Co-administration of nitrous oxide reduces the pressor response against oro-tracheal intubation during induction of anesthesia with propofol infusion at a low rate

This study investigated the effect of co-administration of nitrous oxide on the cardiovascular changes during induction of anesthesia with propofol infusion at a low rate. Sixty patients undergoing general anesthesia were randomly allocated into two groups, and received the inhalation of 100% oxygen (group 1) or 60% nitrous oxide and oxygen (group 2) via face mask for 3 minutes before administration of propofol at 15 mg.kg-1.hr-1. After beginning of propofol infusion, patients inhaled each gas continuously and the loss of response to simple commands by the anesthesiologist was considered as hypnosis. The dose and time for achieving hypnosis were determined, and non-invasive blood pressure, heart rate and arterial oxygen saturation were recorded during induction of anesthesia. Cardiovascular changes during induction were not different between the two groups except mean and diastolic blood pressure immediately after oro-tracheal intubation [126 +/- 21 vs. 113 +/- 21 mmHg and 108 +/- 21 vs. 95 +/- 19 mmHg, respectively (mean +/- SD)]. The dose of propofol and the time for achieving hypnosis showed no significant difference (73 +/- 20 vs. 68 +/- 19 mg and 4.8 +/- 1.0 vs. 4.4 +/- 1.0 min, respectively). Almost all patients were sedated with inhalation of nitrous oxide before infusion of propofol, but no additive effect was observed with nitrous oxide and propofol. Co-administration of nitrous oxide during propofol infusion at a low rate was an effective method to avoid undesirable pressor responses against oro-tracheal intubation without causing adverse cardiovascular depression.     

Effect of etomidate and thiopental on the onset of rocuronium action]

HYPOTHESIS: Differences in the hemodynamic effects of induction agents may cause them to affect the onset of action of rocuronium differently. OBJECTIVES: To compare the onset of action of rocuronium after induction with etomidate and thiopental. PATIENTS AND METHODS: Forty adult ASA I patients received 3 micrograms.kg-1. Three minutes later anesthesia was induced randomly with either 5 mg.kg-1 of thiopental (group I, n = 20) or 0.3 mg.kg-1 of etomidate (group II, n = 20). Rocuronium 0.6 mg.kg-1 was administered over 5 s. Baseline blood pressure and heart rate were measured just before delivery of rocuronium and just before intubation. Onset of action was defined as the time from injection of rocuronium until achievement of a blockade > or = 95% of the first electromyographic response in a trian-of-four stimulus of the short adductor of the thumb. We also studied intubation conditions. RESULTS: Etomidate was associated with a smaller decrease in systolic arterial pressure than was thiopental. Onset of action was 81 +/- 29 s in group I versus 72 +/- 23 s in group II (NS). Similar intubation conditions were observed in both groups. CONCLUSIONS: These results suggest that the induction drug does not affect rocuronium's onset of action.     

Changes of arterial blood pressure and heart rate during induction of anesthesia with propofol--efficacy of propofol titration using bispectral index as an indicator]

Bispectral index (BIS) is a processed EEG parameter that measures the hypnotic effects of anesthetic and sedative agents on the brain. We studied whether propofol titration using BIS allows us to prevent hemodynamic changes during induction of anesthesia and endotracheal intubation. Thirty patients without hypertension and obesity were studied. In the titration group (n = 15), BIS was maintained at 40 during induction of anesthesia with propofol. In the bolus group, anesthesia was induced with a bolus infusion of propofol 2 mg.kg-1 (n = 15). Arterial blood pressure and heart rate were recorded before induction of anesthesia, during induction of anesthesia, immediately after, and 1 min, 2 min, and 3 min after intubation. Diastolic blood pressure and heart rate increased significantly after endotracheal intubation in both groups. Systolic blood pressure significantly increased immediately after intubation in the bolus group, but was unchanged in the titration group. These results suggest that BIS is useful to prevent significant increases in systolic blood pressure associated with endotracheal intubation during induction of anesthesia with propofol.     

