Hemodynamic effects of a lorazepam-fentanyl anesthetic induction for coronary artery bypass surgery

Previous anesthetic induction techniques using the combination of a benzodiazepine (midazolam or diazepam) and fentanyl have been reported to produce marked hypotension. In this study, anesthesia was induced with a combination of lorazepam and fentanylin in patients undergoing coronary artery bypass graft surgery. In 10 patients, anesthesia was induced using an exponentially declining continuous infusion of lorazepam equivalent to a total infused dose of 0.1 mg/kg over 15 minutes, which was supplemented at 10 minutes by fentanyl, 75 μg/kg, given as an infusion over 5 minutes. In 8 additional patients, anesthesia was induced with an exponentially declining infusion of fentanyl to a total dose of 75 μg/kg over 15 minutes, which was supplemented at 10 minutes by lorazepam, 0.1 mg/kg, given as an infusion over 5 minutes. Hemodynamics were recorded during a 20-minute observation period. One patient in each group required treatment for bradycardia during the initial drug infusion (before the second drug was added). Four additional patients in the group receiving lorazepam followed by fentanyl required treatment for bradycardia or hypotension within 10 minutes of the beginning of the fentanyl infusion. When an infusion of lorazepam was added to the fentanyl infusion, hemodynamics remained stable; however, the reverse order produced a high level of bradycardia and hypotension.     

Airway management of the critically ill patient: rapid-sequence intubation

Advances in emergency airway management have allowed intensivists to use intubation techniques that were once the province of anesthesiology and were confined to the operating room. Appropriate rapid-sequence intubation (RSI) with the use of neuromuscular blocking agents, induction drugs, and adjunctive medications in a standardized approach improves clinical outcomes for select patients who require intubation. However, many physicians who work in the ICU have insufficient experience with these techniques to adopt them for routine use. The purpose of this article is to review airway management in the critically ill adult with an emphasis on airway assessment, algorithmic approaches, and RSI.     

Catecholamine responses to anesthetic induction with fentanyl and sufentanil

In a randomized study, the authors examined the changes in plasma epinephrine and norepinephrine concentrations associated with induction of anesthesia and surgery in 33 patients with good ventricular function undergoing elective coronary artery surgery. After premedication with morphine and scopolamine, patients received either fentanyl, 100 μg/kg (n = 16), or sufentanil, 15 μg/kg, (n = 17), intravenously (IV), over 10 minutes to induce anesthesia. Metocurine, 0.42 mg/kg, IV, produced muscle relaxation. Arterial blood for plasma catecholamine determinations was drawn prior to induction, every two minutes throughout induction, one minute following endotracheal intubation, and one minute after sternotomy. Plasma epinephrine concentration was unchanged with either induction agent. Plasma norepinephrine concentration increased significantly after administration of either narcotic, peaked between six and ten minutes into induction, and returned to the preinduction value after intubation. Induction-related changes in arterial pressure and pulmonary capillary wedge pressure were significantly correlated with changes in the logarithm of plasma norepinephrine concentration. Similar degrees of endogenous norepinephrine release appear to accompany induction with equipotent doses of fentanyl and sufentanil in patients premedicated with morphine and scopolamine. Norepinephrine release may influence the hemodynamic response to induction with narcotics.     

Hemodynamic and hormonal responses during captopril therapy for heart failure: Acute,chronic and withdrawal studies

The hemodynamic and hormonal responses to acute and chronic captopril therapy and to its temporary withdrawal were studied in seven patients with congestive heart failure. Maximal hemodynamic and hormonal effects were reached with 25 to 50 mg doses of captoprit. Since plasma angiotensin II levels were significantly higher $\text{6}\text{1}\text{2}$ hours than 1 hour after administration of captopril, the drug should be given not less often than three times daily. No evidence of hormonal “escape” during long-term ($\text{mean}\text{4}\text{1}\text{2}\text{months}$) captopril therapy was observed, and initial hemodynamic responses were well maintained. Cessation of captopril administration resulted in abrupt increases in circulating angiotensin II levels, in arterial pressure, and in both pulse rate and plasma norepinephrine, but no decrease in cardiac function in the short-term was detected.     

