CT) (seconds) 163-480 and 172-457; clot formation time (CFT) (seconds) 104-288 and 94-252, α-angle (degrees) 41-65 and 44-66, and maximum clot firmness (MCF) (no units) 27-43 and 30-46. Moderate to good correlations were observed between the two machines with Lin's concordance correlation coefficients of 0.51-0.9 and a P < 0.002. TEG RIs were similar to previously reported values.

CONCLUSIONS

VCM Vet RIs were generated. Each VCM Vet device should have a unique RI established due to inter-device variability. Direct correlations of VCM Vet values with TEG parameters were not performed due to the narrow range of the normal values and the need to evaluate patients with a wide range of hemostatic abnormalities.

Retrospective evaluation of the influence of azotemia on plasma lactate concentrations in hypotensive dogs and cats (2008-2018): 337 cases

OBJECTIVE

To evaluate the relationship between azotemia and plasma lactate concentration in hypotensive dogs and cats presented to an emergency department.

DESIGN

Retrospective case-control study.

SETTING

University veterinary teaching hospital.

ANIMALS

The electronic medical record database was searched for dogs and cats presented to the emergency department that had severe azotemia (creatinine ≥ 443.1 μmol/L [5 mg/dL]), hypotension (systolic blood pressure ≤ 90 mm Hg), and a plasma lactate measurement within 2 h of each another. Non-azotemic, normotensive dogs and cats; non-azotemic, hypotensive dogs and cats; and azotemic, normotensive dogs and cats that presented to the emergency department were used as control populations.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Severely azotemic, hypotensive dogs (n = 10) and cats (n = 63) had a lower plasma lactate than non-azotemic, hypotensive dogs and cats (P = 0.031 and P < 0.001, respectively). Median plasma lactate concentrations in hypotensive dogs (1.75 mmol/L) and cats (1.90 mmol/L) with severe azotemia were within reference intervals.

CONCLUSIONS

Hypotensive dogs and cats with severe azotemia have decreased plasma lactate concentrations as compared to hypotensive, non-azotemic dogs and cats. The median plasma lactate in azotemic, hypotensive dogs and cats was within reference intervals. This may be due to either decreased cellular production of lactate or increased excretion of lactate. Further research is needed to determine which of these mechanisms is responsible and the clinical significance of plasma lactate concentrations in azotemic, hypotensive dogs and cats.

Evaluation of the placement and maintenance of central venous jugular catheters in critically ill dogs and cats

OBJECTIVE

To describe problems noted during central venous jugular catheter (CVJC) placement, conditions associated with unsuccessful catheterization, and CVJC maintenance complications.

DESIGN

Prospective observational study from September 2014 to September 2015.

SETTING

University veterinary teaching hospital.

ANIMALS

Twenty-seven dogs and 20 cats hospitalized in a veterinary ICU. Patients were excluded if previously hospitalized with a CVJC or lacked sufficient data.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Ninety-one percent of indwelling CVJCs were placed successfully (43/47, 95% CI: 80%, 98%). Procedural-related difficulties that resulted in the inability to place a CVJC totaled 18/63 (28.6%, 95% CI: 18%, 41%) and included the inability to puncture the vessel (10), hematoma (6), malposition (1), and dislodgement (1). Procedural complications occurred in 24/47 patients (51%, 95% CI: 36%, 66%) and included cardiac dysrhythmias (13), hematoma (6), CVJC placement failure (4), and malposition (1). Risk factors associated with multiple catheterization attempts included increased age (7.5 years [± 4.2] vs 10.6 years [± 4.1], P = 0.04), smaller size (8.0 kg [0.6-51.9 kg] vs 4.4 kg [2.6-6.8 kg], P < 0.01) and thinner body condition score (median 5/9 [2/9-9/9] vs 4/9 [2/9-7/9], P = 0.04). The risk factor associated with dysrhythmias was smaller patient size (6.8 kg [2.6-51.9 kg] vs 4.8 kg [0.6-29.5 kg], P = 0.04). Eighteen indwelling complications occurred in 14 patients and included mechanical obstruction (7), skin irritation (6), malposition (4), and inflammation (1). Risk factors for indwelling complications included longer dwell time (5 days [2-30] vs 3 days [1-10], P < 0.01) and the administration of an irritant medication (P = 0.02).

