The cardiopulmonary effects of dobutamine and norepinephrine in isoflurane-anesthetized foals

OBJECTIVE: To evaluate the cardiovascular effects of norepinephrine (NE) and dobutamine (DB) in isoflurane-anesthetized foals. STUDY DESIGN: Prospective laboratory study. METHODS: Norepinephrine (0.05, 0.10, 0.20, and 0.40 microg kg(-1) minute(-1)) and dobutamine (2.5, 5.0, and 10 microg kg(-1) minute(-1)) were alternately administered to seven healthy, 1- to 2-week-old isoflurane-anesthetized foals. Arterial and pulmonary arterial blood pressure, right atrial pressure, pulmonary artery occlusion pressure, heart rate, body temperature, cardiac output, arterial and mixed venous blood pH, partial pressure of carbon dioxide, partial pressure of oxygen [arterial partial pressure of oxygen (PaO(2)) and mixed venous partial pressure of oxygen (PvO(2))], and packed cell volume were measured. Standard base excess, bicarbonate concentration, systemic and pulmonary vascular resistance, cardiac index (CI), stroke volume, left and right stroke work indices, oxygen delivery (DO(2)), consumption, and extraction were calculated. Results Norepinephrine infusion resulted in significant increases in arterial and pulmonary arterial pressure, systemic and pulmonary vascular resistance indices, and PaO(2); heart rate was decreased. Dobutamine infusion resulted in significant increases in heart rate, stroke volume index, CI, and arterial and pulmonary arterial blood pressure. Systemic and pulmonary vascular resistance indices were decreased while the ventricular stroke work indices increased. The PaO(2) decreased while DO(2) and oxygen consumption increased. Oxygen extraction decreased and PvO(2) increased. CONCLUSIONS AND CLINICAL RELEVANCE: Norepinephrine primarily augments arterial blood pressure while decreasing CI. Dobutamine primarily augments CI with only modest increases in arterial blood pressure. Both NE and DB could be useful in the hemodynamic management of anesthetized foals.     

Comparison of PO2, PCO2, and pH in blood collected from the femoral artery and a cut claw of cats

A technique for collection of blood samples from the cut claw of the cat was developed. Forty-six blood samples were collected simultaneously from the cut claw and the femoral artery of 7 healthy cats. Blood gas and pH values were measured and compared. There was no difference between sample pairs for blood PO2 and PCO2, but the pH values were significantly (P less than 0.001) higher in the capillary samples (7.432 +/- 0.033) than in the samples from the femoral artery (7.419 +/- 0.031).     

Feline trauma and critical care medicine

The initial management of the traumatized cat can be a challenging, but rewarding, task for the veterinarian. The pathophysiology of shock, its clinical presentation, and basic elements of treatment are universal to all species. Special care must be taken when dealing with injured cats, due to their increased susceptibility to stress and tendency toward severe hypothermia in shock. The development of pulmonary edema in response to excessive fluid loads, especially in the face of pulmonary injury, must be borne in mind when establishing treatment regimens. The keys to successful management of the traumatized cat lie in correct assessment of the extent and nature of injuries, rapid institution of rational therapy, and constant re-evaluation of the animal's response throughout the post-traumatic period.     

The case for in circuit vaporizers.

In circuit vaporizers have some characteristics that differ from out of circuit vaporizers. In circuit vaporizers are easy to use, effective, and offer several clinical advantages.     

A case‐based review of a simplified quantitative approach to acid‐base analysis

Objective – To present a simplified quantitative approach to acid‐base analysis and to demonstrate its clinical utility. Data Sources – Original research articles and textbooks. Data Synthesis – A simplified quantitative approach to acid‐base analysis is presented, which is derived from the Fencl‐Stewart approach and calculates the magnitude of the effect on the standardized base excess (SBE) of 5 separate variables: (1) a free water effect (marked by sodium concentration), (2) an effect marked by the chloride concentration, (3) an albumin effect, (4) a lactate effect, and (5) a phosphate effect. Six clinical cases with acid‐base abnormalities are presented in which the quantitative approach provides information that is not apparent from the traditional approach. Conclusion – This simplified quantitative approach provides a comprehensive evaluation of complex acid‐base disorders, identifies individual processes and their relative influence on SBE, and aids in the development of an appropriate therapeutic plan.