Optimal endpoints of resuscitation and early goal-directed therapy

Comparison between dexmedetomidine and a combination of medetomidine-vatinoxan on muscle tissue saturation in privately-owned adult dogs undergoing intradermal testing

This double-blinded randomized cross-over study compared the muscle tissue oxygen saturation (StO2) measured at the sartorius muscle after intramuscular (IM) injection of dexmedetomidine hydrochloride (HCl) and co-administration of vatinoxan HCl, a peripheral α2-adrenoceptor antagonist, and medetomidine HCl in healthy privately-owned dogs undergoing intradermal testing (IDAT). After written owner consent, dogs received IM injections of either dexmedetomidine (0.5 mg/m2, DEX) or medetomidine (1 mg/m2) and vatinoxan (20 mg/m2) (MVX). Once sedated, intradermal injections were given on the lateral thorax of each dog, and the study was repeated with the alternative sedation on the opposite side one week later. At the end of the study, sedation was reversed with atipamezole (5 mg/m2). Depth of sedation, cardiopulmonary parameters, StO2, and rectal temperature were recorded and compared using mixed effect linear models (α ≤ 0.05). MVX achieved adequate sedation faster [median (interquartile range), 10 (8, 10) minutes] compared to DEX [18 (15, 22) minutes; hazard ratio = 7.44, p = 0.013), with higher scores at 10- and 15-min post-injection. StO2 was significantly reduced for 30 min after injection (p < 0.001), independently of the treatment (p = 0.68). Cardiopulmonary variables favored MVX. However, higher heart rate did not correlate with improved StO2. There was no difference in either subjective or objective assessment of the wheal size between sedations (p > 0.05). Both sedation protocols, MVX and DEX, were deemed suitable for IDAT in dogs, with mild reductions in StO2 measured at the sartorius muscle that were not significantly different between treatments.

Evaluation of Eosinopenia as a SIRS Biomarker in Critically Ill Horses

Systemic inflammatory response syndrome (SIRS) is a very common finding in critically ill patients. To accurately identify patients with SIRS and those who need intensive care, several markers have been evaluated, including cortisol, WBC or lactate. It is widely known that a stress leukogram includes eosinopenia as one of its main markers (neutrophilia, eosinopenia, lymphopenia and mild monocytes). It is known that cortisol concentration in plasma is the main stress biomarker and is strongly correlated with the severity of disease in horses. However, it is not possible to measure this parameter routinely in clinical conditions. Hence, in this study it was hypothesized that the eosinophil count could be a reliable parameter to identify critically ill horses. Horses included in this study were divided into three groups: Group A (sick horses received at the Emergency Unit which did not fulfil the criteria for SIRS), Group B (horses that meet two or more criteria for inclusion in the definition of SIRS) and a control group of healthy horses. In this study, horses with SIRS showed lower eosinophil counts than healthy horses. Moreover, non-surviving horses exhibited lower eosinophil counts than survivors. Eosinopenia could be used to identify horses with SIRS and can be useful as a prognostic marker.

High-rise syndrome in cats and dogs

OBJECTIVE

To review the current literature pertaining to the pathophysiology, diagnosis, and treatment of injuries sustained from high-rise syndrome in cats and dogs.

ETIOLOGY

High-rise syndrome is defined as a fall from a height of 2 or more stories that results in a constellation of injuries, including thoracic, abdominal, orthopedic, and orofacial trauma. Animals often fall after slipping from windowsills, engaging in mating behavior, or chasing prey. Cats suffer less severe injuries than dogs due to their "righting reflex" and smaller body mass. Affected animals are younger, and the frequency of falls is higher in warmer months.

DIAGNOSIS

Physical examination coupled with radiographs, ultrasound, and computed tomography can diagnose a myriad of injuries that include pneumothorax, pleural or abdominal effusion, orthopedic fractures, and orofacial injuries. Bloodwork may identify anemia, thrombocytopenia, or increases in hepatic, renal, or pancreatic values consistent with trauma to these organs. Serial venous or arterial blood gas can help determine the severity of respiratory compromise and influence resuscitative efforts. Traditional coagulation tests and thromboelastography can assess trauma-induced coagulopathy and guide transfusion therapy.