CONCLUSIONS

Complications were documented in the placement and maintenance of CVJCs in critically ill patients with a low incidence of life-threatening sequelae. Risk factors associated with both unsuccessful CVJC placement and indwelling CVJC complications were identified.

Effect of blood collection by the push-pull technique from an indwelling catheter versus direct venipuncture on venous blood gas values before and after administration of alfaxalone or propofol in dogs

OBJECTIVE To compare the effect of blood collection by a push-pull technique from an indwelling IV catheter versus direct venipuncture on venous blood gas values before and after administration of alfaxalone or propofol to dogs. DESIGN Prospective randomized clinical study. ANIMALS 30 healthy client-owned dogs that weighed ≥ 10 kg (22 lb) and were anesthetized for elective surgical procedures. PROCEDURES All dogs were premedicated with methadone (0.5 mg/kg [0.2 mg/lb], IM), and 20 to 30 minutes later, anesthesia was induced with either alfaxalone (1 to 3 mg/kg [0.5 to 1.4 mg/lb], IV to effect; n = 15) or propofol (2 to 6 mg/kg [0.9 to 2.7 mg/lb], IV to effect; 15). Immediately prior to premedication and after anesthesia induction, paired blood samples were collected from the cephalic veins; 1 by direct venipuncture and 1 by use of a push-pull technique from a 20-gauge catheter. All blood samples underwent venous blood gas analysis immediately after collection. Results were compared between sample collection techniques before and after anesthesia induction and between anesthesia induction protocols. RESULTS All results were within established reference ranges. For many variables, statistically significant but clinically irrelevant differences were detected between samples collected by direct venipuncture and those collected by the push-pull technique but not between the 2 anesthesia induction protocols. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated the push-pull technique was an acceptable method for collection of blood samples from dogs for venous blood gas analysis that could be used instead of direct venipuncture for patients with patent IV catheters.

Retrospective evaluation of the prevalence, risk factors, management, outcome, and necropsy findings of acute lung injury and acute respiratory distress syndrome in dogs and cats: 29 cases (2011-2013)

OBJECTIVE

To determine the prevalence and risk factors for veterinary acute lung injury (VetALI) and veterinary acute respiratory distress syndrome (VetARDS), assess mechanical ventilation settings and patient outcomes, and to evaluate the relationship of clinical diagnoses with necropsy findings.

DESIGN

Retrospective study.

SETTING

University teaching hospital.

ANIMALS

Twenty-four dogs and 5 cats with a clinical diagnosis of VetALI or VetARDS. Control population includes 24 dogs and 5 cats with a clinical diagnosis of respiratory disease other than VetALI or VetARDS.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

VetALI and VetARDS were diagnosed in 3.2% of dogs and 1.3% of cats presenting to the ICU. Systemic inflammatory response syndrome was the most common inciting condition (16/24 dogs, 2/5 cats), followed by vomiting and subsequent aspiration of gastric contents (9/24 dogs), sepsis (5/24 dogs, 3/5 cats), multiple transfusions (4/24 dogs), trauma (3/24 dogs), and adverse drug reactions (1/24 dogs, 1/5 cats).  None of these conditions were found to be significantly associated with a risk of development of VetALI or VetARDS when compared to controls. Twelve dogs (50%) and 4 cats (80%) underwent mechanical ventilation for a median duration of 18 hours in dogs (range: 6-174 h) and 15.5 hours in cats (range: 6-91 h). Overall, 3/29 patients survived to discharge including 2/24 dogs and 1/5 cats. Necropsy results were available for 8/22 dogs and 3/4 cats. A total of 6/8 dogs (75%) dogs and 3/3 (100%) cats met the histopathologic criteria for diagnosis of VetALI or VetARDS.

