Acceptance and effects of a therapeutic renal food in pet cats with chronic kidney disease.

INTRODUCTION: Renal foods are used to manage chronic kidney disease (CKD) in dogs and cats, but their effectiveness may be limited by the ability to transition animals to them. MATERIAL AND METHODS: In a prospective study, pet cats with previously undiagnosed kidney disease (20 International Renal Interest Society (IRIS) 1, 61 IRIS 2, 14 IRIS 3/4, 33 at risk for CKD) were transitioned to a renal food. Markers of renal function were measured and owners answered questionnaires about their pet over one year. RESULTS: All but eight cats (120/128; 94 per cent) successfully transitioned to the renal food. Most of the time, cats moderately or extremely liked the food (89 per cent), ate at least half (73 per cent) and were moderately or extremely enthusiastic while eating (68 per cent). Cats rarely disliked the food (2 per cent) or refused to eat it (1 per cent). Markers of renal function were unchanged in IRIS 1 and 2 cats and changed little in IRIS 3/4 cats. In all groups, owner-assessed quality of life improved initially and then remained stable. Mean bodyweight did not change in cats with CKD. CONCLUSIONS: Most cats with CKD successfully transitioned to the renal food. The results also support previous studies that the renal food can help stabilise cats with CKD.

Effects of soman (pinacolyl methylphosphonofluoridate) on coronary blood flow and cardiac function in swine.

The effects of soman (pinacolyl methylphosphonofluoridate) on coronary blood flow, the electrocardiogram, and cardiac function were measured in alpha-chloralose-anesthetized swine. Coronary blood flow (CBF), mean arterial blood pressure (MAP), peak systolic left ventricular pressure (IVP), maximum rate of left ventricular pressure development (dP/dtmax), cardiac output, and the ECG were monitored continuously. A dose of 2X LD50 of soman (1 LD50 = 4.6 micrograms/kg) was given at 1 LD50/min in the femoral vein, which produced an increase in coronary sinus plasma acetylcholine (ACh) from a control of 0.7 +/- 0.01 nmol/ml to a maximum 314% of control at 15 min and a decrease in CBF from a control of 99 +/- 13 ml/min/100 g to a minimum 55% of control at 15 min. The increase in ACh in the coronary sinus was significantly correlated with a decrease in CBF (r = -0.87, p < 0.001). The fall in CBF was accompanied by concomitant decreases in IVP, MAP, and dP/dtmax, with S-T segment elevation and ventricular fibrillation. The increase in coronary sinus acetylcholine concentration was significantly correlated with a 10-fold fall in coronary sinus acetylcholinesterase levels from a control of 2.47 +/- 0.97 mol acetylcholine hydrolyzed/ml blood/min and was consistent with the time course for the reduced hemodynamic measurements. These studies support the hypothesis that acetylcholine increases following soman toxicity may decrease coronary blood flow, thereby initiating ischemic electrocardiographic changes and reducing cardiac function.

Effects of diaspirin crosslinked haemoglobin during coronary angioplasty in the swine.

OBJECTIVE: Percutaneous transluminal coronary angioplasty produces a transient interruption of coronary blood flow during balloon inflation, giving rise to temporary regional myocardial ischaemia. Diaspirin crosslinked haemoglobin (DCLHbTM) transports oxygen in a similar way to whole blood and can be perfused through the angioplasty catheter during balloon occlusion. The aim of this study was to test the hypothesis that DCLHb may increase myocardial oxygenation and reduce myocardial ischaemia during coronary angioplasty. METHODS: The effect of DCLHb on cardiac function was measured in diazepam sedated swine. Mean arterial blood pressure, peak systolic left intraventricular pressure, maximum rate of left ventricular pressure development (dP/dtmax), pressure-rate product, cardiac output (CO), and ECG were monitored continuously. Variables were compared during control, during 1 min balloon occlusion of the proximal left anterior descending coronary artery with a 2.5-3.5 F angioplasty catheter, during 1 min of DCLHb perfusion (40 ml.min-1) without balloon occlusion, and during 4 min balloon occlusion with DCLHb perfusion (40 ml.min-1) of the occluded region. Measurements were made during balloon occlusion plus DCLHb at 1 min (B + D1), 2 min (B + D2), and 4 min (B + D4). RESULTS: Balloon occlusion decreased cardiac function as compared to control: arterial blood pressure -16%, intraventricular pressure -14%, dP/dtmax -34%, and pressure-rate product -40%. DCLHb alone did not significantly change haemodynamic measurements from control. At B + D4 haemodynamic variables were increased as compared to balloon occlusion alone: arterial blood pressure +32%, intraventricular pressure +29%, dP/dtmax +20%, and pressure-rate product +19%. Only intraventricular pressure and mean arterial pressure were increased compared to control. The S-T segment of the ECG was depressed by 0.109(SEM 0.019) mV during balloon occlusion without DCLHb, while only decreasing by 0.069(0.027) mV at B + D1, by 0.046(0.018) mV at B + D2, and by 0.058(0.018) mV at B + D4. CONCLUSIONS: There is an improvement in cardiac function and a lessening of S-T segment depression during percutaneous transluminal coronary angioplasty balloon occlusion with DCLHb perfusion.

Infrared thermographic measurement of circulatory compromise in trenchfoot-injured Argentine soldiers.

Passive rewarming of a cold-water stressed foot was evaluated in 33 recovered trenchfoot (TF) patients and 15 uninjured men. Infrared images were recorded prior to immersion, immediately following, and at 1-min intervals for 20 min. Individual baseline temperature (IBT) recovery was used to separate subjects into three groups designated Good and Poor Rewarming Controls (GRC and PRC) and Injured Subjects (Inj Sub). IBTs were significantly less (p less than 0.01) for Inj Sub compared to both GRC and PRC while no difference existed between GRC and PRC. This relationship changed when slopes of and areas under the mean rewarming curves were compared. Both these criteria were significantly greater (p less than 0.01) for GRC than for PRC and Inj Sub, while no difference was noted between PRC and Inj Sub. It could not be determined if the poor response of Inj Sub was inherent or a result of injury. We conclude that previously injured subjects and nearly 60% of a normal population may be at significant risk for cold injury.

Enzymatic frostbite eschar debridement by bromelain.

Bromelain is a plant proteinase derived from the stem of the pineapple plant that has been used successfully to debride the eschar from third-degree burn injuries. Its applicability to frostbite eschar removal was extrapolated and investigated. Third-degree frostbite lesions were produced on swine using supercooled air as the freezing media, and the resulting eschars were treated with a bromelain preparation. In the initial trial, no debridement other than that of the superficial layers of the eschar was noted. The experiment then was repeated with the introduction of third-degree burn injuries as a control to validate the efficacy of the enzyme preparation. Although the burn injuries debrided to a graftable bed after two applications of the enzyme, the frostbite injuries remained unaffected. It was concluded that the patent vasculature, resulting tissue edema, and lack of coagulation of proteins found in the freeze injury are sufficient to inactivate the bromelain enzyme before tissue digestion and dissection can be effected.