THERAPY

Animals presenting in shock require hemodynamic stabilization. Initial resuscitation may incorporate crystalloids, colloids, blood products, and analgesics. Thoracic injuries may require oxygen, thoracocentesis, chest tube placement, and mechanical ventilation. Fractures and wounds are decontaminated and splinted/bandaged, with definitive fixation pursued after stabilization. Abdominal injuries are managed medically unless there is severe ongoing bleeding, sepsis, or injury to the urinary tract.

PROGNOSIS

In feline high-rise syndrome, the prognosis is generally excellent following treatment, with survival exceeding 90%. Canine literature is sparse. The largest retrospective study reported a >90% survival to discharge and a greater need for surgical stabilization in this species. There are no prognostic factors identified that are associated with survival for either species.

Investigation of biomarkers for impending fluid overload in a feline acute haemorrhage-resuscitation model

OBJECTIVE

To determine biomarkers for impending fluid overload during intravenous fluid administration in a feline haemorrhage-resuscitation model.

STUDY DESIGN

Randomized crossover study.

ANIMALS

A group of six domestic cats (mean age and weight: 21 months; 4.9 kg, respectively).

METHODS

The cats underwent three treatments, 2 months apart. They were anaesthetized and instrumented to measure a range of physiological, blood gas, haematological and biochemical variables over time. Samples were taken during a health check, before haemorrhage, after haemorrhage and then at 30 minute intervals during fluid resuscitation and 24 hours later. The three treatments were: 1) control, sham haemorrhage and resuscitation; 2) lactated Ringer's solution (LRS); and 3) 6% tetrastarch 130/0.4 (Vol) where the cats underwent a controlled haemorrhage then resuscitation by administering LRS and Vol at 60 and 20 mL kg^-1 hour^-1, respectively, for 120 minutes. Fluid overload was identified by nasal discharge and radiographic evidence. Biomarkers were variables that exceeded the reference interval for cats during treatment. Potential biomarkers were analysed using receiver operating characteristic curves (p < 0.05).

RESULTS

Mean ± standard deviation total blood loss was 10.2 ± 2.3, 29.3 ± 9.0 and 29.1 ± 6.3 mL kg^-1 for control, LRS and Vol, respectively. The total volume of LRS and Vol administered was 120 and 40 mL kg^-1, respectively. Haematocrit, albumin, magnesium, chloride-to-sodium ratio and sodium-chloride difference were identified as potential biomarkers. These variables exceeded the reference intervals from 30 minutes of resuscitation onwards. A chloride-to-sodium ratio > 0.84 was the most sensitive (90%) and specific (75%) of all potential biomarkers.

CONCLUSIONS AND CLINICAL RELEVANCE

Changes in physiological variables, haematocrit and albumin were poor biomarkers of impending fluid overload compared with electrolytes. Finding the ideal biomarker to identify impending fluid overload of commonly used intravenous fluids should improve the safety of their administration in cats.

Perioperative Outcome in Dogs Undergoing Emergency Abdominal Surgery: A Retrospective Study on 82 Cases (2018-2020)

Emergency abdominal surgery carries high morbidity and mortality rates in human medicine; however, there is less evidence characterising the outcome of these surgeries as a single group in dogs. The aim of the study was to characterise the clinical course, associated complications and outcome of dogs undergoing emergency abdominal surgery. A retrospective study was conducted. Dogs undergoing emergency laparotomy were included in the study. Logistic regression analysis was performed to identify variables correlated with death and complications. Eighty-two dogs were included in the study. The most common reason for surgery was a gastrointestinal foreign body. Overall, the 15-day mortality rate was 20.7% (17/82). The median (range) length of hospitalisation was 3 (0.5-15) days. Of the 82 patients, 24 (29.3%) developed major complications and 66 (80.5%) developed minor complications. Perioperative factors significantly associated with death included tachycardia (p < 0.001), hypothermia (p < 0.001), lactate acidosis (p < 0.001), shock index > 1 (p < 0.001), leukopenia (p < 0.001) and thrombocytopenia (p < 0.001) at admission, as well as intraoperative hypotension (p < 0.001) and perioperative use of blood products (p < 0.001). The results of this study suggest that mortality and morbidity rates after emergency abdominal surgery in dogs are high.

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.

Prospective evaluation of plasma lactate parameters for prognosticating dogs with shock

OBJECTIVE

To determine whether admission venous plasma lactate concentration, serially calculated lactate variables, or the Acute Patient Physiologic and Laboratory Evaluation (APPLE_fast ) score could discriminate hospital survivors from non-survivors in dogs presenting to the emergency department with clinical signs of shock.

