Assessment and treatment of perfusion abnormalities in the emergency patient

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.

Evaluation of caudal vena cava size using computed tomography in dogs under general anesthesia

This study investigated the association between caudal vena cava (CVC) size and circulatory dynamics in dogs using computed tomography (CT) under general anesthesia. The subjects were 104 dogs who had undergone CT under general anesthesia in the past. The ratio of short diameter of the CVC to aortic diameter (CVC_S/Ao) and the ratio of long to short diameter of the CVC (CVC_L/CVC_S) in the thorax and abdomen, respectively, were calculated using factors such as mean blood pressure (MBP), shock index (SI), anemia, hypoproteinemia, presence of intra-abdominal mass, and cardiac disease. There was a significant but negligible negative correlation between CVC_S/Ao and MBP. In contrast, no significant correlation was found between CVC size and SI. The low MBP group had significantly higher CVC_S/Ao of the thorax than the normal MBP group. The group with intra-abdominal mass had significantly lower CVC_S/Ao of the abdomen than the group without intra-abdominal mass. The group with cardiac disease had significantly lower CVC_L/CVC_S of the thorax than the group without cardiac disease. In multiple regression analysis, low MBP, cardiac disease, intra-abdominal mass, and anemia were significant factors for CVC_S/Ao of the thorax, CVC_L/CVC_S of the thorax, CVC_S/Ao of the abdomen, and CVC_L/CVC_S of the abdomen, respectively. In conclusion, CVC size assessment using CT in dogs under general anesthesia is influenced by various factors.

Outcomes and Blood Product Use in 89 Surgically Managed and 79 Medically Managed Cases of Acute Spontaneous Hemoperitoneum in the Dog

Objective: To describe a population of dogs with acute spontaneous hemoperitoneum (ASH) that were treated with either surgical or medical management in the first 12 h after presentation, and to perform a preliminary investigation into whether there were differences in achieving cardiovascular stabilization or patterns of red blood cell (RBC) transfusion between patients treated with early (<12 h) surgery vs.medical management. Design: A retrospective multicenter preliminary study performed on 168 dogs presenting with ASH between January 2015 and May 2019. Patients were excluded if they were euthanized or discharged from hospital within the first 12 h, or if clinical records were incomplete. All patients received appropriate medical stabilization efforts. Statistical analysis was performed comparing patients that underwent early (<12 h) surgery and those that did not. Results: Eighty-nine patients were in the early surgical group and 79 patients in the medical group. A significantly higher proportion of medical cases were euthanized (p < 0.001). A significantly higher proportion of early surgical cases were discharged from hospital (p = 0.005). There was no statistically significant difference between groups in achieving cardiovascular stabilization (OR 1.07 p = 0.82). A higher proportion of patients with body-weight over 20 kg achieved stabilization within 12 h than those with body-weight of 20 kg or less (62.7 vs. 41.4%, p < 0.01). A higher proportion of patients with splenic conditions achieved stabilization than patients with non-splenic conditions (56.5 vs. 28.6%, p = 0.05). The odds of receiving an RBC transfusion were higher in the early surgical group than the medical group [OR 3.81 (p < 0.001)]. Conclusions: This preliminary study did not identify a significant difference in the ability to achieve cardiovascular stabilization in the first 12 h in dogs with ASH that underwent early surgical intervention vs. those managed medically. Patients in the early surgical group were more likely to receive a RBC transfusion than those in the medical group. At this time the decision on whether to pursue medical or early surgical management should be made on a case by case basis.

Fluid Therapy in Pulmonary Disease: How Careful Do We Need to Be?