Sympathetic responses to induction of anesthesia in humans with propofol or etomidate.

Anesthetic induction with propofol commonly results in hypotension. This study explored potential mechanisms contributing to hypotension by recording cardiovascular responses including sympathetic neural activity from patients during induction of anesthesia with propofol (2.5 mg.kg-1 plus 200 micrograms.kg-1.min-1) or, for comparison, etomidate (0.3 mg.kg-1 plus 15 micrograms.kg-1.min-1). Twenty-five consenting, nonpremedicated, ASA physical status 1 and 2, surgical patients were evaluated. Measurements of R-R intervals (ECG), blood pressure (radial artery), forearm vascular resistance (plethysmography), and efferent muscle sympathetic nerve activity ([MSNA] microneurography: peroneal nerve) were obtained at rest and during induction of anesthesia. In addition, a sequential bolus of nitroprusside (100 micrograms) followed by phenylephrine (150 micrograms) was used to obtain data to quantitate the baroreflex regulation of cardiac function (R-R interval) and sympathetic outflow (MSNA) in the awake and anesthetized states. Etomidate induction preserved MSNA, forearm vascular resistance, and blood pressure, whereas propofol reduced MSNA by 76 +/- 5% (mean +/- SEM), leading to a reduction in forearm vascular resistance and a significant hypotension. Both cardiac and sympathetic baroslopes were maintained with etomidate but were significantly reduced with propofol, especially in response to hypotension. These findings suggest that propofol-induced hypotension is mediated by an inhibition of the sympathetic nervous system and impairment of baroreflex regulatory mechanisms. Etomidate, conversely, maintains hemodynamic stability through preservation of both sympathetic outflow and autonomic reflexes.     

Electroencephalographic arousal response during tracheal intubation and laryngeal mask airway insertion after induction of anaesthesia with propofol

Laryngoscopy and tracheal intubation, or insertion of a laryngeal mask airway may lead to an arousal response on the electroencephalogram. We studied whether more intense stimulation (laryngoscopy and tracheal intubation) causes a greater arousal response than less intense stimulation (laryngeal mask airway insertion). Thirty-four patients (ASA I-II) were anaesthetised with propofol 3 mg.kg-1, followed by vecuronium 0.15 mg.kg-1 and a propofol infusion of 10 mg.kg-1.h-1. Three minutes after induction of anaesthesia, either laryngoscopy and tracheal intubation (n = 18), or laryngeal mask airway insertion (n = 16) was performed. Laryngoscopy and tracheal intubation caused a significantly greater increase in blood pressure (but not heart rate) than laryngeal mask airway insertion (p < 0.05). Electroencephalogram responses were not different. More intense stimulation does not cause a greater arousal response during propofol anaesthesia.     

Clinical comparison of either small doses of fentanyl or remifentanil for blunting cardiovascular changes induced by tracheal intubation

BACKGROUND: To compare in a prospective, randomized study the effects on cardiovascular changes after tracheal intubation produced by small doses of either remifentanil or fentanyl. METHODS: With Ethical Committee approval, after intravenous midazolam premedication (0.05 mg.kg-1), 30 normotensive, ASA physical status I-II patients, without cardiovascular or respiratory diseases, and with a Mallampati score < 2, were randomly allocated to receive an intravenous bolus of either 3 micrograms.kg-1 fentanyl (n = 15) or 1 microgram.kg-1 remifentanil (n = 15) infused over 60 sec and followed by a 0.15 microgram.kg-1.min-1 continuous intravenous infusion. General anesthesia was then induced with propofol (2 mg.kg-1), followed by atracurium besilate (0.5 mg.kg-1) to facilitate tracheal intubation. Following intubation, the lungs were ventilated mechanically using a 60% nitrous oxide in oxygen mixture with a 1% inspired fraction of sevoflurane. Arterial blood pressure and heart rate were recorded before anesthesia induction (baseline), one minute after induction of anesthesia, immediately after tracheal intubation and every minute for the first five minutes after intubation. RESULTS: Systolic arterial blood pressure values were significantly higher in the Fentanyl than in the Remifentanil group patients from 2 to 5 min after tracheal intubation (p < 0.01), while no differences were observed between the two groups in either diastolic arterial blood pressure or heart rate values. Four patients in the Remifentanil group (26%) but only one patient in the Fentanyl group (7%) showed systolic blood pressure values < 90 mmHg during the study period (p = not significant); however, the observed decreases in systolic arterial blood pressure values were transient and did not require treatment for any subject. CONCLUSION: We conclude that in healthy normotensive patients, the control of cardiovascular responses to tracheal intubation obtained with a 1 microgram.kg-1 loading dose of remifentanil is more effective than that provided by a 3 micrograms.kg-1 bolus of fentanyl, with the advantage of no risks for postoperative respiratory depression.     