DESIGN

Prospective case series performed over a 24-month period.

SETTING

Large urban private teaching hospital.

ANIMALS

Seventy-one dogs admitted to the ICU with initial peripheral venous plasma lactate concentration > 2.5 mmol/L and clinical and hemodynamic parameters consistent with shock.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Heart rate, systolic blood pressure, temperature, initial venous plasma lactate, and APPLE_fast score were recorded at admission. Lactate concentrations were serially recorded at predefined time points and used to calculate lactate variables, including lactime (time lactate > 2.5 mmol/L), lactate clearance ([lactate_initial - lactate_delayed ]/ lactate_initial × 100), and LAC_AREA (area under the lactate concentration versus time curve). Primary outcome was survival to discharge. Overall survival rate was 61%. Admission plasma lactate did not differ between groups (P = 0.28). Lactime was shorter in survivors vs non-survivors (P = 0.03). Lactate clearance at hours (h) 1, 4, 10, and 16 was greater in survivors vs non-survivors (P < 0.05). Final plasma lactate clearance differed between groups (P < 0.05). LAC_AREA at time intervals 1 to 4 hours, 4 to 10 hours, 10 to 16 hours, and 16 to 24 hours was larger in non-survivors vs survivors (P < 0.05). Total LAC_AREA did not differ between groups (P = 0.51). Admission APPLE_fast was not different between survivors and non-survivors (P = 0.16).

CONCLUSIONS

While neither single APPLE_fast nor admission plasma lactate concentration could discriminate between hospital survivors and non-survivors, measures of lactate clearance can prognosticate survival in dogs with shock.

Acute Respiratory Failure after Administration of Hydrogen Peroxide as an Emetic in a Cat

OBJECTIVE AND CASE SUMMARY

This case report describes a 5-year-old domestic short-haired cat that was orally administered with 4 mL of 3% hydrogen peroxide by the owner after suspecting ingestion of a foreign body by the cat. Shortly after the administration, the cat developed severe respiratory distress. Thoracic radiography showed an interstitial-to-alveolar pulmonary pattern, while echocardiography and heart injury markers ruled out a cardiac origin. Intensive management with oxygen, diuretics, bronchodilators, and sedation resulted in survival of the cat without further respiratory complications.

NEW AND UNIQUE INFORMATION PROVIDED

To the best of our knowledge, this is the first report of a lung injury and acute respiratory failure after administration of hydrogen peroxide in a cat with successful management.

Utility of admission lactate concentration, lactate variables, and shock index in outcome assessment in dogs diagnosed with shock

OBJECTIVE

To determine whether admission venous plasma lactate concentration, calculated lactate variables, or shock index (SI) could discriminate hospital survivors from nonsurvivors in dogs admitted with shock.

DESIGN

Prospective investigation performed over a 19-month period.

SETTING

Large urban private teaching hospital.

ANIMALS

Twenty-three dogs consecutively admitted to the ICU from January 2008 to July 2009 with initial peripheral venous plasma lactate concentration >2 mmol/L (18.0 mg/dL) and clinical and hemodynamic parameters consistent with shock.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Heart rate, systolic blood pressure, and venous plasma lactate concentrations were serially recorded at predefined time points and used to calculate SI (SI = heart rate/systolic blood pressure) and lactate variables, including lactime (time lactate > 2.0 mmol/L), lactate clearance ([lactate_initial - lactate_delayed ]/lactate_initial × 100), and LAC_AREA (area under the lactate concentration versus time curve). Primary outcome was survival to discharge. Overall survival rate was 61%. Admission venous plasma lactate concentration did not differ between groups (P = 0.2). Lactime was shorter in survivors versus nonsurvivors (P = 0.02). Lactate clearance at 1, 10, 16, 24, and 36 hours, and final lactate clearance were greater in survivors versus nonsurvivors (P < 0.05). LAC_AREA at time intervals 0-1, 1-4, 4-10, 10-16, 16-24, 24-30, and 30-36 hours was larger in nonsurvivors versus survivors (P < 0.05). Total LAC_AREA did not differ between groups (P = 0.09). Admission SI and time to normalize SI (SI < 0.9) were not different between survivors and nonsurvivors (P > 0.05).