Intravenous fluid therapy is a vital and life-saving therapeutic in veterinary medicine. In the absence of heart or lung disease, trauma or sepsis there is limited evidence that fluid therapy will have a detrimental effect on lung function. In healthy dogs there is a reasonable level of experimental evidence that supraphysiologic rates of fluid are required before signs of fluid overload are made evident. In cats, however, this may not be the case. There are higher rates of asymptomatic myocardial disease, but even in the absence of that it seems that some cats may be susceptible to fluid overload. Where systemic inflammation already exists the careful homeostatic and protective mechanisms within the lung are deranged and increases in hydrostatic pressure are more likely to result in fluid movement into the lung tissues. Strategies including restricting the use of intravenous crystalloid fluid administration and using blood products for management of severe hemorrhage are of increasing importance in human trauma and seem to be associated with fewer pulmonary complications, and lower mortality. Managing dogs and cats with sepsis and acute respiratory distress syndrome is already challenging, but ensuring adequate vascular expansion needs to be balanced with avoiding excessive volume administration which may negatively impact pulmonary function. While fluids remain crucial to management of these conditions, there will be an ongoing requirement to balance need without providing excess. The use of point of care ultrasound may provide clinicians with a non-invasive and accessible way to do this.

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.

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.

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.

Clinical use of plasma lactate concentration. Part 1: Physiology, pathophysiology, and measurement

OBJECTIVE

To review the current literature with respect to the physiology, pathophysiology, and measurement of lactate.

DATA SOURCES

Data were sourced from veterinary and human clinical trials, retrospective studies, experimental studies, and review articles. Articles were retrieved without date restrictions and were sourced primarily via PubMed, Scopus, and CAB Abstracts as well as by manual selection.

HUMAN AND VETERINARY DATA SYNTHESIS

Lactate is an important energy storage molecule, the production of which preserves cellular energy production and mitigates the acidosis from ATP hydrolysis. Although the most common cause of hyperlactatemia is inadequate tissue oxygen delivery, hyperlactatemia can, and does occur in the face of apparently adequate oxygen supply. At a cellular level, the pathogenesis of hyperlactatemia varies widely depending on the underlying cause. Microcirculatory dysfunction, mitochondrial dysfunction, and epinephrine-mediated stimulation of Na⁺ -K⁺ -ATPase pumps are likely important contributors to hyperlactatemia in critically ill patients. Ultimately, hyperlactatemia is a marker of altered cellular bioenergetics.

CONCLUSION

The etiology of hyperlactatemia is complex and multifactorial. Understanding the relevant pathophysiology is helpful when characterizing hyperlactatemia in clinical patients.

Anesthesia-Associated Relative Hypovolemia: Mechanisms, Monitoring, and Treatment Considerations

Although the utility and benefits of anesthesia and analgesia are irrefutable, their practice is not void of risks. Almost all drugs that produce anesthesia endanger cardiovascular stability by producing dose-dependent impairment of cardiac function, vascular reactivity, and compensatory autoregulatory responses. Whereas anesthesia-related depression of cardiac performance and arterial vasodilation are well recognized adverse effects contributing to anesthetic risk, far less emphasis has been placed on effects impacting venous physiology and venous return. The venous circulation, containing about 65–70% of the total blood volume, is a pivotal contributor to stroke volume and cardiac output. Vasodilation, particularly venodilation, is the primary cause of relative hypovolemia produced by anesthetic drugs and is often associated with increased venous compliance, decreased venous return, and reduced response to vasoactive substances. Depending on factors such as patient status and monitoring, a state of relative hypovolemia may remain clinically undetected, with impending consequences owing to impaired oxygen delivery and tissue perfusion. Concurrent processes related to comorbidities, hypothermia, inflammation, trauma, sepsis, or other causes of hemodynamic or metabolic compromise, may further exacerbate the condition. Despite scientific and technological advances, clinical monitoring and treatment of relative hypovolemia still pose relevant challenges to the anesthesiologist. This short perspective seeks to define relative hypovolemia, describe the venous system’s role in supporting normal cardiovascular function, characterize effects of anesthetic drugs on venous physiology, and address current considerations and challenges for monitoring and treatment of relative hypovolemia, with focus on insights for future therapies.

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.