CONCLUSIONS

VetALI and VetARDS can cause life-threatening respiratory distress in dogs and cats necessitating mechanical ventilation in 50% of dogs and 80% of cats in this study. These diseases are associated with a poor clinical outcome and a high rate of humane euthanasia.

Survival analysis of hypotensive cats admitted to an intensive care unit with or without hyperlactatemia: 39 cases (2005-2011)

OBJECTIVE To examine the association between blood lactate concentration and survival to hospital discharge in critically ill hypotensive cats. DESIGN Retrospective case series. ANIMALS 39 cats admitted to an intensive care unit of a university veterinary hospital between January 2005 and December 2011 for which blood lactate concentration was recorded ≤ 1 hour before or after a Doppler-derived arterial blood pressure measurement ≤ 90 mm Hg (ie, hypotension) was obtained. PROCEDURES Medical records of each cat were reviewed to assess survival to hospital discharge, illness severity, duration of hospitalization, age, body weight, and PCV. Results were compared between hypotensive cats with and without hyperlactatemia (blood lactate concentration ≥ 2.5 mmol/L). RESULTS 6 of 39 (15%) hypotensive cats survived to hospital discharge. Twelve (31%) cats were normolactatemic (blood lactate concentration < 2.5 mmol/L), and 27 (69%) were hyperlactatemic. Hypotensive cats with normolactatemia had a higher blood pressure and higher survival rate than hypotensive cats with hyperlactatemia. Five-day Kaplan-Meier survival rates were 57% for normolactatemic cats and 17% for hyperlactatemic cats. Age, body weight, duration of hospitalization, PCV, and illness severity did not differ significantly between hypotensive cats with and without hyperlactatemia. CONCLUSIONS AND CLINICAL RELEVANCE Hypotensive, normolactatemic cats in an intensive care unit had a significantly greater chance of survival to hospital discharge than their hyperlactatemic counterparts. Blood lactate concentration may be a useful prognostic indicator for this patient population when used in conjunction with other clinical and laboratory findings.

Retrospective evaluation of shortened prothrombin time or activated partial thromboplastin time for the diagnosis of hypercoagulability in dogs: 25 cases (2006-2011)

OBJECTIVE

To evaluate the relationship between shortened prothrombin time (PT) or activated partial thromboplastin time (aPTT) values, clinical findings associated with hypercoagulability, suspicion of pulmonary thromboembolism (PTE), D-dimer concentrations, and thromboelastogram (TEG) indices.

DESIGN

Retrospective observational study from 2006 to 2011.

SETTING

University veterinary teaching hospital.

ANIMALS

Twenty-three dogs with TEG tracings and shortened PT or aPTT values and 23 control dogs with TEG tracings and normal PT and aPTT values.

MEASUREMENTS AND MAIN RESULTS

Parameters evaluated included signalment, coagulation testing results (PT, aPTT, D-dimer concentration), TEG measurements (R, K, α, maximal amplitude) and calculated clotting index, findings of clinical hypercoagulability (thrombosis of intravenous/intra-arterial catheters, vessel thrombosis, and suspected PTE). Dogs with shortened PT or aPTT had significantly more thrombus formation (P = 0.038), suspicion of PTE (P < 0.001), and increased D-dimer concentration (P < 0.001) compared to dogs with normal PT and aPTT values. There were no significant findings when compared to TEG values.

CONCLUSIONS

A shortened PT or aPTT in dogs may be indicative of a hypercoagulable state as evidenced by an increased incidence of thrombosis, frequency of suspected PTE, and increased circulating D-dimers. A prospective study is warranted to further evaluate the use of PT and aPTT to diagnose hypercoagulable states.

Survival analysis of critically ill dogs with hypotension with or without hyperlactatemia: 67 cases (2006-2011)

OBJECTIVE

To determine whether critically ill hypotensive dogs without hyperlactatemia have the same prognosis as critically ill hypotensive dogs with hyperlactatemia.

DESIGN

Retrospective case series.

ANIMALS

67 critically ill dogs with hypotension.