异丙酚与依托咪酯复合硬膜外阻滞对血糖和皮质醇的影响

目的和方法：１２０例ＡＳＡⅠ～Ⅱ级成年病人,按照全麻诱导和维持用药随机分成依托咪酯（Ｅ组,ｎ＝６０）和异丙酚（Ｐ组,ｎ＝６０）两组。两组病人均硬膜外穿刺置管,Ｅ组病人诱导用依托咪酯０２５ｍｇ／ｋｇ,维持时负荷剂量为２０μｇ·ｋｇ－１·ｍｉｎ－１,维持剂量为６μｇ·ｋｇ－１·ｍｉｎ－１;Ｐ组病人诱导用异丙酚１５ｍｇ／ｋｇ,维持时负荷剂量为１６０μｇ·ｋｇ－１·ｍｉｎ－１,维持剂量为５０μｇ·ｋｇ－１·ｍｉｎ－１。观察术中心血管反应、血浆皮质醇和血糖的变化。结果：异丙酚和依托咪酯静脉诱导后均可造成血压下降,异丙酚较为严重,但术中两组病人的血压脉率皆容易维持稳定。两组病人术中血糖随着手术进程缓慢升高,Ｐ组病人血浆皮质醇变化与血糖相似,而Ｅ组病人术中血浆皮质醇水平缓慢降低,直至术后２４小时方恢复。结论：在硬膜外阻滞复合异丙酚静脉全麻时,尽管手术创伤所致的心血管应激反应已经控制,但体内应激激素依然保持适度增高。而依托咪酯则抑制肾上腺皮质,致血浆皮质醇水平下降,不适合用作长期静脉麻醉的维持。     

Intravenous ketamine attenuates arterial pressure changes during the induction of anaesthesia with propofol

BACKGROUND AND OBJECTIVE: To investigate whether the administration of ketamine before induction with propofol produces a smaller decrease in arterial pressure. METHODS: Twenty-two patients were assigned to one of two groups to receive either propofol with ketamine (n = 11) or propofol alone (n = 11, control). Anaesthesia was induced with 2 mg kg-1 propofol and 0.5 mg kg-1 ketamine or 2 mg kg-1 propofol alone. Ketamine was administered 1 min prior to induction with propofol. Immediately after induction with propofol, vecuronium (0.15 mg kg-1) was administered. Four minutes after administration of vecuronium, tracheal intubation was performed. Anaesthesia was maintained using sevoflurane (0.5%) in 66% nitrous oxide until 3 min after intubation. Systolic, diastolic and mean arterial pressure and heart rate were recorded on arrival, directly before induction with propofol, prior to tracheal intubation, immediately after intubation and at 3 min after intubation. RESULTS AND CONCLUSIONS: Administration of ketamine before induction with propofol preserved haemodynamic stability compared with induction with propofol alone.     