Controversies in the use of hydroxyethyl starch solutions in small animal emergency and critical care

OBJECTIVES

To (1) review the development and medical applications of hydroxyethyl starch (HES) solutions with particular emphasis on its physiochemical properties; (2) critically appraise the available evidence in human and veterinary medicine, and (3) evaluate the potential risks and benefits associated with their use in critically ill small animals.

DATA SOURCES

Human and veterinary original research articles, scientific reviews, and textbook sources from 1950 to the present.

HUMAN DATA SYNTHESIS

HES solutions have been used extensively in people for over 30 years and ever since its introduction there has been a great deal of debate over its safety and efficacy. Recently, results of seminal trials and meta-analyses showing increased risks related to kidney dysfunction and mortality in septic and critically ill patients, have led to the restriction of HES use in these patient populations by European regulatory authorities. Although the initial ban on the use of HES in Europe has been eased, proof regarding the benefits and safety profile of HES in trauma and surgical patient populations has been requested by these same European regulatory authorities.

VETERINARY DATA SYNTHESIS

The veterinary literature is limited mostly to experimental studies and clinical investigations with small populations of patients with short-term end points and there is insufficient evidence to generate recommendations.

CONCLUSIONS

Currently, there are no consensus recommendations regarding the use of HES in veterinary medicine. Veterinarians and institutions affected by the HES restrictions have had to critically reassess the risks and benefits related to HES usage based on the available information and sometimes adapt their procedures and policies based on their reassessment. Meanwhile, large, prospective, randomized veterinary studies evaluating HES use are needed to achieve relevant levels of evidence to enable formulation of specific veterinary guidelines.

Retrospective evaluation of fluid overload and relationship to outcome in critically ill dogs

OBJECTIVE

To determine if critically ill dogs have an increased risk of fluid overload (FO) during hospitalization compared to less ill dogs, and to determine if FO is associated with increased mortality during hospitalization.

DESIGN

Observational, case-control study.

SETTING

University teaching hospital.

ANIMALS

Thirty-four critically ill dogs and 15 comparatively healthy stable postoperative dogs with neuro-orthopedic disease.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Data recorded included underlying disease, body weight, and APPLEfast score at admission, single-day and composite APPLEfull scores during hospitalization, total fluid volume administered (L), total fluid volume output (L), and outcome. Percent FO (%FO) was calculated using the equation 100 × ([fluid volume administered - fluid volume lost]/1000 mL/L) - (% dehydration at admission), with fluid volume expressed as mL/kg of baseline body weight. Critically ill dogs developed greater %FO during hospitalization compared to stable postoperative dogs (12.1 ± 11.7% vs 0.5 ± 5.2%, P = 0.001), and half (8 out of 16) of the dogs with %FO ≥ 12% died. Composite APPLEfull scores were weakly positively correlated with %FO, whereas APPLEfast and single-day APPLEfull scores recorded at admission were not. The odds ratio for death was 1.08 for every percent increase in FO during hospitalization (95% confidence limits 1.012-1.59, P = 0.02).

CONCLUSIONS

Critically ill dogs are at increased risk for FO during hospitalization, and a weak but significant association exists between %FO, illness severity, and mortality. Prospective studies are warranted to confirm the findings of this retrospective study.

Prospective study of bacteraemia in acute haemorrhagic diarrhoea syndrome in dogs

In dogs with idiopathic acute haemorrhagic diarrhoea syndrome (AHDS), a serious loss of intestinal mucosal barrier integrity occurs. However, the incidence of bacterial translocation in dogs with idiopathic AHDS is not known. Thus, the objectives of this prospective study were to identify the incidence of bacteraemia, to evaluate the frequency of septic events and the influence of bacteraemia on various clinical and laboratory parameters, duration of hospitalisation and survival of dogs with idiopathic AHDS. The study included 87 dogs with idiopathic AHDS. Twenty-one healthy dogs served as control group. To evaluate clinical significance of bacterial translocation, blood culture results were compared between patients and controls. Clinical and laboratory parameters were compared between patients with positive and negative blood cultures. There was no significant difference in either incidence of bacteraemia between patients with idiopathic AHDS (11 per cent) and controls (14 per cent) or in severity of clinical signs, laboratory parameters, duration of hospitalisation or mortality between blood culture-positive and culture-negative dogs with idiopathic AHDS. The results of this study suggest that the incidence of bacteraemia in dogs with idiopathic AHDS is low and not different from that of healthy control dogs. Bacteraemia does not influence the clinical course or survival and thus antibiotic treatment is not indicated to prevent sepsis.

