ISSN:0003-3022    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

To determine whether pregnancy renders women more sensitive to local anesthetics, nine nonpregnant and nine pregnant (third trimester) women underwent median nerve block at the wrist using 1% lidocaine HCl. Inhibition of median nerve Aα sensory and motor fibers was assessed using measurements of sensory nerve action potential (SNAP) amplitude and compound motor action potential (CMAP) amplitude, respectively. Inhibition of median nerve C fibers was assessed by the increase in skin temperature and by the decrease in median (relative to ulnar) galvanic skin potential (GSP) amplitude. Lidocaine inhibited SNAP to a greater extent in pregnant than non-pregnant women at all time points (P = 0.019). CMAP declined differently in the pregnant and nonpregnant groups (P = 0.01): the pregnant subjects achieved steady state inhibition before the nonpregnant subjects. The two groups developed comparable steady state inhibition. Skin temperature was higher in pregnant women at all time points (P < 0.0001); moreover, the increased skin temperature of pregnant women differed from that of the nonpregnant women (P = 0.037), reflecting a more rapid temperature increase in the pregnant women. GSP amplitude declined to 50% of control more rapidly in pregnant (mean = 4 min) than nonpregnant women (mean = 11.5 min), but these differences did not achieve statistical significance. It is concluded that pregnancy increases median nerve susceptibility to lidocaine.

ISSN:0003-3022    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

To examine the cyclic changes in right ventricular (RV) function induced by controlled ventilation, right heart catheterization and two-dimensional echocardiography were combined in a group of 20 patients requiring respiratory support for an episode of acute respiratory failure. Simultaneous measurements of RV pressure (using a modified pulmonary artery catheter), RV stroke output (thermo-dilution), and RV dimensions (two-dimensional echocardiography), permitted a beat to beat evaluation of RV function throughout the mechanical respiratory cycle. When compared with expiration, lung inflation produced an increase in RV systolic pressure and volume, an increase in RV diastolic volume with an unchanged RV diastolic pressure, and a marked decrease in RV ejection fraction. It is concluded that controlled ventilation altered RV function primarily by increasing RV afterload during the lung inflation period.

ISSN:0003-3022    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

This study documented mitral flow velocity patterns in anesthetized patients with ischemic heart disease and left ventricular dysfunction and investigated the relationship between transmitral flow velocity measurements and the hemodynamic response to ventricular pacing. Twenty-four patients in sinus rhythm without evidence of mitral valve disease undergoing elective myocardial revascularization were studied. Anesthesia consisted of a high-dose opioid-muscle relaxant-oxygen technique. After endotracheal intubation a 3.5-MHz phased-array transesophageal echocardiographic probe was inserted and positioned to obtain a long-axis view of the left atrium and left ventricle. The Doppler sample volume was placed at the mitral annulus with minimal cursor angulation, and the biphasic velocity tracing of transmitral blood flow was recorded. A hemodynamic profile was obtained, and cardiac output was measured in triplicate by thermodilution. Ventricular pacing was then instituted and the hemodynamic and thermodilution measurements were repeated. The peak early filling (E) velocity was 0.34 ±0.11 m/s, and the peak atrial (A) velocity was 0.38 ± 0.09 m/s. The mean E:A ratio was 0.91 ± 0.3, and the median value was 0.88. In sinus rhythm the cardiac index of those patients with an E:A>0.88 (group 1) was 1.97 ± 0.32 1/min and those with an E:A < 0.88 (group 2) was 1.76 ± 0.50 (NS). During ventricular pacing the patients in group 1 (1.56 ± 0.32 1/ min) had significantly higher cardiac indices than those in group 2 (1.21 ± 0.31 I/min) (P < 0.02). It is concluded that peak E velocities and E:A ratios are markedly lower in anesthetized patients with ischemic heart disease whose lungs are mechanically ventilated than in awake normals and that patients with E:A ratios < 0.88 had more marked decreases in cardiac index and stroke index with the loss of atrial contraction during ventricular pacing.

