Central venous blood gas and acid-base status in conscious dogs and cats

Relationship between Respiratory Rate, Oxygen Saturation, and Blood Test Results in Dogs with Chronic or Acute Respiratory Disease: A Retrospective Study

This study aimed to investigate the association of respiratory rate (RR), oxygen saturation (SpO2), and blood findings with respiratory disease in dogs and to compare the examination findings in the chronic and acute phases. Dogs that visited a veterinary referral hospital with respiratory symptoms were classified into the chronic disease group (GC), and those that visited the emergency veterinary hospital were classified into the acute disease group (GA). In total, 704 and 682 dogs were included in GC and GA, respectively. The RR and SpO2 were significantly higher and lower, respectively, in patients with lung disease compared to other disease sites in both groups. White blood cell counts were significantly increased in patients with lung and pleural diseases in both groups. Respiratory alkalosis and respiratory acidosis were most common in GC and GA, respectively. The C-reactive protein levels were elevated in both groups, primarily in patients with lung disease. Associations between the results of several tests for understanding and diagnosing respiratory conditions and diseases were recognized, and differences in the trends of the chronic and acute phases were clarified. These tools may be used as adjuncts to other tests for the diagnosis and monitoring of treatment responses.

Mechanical ventilation in dogs and cats with tick paralysis

Respiratory failure from tick paralysis (TP) is an important cause of mortality in cats and dogs in Australia, occurring from a combination of respiratory muscle paralysis, upper respiratory tract obstruction and pulmonary disease. Patients may require positive-pressure ventilation in management of any combination of hypoxemia, hypoventilation or respiratory fatigue, but may also require airway management due to laryngeal paralysis. No single ventilation strategy is recommended due to the heterogenous disease presentations. Lung protective ventilation should be used in patients with pulmonary disease. Due to local and systemic effects of TP, patients are at higher risk of complications such as aspiration pneumonia and corneal ulceration and may have additional intravenous fluid and nutritional considerations. Treatment with hyperimmune serum is associated with improved outcomes. Prognosis is considered good with documented survival to discharge (STD) of 52.6-77% for animals with TP ventilated with lung disease and 90.5% for animals without lung disease. Median reported duration of ventilation for TP ranges from 23 to 48 h (range 3 h-10 days). The severity of individual neuromuscular signs and the presence of associated conditions such as aspiration pneumonia and laryngeal paralysis may necessitate longer periods of mechanical ventilation. This review aims to summarize the current recommendations regarding indications, management and prognosis of cats and dogs undergoing MV for TP and to identify areas for future research.

Usefulness of peripheral venous blood gas analyses in cats with arterial thromboembolism

Feline arterial thromboembolism (ATE) is a condition with a high mortality rate. Acid-base abnormalities may be beneficial to the prognosis of cats with ATE. Venous blood gas and electrolytes data on the first day of ATE presentation of 47 cats with ATE were retrospectively reviewed and analysed. The Cox and logistic regression were analysed to evaluate the relationship between acid-base parameters and death. The most common venous acid-base disorder was simple metabolic acidosis. Age, body weight, and partial venous pressure of carbon dioxide (PvCO2) differed between the dead and alive groups within 7 days of the onset of ATE presentation (p < 0.05). Cox-regression showed that increasing age (HR=1.175 [95% CI: 1.027-1.343], p = 0.019), increasing PvCO2 (HR=1.066 [95% CI: 1.010-1.125], p = 0.021) and PvCO2 more than 34 mmHg (HR=7.878 [95% CI: 1.036- 59.915], p = 0.046) were associated with increased hazard of death. Multivariable logistic regression showed that age > 5 years (OR=9.030, 95% CI: 1.258- 64.823; p=0.029), and PvCO2 > 34 mmHg (OR=21.764, 95% CI: 1.747-271.141; p=0.017) were associated with an increased risk of death, while concomitant administration of enoxaparin with clopidogrel (OR=0.111, 95% CI: 0.015-0.795; p=0.029) were associated with a decreased risk of death within 7 days of the onset of ATE presentation. This study demonstrated the power of venous blood gas analysis which may be used as prognostic indicators for cats with ATE.

Prediction of arterial blood gas values from venous blood gas values in Asiatic black bears (Ursus thibetanus) anesthetized with intramuscular medetomidine and zolazepam-tiletamine

The objective of this study was to measure differences between arterial and venous blood gas parameters and to evaluate whether arterial blood gas values can be estimated from venous blood in Asiatic black bears (ABBs). Twelve healthy captive ABBs (8 males and 4 females; 8-16 years; 76.8-220 kg) were included in this study. The bears were immobilized with medetomidine and zolazepam-tiletamine using a dart gun. Arterial and venous samples were collected simultaneously at 5 and 35 min after recumbency (5- and 35-min points). Partial pressure of oxygen (PO2), partial pressure of carbon dioxide (PCO2), pH, bicarbonate (HCO3-), total carbon dioxide (TCO2), oxygen saturation of hemoglobin (SO2) and base excess (BEecf) were analyzed using a portable blood gas analyzer. There was no marked difference in measured and calculated variables over time in both venous and arterial blood except for PO2. However, arterial PO2, SO2 and pH were significantly higher and arterial PCO2, TCO2 and HCO3- were lower than those of venous samples at both 5- and 35-min points. In the regression analysis to estimate arterial values from venous values, PCO2, TCO2, HCO3-, BEecf and pH significantly showed over 0.45 in coefficient of determination value (R2), and there were little differences between actual and predicted arterial values. Although there were limits in venous gas values replaced those of arterial blood, if we could not get the arterial samples, the regression formulas for arterial values from venous blood in this study would be useful clinically, except for PO2 and SO2.

Determination of reference intervals and comparison of venous blood gas parameters using standard and non-standard collection methods in 24 cats

Objectives The aim of this study was to determine in-house reference intervals (RIs) for venous blood analysis with the RAPIDPoint 500 blood gas analyser using blood gas syringes (BGSs) and to determine whether immediate analysis of venous blood collected into lithium heparin (LH) tubes can replace anaerobic blood sampling into BGSs. Methods Venous blood was collected from 24 healthy cats and directly transferred into a BGS and an LH tube. The BGS was immediately analysed on the RAPIDPoint 500 followed by the LH tube. The BGSs and LH tubes were compared using paired t-test or Wilcoxon matched-pairs signed-rank test, Bland-Altman and Passing-Bablok analysis. To assess clinical relevance, bias or percentage bias between BGSs and LH tubes was compared with the allowable total error (TEa) recommended for the respective parameter. Results Based on the values obtained from the BGSs, RIs were calculated for the evaluated parameters, including blood gases, electrolytes, glucose and lactate. Values derived from LH tubes showed no significant difference for standard bicarbonate, whole blood base excess, haematocrit, total haemoglobin, sodium, potassium, chloride, glucose and lactate, while pH, partial pressure of carbon dioxide and oxygen, actual bicarbonate, extracellular base excess, ionised calcium and anion gap were significantly different to the samples collected in BGSs ( P <0.05). Furthermore, pH, partial pressure of carbon dioxide and oxygen, extracellular base excess, ionised calcium and anion gap exceeded the recommended TEa. Conclusions and relevance Assessment of actual and standard bicarbonate, whole blood base excess, haematocrit, total haemoglobin, sodium, potassium, chloride, glucose and lactate can be made based on blood collected in LH tubes and analysed within 5 mins. For pH, partial pressure of carbon dioxide and oxygen, extracellular base excess, anion gap and ionised calcium the clinically relevant alterations have to be considered if analysed in LH tubes.