Traumatic coagulopathy--part 2: Resuscitative strategies

OBJECTIVE

To discuss the current resuscitative strategies for trauma-induced hemorrhagic shock and acute traumatic coagulopathy (ATC).

ETIOLOGY

Hemorrhagic shock can be acutely fatal if not immediately and appropriately treated. The primary tenets of hemorrhagic shock resuscitation are to arrest hemorrhage and restore the effective circulating volume. Large volumes of isotonic crystalloids have been the resuscitative strategy of choice; however, data from experimental animal models and retrospective human analyses now recognize that large-volume fluid resuscitation in uncontrolled hemorrhage may be deleterious. The optimal resuscitative strategy has yet to be defined. In human trauma, implementing damage control resuscitation with damage control surgery for controlling ongoing hemorrhage, acidosis, and hypothermia; managing ATC; and restoring effective circulating volume is emerging as a more optimal resuscitative strategy. With hyperfibrinolysis playing an integral role in the manifestation of ATC, the use of antifibrinolytics (eg, tranexamic acid and aminocaproic acid) may also serve a beneficial role in the early posttraumatic period. Considering the sparse information regarding these resuscitative techniques in veterinary medicine, veterinarians are left with extrapolating information from human trials and experimental animal models.

DIAGNOSIS

Viscoelastic tests integrated with predictive scoring systems may prove to be the most reliable methods for early detection of ATC as well as for guiding transfusion requirements.

SUMMARY

Hemorrhage accounts for up to 40% of human trauma-related deaths and remains the leading cause of preventable death in human trauma. The exact proportion of trauma-related deaths due to exsanguinations in veterinary patients remains uncertain. Survivability depends upon achieving rapid definitive hemostasis, early attenuation of posttraumatic coagulopathy, and timely restoration of effective circulating volume. Early institution of damage control resuscitation in severely injured patients with uncontrolled hemorrhage has the ability to curtail posttraumatic coagulopathy and the exacerbation of metabolic acidosis and hypothermia and improve survival until definitive hemostasis is achieved.

Admission base excess as a predictor of transfusion requirement and mortality in dogs with blunt trauma: 52 cases (2007-2009)

OBJECTIVE

To evaluate the ability of admission base excess (ABE) to predict blood transfusion requirement and mortality in dogs following blunt trauma.

DESIGN

Retrospective study 2007-2009.

SETTING

University Veterinary Teaching Hospital.

ANIMALS

Fifty-two dogs admitted to the intensive care unit for treatment following blunt trauma.

MEASUREMENTS AND MAIN RESULTS

Animals requiring red blood cell transfusion (N = 8) had significantly lower ABE than those not requiring transfusion (N = 44; median base excess [BE] = -8.4 versus -4.7, P = .0034), while there was no difference in admission packed cell volume (PCV) or age. Animals that died or were euthanized due to progression of signs (N = 5) had lower median ABE than those that survived (N = 47; median BE = -7.3 versus -4.9, P = 0.018). Admission PCV and age were not significantly different between survivors and nonsurvivors. Receiver operator characteristic curve analysis showed an ABE cutoff of -6.6 was 88% sensitive and 73% specific for transfusion requirement (P < 0.001), and a cutoff of -7.3 was 81% sensitive and 80% specific for survival (P < 0.001). Multivariate logistic regression analysis demonstrated that ABE was a predictor of transfusion requirement that was independent of overall severity of injury as measured by the Animal Triage Trauma (ATT) score, but a similar analysis showed that only ATT was an independent predictor of survival.