ISSN:0003-3022    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

The authors evaluated the effect of transdermal scopolamine on the incidence of postoperative nausea, retching, and vomiting after outpatient laparoscopy in a double-blind, placebo-controlled study. A Band-Aid® -like patch containing either scopolamine or placebo was placed behind the ear the night before surgery. Anesthesia was induced with fentanyl (0.5–2 μg/kg iv), thiopental (3–5 mg/kg iv), and succinylcholine (1–1.5 mg/kg iv) and maintained with isoflurane (0.2–2%) and nitrous oxide (60%) in oxygen. Scopolamine-treated patients had less nausea, retching, and vomiting compared with placebo-treated patients (P = 0.0029). Severe nausea and/or vomiting was present in 62% of the placebo group but only 37% of those getting the scopolamine patch. Repeated episodes of retching and vomiting were also less frequent in the scopolamine group compared with the placebo group (23% vs. 41%; P = 0.0213) as was the need for additional antiemetic therapy (13% vs. 32%; P = 0.0013). Patients in the scopolamine group were also discharged from the hospital sooner (4 ± 1.3 vs. 4.5 ± 1.5 h; P = 0.0487). Side effects were more frequent among those patients treated with the scopolamine patch (91% vs. 45%; P < 0.05) but were not troublesome. The authors conclude that transdermal scopolamine is a safe and effective antiemetic for outpatients undergoing laparascopy.

ISSN:0003-3022    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

The authors conducted a randomized double-blind controlled study comparing groups of patients receiving iv or epidural fentanyl infusions to determine whether, at comparable levels of analgesia, 1) the severity of side effects was different; and 2) plasma fentanyl concentrations differed between the two groups. Twenty-eight ASA physical status 2 women scheduled to undergo elective cesarean section were randomized into two groups to either receive fentanyl intravenously and saline epidurally or fentanyl epidurally and saline intravenously. After delivery of the infants under epidural anesthesia, each patient received a bolus of fentanyl 1.5 μg/kg either intravenously or epidurally, and a fentanyl infusion was begun via the same route. Concurrently, a saline bolus and infusion were given via the alternate route. The rates of the fentanyl and saline infusions were adjusted until each patient was comfortable. Patients rated their pain, nausea, and pruritus on visual analogue scales. Sedation was evaluated by an observer. Respiratory depression was evaluated by end-tidal Pco2Data were analyzed by unpaired two-tail t tests. Plasma fentanyl concentrations were measured at 12 and 24 h. Three patients in the iv group were dropped from the study because of inadequate pain relief. For the remaining 25 patients, similar infusion rates of fentanyl were required to produce similar levels of analgesia at 12 and 24 h. The severity of nausea, pruritus and sedation, and end-tidal Pco2were similar for both groups. The plasma concentrations of fentanyl were significantly greater in those who received iv fentanyl at 12 h but not at 24 h. In conclusion, there appears to be no clinical advantage to epidural infusion over iv infusion of fentanyl for analgesia after cesarean section.

ISSN:0003-3022    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

The effects on blood glucose concentrations of packed red blood cells (AS-1) (group I) versus washed red blood cells (group II) for cardiopulmonary bypass prime were compared in 20 infants weighing less than 10 kg undergoing cardiac surgical procedures. All patients were anesthetized with N2O/O2/isoflurane/fentanyl and received lactated Ringer's solution prior to bypass. Blood glucose concentrations prior to bypass were 85 ± 15 mg/dl (mean + SD) in group I and 81 ± 14 mg/dl in group II. Blood glucose concentrations were 210 ± 21 mg/dlversus78 ± 14 mg/dl (P < 0.001) 10 min after initiation of bypass, 241 ± 48 mg/dlversus107 ± 28 mg/dl (P < 0.001) prior to separation from bypass, and 214 ± 52 mg/dlversus97 ± 19 mg/dl (P < 0.001) after protamine administration in group I and group II, respectively. The use of washed red blood cells for cardiopulmonary bypass priming solution in infants significantly attenuates the increase in blood glucose concentration otherwise observed during cardiopulmonary bypass.

