产科麻醉英文版_课件.pptVIP

Obstetric Anesthesia Physiologic Changes Of Pregnancy Cardiovascular System : cardiac output , heart rate Hematologic System : blood volume increases by up to 45% , red cell volume increases by only 30% physiologic anemia Respiratory System : increase in the respiratory minute volume and work of breathing Gastrointestinal System : risk of incidence of aspiration↑ endotracheal intubation↑ Renal System : GFR rises 50% ; glycosuria Central Nervous System :↑?sensitivity to anesthetics. Changes Of Respiratory System O2 (Consumption 消耗 ) +20 to +50% MV(Minute Ventilation分钟通气量) +50% TV +40% PaO2 +10% PaCO2 -15% HCO3 -15% FRC -20% Placental Transfer Of Anesthetic Drugs Placenta transport : Simple diffusion Facilitated diffusion Active transport Pinocytosis Readily cross : low molecular weights, high lipid solubility , non-ionized Approximately 50% of the umbilical venous blood bypasses the liver. Narcotic analgesic morphine pethidine fentanyl alfentanil sufentanil General anesthetics propofol 吗啡、哌替啶、芬太尼 Morphine Placental transfer is rapid Mother: uterus reactiveness↓ orthostatic hypotension nausea vomiting delayed gastric emptying Fetus: respiratory depression Pethidine Most commonly used during labor intramuscular dose : 50 -100 mg Time of IM: before expulsion 1 h or 4 h uterine contraction, frequency and intension ↑ Fentanyl Alfentanil Sufentanil Placental transfer is rapid??? Low dose: 10 -25 μg fentanyl or 5-10 μg sufentanil in subarachnoid space PCEA: low dose of fentanyl and 0.1%- 0.3% ropivacaine Tramadol Placental transfer No inhibiting uterine contraction No Respiratory depression Diazepam Readily cross the placenta Half-lives: 48 hours Problems: sedation, hypotonia,