葛根素对高血压病病人气管插管期心血管反应的影响

目的:探讨葛根素注射液控制高血压病病人插管期心血管反应的有效性.方法:30例原发性高血压全麻病人,随机均分为葛根素组(P组)和对照组(C组),分别于诱导前1 h静脉输注中药葛根素注射液500 mg或不用降压药,观察插管期收缩压(SBP)、舒张压(DBP)、心率(HR)、平均动脉压(MAP)和心率收缩压乘积(RPP).结果:与诱导前比较,两组诱导后SBP、DBP、MAP均明显下降(P＜0.01);C组插管时及插管后等时段SBP、DBP、MAP、HR及RPP均明显增加(P＜0.01或P＜0.05);P组插管时及插管后1 min SBP、DBP、MAP均有不同程度下降(P＜0.01或P＜0.05),HR及RPP未见明显变化.与C组比较,P组插管时及插管后1 min、3 min等时段SBP、HR及RPP均显著降低(P＜0.01或P＜0.05).结论:中药葛根素注射液静脉输注能有效控制插管刺激引起的心血管反应,有助于高血压病病人插管期维持血流动力学相对稳定.     

Hemodynamic, metabolic and hormonal responses to oral glibenclamide in patients with cirrhosis receiving glucose

BACKGROUND: In patients with cirrhosis, glucose may induce splanchnic and renal vasodilation. Since the antidiabetic sulfonylurea glibenclamide is known to induce splanchnic and renal vasoconstriction in portal hypertensive animals, this drug may inhibit glucose-induced hemodynamic responses in patients with cirrhosis. The aim of the present study was to investigate, in patients with cirrhosis, the short-term effects of glibenclamide on hemodynamic and humoral responses to glucose. METHODS: Patients were randomly assigned to receive either glibenclamide (5-mg tablet) or a placebo. All patients received an infusion of 10% glucose (62.5 ml/h for 12 h) that was started at the same time as glibenclamide or placebo administration. Studies were performed prior to and 90 min after glibenclamide or placebo. RESULTS: Glibenclamide (i.e. glibenclamide plus glucose) significantly increased plasma insulin concentrations and glycemia while placebo (i.e. glucose alone) significantly increased glycemia but did not change plasma insulin levels. Glibenclamide did not significantly change the hepatic venous pressure gradient while this value was significantly increased following glucose alone. Glibenclamide did not significantly change renal blood flow and glomerular filtration rate while glucose alone significantly increased renal blood flow without affecting the glomerular filtration rate. Glibenclamide significantly decreased cardiac index while glucose alone did not change this value. CONCLUSIONS: In patients with cirrhosis receiving glucose, glibenclamide blunted glucose-induced splanchnic and renal vasodilation. In addition, glibenclamide per se induced a decrease in cardiac index. These findings should be taken into account when glibenclamide is administered to patients with cirrhosis and type 2 diabetes.     

七氟醚对插管应激时心率变异性的影响

目的 :观察不同浓度的七氟醚对插管应激时心率变异性的影响。方法 :ASA I～ II级外科择期手术患者 2 3例 ,随机分为 A ,B两组。面罩吸入 1.0 vol% （A组 ）或 3.0 vol% （B组 ）七氟醚和 N2 O∶ O2 （2∶ 1）混和气进行麻醉诱导 ;气管内插管行机械通气。持续监测血流动力学指标 ,记录心电图并进行心率变异功率频谱分析 （HRV - PSA） ;抽取静脉血测定 Pc AMP及 Pc GMP。结果 :插管后 ,所有患者的血压、心率、HRV- PSA有关参数值及 Pc AMP和 Pc GMP均有所增加 （P<0 .0 5 ） ,以 A组 （1.0 vol%七氟醚 ）患者的反应较显著 （P<0 .0 5 ）。结论 :七氟醚用于麻醉诱导可有效地降低低插管所致的循环反应和自主神经反应 ,从而为临床麻醉管理提供依据。     