不同全麻诱导药对循环及内分泌功能的影响

目的 评价三种静脉药在全麻诱导时对循环、垂体－肾上腺皮、髓抽内分泌功能的影响。方法 将择期全麻手术病人43例,随机分为三组：Ⅰ（组（异丙酚2.5mg/kg）;Ⅱ组（硫喷妥钠5mg/kg）和Ⅲ组（依托咪酯03mg/kg）各14例。行桡动脉直接测压,同时边疆监测ECG、SpO2。快速静注琥珀碱1.5-2.0mg/kg行气管插管。插管2min后静注维库溴铵4mg,5min后各组吸入安氟醚维持1.3MAC,15min后复合吸入N2O。在诱导前（T0）,窥喉插管即刻（T1）,插管后2min（T2）,5min(T3),15min(T4)取外周静脉血测定血浆去甲肾上腺素（NE）、肾上腺素（E）、皮质醇（cort）、泌乳素（PRL）、生长素（GH）、β－内啡肽（β－EP）、胰岛素和血糖的水平。结果 异丙酚诱导气管插管能抑制高血压反应,不增加心肌耗氧量,明显优于友喷妥钠和依插咪酯;三药诱导气管插管均不能抑制E和NE升高;均使腺垂体分泌PRL增加,而H、β-EP无变化;插管后15min依托咪酯使肾上腺皮质分泌cort减少;使血糖升高,胰岛素降低;说明对糖耐量呈现抑制作用。结论 异丙酚对循环和内分泌影响较小,是目前首选的全麻诱导药。     

Tracheal intubation without the use of muscle relaxants: a technique using propofol and varying doses of alfentanil.

We have noted that tracheal intubation can be accomplished in many patients after induction of anesthesia with propofol and alfentanil without the simultaneous use of muscle relaxants. This study was designed to evaluate airway and intubating conditions after administration of propofol and alfentanil in 75 ASA physical status I or II outpatients with Mallampati class I airways undergoing various surgical procedures. The patients were randomly assigned to one of five groups for induction of anesthesia. All patients received midazolam 1 mg IV before induction of anesthesia. Group I patients (n = 15) received d-tubocurarine 3 mg, thiamylal 4 mg/kg, and succinylcholine 1 mg/kg IV. Groups II-V patients (n = 15 each) received alfentanil 30, 40, 50, or 60 micrograms/kg followed by propofol 2 mg/kg IV. No muscle relaxants were given to patients in groups II-V. Airway management was performed by one of the authors who was blinded as to the dose of alfentanil administered. After loss of consciousness, patients' lungs were ventilated via face mask, and the ease of ventilation was recorded. Jaw mobility was also assessed. Ninety seconds after administration of the propofol or thiamylal, laryngoscopy was performed and exposure of the glottis and position of the vocal cords were noted. Intubation of the trachea was performed and patient response was noted. Heart rate and arterial blood pressure were also recorded before induction of anesthesia, after induction, and then again after intubation of the trachea. The lungs of all patients were easily ventilated via mask, and the jaw was judged to be relaxed in all patients.(ABSTRACT TRUNCATED AT 250 WORDS)     

依托咪酯和异丙酚复合麻醉对腹部手术患者脑氧代谢影响的比较

目的 比较依托咪酯和异丙酚复合麻醉对腹部手术患者脑氧代谢的影响.方法 择期全麻下拟行腹部手术患者36例,ASA Ⅰ或Ⅱ级,随机分为异丙酚复合麻醉组(P组)和依托咪酯复合麻醉组(E组),每组18例.两组均静脉注射咪达唑仑0.08 mg/kg、芬太尼3μg/kg、维库溴铵0.1 mg/kg,P组静脉注射异丙酚1.5 mg/kg、E组静脉注射依托咪酯0.3 mg/kg行麻醉诱导,P组静脉输注异丙酚4～6mg·kg-1·h-1、E组静脉输注依托咪酯0.4～0.7 mg·kg-1·h-1,术中均间断注射维库溴铵和芬太尼维持麻醉.分别于麻醉前(T1)、气管插管后即刻(T2)、手术开始30 min(T3)及术毕即刻(T4)时监测HR、MAP和SpO2,抽取桡动脉血和颈内静脉球部血样行血气分析,测定乳酸浓度,计算动脉血氧含量(CaO2)、颈内静脉氧含量(cjvO2)、脑氧摄取率(CERO2).结果 两组HR、MAP和SpO2均在正常范围内.与T1时相比,两组SaO2、SjvO2、PaO2、PjvO2升高,T2-4时Da-jvO2和CERO2降低(P<0.01);两组问比较各时点SaO2、SjrO2、PaO2、PjvO2、CaO2、CjvO2、Da-jvO2、CERO2及乳酸水平差异均无统计学意义(P>0.05).结论 依托眯酯和异丙酚复合麻醉均可降低腹部手术患者的脑氧代谢率,且无明显差别.     

