摘要:

Background and MethodsRenal cortical and serum carnitine concentrations were studied in seven anesthetized beagle dogs in which acute circulatory collapse was induced by an iv injection ofEscherichia coliendotoxin, 0.5 mg/kg given over 15 mins. Four controls received normal saline.ResultsThe endotoxin injection resulted in cardiac depression, renal hypoperfusion, acidosis with a decrease in urinary output, and hematuria. Arterial and renal venous free carnitine concentrations increased significantly in endotoxemia during the 5-hr experiment, but remained low and unchanged in the controls. Circulating acyl-carnitine concentrations underwent no essential changes in either group. Total, free, and acyl-carnitine concentrations decreased in endotoxic renal tissue.ConclusionsThese data suggest that endotoxemia decreases carnitine concentrations in the renal cortex, but increases free carnitine concentrations in the circulation.

ISSN:0090-3493    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Background and MethodsThe purpose of the present study was to examine the effect of various levels of positive end-expiratory pressure on intraocular pressure in cats. Fourteen healthy adult cats (2.6 to 3.7 kg) without evidence of ocular disease were anesthetized with pentobarbital, paralyzed, and placed on mechanical ventilation. Direct continuous measurements of heart rate (HR), mean arterial pressure (MAP), CVP, CSF pressure, and intraocular pressure were recorded at zero end-expiratory pressure, and at 5,10, and 15 cm H2O positive end-expiratory pressure, applied in random order.Main ResultsThere were no significant changes in pHa, Paco2, HR, MAP, hematocrit, and temperature. Intraocular pressure increased significantly from 17 (during zero end-expiratory pressure) to 20 mm Hg at 10 cm H2O positive end-expiratory pressure; at 15 cm H2O positive end-expiratory pressure, intraocular pressure increased significantly to 21 mm Hg. CVP and CSF pressure increased significantly in parallel with intraocular pressure at 5, 10, and 15 cm H2O positive end-expiratory pressure.ConclusionsWe speculate that similar responses occur in man, and may be undesirable in patients with already increased intraocular pressure, when higher levels of positive end-expiratory pressure are used.

ISSN:0090-3493    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Background and MethodsSmall-volume resuscitation by means of bolus application of hypertonic saline solutions has been demonstrated to restore central hemodynamics and regional blood flow in severe hemorrhagic and traumatic shock. The aim of this study was to elucidate the potential of this new concept for treatment of profound hypovolemia and microcirculatory deterioration associated with sepsis and endotoxic shock.In a porcine model of acute hyperdynamic endotoxemia (elicited by continuous i v infusion ofSalmonella abortus equiendotoxin for 3.5 hrs), small-volume resuscitation applying hypertonic-hyperoncotic solutions was analyzed for its effect on central hemodynamics, oxygen delivery (Do2), and regional blood flow. Fluid therapy was initiated when the pulmonary artery occlusion pressure (PAOP) tended to decrease (at 43 to 52 mins of endotoxemia), and consisted of 4 mL/kg bolus infusion of either 7.2% sodium chloride, 10% dextran, or 10% dextran in 7.2% sodium chloride; thereafter, PAOP was maintained by controlled infusion of 6% dextran-60. In a control group, 6% dextran-60 was given without preinjection of hypertonic-hyperoncotic solutions.ResultsOn small-volume resuscitation, cardiac index significantly increased within 5 mins in all groups, while mean arterial pressure remained unchanged. Fluid requirements were significantly reduced after small-volume resuscitation and the hyperdynamic circulatory state was maintained until the end of the observation period; Do2as well as blood flow to heart, kidneys, and splanchnic organs remained high.ConclusionSmall-volume resuscitation by means of hypertonic saline-dextran proved the most effective, and seems to be an attractive supportive therapy to prevent microcirculatory failure in sepsis and endotoxemia.

ISSN:0090-3493    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

ObjectivesTo evaluate strategies for thermodilution-based measurement of cardiac output and right ventricular (RV) ejection fraction and to assess the effects of controlled mechanical ventilation in patients. Furthermore, to compare strategy-associated repro-ducibility with reference values obtained during long-term apnea.DesignCrossover trial in patients; reference values from apneic animals.SettingUniversity ICU and physiology laboratory.PatientsSix consecutive male ICU patients (48 to 70 yrs) after major abdominal vascular surgery. Animals: two adult female sheep.InterventionsThree ventilatory rates (8,16, and 24 cycles/min) and 15-sec periods of apnea were selected for measurements in patients. In animals, continuous apnea was achieved with extracorporeal CO2removal and apneic oxygenation.MeasurementsMeasurements were performed using an appropriate pulmonary artery catheter and an ejection fraction/cardiac output computer prototype. The thermal indicator was injected automatically at four defined points of the ventilatory cycle, but triggered manually during apnea.Main ResultsAt 8 cycles/min, there was a wide mean range of cyclic variable modulation, with a coefficient of variation of 11.6% and 23.2% for cardiac output and RV ejection fraction, respectively. Allowing for ventilatory phase or changing from 8 to 16 cycles/min reduced errors by half. Combining both procedures resulted in a coefficient of variation of 4.7% and 6.6% for cardiac output and RV ejection fraction, respectively. The best coefficient of variation values obtained during 15 sees of apnea in patients approached those variations in experimental apnea (coefficient of variation of 2.1% and 4.5% for cardiac output and RV ejection fraction, respectively).ConclusionsAt low ventilatory rates, best results are achieved by averaging four phase-selected measurements. One-point measurements were less accurate and random point measurements less reproducible.

