Inflammatory Reactions after Subdermal Injection of Thiopental and Propofol in Rabbits / 대한마취과학회지

BACKGROUND: Thiopental and propofol are the most widely used intravenous anesthetics as induction agents in general anesthesia. Thiopental is a very strong alkaline drug, and when it is extravasated, it can cause pain and skin necrosis. Propofol also can cause pain on injection in many populations. Therefore, we planed this study to compare inflammatory reactions of skin tissues after subdermal injections of thiopental and propofol in rabbits. METHODS: Four rabbits were divided into 2 groups: Standard dose (S) group and double dose (D) group. In the S group, thiopental 0.4 ml and propofol 0.4 ml were injected subcutaneously on each side of the posterior proximal ear. In the D group, the dose was doubled to 0.8 ml of each drug and injection was done in the same manner. Skin tissue at the injection sites were excised after 1 day, 3 days, and 7 days. Then each skin tissue slide was examined under an optical microsccpe. RESULTS: In the S group, the inflammatory reaction after the subdermal injection of 2.5% thiopental revealed a more progressed and more severe pattern than 1% propofol. In the D group, the inflammatory reaction after a subdermal injection of 2.5% thiopental revealed a more progressed and more severe pattern than 1% propofol at 3 days, but there was no significant difference in the degree of progression and severity between the 2 drugs at 7 days. CONCLUSIONS: When propofol is extravasated during continuous infusion for maintenance of anesthesia, it can cause distinct inflammatory reaction; though the inflammatory reaction is milder and the possibility of complications is lower than with thiopental.

Comparison of Amrinone and Dopamine-Nitroglycerin on Hemodynamic Parameters in Dogs with Postinfarct Heart Failure / 대한마취과학회지

BACKGROUND: Left ventricular failure (LVF) after an acute myocardial infarction occurs during the perioperative period, and since this condition can lead to severe complications, intensive care is required for the patient. LVF is characterized hemodynamically by a raised left heart filling pressure and volume and global depression of the hearts pumping performance. Several effective drugs for patients with heart failure are catecholamines such as dopamine and dobutamine, vasodilators such as nitroglycerin and nitroprusside, and noncatecholamine inotropes such as amrinone, which are either infused alone or in combination. However, as of now, there has been no study as to clarifying either the exact dosage, drug combination, or how they affect the heart. METHODS: By inducing a state of experimental acute left ventricular failure in 20 dogs through ligation of the left anterior descending coronary artery, this study compared the hemodynamic parameters of two treatment groups-one group using amrinone alone (bolus 1 mg/kg, continuous infusion 15micro gram/kg/min), and another group using a combination of dopamine (10micro gram/kg/min) and nitroglycerin (2micro gram/kg/min). RESULTS: Cardiac output of dogs with postinfarct heart failure increased in both treatment groups. But, there was a significant decrease in systemic vascular resistance, pulmonary vascular resistance and left ventricular end diastolic pressure in the group treated with amrinone than dopamine-nitroglycerin. Amrinone also revealed a favorable effect on oxygen utility. CONCLUSIONS: These results showed that amrinone might be more effective than the combination of dopamine and nitroglycerin for acute left ventricular failure in terms of myocardial function, hemodynamic stability and oxygen utility.

Comparison of Amrinone and Dopamine-Nitroglycerin on Hemodynamic Parameters in Dogs with Postinfarct Heart Failure / 대한마취과학회지

BACKGROUND: Left ventricular failure (LVF) after an acute myocardial infarction occurs during the perioperative period, and since this condition can lead to severe complications, intensive care is required for the patient. LVF is characterized hemodynamically by a raised left heart filling pressure and volume and global depression of the hearts pumping performance. Several effective drugs for patients with heart failure are catecholamines such as dopamine and dobutamine, vasodilators such as nitroglycerin and nitroprusside, and noncatecholamine inotropes such as amrinone, which are either infused alone or in combination. However, as of now, there has been no study as to clarifying either the exact dosage, drug combination, or how they affect the heart. METHODS: By inducing a state of experimental acute left ventricular failure in 20 dogs through ligation of the left anterior descending coronary artery, this study compared the hemodynamic parameters of two treatment groups-one group using amrinone alone (bolus 1 mg/kg, continuous infusion 15micro gram/kg/min), and another group using a combination of dopamine (10micro gram/kg/min) and nitroglycerin (2micro gram/kg/min). RESULTS: Cardiac output of dogs with postinfarct heart failure increased in both treatment groups. But, there was a significant decrease in systemic vascular resistance, pulmonary vascular resistance and left ventricular end diastolic pressure in the group treated with amrinone than dopamine-nitroglycerin. Amrinone also revealed a favorable effect on oxygen utility. CONCLUSIONS: These results showed that amrinone might be more effective than the combination of dopamine and nitroglycerin for acute left ventricular failure in terms of myocardial function, hemodynamic stability and oxygen utility.

The Effects of Propranolol and Esmolol on Blood Flow of Common Carotid Artery and Vital Signs in Rabbits / 대한마취과학회지

BACKGROUND: This study was planned to evaluate the influence of propranolol and esmolol on cerebral circulation and to estimate clinical implications and usefulness. METHODS: This study was designed to measure vital signs, cerebrospinal fluid pressure, cerebral perfusion pressure and blood flow velocity of common carotid artery. This was measured by Doppler Flowmeter after intravenous administration of propranolol 12.5, 25, 50 microgram/kg (P-12.5, P-25, P-50, respectively), and esmolol 0.5, 1.0, 2.0 mg/kg (E-0.5, E-1.0, E-2.0 group, respectively) at 1 or 2 minute intervals for 14 minutes. RESULTS: In the propranolol group (P-12.5, P-25 and P-50), the systolic blood pressure (SBP) significantly decreased since postinjection 1 minute and this decreased pressure continued throughout the entire experiment. But in esmolol group (E-0.5, E-1.0 and E-2.0), the SBP decreased significantly and rapidly recovered within 4 minutes. Heart rate significantly decreased in the propranolol group and continued throughout the experiment, but in the esmolol group the heart rate decreased and rapidly recovered within 10 minutes. The duration of the decreased heart rate in the esmolol group was shortened by decreasing the dosage. The blood flow velocity of the common carotid artery significantly decreased at 1 to 14 minutes after the injection of propranolol, but in group E-1.0, it was significantly decreased at 1 to 2 minutes, and in group E-2.0 at 1 to 3 minutes. CONCLUSIONS: The esmolol group showed less changes of SBP, heart rate and common carotid artery flow, and shorter duration of effect than the propranolol group. Mean blood pressure, cerebrospinal fluid pressure and cerebral perfusion pressure had no significant differences between propranolol and esmolol groups.