PROCEDURES

Medical records were searched from January 2006 through December 2011 for dogs that were hospitalized in the intensive care unit and that had hypotension and measurement of blood lactate concentration. Blood lactate concentration, systolic blood pressure, and survival rate were compared between hypotensive dogs with and without hyperlactatemia.

RESULTS

19 of 67 (28%) dogs survived and were discharged from the hospital. Hypotensive dogs without hyperlactatemia had a significantly higher systolic blood pressure and were 3.23 (95% confidence interval, 1.04 to 9.43) times as likely to survive, compared with hypotensive dogs with hyperlactatemia. Age, weight, severity of clinical illness, and duration of hospitalization did not differ significantly between hypotensive dogs with and without hyperlactatemia.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested that hypotensive dogs without hyperlactatemia had a better prognosis and chance of surviving to hospital discharge than did hypotensive dogs with hyperlactatemia. Because blood lactate concentration was negatively associated with systolic blood pressure and survival probability, it may be a useful metric for determining the prognosis of hypotensive dogs.

Controversies in the use of fresh frozen plasma in critically ill small animal patients

OBJECTIVE

To review the literature supporting or discouraging the use of fresh frozen plasma (FFP) transfusion in critically ill patients.

DATA SOURCES

Human and animal publications were searched using PubMed without time limits and the following keywords were used: "fresh frozen plasma," "coagulopathy," "hypocoagulable state," "hypercoagulable states," and "critical illness."

HUMAN DATA SYNTHESIS

The commonly used tests of coagulation (eg, prothrombin time, activated partial thromboplastin time, international normalized ratio) are poorly predictive of clinical bleeding. FFP use in critically ill patients is unlikely to result in improved outcomes and may be associated with increased risks.

VETERINARY DATA SYNTHESIS

There is insufficient evidence to make definitive conclusions regarding the use of FFP in critically ill animals, but clinical studies are underway that may provide further data that clarify the optimal use of FFP in animals.

CONCLUSIONS

The use of FFP in critically ill patients remains controversial. In the absence of clinical bleeding or a risk for clinical bleeding associated with a planned procedure, treatment use of FFP is not recommended in human patients. There are insufficient data in critically ill animals to enable formulation of recommendations. Further research is warranted in dogs and cats to establish evidence-based guidelines.

Microcirculatory effects of intravenous fluid administration in anesthetized dogs undergoing elective ovariohysterectomy

OBJECTIVE

To assess the microcirculatory effects of IV fluid administration in healthy anesthetized dogs undergoing elective ovariohysterectomy.

ANIMALS

49 client-owned dogs.

PROCEDURES

Dogs were sedated, and anesthesia was induced with propofol and diazepam and maintained with isoflurane in oxygen. Dogs received lactated Ringer's solution (LRS) IV at rates of 0, 10, or 20 mL/kg/h. Videomicroscopy was used to assess and record effects of LRS administration on microcirculation in the buccal mucosa. Measurements of microcirculatory (total vessel density, proportion of perfused vessels, microcirculatory flow index, and perfused vessel density by vessel size [< 20 μm, ≥ 20 μm, and all diameters]) and other physiologic variables (heart rate, Doppler-measured blood pressure, oxygen saturation as measured by pulse oximetry, capillary refill time, and body temperature) were compared among groups at baseline (immediately after anesthetic induction), 30 and 60 minutes afterward, and overall.

RESULTS

Neither the proportion of perfused vessels nor microcirculatory flow index varied among treatment groups at any time point, regardless of vessel size. For vessels < 20 μm in diameter and for all vessels combined, total and perfused vessel density were similar among groups. For vessels ≥ 20 μm in diameter, total vessel density was significantly greater in the 20 mL/kg/h group than in other groups, and perfused vessel density was significantly greater in the 20 mL/kg/h group than in the 0 mL/kg/h group, when all time points were considered. Other physiologic variables were similar among groups.

