| Popis: |
In humans, echocardiography is the standard of care in patients in shock, helping intensivists to characterize the haemodynamic disorder, to select a therapeutic approach and to monitor the response to treatment. In veterinary medicine the use of ultrasonography is limited to the assessment of the caudal vena cava (CVC), as a method of estimating volaemia. The current study aimed to explore whether echocardiographic measurements can be useful in the diagnosis and monitoring of the response to treatment in cases of suspected hypovolaemia. The study cohort comprised of eighteen dogs presented to an out of hours service for suspicion of hypovolaemia, and the control cohort consisted of nineteen dogs presented for echocardiography that were diagnosed as not having substantial cardiac disease. Data from the physical exam (mucous membrane colour, heart rate, pulse quality, capillary refill time), systolic blood pressure (SBP), and laboratory findings (lactate concentration (LAC), total protein (TP), packed cell volume (PCV)) were recorded for the study cohort and used to decide if the patients were suspected to be hypovolaemic. Dogs from both cohorts were scanned conscious in right lateral recumbency. Ultrasonographic measurements comprised: maximal diameter of the CVC (CVCmax), CVC collapsibility index (CVC CI), CVC to aorta ratio (CVC/Ao), maximal dimension of left atrium to aorta ratio (LAmajor/Ao), left ventricular internal diameter in diastole normalized for bodyweight by allometric scaling (LVIDdN), end diastolic ventricular volume index (EDVI), and stroke volume (SV) obtained from the aortic velocity- time integral. All the physical exam variables, laboratory tests and ultrasonographic measurements were measured again in the study cohort after the administration of intravenous fluid therapy. The median time to perform the ultrasonographic protocol was 4 (3-4) minutes. The best discriminator to differentiate between cases and controls was the EDVI (P=0.047), however the specificity (42%) and sensitivity (53%) were very low. The heart rate, capillary refill time, TP, PCV, CVCmax, CVC/Ao, LAmajor/Ao, LVIDdN, EDVI and SV were significantly different (P≤0.05) after treatment. This study shows that a simplified echocardiographic protocol, that can be performed in a limited time can provide useful information about the volume status of the conscious, spontaneously breathing, clinically ill dog and can be helpful in monitoring the response to treatment. |