Cerebral arterial blood flow velocity during induction of general anesthesia: rapid intravenous induction versus awake intubation.

Changes in middle cerebral arterial flow velocity (MCAV) during rapid intravenous induction and awake intubation using transcranial Doppler sonography were investigated. The study involved 20 patients without disorders of the central nervous or cardiovascular systems who were scheduled for maxillofacial surgery. In the intravenous induction group, anesthesia was induced with sodium thiopental, and orotracheal or nasotracheal intubation was facilitated with succinylcholine chloride or alcuronium chloride. In the awake intubation group, orotracheal or nasotracheal intubation was performed under intravenous sedation with diazepam and topical anesthesia with 4% lidocaine. Arterial blood pressures, heart rate, and MCAV were monitored at specific intervals. During intravenous induction, blood pressures decreased after the administration of thiopental and muscle relaxants and increased during endotracheal intubation. MCAV was remarkably slowed after the administration of thiopental and during mask ventilation. During awake intubation, blood pressures were increased by endotracheal intubation. MCAV was decreased from the administration of diazepam to the transtracheal injection of lidocaine, but returned to the control value from endotracheal spray to endotracheal intubation. These results suggest that smooth awake intubation may be the safest method of induction for patients with cerebrovascular disorders.     

Propofol, but not etomidate, reduces desflurane-mediated sympathetic activation in humans

PURPOSE: The administration of desflurane to humans can lead to substantial activation of the neurohumoral axis. Propofol can inhibit the sympathetic response to stress. This study compared the neurocirculatory effects of induction of anesthesia with propofol with those of etomidate on desflurane-mediated sympathetic activation. METHODS: After informed consent, awake baseline recordings of heart rate (HR), mean arterial blood pressure (MAP), and efferent sympathetic nerve activity (SNA, peroneal nerve) were obtained from healthy volunteers randomly assigned to receive either 2.5 mg x kg(-1) propofol (n=8) or 0.3 mg x kg(-1) etomidate (n=7). Two minutes after i.v. induction, desflurane 3.6% was added to the inspired gas, and increased in consecutive minutes to 7% and 10.9%. Ventilation via mask was continued for an additional seven minutes. Normocarbia was maintained while neurocirculatory parameters were continuously recorded. RESULTS: There were no differences between groups at baseline. The administration of desflurane via mask after etomidate led to increases in HR, MAP and SNA. Propofol significantly reduced the MAP response and delayed and attenuated the sympatho-excitation. CONCLUSION: Propofol induction reduced the sympathetic activation and hypertension associated with desflurane.     

