ISSN:0003-3022    

出版商:OVID    

年代:2003

数据来源: OVID

ISSN:0003-3022    

出版商:OVID    

年代:2003

数据来源: OVID

ISSN:0003-3022    

出版商:OVID    

年代:2003

数据来源: OVID

ISSN:0003-3022    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

BackgroundThe placement of an endotracheal tube (ETT) may promote laryngeal swelling, which is an important cause of upper airway obstruction after extubation. The authors hypothesized that laryngeal swelling after ETT placement increases laryngeal resistance and tested that hypothesis by comparing postoperative laryngeal patency between patients with ETT placement and those with a Laryngeal Mask Airway™ (LMA™).MethodsFourteen adult patients who underwent elective minor surgeries were randomly allocated to two groups whose airway would be managed through ETTs (the ETT group) or LMAs™ (the LMA™ group) during the surgery. While maintaining at sevoflurane 1 minimum alveolar concentration, the authors measured laryngeal resistance before and after surgery, during both spontaneous breathing and mechanical ventilation under complete paralysis. In addition, they endoscopically measured the vocal cord angle under complete paralysis.ResultsIn association with marked swelling of the vocal cords, the vocal cord angle significantly decreased after surgery in the ETT group, whereas the angle did not change in the LMA group. Laryngeal resistance during mechanical ventilation significantly increased only in the ETT group. Laryngeal resistance during spontaneous breathing significantly increased after surgeries in both groups.ConclusionsPostoperative laryngeal resistance increases at least in part because of laryngeal swelling in patients with ETT placement, whereas alteration of laryngeal neural control mechanisms has been also indicated. The use of the LMA™ has an advantage over ETT placement in order to avoid postoperative laryngeal swelling.

ISSN:0003-3022    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

BackgroundThe authors determined the incidence of cardiac arrest and predictors of survival following perioperative cardiac arrest in a large population of patients at a tertiary referral center.MethodsMedical records of patients who experienced cardiac arrest in the perioperative period surrounding noncardiac surgery between January 1, 1990, and December 31, 2000, were reviewed. Logistic regression identified characteristics associated with immediate (≥ 1 h) and hospital survival, withP≤ 0.01 considered statistically significant.ResultsCardiac arrest occurred in 223 of 518,294 anesthetics (4.3 per 10,000) during the study period. Frequency of arrest for patients receiving general anesthesia decreased over time (7.8 per 10,000 during 1990–1992; 3.2 per 10,000 during 1998–2000). The frequency of arrest during regional anesthesia (1.5 per 10,000) and monitored anesthesia care (0.7 per 10,000) remained consistent. Immediate survival after arrest was 46.6%, and hospital survival was 34.5%. Twenty-four patients (0.5 per 10,000) had cardiac arrest related primarily to anesthesia. From multivariate analysis, patients who experienced arrest due to bleeding were less likely to survive hospitalization (P= 0.001). Survival was also lower for patients who experienced arrest during nonstandard working hours (P= 0.006) and for patients who had protracted hypotension before arrest (P< 0.001).ConclusionsThe overall frequency of arrest for patients receiving anesthesia decreased during the study period. Most arrests were not due to anesthesia-related causes, and most patients experiencing anesthesia-related arrest survived to hospital discharge. Although many factors determining survival may not be amenable to modification, the fact that arrests during nonregular working hours had worse outcomes may indicate that the availability of human resources influences survival.

ISSN:0003-3022    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

BackgroundThe value of postoperative cardiac troponin I (cTnI) has been shown to indicate a higher risk of in-hospital death after cardiac surgery. The authors therefore assessed the long-term prognostic value of cTnI in patients undergoing elective coronary artery bypass grafting.MethodsConsecutive patients (n = 202) were included and divided into two groups according to the postoperative value of cTnI (< or ≥ 13 ng/ml). In-hospital mortality and nonfatal cardiac events (delayed extubation > 24 h; postoperative requirement of inotropic agent; ventricular and supraventricular arrhythmia; postoperative myocardial infarction) were recorded. Survivors were then followed up over a 2-yr period. Data are median and odds ratio (95% confidence interval).ResultsOf all patients, 174 (86%) had a low cTnI (4.1 ng/ml; range, 1.1–12.6) and 28 (14%) had a high cTnI (23.8 ng/ml; range, 13.4–174.6). In-hospital mortality was not significantly different (4vs.2%), whereas long-term mortality (18vs.3%,P= 0.006) and mortality from cardiac cause (18vs.1%,P< 0.001) was greater in patients with a high cTnI. A high cTnI was a significant factor predicting death (odds ratio, 7.3 [2.0–27.1]) or death from cardiac causes (odds ratio, 37.4 [4.2–334.4]). Nonfatal cardiac events were also more frequent in the hospital (64vs.41%,P= 0.02) and within the 2-yr follow-up period (39%vs.16%,P= 0.03) in patients with high cTnI.ConclusionA high postoperative peak of cTnI is associated with increased risk of death, death from cardiac causes, and nonfatal cardiac events within 2 yr after coronary artery bypass grafting.