ISSN:0090-3493    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

ObjectiveTo compare three devices that measure core body temperature at the bedside in ICU patients.DesignProspective, consecutive sample.SettingVoluntary community teaching hospital.PatientsFifteen patients, 78 ± 6 (SD) yrs of age, admitted to the medical ICU over a 5-month period who had pulmonary artery catheters inserted as part of their routine care were studied. Thirteen patients were studied once, one patient twice, and one patient six times for a total of 21 sets of measurements.InterventionsAll patients had urinary bladder thermistor catheters inserted just before pulmonary artery catheterization. Simultaneous core temperatures were measured for the duration of pulmonary artery catheterization every 4 hrs by the pulmonary artery thermistor catheter, the bladder thermistor catheter, and by a tympanic membrane infrared probe set on its core temperature setting. The three devices were then compared with each other in vitro using a specialized constant water bath setup. Finally, two of the tympanic membrane infrared probes were compared with each other in 20 ambulatory emergency department patients.Measurements and Main ResultsOver 32 hrs of pulmonary artery catheterization, the pulmonary artery thermistor catheters and bladder thermistor catheters showed excellent agreement, with a bias of only −0.04°C between the two. However, the bias comparing the tympanic membrane infrared probe with the pulmonary artery thermistor catheter was −0.38°C, and the bias was −0.34°C comparing the tympanic membrane infrared probe with the bladder thermistor catheter. The tympanic membrane infrared probe readings remained significantly higher than the pulmonary artery thermistor catheter or bladder thermistor catheter readings over the entire 32-hr period. The two tympanic membrane infrared probes compared with each other in emergency room patients showed excellent agreement (p < .001). In the in vivo water bath setup, the tympanic membrane infrared probe on most of its settings again registered significantly (p < .01) higher than both the pulmonary artery thermistor catheter and the bladder thermistor catheter.ConclusionsPulmonary artery thermistor catheters and bladder thermistor catheters appear to give consistent, highly reliable bedside measurements of core body temperature in ICU patients. The currently available device that measures core body temperature from the tympanic membrane appears to give erroneously high readings, and should be used with caution.

ISSN:0090-3493    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

The focus of this study was to determine if the practice of cardiac surgery is affected by the shortage of critical care nurses. We conducted a survey encompassing 25 institutions in the state of New York, representing 10,827 patients. In addition to determining the statewide effect of the nursing shortage, the questionnaire was designed to yield answers to the coping mechanisms of individual institutions.In July 1988, the American Association of Critical Care Nurses (1) published a summary analysis of the supply and requirements for critical care nurses in order to practice critical care. The following data from that report serve as introduction and illustration of the nationwide problem: a) In 1988, the combined part-time and full-time percentage of vacancies in critical care nursing was 13.8% (rates >10% represent a severe nursing shortage) (2). b) In 1986, critical care beds represented 10.8% of inpatient beds, an increase from the 7.4% reported in 1979. c) The number of critical care beds in the United States increased by >20,000 from 1979 to 1986. d) Critical care units report an average bed increase of nearly 30%. e) The occupancy rate in critical care units averaged 84%, which was greater than the average for total hospital occupancy, which was 70%.

ISSN:0090-3493    

出版商:OVID    

年代:1991

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Lithium carbonate is a widely prescribed and effective psychotropic drug which, unfortunately, has a low therapeutic index and important acute and chronic toxicity (1). In particular, acute lithium poisoning, due to deliberate or accidental overdosage, can be fatal or lead to permanent neurologic sequelae. The management of acute lithium intoxication includes cardiorespiratory support, seizure control, and drug elimination enhancement. Increased elimination may be achieved with forced saline diuresis. At lithium concentrations ≥3.5 to 4 mmol/L, saline diuresis may be inadequate and hemodialysis (sometimes prolonged and repeated) is considered the treatment of choice. Lack of hemodialysis facilities may delay appropriate therapy. Continuous arterio-venous hemodiafiltration is a dialytic therapy increasingly used in critically ill patients (2). We report its effective use in increasing lithium clearance in a patient with acute lithium poisoning. Continuous arterio-venous hemodiafiltration can be rapidly instituted in a critical care environment without the need for specialized staff or facilities, and could replace the use of conventional hemodialysis in acute lithium intoxication.

ISSN:0090-3493    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

“Bezoar” is derived from the Arabic word “badzehr,” meaning antidote. It was once believed that bezoars extracted from animals had healing powers, and they were used to treat such ailments as plague and snake bites. Today, bezoars are not uncommonly found during upper GI investigations, and are known to be associated with conditions causing stasis changes in the GI tract, such as gastric outlet obstruction, diabetes mellitus, postvagotomy, and peripheral neuropathy. They mainly originate and are found in the stomach.Three categories based on composition can be used to describe bezoars: a) phytobezoars or undigested food material; b) trichobezoars or undigested hair; c) miscellaneous material, such as inanimate objects and medications. We describe here a curious presentation of an esophageal bezoar associated with multiple medications and tube feeding.

ISSN:0090-3493    

出版商:OVID    

年代:1991

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1991

数据来源: OVID