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

Evaluation of Blood Lactate, Heart Rate, Blood Pressure, and Shock Index, and Their Association with Prognosis in Calves

Diseases in young calves received as emergencies are often associated with hypovolemic and/or septic shocks. The objectives of our study were to (1) assess the correlation between clinical hemodynamic parameters and blood L-lactates (LAC), systolic blood pressure (SBP), and the shock index (SI) recorded upon arrival; and (2) to evaluate how these parameters were related to short-term outcomes in calves under 4 months of age presented as emergencies. We conducted a single-observer prospective observational study on calves aged from 1 day to 4 months, presented to the Veterinary Clinic for Ruminants of Liège from December 2020 to May 2022. Forty-five calves were included in the study. The statistical analysis revealed a significant correlation between LAC and heart rate (r = 0.570; p < 0.05) and LAC and SI (r = 0.373; p < 0.05). A high LAC value at admission was significantly associated with a negative outcome (death) (p < 0.05). In calves suffering from obstructive digestive diseases, the SI was related to the outcome and the analysis indicated a cut-off value of 1.13 (Se = 0.77, Spe = 1). In conclusion, in our study, the initial blood L-lactate value was correlated with heart rate, the shock index, and the clinical shock score, and admission hyperlactatemia was associated with a poor prognosis in calves under 4 months of age. In this cohort, the shock index in calves suffering from digestive diseases was linked with mortality.

Propofol versus sodium thiopentone for the treatment of status epilepticus and refractory status epilepticus in dogs

AIMS

To compare the effect on mortality and length of hospital stay of propofol with that of sodium thiopentone for the management of dogs with status epilepticus (SE) and refractory status epilepticus (RSE).

METHODS

In this cohort study, medical records of a veterinary referral clinic in Argentina were retrospectively searched for dogs that were hospitalised and required induction of therapeutic coma (TC) with either propofol or sodium thiopentone for the management of SE or RSE of any cause. A logistic regression model was performed to evaluate the association between the type of anaesthetic used and in-hospital mortality adjusting for the type of epilepsy (idiopathic, structural, or reactive). Kaplan-Meier estimated survival curves for the length of hospital stay by the type of anaesthetic drug were compared using the log-rank test (deaths were considered censored events). Cox proportional hazards regression was used to estimate hazard ratios for time to hospital discharge, unadjusted and adjusted for type of epilepsy.

RESULTS

A total of 24 dogs with SE were included in the study: eight treated with propofol and 16 treated with sodium thiopentone. Four dogs treated with propofol (proportion = 0.50; 95% CI = 0.15-0.84), and eight treated with sodium thiopentone (proportion = 0.50; 95% CI = 0.50-0.74) died during hospitalisation. The median hospitalisation time was 43 (IQR 24-56) hours for dogs that were treated with propofol and 72 (IQR 64-96) hours for dogs that were treated with sodium thiopentone. There was no evidence of a difference in the median duration of TC in dogs treated with propofol (12 (IQR 8-24) hours) or with sodium thiopentone (12 (IQR 7.5-20) hours; p = 0.946). In the logistic regression model, no evidence of association between the anaesthetic protocol for the management of RSE and in-hospital mortality, adjusted for the type of epilepsy, was found (OR 1.09 (95% CI = 0.17-6.87); p = 0.925). Cox regression analysis revealed a difference in the time to hospital discharge, adjusted by the type of epilepsy, between treatment groups (HR = 0.05 (95% CI = 0.01-0.54); p = 0.013).

CONCLUSIONS AND CLINICAL RELEVANCE

The time spent in hospital before discharge was longer in dogs with RSE treated with sodium thiopentone compared to those treated with propofol. However, as the sample size was very small, the results obtained in the present study should be analysed with caution. Further studies including a greater number of dogs are required.

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.

Glucocorticoid metabolism in critically ill dogs (Canis lupus familiaris)

Critical illness due to sepsis is a major global health concern associated with a high burden of mortality and cost. Glucocorticoid dysregulation in human sepsis is associated with poorer outcomes. This study examines glucocorticoid metabolism in septic canine patients to delineate elements of cellular dysregulation in common with critically ill humans and explore potential differences. This was a prospective case-control study conducted in the veterinary specialist critical care departments of two University teaching hospitals. Critically ill canine patients with naturally occurring sepsis or septic shock were compared with an in-hospital control population. Serum total, bound, and free cortisol concentrations were increased in septic shock (P < 0.001), and higher bound cortisol was associated with nonsurvival (P = 0.026). Urinary Gas Chromatography-Tandem Mass Spectrometry was performed to assess urinary glucocorticoid metabolites and estimate intracellular glucocorticoid metabolism. Decreased renal 11β-hydroxysteroid dehydrogenase 2 (11βHSD2) activity inferred from increased urinary cortisol-to-cortisone ratio was observed in critically ill dogs (P < 0.001). Decreased 11βHSD2 activity (P = 0.019) and increased A-ring reduction of cortisone (P = 0.001) were associated with nonsurvival within the critically ill dogs. Intriguingly, two dogs were identified with low circulating total cortisol (<2 mg/dL) associated with increased A-ring reduction of cortisol, not previously described. Investigation of spontaneous canine sepsis and septic shock reveals dysregulation of cortisol to cortisone conversion similar to that observed in human patients, but with differences in A-ring reduction compared with those reported in humans. In addition, two dogs with high levels of cortisol inactivation associated with low circulating cortisol concentrations were identified.