CONCLUSIONS AND CLINICAL RELEVANCE

Total and perfused vessel density of vessels ≥ 20 μm in diameter (mostly venules) were greatest in dogs that received 20 mL of LRS/kg/h. Further research is required to evaluate clinical importance of these findings.

Evaluation of a rapid bedside scoring system for microcirculation videos acquired from dogs

OBJECTIVE

To appraise a novel scoring system (Bedside Evaluation of Microcirculation [BEM]) to provide qualitative and semiquantitative assessment of canine microcirculatory videos generated by sidestream dark field imaging.

DESIGN

Prospective observational study.

SETTING

University teaching hospital.

ANIMALS

No animals were used in this study. Twenty microcirculatory videos (>20 s in length) acquired from the mucosa adjacent to the upper canine tooth of dogs were selected from a database of sidestream dark field microcirculatory videos with available current standard analysis (CSA).

INTERVENTION

Three observers were trained to evaluate 5 video quality parameters (stability, content, illumination, focus, and pressure) and four perfusion parameters (total vessel density [TVD], capillary vessel density [CVD], perfused vessel density [PVD] and microvascular flow index [MFI]). Quality parameters were scored (excellent [0], sufficient [1], and insufficient [2]) similar to CSA recommendations. Each perfusion parameter was subjectively scored (1 lowest - 5 highest) using sample clips from the training video for comparison. Videos passed quality analysis if no parameter was scored insufficient. Repeatability and reproducibility were evaluated by assessing all films in a random order three times daily for 3 days. Strength of correlation of BEM with CSA for both qualitative and semiquantitative parameters was assessed.

MEASUREMENTS AND MAIN RESULTS

The qualitative evaluation pass/fail assessment matched CSA 86% of the time with individual observer agreements of 84-88%. Agreement with CSA did not change significantly over the study period (84%, 88%, and 84% on days 1, 2, and 3, respectively). No significant correlations were demonstrated between any BEM perfusion parameter and the corresponding CSA values.

CONCLUSIONS

Rapid bedside assessment of microcirculatory video quality can be achieved. However, semiquantitative analysis by BEM demonstrated a lack of correlation with CSA for any of the perfusion parameters assessed.

Feline secondary spontaneous pneumothorax: a retrospective study of 16 cases (2000-2012)

OBJECTIVE

To describe the demographics, clinical characteristics, diagnostic findings, underlying etiologies, treatment, and outcome associated with secondary spontaneous pneumothorax (SSP) in cats; and to identify clinical feature differences among cats with asthma associated secondary spontaneous pneumothorax (AASSP) versus nonasthma-associated secondary spontaneous pneumothorax (NAASSP).

DESIGN

Retrospective case series.

SETTING

University teaching hospital.

ANIMALS

Sixteen client-owned cats with secondary spontaneous pneumothorax.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Domestic short hair was the predominant breed in this study (n = 15). The median age was 8 years old (range: 7 weeks to 17 years) with no sex predilection. Fourteen cats were affected by multi-lobar pulmonary pathology of infectious, inflammatory, or neoplastic causes. Asthma was the most common cause of spontaneous pneumothorax (25%). Ten of 12 treated cats survived the initial episode of spontaneous pneumothorax to discharge with medical management, including all 4 cats with AASSP. Reoccurrence was documented in 4 cats. Pulmonary lobectomy was curative for 1 cat with congenital accessory lung lobe emphysema. No difference in clinical presentation was identified between cats with AASSP and cats with NAASSP.

CONCLUSIONS

Feline SSP is frequently associated with extensive pulmonary pathology. Supportive medical management is most appropriate, except in rare cases with focal congenital abnormalities that may benefit from surgical intervention. AASSP appears to carry a good prognosis for short-term outcome (survival to discharge). Clinical assessment, imaging, and invasive diagnostics were required to differentiate between AASSP and NAASSP.

Ionized calcium concentrations in cats with septic peritonitis: 55 cases (1990-2008)

OBJECTIVE

To report the prevalence of ionized hypocalcemia (iHCa) in cats with septic peritonitis, and to determine whether hypocalcemic cats had increased morbidity and mortality when compared with normocalcemic cats.