Myocardial metabolism as affected by propofol in geriatric patients. A comparison with etomidate

This study was designed to compare the effects of propofol and etomidate on myocardial metabolism in elderly patients without clinical manifestations of heart failure or coronary artery disease. Twenty geriatric patients (age 65-82 years) scheduled to undergo elective major upper-abdominal surgery were studied and randomly allocated to two equal groups (propofol and etomidate). All patients were premedicated with piritramide, 7.5 mg, and promethazine, 25 mg, intramuscularly 1 h before arrival in the anesthesia room. Ten patients received propofol (1.5 mg/kg) for induction of anesthesia, followed by 10-min infusion of an induction dose; thereafter, anesthesia was maintained with a continuous infusion of 0.1 mg/kg per min. Ten patients received etomidate, 18 mg, for induction, followed by 2.4 mg/min for maintenance. Vecuronium was used for neuromuscular blockade. Cardiovascular dynamics were recorded while the patients were awake, 1-2 min after induction during apnoea, and 1, 5 and 30 min after tracheal intubation without surgical stimulation. Coronary blood flow (argon wash-in technique with sampling of blood from the coronary sinus), myocardial oxygen consumption and myocardial uptake of glucose, free fatty acids and lactate were determined in the awake state and 5 and 30 min after intubation. Arterial plasma concentrations of propofol (high-pressure liquid chromatography with fluorescence detection) and etomidate (gas chromatography) were measured every 5 min throughout the investigation period, which lasted 45 min. Overall mean plasma concentrations of propofol were 3.69 +/- 0.16 micrograms/ml and of etomidate 1.1 +/- 0.16 microgram/ml.(ABSTRACT TRUNCATED AT 250 WORDS)     

异丙酚诱导插管对血浆降钙素基因相关肽及内皮素水平的影响

目的 探讨异丙酚诱导插管对血浆ＣＧＲＰ含量的影响。方法 择期手术病人３６例,ＡＳＡⅠ～Ⅱ级,随机分为异丙酚（ＰＰ组,２０例）硫喷妥钠（ＳＰ组,１６例）两组,分别于麻醉前、用药后、插管后２ｍｉｎ、７ｍｉｎ、１５ｍｉｎ测定血浆中ＣＧＲＰ、ＥＴ的含理及血液动力学变化。结果 两组给药后血压均下降,插管后硫喷妥钠组血压迅速上升,异丙酚组插管后ＣＧＲＰ、ＥＴ含量略有下降,但无统计学意义（Ｐ〉０．０５）。硫喷妥     

Propofol und Etomidat®Lipuro zur Einleitung einer Allgemeinanästhesie

Etomidate has become an important induction agent in high-risk patients because of its cardiovascular stability. Its unwanted side-effects such as pain on injection and thrombophlebitis could be significantly reduced by a new (medium chain triglyceride and soya bean) emulsion formulation. Propofol is solved in a mixture of long chain triglyceride and soya bean emulsion. In this double-blind, randomized study we compared the haemodynamic effects, the patients' sensations, signs of thrombophlebitis and postoperative nausea and vomiting (PONV) following injection of both drugs. Methods. Following premedication with 2 mg Lormetazepam p.o. in 50 patients per group, anaesthesia was induced with either 0.51 mg etomidate in lipid emulsion or 3.04 mg propofol per kg bw. No opioid or benzdiazepine was given i.v. before induction. After injection of the tested drug, the cannula was removed. Changes in blood pressure and heart rate were recorded as well as signs of discomfort during and after injection (pain, burning, tension, cold). Venous sequelae were assessed for 5 days after injection to register signs of thrombophlebitis. Results. Demographic data showed no difference between the two groups. After propofol more often a fall in blood pressure was seen. Pain (25 vs 1 pt), burning 19 vs 1), tension 15 vs 3), cold (35 vs 17) after injection was registered significantly more often in the propofol group, whereas myocloni predominated in the etomidate group (13 vs 6) P<0.05, chi-squared-test). No difference was seen in PONV in either groups. Conclusion. Etomidate formulated in a medium chain lipid emulsion causes significant less discomfort for the patients than propofol, which is solved in a long chain formulation. Myocloni, however, occur significantly more frequently after etomidate than after propofol.     