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.

Clinical use of plasma lactate concentration. Part 2: Prognostic and diagnostic utility and the clinical management of hyperlactatemia

OBJECTIVE

To review the current literature pertaining to the use of lactate as a prognostic indicator and therapeutic guide, the utility of measuring lactate concentrations in body fluids other than blood or plasma, and the clinical management of hyperlactatemia in dogs, cats, and horses.

DATA SOURCES

Articles were retrieved without date restrictions primarily via PubMed, Scopus, and CAB Abstracts as well as by manual selection.

HUMAN AND VETERINARY DATA SYNTHESIS

Increased plasma lactate concentrations are associated with increased morbidity and mortality. In populations with high mortality, hyperlactatemia is moderately predictive in identifying nonsurvivors. Importantly, eulactatemia predicts survival better than hyperlactatemia predicts death. Consecutive lactate measurements and calculated relative measures appear to outperform single measurements. The use of lactate as a therapeutic guide has shown promising results in people but is relatively uninvestigated in veterinary species. Increased lactate concentrations in body fluids other than blood should raise the index of suspicion for septic or malignant processes. Management of hyperlactatemia should target the underlying cause.

CONCLUSION

Lactate is a valuable triage and risk stratification tool that can be used to separate patients into higher and lower risk categories. The utility of lactate concentration as a therapeutic target and the measurement of lactate in body fluids shows promise but requires further research.

Deep tissue culture and hemoculture in dogs with wounds and sepsis

ABSTRACT: Contaminated and infected wounds occur very frequently in veterinary medicine and can cause systemic inflammatory response syndrome, sepsis, and death. This study aimed to test the feasibility of collecting wound material by deep-tissue or punch biopsy for microbial culture, determine the frequency of bacteria in the wound(s) and blood cultures and the susceptibility of these microbes to antimicrobials, and evaluate clinical parameters that could be related to prognosis. Thirty dogs with wounds and signs of SIRS/sepsis were included in this study. Bacteria were isolated from all wounds and 41 bacterial isolates could be identified based on culture of the materials collected by punch biopsy; 53.66% of the isolates were gram-negative, mainly involving Pseudomonas aeruginosa, Klebsiella pneumoniae, and Enterococcus spp., and 46.34% were gram-positive bacteria such as Streptococcus spp., Enterococcus spp., and Staphylococcus spp. The survival rate was 66.67%. Based on blood culture analysis, we identified bacteremia in seven patients, predominantly of gram-negative bacteria, which negatively affected patient survival, as six dogs died. Hypoglycemia (≤60mg/dL) and severe hyperglycemia (≥180mg/dL) also negatively affected survival as 23.33% of the hypo/hyperglycemic dogs died. Factors such as blood lactate level at admission and hematocrit levels, and mean arterial pressure were not significantly correlated with death or survival of the dogs.

Assessment of a portable lactate meter for field use in the white rhinoceros (<i>Ceratotherium simum</i>)

Blood lactate is a predictor of mortality in critically ill humans and animals. Handheld lactate meters have the potential to be used in the field to evaluate the condition of severely injured rhinoceroses but have not been compared with laboratory-based methods. Agreement between a handheld lactate meter and a laboratory method was assessed, as was the stability of rhino blood lactate in the anticoagulant sodium fluoride/potassium oxalate (fluoride/oxalate). Blood samples were obtained from 53 white rhinos that had been immobilised for management reasons. Lactate was measured by means of a handheld meter using whole blood in heparin (WBHEP), whole blood in fluoride/oxalate (WBFO) and fluoride/oxalate plasma (PFO). Results were recorded in both blood (BL) and plasma (PL) modes and compared to an established laboratory method for measuring plasma lactate. To assess the stability of lactate over time, blood lactate in fluoride/oxalate was measured on the handheld meter at intervals for up to 91 h. Agreement was best using WBFO in PL mode, with small bias (−0.16), tight 95% limits of agreement (LOA) (−1.46, 1.14) and a Pc (95% CI) of 0.97 (0.92, 0.99). The agreement was improved for all sample types when using the PL mode compared to the blood lactate (BL) mode. Blood lactate was stable in fluoride/oxalate for 91 h, with a mean change from baseline of 0.15 (−0.178, 0.478) mmol/L (mean, 95% CI). The handheld meter was found to be suitable for field use in white rhinos but provided more reliable results with the device in PL mode. Furthermore, rhino blood lactate was found to be stable in fluoride/oxalate for as long as 3 days.