DESIGN

Retrospective clinical study.

SETTING

University teaching hospital.

ANIMALS

Fifty-five client-owned cats with septic peritonitis.

MEASUREMENTS

Medical records of 55 cats with confirmed septic peritonitis meeting the study inclusion criteria were reviewed. Information obtained included signalment, cause of peritonitis, length of hospitalization (LOH), length of ICU stay, and outcome. Results from serum biochemical analysis, blood gas analysis, and coagulation testing from the time of diagnosis, and all ionized calcium (iCa) measurements during hospitalization were recorded. Systolic blood pressure, the presence of arrhythmias and administration of vasopressor agents, blood products, and sodium bicarbonate were documented. iCa concentration at the time of diagnosis and lowest recorded value during hospitalization were compared with LOH and length of ICU stay, survival to hospital discharge, and clinical and clinicopathologic data.

MAIN RESULTS

iHCa (iCa<1.20 mmol/L) was found in 89% of cats (49/55) at the time of diagnosis of septic peritonitis and 93% (51/55) at any time during hospitalization. There was no association between the presence or severity of iHCa at diagnosis and survival to hospital discharge. LOH (P=0.046) and duration of ICU stay (P=0.026) were significantly correlated with the lowest iCa recorded during hospitalization. Failure to normalize iCa during hospitalization was associated with a decreased survival rate to discharge (P=0.029) in patients with iHCa. iHCa was not associated with an increased prevalence of hypotension, coagulopathy, arrhythmias, or evaluated therapies.

CONCLUSIONS

iHCa is more prevalent in cats with septic peritonitis than described previously. Failure of iCa to normalize during hospitalization may be a negative prognostic indicator. iHCa may be predictive of a longer LOH and ICU stay, but is not necessarily associated with a poorer prognosis.

Indication, management, and outcome of brachycephalic dogs requiring mechanical ventilation

OBJECTIVES

To evaluate the frequency, and need for mechanical ventilation (MV) in a population of brachycephalic dogs (BD) compared with non-BD. Also, to describe the pre-MV abnormalities, ventilator settings used, the cardiovascular and pulmonary monitoring results and complications encountered in the same BD population. In addition, we sought to identify factors associated with successful weaning and describe outcomes of BD requiring MV.

DESIGN

Retrospective observational study (1990-2008).

SETTING

University Small Animal Teaching Hospital.

ANIMALS

Fifteen BD managed with MV.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Signalment, indication for MV, ventilator settings, arterial blood gas values, duration of MV, complications, and outcome were recorded for each patient enrolled in study. BD were more likely to receive MV than non-BD (P=0.036). Out of the 15 dogs that fulfilled the inclusion criteria 7 (47%) underwent MV for impending respiratory fatigue, 6 (40%) for hypoxemia and 2 for hypercapnea. The most common underlying disease was aspiration pneumonia. Duration of MV ranged from 2 to 240 hours (median 15 hours). Seven patients were weaned (47%). Seven dogs had a temporary tracheostomy tube and 5 of them (71%) were weaned. Dogs that were weaned had a significantly greater preweaning trial PaO₂/FiO₂ ratio than those that were not (359 ± 92 versus 210 ± 57 mm Hg, P=0.025). No significant difference for weaning success between dogs with and those without a tracheostomy was detected (P=0.132). The discharge rate was 27% (all from the respiratory fatigue group).

CONCLUSION

Among all dogs admitted to ICU, BD were more likely to receive MV than non-BD. Aspiration pneumonia was frequently identified as the underlying cause of respiratory compromise. The survival rate for BD undergoing MV was not markedly different from previous studies. Weaning of BD from MV may be facilitated by employing preemptive strategies such as performing tracheostomy tube placements.

Comparison of regular insulin infusion doses in critically ill diabetic cats: 29 cases (1999-2007)

OBJECTIVE

To compare biochemical parameters, neurologic changes, length of hospital stay, and clinical improvement in 3 groups of cats with diabetic ketosis/diabetic ketoacidosis (DK/DKA) prescribed varied doses of regular insulin as a continuous rate of infusion (CRI).