丙泊酚复合咪达唑仑或氯胺酮用于老年人麻醉诱导的比较

目的研究丙泊酚复合咪达唑仑(咪唑安定)或氯胺酮麻醉诱导对老年人插管期血流动力学及苏醒后精神状态的影响。方法行气管插管全麻老年病人40例,随机分成两组:咪唑安定组(M组)和氯胺酮(K组)。麻醉诱导开始时,两组分别静注咪唑安定0.05 mg/kg或氯胺酮0.5 mg/kg,再依次给予同样剂量的丙泊酚、维库溴铵、芬太尼,辅助通气3 min后行气管插管,记录插管前后血压、心率的变化。术后随访病人有无躁动、噩梦等精神方面不良反应。结果两组病人麻醉诱导过程血压、心率组间总的变化比较没有差异(P>0.05),氯胺酮组插管前后的血压、心率变化程度小于咪唑安定组(P<0.05)。M组、K组诱导期出现平均动脉压<60 mmHg分别有4例、1例,均可用麻黄素治疗,组间无差异(P<0.05)。苏醒期两组各有2例,3例患者出现轻度躁动,组间无差异(P<0.05)。术后第1、2天两组患者均无噩梦、幻觉等精神方面不良反应。结论丙泊酚复合氯胺酮较复合咪唑安定在老年患者麻醉诱导插管前、后的血流动力学稳定,且苏醒后无更多躁动、噩梦、幻觉等精神方面不良反应。     

Effects of intravenous lidocaine on QTd and HRV changes due to tracheal intubation during sevoflurane induction

The aim of the present study was to evaluate the effects of IV lidocaine on autonomic cardiac function changes in tracheal intubation (TI) during sevoflurane anaesthesia by using more reliable parameters, namely, the analysis of QT dispersion and heart rate variability (HRV) from Holter monitoring. In this prospective, double-blind study, 44 American Society of Anaesthesiologists class I-II patients scheduled for hysterectomy were randomly and equally divided into 2 groups; a control sevoflurane group (group S, n = 22) and a lidocaine sevoflurane group (group LS, n = 22). Before the induction of anaesthesia, the electrocardiograms (ECG) of all patients were recorded for 3 minutes as baseline parameters. In both groups, the anaesthesia was induced with 7% sevoflurane in O(2 )at 6L min(-1) via a facemask for 2 minutes. However, before the induction of sevoflurane anaesthesia in group LS, 1 mg kg(-1) of lidocaine was given intravenously (IV). For muscle relaxation during TI, vecuronium was given to all participants. Three minutes after administration of vecuronium, TI was performed and an ECG was recorded synchronously for another 3 minutes. The results from the later records were used as postintubation parameters. Baseline and postintubation data were analysed. When compared to baseline values, postintubation LF/HF and SDNN values were increased in group S (P = 0.005, P = 0.001, respectively), whereas postintubation LF and HF values were decreased in group LS (P = 0.014, P = 0.041, respectively). Under the influence of sevoflurane anaesthesia, TI resulted in sympathetic activation. However, this activation was attenuated by the administration of IV 1 mg kg(-1) lidocaine 5 minutes prior to TI.     