ISSN:0003-3022    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

BackgroundAlthough the pharmacokinetics of midazolam in critically ill children has been described, there are no such reports in extracorporeal membrane oxygenation.MethodsThe pharmacokinetics of midazolam and 1-hydroxy midazolam after continuous infusion (50–250 &mgr;g · kg−1· h−1) were determined in 20 neonates undergoing extracorporeal membrane oxygenation. Patients were randomized into two groups: group 1 (n = 10) received midazolam extracorporeally (into the circuit), and group 2 received drugviacentral or peripheral access. Blood samples for determination of plasma concentrations were taken at baseline, 2, 4, 6, 12, 18, and 24 h, then every 12 h. Population pharmacokinetic analysis and model building was conducted using WinNonMix (Pharsight Corporation, Mountain View, CA). The 1-hydroxy midazolam/midazolam metabolic ratio was determined as a surrogate marker of cytochrome P450 3A activity.ResultsThe parameter estimates (n = 19) were based on a one-compartment model with time-dependent change in volume of distribution. Volume (mean ± standard error) expanded monoexponentially from the onset of extracorporeal membrane oxygenation to a maximum value, 0.8 l ± 0.5 and 4.1 ± 0.5 l/kg, respectively. Consequently, plasma half-life was substantially prolonged (median [range]) from onset to steady-state: 6.8 (2.2–39.8) and 33.3 (7.4–178) h, respectively. Total body clearance was determined as (mean ± standard error) 1.4 ± 0.15 ml · kg−1· min−1. The median metabolic ratio was 0.17 (0.03–0.9). No significant differences were observed between the two groups with respect to parameter estimates. Simulations of plasma concentration profiles revealed excess levels at conventional doses.ConclusionsThese results reveal significantly increased volume of distribution and plasma half-life in neonates receiving extracorporeal membrane oxygenation. Altered kinetics may reflect sequestration of midazolam by components of the extracorporeal membrane oxygenation circuit.

ISSN:0003-3022    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

BackgroundIn the partial CO2rebreathing method, monitored changes in CO2elimination and end-tidal CO2in response to a brief rebreathing period are used to estimate cardiac output. However, dynamic changes in CO2production during ischemia and reperfusion may affect the accuracy of these estimates. This study was designed to compare measurements of cardiac output as produced by the partial CO2rebreathing (NICO), bolus (BCO), and continuous thermodilution (CCO) methods of monitoring cardiac output.MethodsCardiac output was continuously monitored using both NICO and CCO in 28 patients undergoing aortic reconstruction. BCO measurements were taken at the following intervals when hemodynamic stability was achieved: (1) after anesthetic induction; (2) during aortic cross-clamp; (3) at reperfusion of the iliac artery; and, (4) during peritoneal closure.ResultsThe bias and precision (1 SD) derived from all the measurements between NICO and BCO was −0.58 ± 0.9 l/min, whereas for CCO and BCO it was 0.38 ± 1.17 l/min. The bias between NICO and BCO was small after anesthetic induction and during cross-clamp, but increased following reperfusion. The bias between CCO and BCO was relatively small until reperfusion but increased significantly at peritoneal closure.ConclusionsResults indicate that in aortic reconstruction surgery the performance of NICO monitoring is comparable with that of CCO; however, the direction of bias in these continuous measurement devices is the opposite.

ISSN:0003-3022    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

BackgroundThe search for novel mutations in the ryanodine receptor subtype 1 (RYR1) gene causing malignant hyperthermia and central core disease is hampered by the fact that the gene contains 106 exons. Searching for novel mutations in complementary DNA (cDNA) requires an invasive muscle biopsy. Accordingly, an alternate source ofRYR1cDNA was sought for sequence analysis.MethodsLeukocytes were isolated from human blood and used for extraction of RNA and reverse transcription of messenger RNA into cDNA. A detailed protocol was developed in which overlapping fragments ofRYR1cDNA were amplified by polymerase chain reaction in a series of steps and used for double-strand sequencing.ResultsThe sequences of full-length leukocyteRYR1cDNA obtained from four human blood samples were shown to be identical to the sequence of a human muscleRYR1cDNA. The incidence of aberrant splicing was more pronounced in the blood-derived cDNAs, but this could be minimized by adequate sample preparation. Protocols to sequence alternatively spliced products were also developed. Several silent nucleotide polymorphisms were detected, and minor revisions were made to theRYR1sequence.ConclusionsBecause there are no differences inRYR1transcript structure between muscle and leukocytes, aside from those that may be ascribed to RNA splicing aberrations during processing, leukocytes seem to be an adequate substitute tissue for screening theRYR1gene for previously undiscovered mutations in families with malignant hyperthermia or central core disease.

ISSN:0003-3022    

出版商:OVID    

年代:2003

数据来源: OVID