CONCLUSIONS

While admission venous plasma lactate concentration could not discriminate between hospital survivors and nonsurvivors, lactate variables showed clinical utility to predict outcome in dogs with shock. Further studies are needed to determine SI reference ranges and optimal SI cut-off values to improve its prognostic ability in sick dogs.

Assessment of plasma lactate and core-peripheral temperature gradient in association with stages of naturally occurring myxomatous mitral valve disease in dogs

OBJECTIVE

To evaluate plasma lactate concentrations and core-peripheral temperature gradients as perfusion parameters in dogs with heart failure caused by myxomatous mitral valve disease (MMVD) and to determine whether the above perfusion parameters are correlated with disease stages.

DESIGN

Prospective observational study.

SETTING

University teaching hospital.

ANIMALS

After excluding 129 dogs because of exclusion criteria, 7 dogs with heart failure classified as stage B2 and 10 dogs classified as stage C according to the American Heart Association (AHA)/American College of Cardiology (ACC) were included in the study. Six dogs without MMVD were evaluated as the control group.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Among the evaluated parameters, the plasma lactate concentrations were increased in stage C (median 3.70 mmol/L [33.3 mg/dL], interquartile range (IQR) 0.72 mmol/L [6.5 mg/dL]) compared with those in the control (median 2.80 mmol/L [25.2 mg/dL], IQR 0.8 mmol/L [7.2 mg/dL]; P = 0.024) and stage B2 groups (median 2.70 mmol/L [24.3 mg/dL], IQR 1.8 mmol/L [16.2 mg/dL]; P = 0.045). Significant differences were not observed in the core-peripheral temperature gradients among the control, stage B2, and stage C dogs.

CONCLUSIONS

Dogs with structural heart disease as a result of MMVD may have occult tissue hypoperfusion in stage C that is demonstrated by hyperlactatemia.

Tissue oxygen saturation in dogs with acute hemorrhage

OBJECTIVE

To evaluate initial tissue hemoglobin oxygen saturation (StO₂ ) in dogs presenting to an emergency room (ER) for acute hemorrhage.

DESIGN

Prospective, observational study.

SETTING

University veterinary teaching hospital.

ANIMALS

Thirty-eight dogs with acute hemorrhage were enrolled between July 2009 and October 2010. Seventy-eight normal dogs from a previous observational study were included to represent healthy controls ("no shock").

INTERVENTIONS

Tissue oxygen saturation measurement was obtained at enrollment on dogs presented to the ER for acute hemorrhage. Baseline clinicopathologic (CBC, serum biochemical profile, prothrombin time, and activated partial thromboplastin time) and physiologic (plasma lactate concentration, venous blood gas, blood pressure, and hemoglobin oxygen saturation by pulse oximetry) data were recorded from all patients with hemorrhage. An ER clinician blinded to the StO₂ value guided patient management. Patient survival to discharge from the hospital in the study group was recorded. Once data collection was complete, 3 emergency and critical care clinicians blinded to the StO₂ data retrospectively classified patients into 1 of 4 shock categories (no shock, mild, moderate, or severe shock).

MEASUREMENTS AND MAIN RESULTS

The historical group of healthy dogs had higher StO₂ concentrations compared to the dogs classified with shock at all 3 levels (mild, moderate, and severe, P = 0.0006, <0.0001, and 0.0018, respectively); however, there was no statistical difference in StO₂ between the levels of shock. A cut-off StO₂ value of 87.6% identified a patient as having shock (area under the curve: 0.824, 95% confidence interval 0.749, 0.899).

CONCLUSIONS

Dogs with hemorrhagic shock have lower StO₂ than a population of healthy dogs.

Bacterial translocation in critical illness

Bacterial translocation involves the passage of intestinal bacteria to extraintestinal sites and has been shown to increase morbidity and mortality in critical illness. This review outlines the pathophysiology of bacterial translocation, host defence mechanisms, and reviews the evidence for the clinical management of critically ill patients in order to minimise the negative outcomes associated with bacterial translocation.

Comparison of cephalic and jugular plasma lactate concentrations in sick cats: a pilot study

OBJECTIVES

To compare plasma lactate concentration (PLC) in paired cephalic and jugular blood samples from sick cats. An additional objective was to determine whether hypotensive cats (Doppler blood pressure < 90 mm Hg) have a significant difference between cephalic and jugular PLC.