听觉诱发电位指数监测老年患者诱导气管插管期间麻醉深度的评价

目的　研究听觉诱发电位指数 (AEPindex)用于老年患者诱导气管插管期间麻醉深度监测的可行性与有效性。　方法　选择听力正常拟行气管插管全麻患者 10 2例 ,观察记录诱导前 (T0 )、诱导后气管插管前 (T1 )、插管时 (T2 )及插管后 1、3、5min(T3 、T4、T5)患者AEPindex、脑电双频谱指数(BIS)、平均动脉压 (MAP)及心率 (HR)的变化。根据患者年龄分为老年组和非老年组 ,观察分析 2组患者诱导插管期间各项指标变化。　结果　老年组和非老年组患者T0 期AEPindex分别为 75 6± 14 9和 79 5± 17 7(P >0 0 5) ,BIS分别为 83 9± 14 9和 87 0± 11 0 (P >0 0 5)。诱导后所有患者T0 期AEPindex和BIS分别下降到 3 0和 55以下 (T1 与T0 比较 ,P <0 0 1) ;插管应激使AEPindex、BIS、MAP、HR显著升高 ,T1～ 5时点各参数均表现为先升后降 ,但插管后 5min除AEPindex回落至插管前水平 (T5与T1 相比 ,P >0 0 5)外 ,其余参数仍明显高于插管前水平 (T5与T1 相比 ,,两组变化趋势一致。　结论　AEPindex能有效反映无明显听力障碍老年人气管插管期间麻醉深度的变化     

Atrial natriuretic peptide in patients with essential hypertension. Hemodynamic, renal, and hormonal responses.

In six patients with essential hypertension (EH) and in six healthy volunteers (C) the effects of a 60-min intravenous (iv) infusion of human atrial natriuretic peptide (alpha-hANP) (24 ng/min/kg) on systemic and renal hemodynamics and renal excretory function were evaluated. Basal plasma ANP concentrations in patients with EH were higher (P less than .05) than in C (30.9 +/- 4.5 v14.0 +/- 1.7 pmol/L). Maximal effects of alpha-hANP infusion occurred after 30 to 60 min. Blood pressure (BP) declined from 154 +/- 5/109 +/- 4 to 139 +/- 7/94 +/- 4 in EH and from 117 +/- 1/72 +/- 2 to 106 +/- 1/65 +/- 3 mm Hg in C (P less than .05). Cardiac output (CO) increased transiently from 6.1 +/- 0.3 to 6.5 +/- 0.4 L/min in EH and from 6.8 +/- 0.3 to 7.2 +/- 0.5 L/min in C, whereas heart rate (HR) remained constant both in patients with EH and in C (69 +/- 3 to 72 +/- 5 and 60 +/- 3 to 63 +/- 3/min). The increases in urine flow and in urinary sodium excretion from 3.6 +/- 0.2 to 16.0 +/- 2.0 mL/min and from 230 +/- 33 to 1004 +/- 137 mumol/min, respectively, in EH were more pronounced than in C (from 3.9 +/- 1.0 to 8.4 +/- 0.8 mL/min and from 211 +/- 37 to 451 +/- 84 mumol/min); (P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Management of tracheal deformity during intubation: a case report

Failure or difficulty in intubating the trachea can be either due to inability to visualize the glottis or some pathology at the level of or below the cords. This report describes a case of difficult intubation suspected of being related to neck scarring from previous surgery. Computed tomography (CT) was used to evaluate the patient's airway and revealed upper tracheal angulation. We describe a method to secure the airway in this patient with a two-person technique by rotating an oral endotracheal tube 180 degrees counterclockwise to adjust to the curvature of the trachea. Problems with intubation should be anticipated in patients with scarring of the neck, and equipment for aiding intubation should be on hand. Furthermore, we found that CT contributed to the assessment of the difficulty of intubation in this kind of patient.     

Hemodynamic, renal, and hormonal responses to brain natriuretic peptide infusion in patients with congestive heart failure