CONCLUSIONS

The ABE in dogs with blunt trauma was a predictor of mortality and blood transfusion requirement within 24 hours.

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.

Changes in tissue perfusion parameters in dogs with severe sepsis/septic shock in response to goal-directed hemodynamic optimization at admission to ICU and the relation to outcome

OBJECTIVE

To evaluate the changes in tissue perfusion parameters in dogs with severe sepsis/septic shock in response to goal-directed hemodynamic optimization in the ICU and their relation to outcome.

DESIGN

Prospective observational study.

SETTING

ICU of a veterinary university medical center.

ANIMALS

Thirty dogs with severe sepsis or septic shock caused by pyometra who underwent surgery and were admitted to the ICU.

MEASUREMENTS AND MAIN RESULTS

Severe sepsis was defined as the presence of sepsis and sepsis-induced dysfunction of one or more organs. Septic shock was defined as the presence of severe sepsis plus hypotension not reversed with fluid resuscitation. After the presumptive diagnosis of sepsis secondary to pyometra, blood samples were collected and clinical findings were recorded. Volume resuscitation with 0.9% saline solution and antimicrobial therapy were initiated. Following abdominal ultrasonography and confirmation of increased uterine volume, dogs underwent corrective surgery. After surgery, the animals were admitted to the ICU, where resuscitation was guided by the clinical parameters, central venous oxygen saturation (ScvO(2)), lactate, and base deficit. Between survivors and nonsurvivors it was observed that the ScvO(2), lactate, and base deficit on ICU admission were each related independently to death (P = 0.001, P = 0.030, and P < 0.001, respectively). ScvO(2) and base deficit were found to be the best discriminators between survivors and nonsurvivors as assessed via receiver operator characteristic curve analysis.

CONCLUSION

Our study suggests that ScvO(2) and base deficit are useful in predicting the prognosis of dogs with severe sepsis and septic shock; animals with a higher ScvO(2) and lower base deficit at admission to the ICU have a lower probability of death.

Head Trauma in the Cat: 1. Assessment and Management of Craniofacial Injury

Practical relevance Feline trauma is commonly seen in general practice and frequently involves damage to the head.

Clinical challenges While craniofacial injuries following trauma vary widely in severity, affected cats can often be severely compromised in terms of their neurological, respiratory and cardiovascular status, and their management can be challenging in both the short and long term. They need prompt stabilisation and careful monitoring in the initial period to maximise prospects of a successful outcome. Many cats with severe facial trauma will require surgery to stabilise skull fractures or address injuries to the eyes, with its inherent issues surrounding pain management, ensuring adequate nutrition and the necessity for ongoing hospitalisation.

Diagnostics Cats with head trauma benefit from imaging of the injured areas as well as thoracic radiography. Imaging the skull can be challenging and is best performed under general anaesthesia. In unstable patients this can be delayed to prevent any associated morbidity.

Evidence base The clinical evidence base relating to injury to the feline head is limited, despite its relative frequency in general practice. This review focuses on the initial approach to craniofacial (in particular, ocular and jaw) trauma, and outlines simple techniques for management of soft tissue and bone injuries. Much of the information is based on the authors' clinical experience, as there is a paucity of well-described clinical case material.

Low central venous oxygen saturation is associated with increased mortality in critically ill dogs

OBJECTIVES

To investigate relationships between central venous oxygen saturation (ScvO(2)) and survival to hospital discharge in dogs. Central venous oxygen saturation is an accessible measure of the balance between systemic oxygen delivery and consumption.

METHODS

Prospective observational cohort study, enrolling 126 client-owned dogs with central venous catheters. Central venous oxygen saturation was measured over the 24 hours following intensive care unit admission. Poor outcome was defined as death or euthanasia performed for moribund status. Regression analysis identified independent predictors of non-survival and physiologic parameters associated with central venous oxygen saturation. Area under the receiver operator curve analysis identified a cut-off point of central venous oxygen saturation, below which central venous oxygen saturation decrease was associated with increased mortality risk.