DESIGN

Prospective observational pilot study performed from December 2013 to August 2014.

SETTING

Private veterinary referral center.

ANIMALS

Twenty client-owned cats.

INTERVENTIONS

Doppler blood pressure measurements were obtained and then blood samples were collected from both a cephalic intravenous catheter at the time of placement and from a jugular vein by direct venipuncture.

MEASUREMENTS AND MAIN RESULTS

There was no significant difference between the mean cephalic PLC (2.0 mmol/L, standard deviation [SD]: 1.1, min-max: 0.6-5.3) and the mean jugular PLC (2.1 mmol/L, SD: 1.6, min-max: 0.7-7.8; P = 0.88) in this population of sick cats. Hypotensive cats also had no significant difference between the mean cephalic PLC (2.8 mmol/L, SD: 1.4, min-max: 1.6-5.3) and the mean jugular PLC (3.2 mmol/L, SD: 2.6, min-max: 0.7-7.8; P = 0.77).

CONCLUSIONS

There was not a significant difference between cephalic and jugular PLC in this population of sick cats. Further studies are needed to confirm whether cephalic and jugular PLCs may be used interchangeably in sick and hypotensive cats.

Biochemical evaluation of the effects of storage on feline erythrocytes

OBJECTIVE

To describe the biochemical changes that occur during storage of feline packed red blood cells.

METHODS

Feline packed red blood cells were obtained from the manufacturer via overnight delivery immediately following collection. Bag spikes were placed using aseptic technique and samples were drawn on days 1, 4, 7, 14, 21, 28 and 35. Sodium, potassium, chloride, glucose, lactate, pH and ammonia were measured at each time point. Aerobic and anaerobic bacterial cultures were submitted following collection on day 35.

RESULTS

There were statistically significant increases in the median concentrations of lactate and ammonia within the first 2 weeks of storage to a concentration of 12·38 mmol/L and 447·96 µmol/L, respectively. Glucose concentrations decreased significantly by day 28 to a mean of 1·86 mmol/L. Median sodium and chloride concentrations increased throughout the course of storage to a concentration of 158·20 and 131·00 mmol/L, respectively. Mean potassium concentrations decreased to a concentration of 2·40 mmol/L.

CLINICAL SIGNIFICANCE

These results show that biochemical derangements within feline packed red blood cells are progressive, with some alterations, such as lactate and ammonia, occurring early within the storage periods, while others, including glucose and electrolytes, are slower to develop. Additional prospective research evaluating the clinical effects of these biochemical alterations is required.

A Review of Central Venous Pressure and Its Reliability as a Hemodynamic Monitoring Tool in Veterinary Medicine

OBJECTIVE

To review the current literature regarding central venous pressure (CVP) in veterinary patients pertaining to placement (of central line), measurement, interpretation, use in veterinary medicine, limitations, and controversies in human medicine.

ETIOLOGY

CVP use in human medicine is a widely debated topic, as numerous sources have shown poor correlation of CVP measurements to the volume status of a patient. Owing to the ease of placement and monitoring in veterinary medicine, CVP remains a widely used modality for evaluating the hemodynamic status of a patient. A thorough evaluation of the veterinary and human literature should be performed to evaluate the role of CVP measurements in assessing volume status in veterinary patients.

DIAGNOSIS

Veterinary patients that benefit from accurate CVP readings include those suffering from hypovolemic or septic shock, heart disease, or renal disease or all of these. Other patients that may benefit from CVP monitoring include high-risk anesthetic patients undergoing major surgery, trending of fluid volume status in critically ill patients, patients with continued shock, and patients that require rapid or large amounts of fluids.

THERAPY

The goal of CVP use is to better understand a patient's intravascular volume status, which would allow early goal-directed therapy.

PROGNOSIS

CVP would most likely continue to play an important role in the hemodynamic monitoring of the critically ill veterinary patient; however, when available, cardiac output methods should be considered the first choice for hemodynamic monitoring.

Hyperlactatemia and serial lactate measurements in sick cats

OBJECTIVES

To document the incidence of hyperlactatemia in sick cats hospitalized for emergency care and to evaluate the prognostic utility of serial lactate measurements in cats with hyperlactatemia.

DESIGN

Prospective observational study over a 10-month period (July 2010-May 2011).

SETTING

Private veterinary referral center with 24-hour hospital care.