BACKGROUND. This study was designed to examine the hemodynamic, renal, and hormonal effects of brain natriuretic peptide (BNP) infusion in patients with congestive heart failure (CHF) and in control subjects. METHODS AND RESULTS. We infused synthetic human BNP at a rate of 0.1 micrograms/kg/min. BNP infusion decreased pulmonary capillary wedge pressure (control, from 5 +/- 1 to 2 +/- 1 mm Hg, p less than 0.01; CHF, from 21 +/- 3 to 14 +/- 4 mm Hg, p less than 0.05) and systemic vascular resistance (control, from 1,264 +/- 75 to 934 +/- 52 dyne.sec.cm-5; CHF, from 2,485 +/- 379 to 1,771 +/- 195 dyne.sec.cm-5; p less than 0.01, respectively) and increased stroke volume index (control, from 49.9 +/- 2.7 to 51.5 +/- 2.3 ml/m2, p = NS; CHF, from 25.6 +/- 3.8 to 32.0 +/- 3.9 ml/m2, p less than 0.01). BNP infusion significantly increased urine volume (control, from 2.3 +/- 0.7 to 7.5 +/- 1.9 ml/min; CHF, from 0.8 +/- 0.2 to 5.3 +/- 1.0 ml/min; p less than 0.01, respectively), excretion of sodium (control, from 79.2 +/- 21.6 to 332.8 +/- 70.9 microEq/min; CHF, from 77.4 +/- 20.8 to 753.5 +/- 108.0 microEq/min; p less than 0.01, respectively), and excretion of chloride (control, from 72.5 +/- 18.4 to 256.0 +/- 43.3 microEq/min; CHF, from 74.0 +/- 19.6 to 708.8 +/- 103.3 microEq/min; p less than 0.01, respectively). Urinary excretion of sodium and of chloride in response to BNP infusion was higher in patients with CHF than in control subjects (p less than 0.01, respectively). BNP infusion increased the levels of plasma atrial natriuretic peptide (control, from 65 +/- 11 to 84 +/- 14 pg/ml; CHF, from 262 +/- 65 to 301 +/- 62 pg/ml; p less than 0.05, respectively) and decreased plasma aldosterone concentrations in both groups (control, from 43.3 +/- 12.1 to 27.3 +/- 7.1 pg/ml; CHF, from 91.1 +/- 34.3 to 66.3 +/- 27.2 pg/ml; p less than 0.05, respectively). CONCLUSIONS. We conclude that BNP infusion improves left ventricular function in patients with CHF by vasodilation and prominent natriuretic action.     

老年高血压患者诱导前予右美托咪啶对插管期血流动力学的影响

目的观察右美托咪啶预注对老年高血压,尤其是未控制的老年高血压患者的全麻诱导期气管插管时血流动力学改变的影响。方法：选择未控制和控制良好拟在全麻下行择期手术的老年高血压患者各40例,ASA均为Ⅱ级。分为4组：D1组（血压控制良好组,术前规则服用降压药,血压维持在140—160／80—90mmHg,麻醉诱导前静脉滴注右美托咪啶0．7gg／kg,输注时间10min）,D2组（入院后方诊断为高血压,收缩压〉160mg,麻醉诱导前静脉滴注右美托咪啶0．7gg／kg,输注时间10min）,C1组（入选标准同D1,麻醉诱导前静脉滴注等量生理盐水）和C2组（入选标准同D：组,麻醉诱导前静脉滴注等量生理盐水）,每组各20例。分别记录人室（T0）、用药前（T1）、全麻诱导前（T2）、气管插管前（T2）、插管后即刻（T4）、插管后5min（T5）患者的肱动脉收缩压（SAP）、舒张压（DAP）、心率（HR）和脉搏血氧饱和度（SpO2）。结果：各组基本信息无统计学差异。各组在T0和T1时间点,各观察指标亦无差异俨〉O．05）。与T0相比,右美托咪啶组（Dl和D2）在T2和T3时间点SAP和HR降低（P〈0．05）,插管后（T4）血流动力学基本没有变化;C1和C2组插管后（T4）,SAP、DAP和HR较插管前（T3）上升（P〈0．05）。结论全麻诱导前静脉预注右美托咪啶,不仅能使血压控制良好的老年高血压患者全麻诱导及气管插管期间的血流动力学维持稳定,对血压未经控制的老年高血压患者同样安全有效,且有利于对老年高血压患者更好地进行围术期血流动力学管理。     

The impact of tracheal intubation on host defenses and risks for nosocomial pneumonia