ISSN:0003-3022    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Many children with malignant diseases who present with an anterior mediastinal mass must undergo general anesthesia for tissue diagnosis or tumor resection. One hundred sixty-three pediatric patients over a period of 6 yr were admitted to Memorial Sloan-Kettering Cancer Center with a diagnosis of anterior mediastinal mass. Forty four of these patients required surgery and their records were reviewed. In recent years perioperative radiation therapy has been advocated for this patient group prior to their receiving general anesthesia. If a tissue diagnosis has not been made, preoperative radiation therapy may distort histologic findings and prevent accurate diagnosis. All patients with an anterior mediastinal mass who must receive general anesthesia in our institution do so prior to treatment with radiation or chemotherapy even in the presence of cardiovascular or respiratory symptoms. No patient died or sustained permanent injury as a result of their anesthetic or operative experience. Two patients who experienced difficulty on induction of anesthesia required tracheal intubation with a rigid bronchoscope. Two patients developed airway obstruction during anesthetic maintenance that was corrected with changes in patient position. Four patients were unable to have their tracheas extubated at the conclusion of surgery and one patient required tracheal reintubation in the immediate postoperative period. These patients were treated with radiation therapy and chemotherapy after tissue for diagnosis had been obtained. The authors conclude that in the absence of life-threatening preoperative airway obstruction and severe clinical symptoms general anesthesia may be safely induced prior to radiation therapy.

ISSN:0003-3022    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Little is known about the mechanism of action of anesthetics at the biochemical level. The present work, however, gives evidence that barbiturates inhibit inositol phospholipid hydrolysis in both intact and permeabilized rat basophilic leukemia (RBL-2H3) cells by an effect on GTP-binding proteins (G-proteins). Inhibition of hydrolysis was observed when intact cells were stimulated with antigen (DNP24BSA) or with oligomers of IgE. The inhibition was dependent on the concentration and type of barbiturate used with an order of inhibitory action of secobarbital < S(-) pentobarbital < pentobarbital < R(+) pentobarbital < phenobarbital. The relatively inactive analogue, (l'RS, 3'SR) 3-hydroxypentobarbital caused little (<30% at 1 mM) or no inhibition (at 0.1–0.5 mM). In permeabilized cells, the hydrolysis induced by DNP24BSA and the nonhydrolyzable analogue of GTP, GTPγS (2–100 MM), was also inhibited by pentobarbital. The inhibition of hydrolysis was decreased as pH increased, and was no longer apparent at pH 7.8, a possible indication that the inhibitory effect was due to the unionized form of the drug. In permeabilized cells, the inhibition by pentobarbital occurred in the presence or absence of Ca2+and was uncompetitive in nature (Km= 7.1 μM for GTP in controls vs. 1.6 μM in the presence of 0.5 μM pentobarbital). Taken together, the data suggest that barbiturates alter the activity of G-proteins independently of Ca2+, and the inhibition may depend on both the hydrophobic properties and the stereospecific and structural features of the molecule.

ISSN:0003-3022    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

The effects of glucose on neurologic and neuropathologic outcome following global cerebral ischemia were examined in 20 cats subjected to 14 min of cardiac arrest, followed by closed chest resuscitation and intensive care monitoring. Beginning 30 min prior to cardiac arrest, 15 ml/kg of 5% dextrose in 0.45% saline or the same volume of 0.9% saline was administered in a blinded fashion over 15 min. Ventricular fibrillation was electrically induced and cardiac resuscitation was performed according to a standardized protocol, which included closed chest cardiac compressions, epinephrine, lidocaine, sodium bicarbonate administration, and electrical defibrillation. Animals not resuscitated within 4 min were excluded from further study. Resuscitated animals were managed in an intensive care setting for 24 h postresuscitation. Neurologic deficits were scored at 2, 4, and 7 days postresuscitation. Subsequently, the animals' brains underwent histologic examination. Nine cats were excluded from data analysis. Three did not meet protocol criteria and six could not be resuscitated within 4 min. As a result of a technical error, the brain of one glucose-treated cat was not analyzed. Six saline-treated and five glucose-treated animals met all protocol criteria and survived for 7 days postresuscitation. Plasma glucose concentration before cardiac arrest was 118 ± 24 mg/dl (mean ± SD) in the saline group and 269 ± 21 mg/dl in the glucose group (P < 0.01). Neurologic outcome rank at 2, 4, and 7 days postresuscitation was significantly worse in glucose-treated cats (P < 0.01, P < 0.01, and P < 0.01, respectively). The neuropathologic score did not differ between glucose- and saline-treated groups (P = 0.07). This study demonstrated that a clinically relevant dose of glucose administered prior to cardiac arrest exacerbates postresuscitation neurologic injury in a feline cardiac arrest model of global cerebral ischemia.

ISSN:0003-3022    

出版商:OVID    

年代:1990

数据来源: OVID