Effect of Intravenously Administered Crystalloid Solutions on Acid-Base Balance in Domestic Animals

Intravenous fluid therapy can alter plasma acid-base balance. The Stewart approach to acid-base balance is uniquely suited to identify and quantify the effects of the cationic and anionic constituents of crystalloid solutions on plasma pH. The plasma strong ion difference (SID) and weak acid concentrations are similar to those of the administered fluid, more so at higher administration rates and with larger volumes. A crystalloid's in vivo effects on plasma pH are described by 3 general rules: SID > [HCO3-] increases plasma pH (alkalosis); SID < [HCO3-] decreases plasma pH (alkalosis); and SID = [HCO3-] yields no change in plasma pH. The in vitro pH of commercially prepared crystalloid solutions has little to no effect on plasma pH because of their low titratable acidity. Appreciation of IV fluid composition and an understanding of basic physicochemical principles provide therapeutically valuable insights about how and why fluid therapy can produce and correct alterations of plasma acid-base equilibrium. The ideal balanced crystalloid should (1) contain species-specific concentrations of key electrolytes (Na+ , Cl- , K+ , Ca++ , Mg++ ), particularly Na+ and Cl- ; (2) maintain or normalize acid-base balance (provide an appropriate SID); and (3) be isosmotic and isotonic (not induce inappropriate fluid shifts) with normal plasma.

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.

Effects of various factors on Doppler flow ultrasonic radial and coccygeal artery systolic blood pressure measurements in privately-owned, conscious dogs

OBJECTIVE

The purpose of this study was to assess the effects of age, body condition score (BCS) and muscle condition score (MCS) on indirect radial and coccygeal Doppler systolic arterial blood pressure (SAP) measurements in dogs.

METHODS

Sixty-two privately-owned dogs were enrolled between June and July 2016. The BCS and MCS were determined by two investigators. Blood pressure was measured per published guidelines and using headphones, and the order of measurement site was randomized. Dogs were positioned in right lateral recumbency for radial measurements and sternal recumbency or standing for coccygeal measurements. Associations between SAP and other variables were assessed by correlation coefficients and analysis of covariance.

RESULTS

Radial and coccygeal SAP measurements were moderately correlated (r = 0.45, P < 0.01). Radial SAP measurements were higher than coccygeal SAP measurements (mean difference 9 mmHg, P < 0.01), but discordance occurred in both directions. No difference was observed between the first measurement taken, the average of measurements 2-6, or the average of all 6 measurements for either the radial (128, 129, and 129 mmHg; P = 0.36) or coccygeal (121, 122, and 122 mmHg; P = 0.82) site. Associations were not found between SAP measurements for either site and age, weight, BCS, MCS, anxiety score, or cuff size. Heart rate decreased significantly from the start of acclimation to the end of the first data collection series regardless of site (P < 0.01).

CONCLUSIONS AND CLINICAL RELEVANCE

Initial measurement site can be based on patient and operator preference given lack of associations with patient variables, but the same site should be used for serial SAP measurements given discordant results between sites.

Point of Care Measurement of Lactate

Lactate is generated as a consequence of anaerobic glycolysis by all tissues of the body. Increased l-lactate, the isoform produced by most mammals, reflects increased anaerobic metabolism secondary to tissue hypoperfusion or tissue hypoxia in most clinical situations, and is called type A lactic acidosis. The utility of lactate measurement and serial lactate monitoring in veterinary patients has been demonstrated in multiple studies. Blood lactate concentration is significantly elevated in many disease processes including septic peritonitis, immune-mediated hemolytic anemia, Babesiosis, trauma, gastric dilation and volvulus, and intracranial disease. Lactate clearance can be used to assess response to fluid therapy, cardiovascular therapeutics, and blood product transfusion in patients affected by type A lactic acidosis. Lactate concentration in peritoneal, pericardial, and synovial fluid can also be used as a diagnostic tool. Point of care analyzers such as the Lactate Pro, Lactate Scout, Accutrend, iSTAT, and Lactate Plus have been shown to be accurate lactate measurement instruments in small animal patients.

Assessment of Fluid Balance and the Approach to Fluid Therapy in the Perioperative Patient

Perioperative patients can be highly dynamic and have various metabolic, physiologic, and organ system derangements that necessitate smart monitoring strategies and careful fluid therapy. The interplay between changing patient status, therapeutic interventions, and patient response makes effective monitoring crucial to successful treatment. Monitoring the perioperative patient and an approach to fluid therapy are discussed in this text.