RESUMEN
BACKGROUND: To reduce massive blood loss during a hepatectomy, many anesthesiologists have used the technique of low central venous pressure maintenance by administration of low dose nitroglycerin (NTG) and/or intravenous fluid reduction. However, so far there have been no studies about local liver perfusion (LLP) changes after hepatic artery (HA) or portal vein (PV) reperfusion in patients receiving nitroglycerin administration. In this study, the changes in hemodynamics and LLP following HA and PV reperfusion along with low dose (2micro gram/kg/min) NTG administration in dogs were observed. METHODS: A total of 20 mongrel dogs were divided into four groups; HA occlusion and reperfusion group (H, n = 5), NTG administration group during the reperfusion on H (H-NTG, n = 5), PV occlusion and reperfusion group (P, n = 5), NTG administration group during the reperfusion on P (P-NTG, n = 5). After femoral and pulmonary arterial catheterization, a midline abdominal incision was made. HA and PV were exposed to clamp and declamp. A thermal diffusion microprobe was inserted in the liver parenchyme to measure LLP. RESULTS: The PV blood flow was not changed after HA occlusion, but HA blood flow increased after PV occlusion. The LLP decreased after HA and PV occlusion. The LLP recovered to the baseline level in group H-NTG after HA reperfusion, but the LLP was more increased compared to the baseline level in group H. In group P, the LLP did not recover after PV reperfusion, but the LLP in group P-NTG recovered to the baseline level after PV reperfusion. CONCLUSIONS: In conclusion, it was observed that the LLP recovered to the baseline level by administration of NTG after PV reperfusion. However, the LLP did not increase after HA reperfusion by administration of low dose NTG.
Asunto(s)
Animales , Perros , Humanos , Cateterismo , Catéteres , Presión Venosa Central , Hemodinámica , Hepatectomía , Arteria Hepática , Hígado , Nitroglicerina , Perfusión , Vena Porta , Reperfusión , Difusión TérmicaRESUMEN
BACKGROUND: The purpose of this study was to determine whether the injection rate affects the spread of spinal anesthesia in cesarean sections. METHODS: Spinal anesthesia was performed on 45 parturients in a cesaren section. Dural puncture was performed in the sitting position with a 27-gauge Whitacre needle. All patients received a mixture of 10 mg hyperbaric bupivacaine and 15 microgram fentanyl. Twenty five (Group I) patients received rapid injections (about 0.2-0.3 ml/sec) and twenty (Group II) received slow injections (about 0.1 ml/sec). Anesthetic levels, time to T4 sensory block, maximal height sensory block and incidence of hypotension were measured. RESULTS: There was significantly rapid T4 sensory block in group I but no differences in maximal height of sensory block and incidence of hypotension between the two groups. CONCLSIONS: We conclude that injection rate (about 0.1-0.3 ml/sec) has a statistically insignificant influence on the maximal height sensory block and incidence of hypotension.