ANIMALS

One hundred and twenty-three privately owned cats admitted to a private referral center.

INTERVENTIONS

Blood was collected by direct venipuncture from the jugular or medial saphenous vein at the time of hospital admission and at 6 and 24 hours following admission.

MEASUREMENTS AND MAIN RESULTS

The median plasma lactate concentration for all cats at admission (T0) was 1.89 mmol/L (17.0 mg/dL) (range: 0.3-12.48). Twenty-three percent (28/123) of cats admitted were hyperlactatemic (ie, >2.87 mmol/L; >25.86 mg/dL) upon admission. Lactate concentration at presentation and serial lactate measurements were not found to be related with survival to discharge or correlated with duration of hospitalization. The overall survival rate of all cats in this study was 81%.

CONCLUSIONS

This study demonstrated that the incidence of hyperlactatemia in sick cats being admitted for hospitalization in a private referral center was 23%, and that lactate concentration on admission and serial lactate measurements over time were not prognostic in this group of hospitalized cats. Future studies are needed to evaluate the prognostic utility of lactate and serial lactate measurements in specific disease states and in a larger population of critically ill cats.

A systematic review of human and veterinary applications of noninvasive tissue oxygen monitoring

OBJECTIVE

To describe the methodology for and utilization of tissue oxygen monitoring by near infrared spectroscopy, and to review the current literature on the use of this monitoring modality in human and veterinary settings.

DATA SOURCES

Scientific reviews and original research found using the PubMed and CAB Abstract search engines with the following keywords: "tissue oxygen monitoring," "near-infrared tissue spectroscopy," and "tissue oxygen saturation (StO2 )."

HUMAN DATA SYNTHESIS

Tissue oxygen monitors have been evaluated in a wide variety of human clinical applications including trauma and triage, surgery, sepsis, and septic shock, and early goal-directed therapy. StO2 more rapidly identifies occult shock in human patients compared to traditional methods, which can lead to earlier intervention in these patients.

VETERINARY DATA SYNTHESIS

Veterinary studies involving tissue oxygen monitoring are limited, but the technology may have utility for identification of hemorrhagic shock earlier than changes in base excess, blood lactate concentration, or other traditional perfusion parameters.

CONCLUSION

Tissue oxygen monitoring is most commonly performed utilizing a noninvasive, portable monitor, which provides real-time, continuous, repeatable StO2 measurements. A decline in StO2 is an early indicator of shock in both human and veterinary patients. Low StO2 values in human patients are associated with increased morbidity, mortality, and length of hospitalization, as well as the development of multiple organ system dysfunction and surgical site infections.

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.

The clinical value of whole blood point-of-care biomarkers in large animal emergency and critical care medicine

OBJECTIVE

To summarize the current medical literature and provide a clinical perspective of whole blood point-of-care (POC) biomarkers in large animal emergency and critical care practice.

DATA SOURCES

Original studies, reviews, and textbook chapters in the human and veterinary medical fields.

SUMMARY

POC biomarkers are tests used to monitor normal or disease processes at or near the patient. In both human and veterinary medicine these tools are playing an increasingly important role in the management of critical diseases. The most important whole blood POC biomarkers available for veterinary practitioners include l-lactate, cardiac troponin I, serum amyloid A, triglyceride, creatinine, and glucose, although many other tests are available or on the horizon.

CONCLUSION

Whole blood POC biomarkers enable clinicians to provide improved management of critical diseases in large animals. These tools are especially useful for establishing a diagnosis, guiding therapy, and estimating disease risk and prognosis.

Decreased central venous oxygen saturation despite normalization of heart rate and blood pressure post shock resuscitation in sick dogs

OBJECTIVE

To evaluate traditional and global perfusion parameters in clinical canine shock patients, and to evaluate for occult hypoperfusion as evidenced by low central venous oxygen saturation or high plasma lactate concentrations in clinical patients resuscitated to traditional endpoints.

DESIGN

Clinical observational trial designed with a 1-year data entry period and patient follow-up of 28 days posthospital presentation.

SETTING

Large, private urban teaching hospital, and emergency and critical care center.

ANIMALS

Adult canine patients presenting to the emergency department with untreated shock.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Patients received fluid resuscitation to normalize perfusion parameters based on physical examination and arterial blood pressure (BP). Monitoring of central venous pressure (CVP) and central venous oxygen saturation (ScvO2 ) was feasible with current standard of care interventions in critically ill, client-owned dogs. Decreased ScvO2 was observed in 37.8% of patients resuscitated to normal traditional perfusion parameters. Hyperlactatemia was commonly recorded.