DESIGN

Retrospective study.

SETTING

University teaching hospital.

ANIMALS

Twenty-nine client-owned cats with DK/DKA prescribed a regular insulin CRI.

INTERVENTIONS

Cats were grouped as follows: 7 cats each in Group 1 and 2, (prescribed 1.1 and 2.2 U/kg/d, respectively), and 15 cats in Group 3 (prescribed increasing doses as needed).

MEASUREMENTS AND MAIN RESULTS

None of the groups received the total prescribed dose of insulin. The mean actual dose administered/kg/d ranged from 0.30 (0.21) to 0.87 (0.32) U/kg/d in Groups 1, 2, and 3. There was no difference in mean minimum blood glucose (BG) per 4 hours or change in BG from baseline per 4 hours between Groups 1 and 2 (P=0.63, 0.50). There was no difference between groups regarding the time required to reach a BG ≤ 13.9 mmol/L (250 mg/dL), serum phosphorus or potassium concentrations relative to baseline values (P=0.53, 0.90), length of time until urine or serum ketones were no longer detected (P=0.73), the animal commenced eating (P=0.24), or length of hospital stay (P=0.63). Four of the cats had declining mentation during hospitalization; there were no relationships between osmolality at presentation, either prescribed or administered insulin dose, and mentation changes. Three of the 4 cats with declining mentation survived. Twenty-seven of the 29 cats (93%) survived to discharge.

CONCLUSIONS

In this study, prescribing the published canine dose (2.2 U/kg/d) of regular insulin to cats with DK/DKA does not appear to increase the frequency of adverse neurologic or biochemical sequelae compared with cats that are prescribed the published cat dose (1.1 U/kg/d). The use of a sliding scale for determination of infusion rates significantly reduces the amount of insulin cats receive in this setting. Determination of whether adverse sequelae would occur more frequently if cats with DK/DKA received the full insulin prescribed doses of 1.1, 2.2, or >2.2 U/kg/d is warranted. Further controlled studies are necessary to determine if higher doses of insulin are associated with beneficial effects on morbidity or mortality.

Measurements of microvascular perfusion in healthy anesthetized dogs using orthogonal polarization spectral imaging

OBJECTIVE

To determine normal microvascular assessment parameters for healthy, anesthetized dogs.

DESIGN

Prospective investigational descriptive study.

SETTING

University Teaching Hospital.

ANIMALS

Fifteen client-owned, systemically healthy dogs that were undergoing general anesthesia for an elective procedure.

INTERVENTIONS

A sidestream dark-field videomicroscope probe was placed in the mouth at the mucogingival junction above the canine tooth and 3 video recordings of the microcirculation were made for later analysis by 2 independent, blinded reviewers.

MEASUREMENTS AND MAIN RESULTS

The videos were analyzed to determine the total vessel density, proportion of perfused vessels, microcirculatory flow index, and perfused vessel density. A range of values for these indices were obtained and reported.

CONCLUSIONS

The microcirculation of normal dogs is readily observable using the videomicroscope and recorded video segments can be used to determine microcirculatory measurements. These values may prove useful for comparison in future studies that examine canine microcirculatory parameters.

The association between vascular endothelial growth factor levels and clinically evident peripheral edema in dogs with systemic inflammatory response syndrome

OBJECTIVE

To determine the relationship between plasma vascular endothelial growth factor (VEGF) levels, severity of illness, and edema formation in critically ill dogs.

DESIGN

Prospective, observational, descriptive, clinical study.

SETTING

University Teaching Hospital.