Pretreatment with sufentanil reduces myoclonus after etomidate

BACKGROUND: Myoclonic movements are a common problem during the induction of general anesthesia with etomidate. We investigated the influence of pretreatment with the opioid sufentanil on the incidence of etomidate-induced myoclonus. METHODS: Forty female patients (ASA physical status I-III) were randomly assigned to receive double-blinded either 0.3 micro g kg-1 of sufentanil or placebo 150 s before the induction of sleep with 0.3 mg kg-1 of etomidate. The patients were observed for any myoclonic movement. Grade of dizziness, breathing frequency, non-invasive blood pressure and heart rate were measured during the study period. RESULTS: None of the 20 patients receiving sufentanil had myoclonic movements after the administration of etomidate, whereas 16 patients in the placebo group (80%) experienced such movements (P<0.01). No cases of apnoea before induction of sleep were seen in the sufentanil group. CONCLUSION: Sufentanil 0.3 micro g kg-1 is an effective and safe drug to reduce myoclonus after etomidate without causing any harmful side-effect.     

Comparative study of propofol with thiopental and etomidate in anesthetic induction]

Anesthetic characteristics were studied in three homogeneous groups of twenty patients ASA I who underwent intravenous anesthetic induction with propofol 2 mg/kg; thiopental 5 mg/kg; or etomidate 0.3 mg/kg. The unconsciousness time was similar in the three groups, whereas awaking time and time of response and orientation were longer after thiopental and etomidate than after propofol. Intravenous injection of the three anesthetic agents was followed by a decrease in systolic and diastolic arterial pressure. Heart rate increased after thiopental and etomidate and had only slight fluctuations after propofol. After tracheal intubation there was a significant increase in systolic and diastolic arterial pressure and heart rate in thiopental and etomidate group. These changes were minimal after propofol. The highest number of complications occurred after etomidate.     

腹腔镜胆囊切除术喉罩通气的探讨（附1800例报告）

目的 喉罩通气代替插管用于腹腔镜胆囊切除术,探讨更适合快速短效,但心率、血压滚动大的腹腔镜术麻醉。方法 该手术１８００例,快速诱导后置喉罩通气。观察放置及通气情况,并从该组及同期插管病例各随机抽取４４例比较。结果：１８００例,９０％用３号,１０％用４号,顺利放入率９８％,调整后漏气率２．１％（３７／１８００）。抽样对比,插入后至气腹１０ｍｉｎ,心率、血压明显小于插管组（Ｐ〈０．０１或Ｐ〈０．０５）     

Etomidate versus etomidate and hydrocortisone for anesthesia induction in abdominal surgical interventions

The imidazole derivative etomidate has been shown to block (reversibly) adrenocortical steroid synthesis. Long-term sedation with etomidate has been associated with adrenocortical insufficiency and increased mortality in severely ill patients. The significance of adrenocortical blockade after a single induction dose of etomidate remains a matter of debate. This study was designed to analyze the role of glucocorticoid deficiency after a single induction dose of etomidate for major surgery. In a prospective controlled double-blind study, 20 consecutive patients scheduled for colorectal surgery were randomly allocated to either hydrocortisone substitution or placebo (glucose 5%). Hydrocortisone was given as a continuous infusion in a dose of 100 mg dissolved in 5% glucose over 10 h. We combined general anesthesia and epidural anesthesia (L3-4) using bupivacaine (0.5%). Induction of anesthesia: etomidate (0.2-0.3 mg/kg), fentanyl (0.1-0.2 mg), pancuronium (2 mg), and succinyl-choline (1.0-1.5 mg/kg), with endotracheal intubation and mechanical ventilation. Anesthesia was maintained at N2O/O2 2:1 and fluothane (0.4-0.6 vol%). At the end of surgery patients were extubated after oxygenation. In all patients blood pressure, heart rate, central venous pressure, and ECG were monitored continuously, both intra- and postoperatively. During induction, patients received 1,000 ml 0.9% NaCl, followed by continuous administration of 0.9% NaCl, 6 ml/kg per hour intraoperatively and 40 ml/kg per 24 hours post-operatively.(ABSTRACT TRUNCATED AT 250 WORDS)