Nosocomial pneumonia remains a common complication in patients treated with endotracheal intubation and mechanical ventilation and continues to have a significant impact on the mortality rate of these patients. Epidemiologic studies have shown that the risk of pneumonia increases with the duration of intubation but that the period of highest risk is the first 2 weeks of therapy. Gram-negative bacteria account for most nosocomial pneumonias in intubated patients, but Staphylococcus aureus may also play a role in what may be a polymicrobial infection. In the most seriously ill individuals, and in those treated with long-term mechanical ventilation, Pseudomonas aeruginosa is a common pathogen. Endotracheal intubation and mechanical ventilation predispose to pneumonia for a variety of reasons (see Fig. 1). The endotracheal tube can have direct effects on the airway that result in a reduction in local host defenses. Thus, mucosal injury can reduce mucociliary function, while upper airway defenses are bypassed and the effectiveness of cough is reduced. Indirectly, intubation can result in an enhanced capacity of tracheobronchial cells to bind gram-negative bacteria, an effect that favors airway colonization and pneumonia. The injury to the airway can create binding sites for bacteria in the basement membrane of the bronchial tree and the stimulation of the secretion of mucus, which then stagnates and can create potential sites for bacterial adherence. The endotracheal tube also enhances bacterial entry to the lung by serving as a reservoir for bacteria to remain sequestered, safe from host defenses. Respiratory therapy devices can allow bacteria to proliferate and can then introduce them into the patient if not handled properly. Finally, patients who are ill enough to require intubation also have disease-associated impairments in systemic host defense, which add to the impairments caused by the use of an artificial airway. The host defense impairments that occur in mechanically ventilated patients can lead to respiratory tract infection in the form of either febrile tracheobronchitis or pneumonia. The diagnosis of pneumonia in intubated patients is difficult and controversial. It can be made by either clinical criteria or microbiologic criteria, the latter by using a bronchoscopically directed protected specimen brush. Therapy of pneumonia in mechanically ventilated patients is not always successful, and systemic antibiotics may need to be supplemented by topical antimicrobials. No clearly effective prophylactic strategy currently exists, but our understanding of pneumonia pathogenesis has led to some promising directions. As more data are collected, inhaled antibiotics, selective digestive decontamination, and enhancement of host defenses by cytokines and pre-formed antibodies may emerge as useful approaches.     

Rapid-sequence intubation of head trauma patients: prevention of fasciculations with pancuronium versus minidose succinylcholine.

INTRODUCTION: Fasciculations during rapid-sequence intubation may lead to increased intracranial pressure and emesis with aspiration. Standard rapid-sequence intubation requires a nondepolarizing blocking agent before succinylcholine administration. HYPOTHESIS: Prevention of fasciculations during rapid-sequence intubation of head trauma patients can be accomplished as safely and effectively with minidose succinylcholine as with a defasciculating dose of pancuronium. DESIGN: A prospective, randomized, double-blind study. SETTING: An inner-city county trauma center with 70,000 patient visits per year. PARTICIPANTS: Sequential adult head trauma patients requiring rapid-sequence intubation who had no contraindications to succinylcholine or pancuronium. INTERVENTIONS: Each head trauma patient requiring rapid-sequence intubation who met the inclusion criteria received standard rapid-sequence intubation maneuvers and lidocaine (1 mg/kg) IV. Patients were randomized to receive either minidose succinylcholine (0.1 mg/kg) or pancuronium (0.03 mg/kg) IV one minute prior to the full paralytic dose of succinylcholine (1.5 mg/kg) IV. Fasciculations were recorded using a graded visual scale. RESULTS: Of 46 patients, eight of 19 (42%) in the pancuronium group and six of 27 (22%) in the succinylcholine group experienced fasciculations. No statistically significant difference in fasciculations was detected between the two groups using chi 2 analysis. Complete relaxation of the cords was present in all but two patients, one in each group. No patient in either group experienced emesis or significant dysrhythmias. CONCLUSION: Pretreatment with minidose succinylcholine causes no greater incidence of fasciculations than pancuronium in rapid-sequence intubation of head trauma patients in an ED setting. Thus succinylcholine may be used as the sole paralytic agent in rapid-sequence intubation of head trauma patients.