ANIMALS

Twenty-eight dogs.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Physical examination and multifrequency bioimpedance (MFBIA) measurements were performed daily on 28 critically ill dogs with evidence of severe inflammatory disease and compared with the corresponding plasma VEGF levels. The change in VEGF values and the relationship between MFBIA measurements and clinical evidence of edema were also examined. Eighteen dogs had a positive VEGF level, 12 dogs had clinical evidence of edema, and 7 dogs had both a positive VEGF level and clinical evidence of edema. There was no statistically significant correlation between VEGF levels and the presence of edema on physical examination (P=0.2). VEGF values were also evaluated with respect to WBC count, survival prediction index, presence of known sepsis, change in extracellular water, and outcome. No statistical relationship could be identified between VEGF levels in the blood of dogs with inflammatory disease and their survival prediction index (P=0.1), the WBC count (P=0.2), or presence of sepsis (P=0.2). Dogs with a VEGF level >70 pg/mL (n=3) were less likely to survive (P=0.04). Because of high variability within and between animals, conclusions regarding changes in MFBIA could not be made, suggesting that this technology requires further refinement and investigation in critically ill dogs.

CONCLUSIONS

A relationship between VEGF and clinically evident increased vascular permeability was not found in this study. Dogs with markedly elevated VEGF levels may be more likely to die, but further studies are needed to determine the diagnostic and prognostic value of VEGF in critically ill dogs.

Relationship between Doppler blood pressure and survival or response to treatment in critically ill cats: 83 cases (2003-2004)

OBJECTIVE

To evaluate the relationship between Doppler blood pressure (DBP) and survival or response to treatment in critically ill cats.

DESIGN

Retrospective case series.

ANIMALS

83 cats.

PROCEDURES

Medical records from cats admitted to the intensive care unit with at least 2 recorded DBP measurements were included in the study. Hypotension was defined as 1 or more DBP measurements d 90 mm Hg. Change in blood pressure, survival to hospital discharge, heart rate, rectal temperature, PCV, plasma pH, serum ionized calcium concentration, disease process, body weight, age, duration of hospitalization, and catecholamine treatment were also evaluated.

RESULTS

39 cats were included in the hypotensive group, and 44 were consistently normotensive. Overall survival rate was 53% (44/83), with a significantly higher mortality rate in the hypotensive group (64% vs 32%). Among other variables, only low rectal temperature and low PCV were significantly associated with hypotension. Hypotensive cats with an increase in blood pressure of >or=20 mm Hg during hospitalization were more likely to survive to discharge (mortality rate, 69% vs 17%).

CONCLUSIONS AND CLINICAL RELEVANCE

Hypotensive cats had increased mortality rate with lower rectal temperatures and lower PCV, compared with normotensive critically ill cats. The implications of these findings with regard to treatment remain to be elucidated, but addressing these abnormalities may be appropriate.

Idiopathic localized eosinophilic synovitis in a cat

A 4-year-old male castrated Seal Point Himalayan cat was presented for evaluation of right thoracic limb lameness of 6 weeks duration. Synovial fluid analysis of the swollen right carpal joint revealed a mixed cell synovitis, with a total nucleated cell count of 13,200/microliter and 34% eosinophils. A diagnosis of idiopathic localized eosinophilic arthritis was made. Additional clinical and diagnostic findings included mild lymphadenopathy with lymphoid hyperplasia and an antinuclear antibody titer of 1:320. Lack of multisystem involvement made systemic lupus erythematosis unlikely. Immunosuppressive therapy with oral prednisone alleviated the lameness. Eosinophilic synovitis has not previously been reported in cats. An immune-mediated mechanism was likely in this case; however, the exact etiology remains unknown.

Multiple myeloma in cats: variable presentation with different immunoglobulin isotypes in two cats

Multiple myeloma was diagnosed in two cats with monoclonal hyperglobulinemia, proteinuria, and plasma cell proliferations in bone marrow. An immunoglobulin G-producing myeloma occurred in the vertebral bone marrow of one cat, and twice responded to surgical reduction followed by a combination of local irradiation and chemotherapy. The cat's survival time was approximately 2 years. The other myeloma in a cat that presented with hypercalcemia and renal insufficiency involved visceral organs and produced a biclonal peak due to immunoglobulin A dimer formation on serum electrophoresis. This cat's tumor did not respond to chemotherapy.