CONCLUSIONS

Decreased ScvO2 exists in a significant proportion of critically ill dogs following standard fluid resuscitation for shock, providing a relevant target population for implementation of a more standardized early goal-directed therapy bundle in veterinary patients. Normalization of heart rate, blood pressure, mentation, and perfusion parameters directed by physical examination may be attained despite the persistence of significant tissue hypoperfusion and oxygen debt.

The Flat Cat

Aim:

Detailed information regarding the causes and treatment of acute collapse in the cat can be difficult to locate in a single published source. This two-part review aims to provide a logical approach to the clinical assessment and stabilisation of the critically ill collapsed cat.

Practical relevance:

Cats are particularly challenging when presented as emergency patients, often in the later stages of an illness or with a vague history and non-specific signs. The nuances of the critically ill cat are considered, especially for shock and its management.

Clinical challenges:

Shocked cats do not present in the classic stages typically seen in dogs, and the signs are more subtle. Therefore, the clinician must consider whether physical parameters are appropriate for the state and environment of the patient; for example, a normal heart rate in a shocked cat would be considered inappropriate.

Audience:

This review is directed at any veterinarian working with feline patients, and particularly those dealing with emergencies on a regular basis.

Evidence base:

There is an extensive body of published literature, both original studies and textbook chapters, pertaining to the causes and treatment of collapse in the cat. In this article the authors draw on information from original publications, reviews and their clinical experience to provide practical guidance to assist in the emergency setting.

Goal-directed therapy in small animal critical illness

Monitoring critically ill patients can be a daunting task even for experienced clinicians. Goal-directed therapy is a technique involving intensive monitoring and aggressive management of hemodynamics in patients with high risk of morbidity and mortality. The aim of goal-directed therapy is to ensure adequate tissue oxygenation and survival. This article reviews commonly used diagnostics in critical care medicine and what the information gathered signifies and discusses clinical decision making on the basis of diagnostic test results. One example is early goal-directed therapy for severe sepsis and septic shock. The components and application of goals in early goal-directed therapy are discussed.

The association of blood lactate concentration with outcome in dogs with idiopathic immune-mediated hemolytic anemia: 173 cases (2003-2006)

OBJECTIVE

To determine the association of blood lactate with outcome and response to transfusion therapy in dogs with idiopathic immune-mediated hemolytic anemia (IMHA).

DESIGN

Retrospective study.

SETTING

Urban veterinary small animal emergency hospital.

ANIMALS

One hundred and seventy-three client-owned dogs with IMHA.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Serial blood lactate concentration, therapeutic interventions, and outcome were recorded. Nonsurvivors were defined as those that died or were euthanized. One hundred and thirty-three dogs (77%) survived, 35 (20%) were euthanized, and 5 (3%) died. One hundred forty-five dogs (84%; 145/173) had a lactate concentration above the laboratory reference interval [0.46-2.31 mmol/L] on presentation. Blood lactate at presentation was higher in the nonsurvivors (median 4.8 mmol/L; 0.5-13.6) compared with survivors (median 2.9 mmol/L; 0.3-13.2) (P<0.01). All dogs presenting with hyperlactatemia that normalized (<2.0 mmol/L) within 6 hours of admission survived, whereas, 71% of dogs that had a persistent hyperlactatemia at 6 hours survived (P=0.034). Lactate was positively correlated with age, BUN, and alkaline phosphatase, and inversely correlated with PCV. Receiver operating curve analysis for lactate concentration at admission as a test for outcome had an area under the curve of 0.69 with an optimal lactate cutoff concentration of 4.4 mmol/L correctly predicting outcome 73% of the time (sensitivity 60%, specificity 77%).

CONCLUSIONS

Lactate concentration at presentation was significantly higher in nonsurvivors than survivors. Lactate was significantly correlated with previously reported outcome variables but lactate concentration at admission, as a predictor for outcome was less than optimal. However, serial lactate concentration measurements may be more predictive as patients with persistent hyperlactatemia 6 hours after admission were less likely to survive. Prospective studies evaluating serial lactate concentration while controlling for other variables may provide further insight into lactate measurement as a prognostic indicator in animals with IMHA.