RESULTS

Mortality risk was 30·9%. Low central venous oxygen saturation was associated with poor outcome (P<0·05). Area under the receiver operator curve analysis selected a central venous oxygen saturation of 68% as the point below which a fall in central venous oxygen saturation was associated with increased mortality risk. For each 10% drop in central venous oxygen saturation below 68%, odds of non-survival increased by 2·66 times (P=0·0002, 95% confidence interval of odds ratio=1·45 to 4·85). Central venous oxygen saturation was equivalent to lactate in predicting non-survival. Predictors of central venous oxygen saturation (packed cell volume, mean arterial blood pressure, fever, % arterial haemoglobin saturation as measured by pulse oximeter) were consistent with hypothesised physiologic mechanisms.

CLINICAL SIGNIFICANCE

Central venous oxygen saturation was a strong mortality predictor. Further work is needed to determine if therapy targeting central venous oxygen saturation can reduce mortality in canine intensive care unit patients.

Feline toxicological emergencies: when to suspect and what to do

PRACTICAL RELEVANCE

Confirmed or suspected intoxications with a wide variety of agents represent a small but important group of feline emergency cases. Generally it is thought that toxicities are less common in cats compared with dogs, with a higher proportion relating to dermal as opposed to oral exposure.

CLINICAL CHALLENGES

Once toxicity is suspected or diagnosed, it must be recognised that treatment regimes may need modification compared with those established for dogs. Different drugs or different dosages may be warranted and the choice of available drugs may be reduced.

EVIDENCE BASE

This review draws on published studies, case reports and clinical experience to summarise key features of the general management of the intoxicated feline patient before describing some of the more serious and common intoxications in more detail.

AUDIENCE

The focus throughout the review is on the peculiarities of feline metabolism and how they may impact on presentation and treatment. The aim is to assist companion animal and feline practitioners, who are in the frontline when it comes to managing these emergency cases.

Assessment and treatment of hypovolemic states

Hypovolemia and hypoperfusion are common life-threatening problems in animals presented to the emergency veterinarian. Assessment of physical findings and rapid recognition and treatment of abnormal tissue perfusion are crucial in optimizing outcome. The clinician should be familiar with the disease being treated and the types of fluids that are available. Development of a fluid therapy plan to correct life-threatening abnormalities and patient monitoring during treatment play an important role in patient outcome.

Vasopressor Therapy Using Vasopressin Prior to Crystalloid Resuscitation in Irreversible Hemorrhagic Shock under Isoflurane Anesthesia in Dogs

In the present study, we tested the hypothesis that vasopressin administration prior to crystalloid resuscitation can be used to improve hemodynamic and oxygen delivery functions. Hemorrhagic shock was experimentally induced by maintaining mean arterial pressure at 60 mmHg for 30 min in sixteen healthy dogs weighing from 8 to 10.6 kg. Vasopressin was administered and then volume resuscitation was performed for the 6 dogs of V-C group, while vasopressin was administered at the end of volume resuscitation in the 5 dogs of C-V group. The control group (n=5) was administered 0.4 IU/kg of vasopressin after induction of shock without fluid resuscitation. In all groups, hemodynamic parameters were measured pre- and post-hemorrhage and for 60 min after fluid resuscitation. The dogs in V-C group had substantially increased systolic arterial pressure (SAP) for 60 min and improved pulmonary capillary wedge pressure (PCWP), cardiac output (CO), oxygen delivery, and oxygen consumption indexes compared with C-V and control groups. Diastolic pressure and systemic vascular resistance was significantly lower in the V-C group than those in the C-V and control groups (P<0.05). In the V-C group, there was effective and rapid restoration of the SAP, CO, PCWP, and oxygen delivery parameters after treatment. This study indicates that vasopressin administration before crystalloid resuscitation is a more efficient way of improving hemodynamic and oxygen delivery functions in hemorrhagic shock in dogs.