摘要:

We compared the degree of complement activation in 15 patients receiving massive blood transfusions and 21 patients with the septic syndrome and examined its association with other risk factors for adult respiratory distress syndrome (ARDS). Patients with massive transfusion (n = 8) as their only risk factor for ARDS had lower C3a levels (250 ± 80 ng/ml) and a lower incidence of ARDS (0%) than patients with massive transfusion plus other risk factors (n = 7; C3a, 600 ± 120 ng/ml; ARDS, 55%) or patients with the septic syndrome (n = 21; C3a, 540 ± 80 ng/ml; ARDS, 19%). In our patients, the degree of complement activation appeared to reflect the presence of complicating clinical conditions.

ISSN:0090-3493    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

Placement of an unheated miniaturized oxygen electrode against the palpebral conjunctiva permits noninvasive measurement of tissue oxygen tension. In this study, the relationship between conjunctival oxygen tension (Pcjo2) and standard cardiorespiratory variables was examined during a sequential resuscitation protocol after acute hemorrhage. Anesthetized dogs were rapidly bled to a mean arterial pressure of 40 mm Hg and then retransfused with the shed blood in a stepwise fashion. Pcjo2fell to 2% of control values after hemorrhage and did not return to prehemorrhage values until more than 90% of the shed blood had been reinfused. Pcjo2was among the last set of cardiorespiratory variables to return to control values during resuscitation and was the last noninvasive variable to normalize. The ratio of Pcjo2to arterial oxygen tension decreased from a prehemorrhage value of 0.76 ± 0.05 (SEM) to 0.02 ± 0.003 after hemorrhage, and did not increase to values greater than 0.50 until resuscitation was more than 90% complete. Conjunctival oxygen monitoring may play an important role in assessing the adequacy of resuscitation after acute hemorrhage.

ISSN:0090-3493    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

The levels of alpha-atrial natriuretic peptide (ANP) in the right atrium, pulmonary artery, radial artery, and superior vena cava plasma were measured by radioimmunoassay in eight patients with volume-expansion due to different diseases. The alpha-ANP levels were significantly increased, but became decreased after fluid removal by continuous veno-venous hemofiltration. When all alpha-ANP concentrations of different anatomical locations and hemodynamic variables were grouped, pulmonary capillary wedge pressure correlated significantly with all alpha-ANP groups, whereas right atrial mean pressure correlated with alpha-ANP levels in pulmonary artery plasma only. Alpha-ANP concentrations were distinctly lower in superior vena cava plasma than in plasma from the right atrium, pulmonary artery, and radial artery. Since alpha-ANP plays an important role in the homeostasis of sodium and fluid balance, measurement of alpha-ANP concentrations, particularly in right atrium, pulmonary artery, or radial artery plasma, might provide valuable information on the status of the critically ill.

ISSN:0090-3493    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

CO2kinetics during CPR was investigated in 15 anesthetized piglets. BP, blood gases, and acid-base balance were monitored through catheters in the carotid artery and a central vein, as well as in cerebrospinal fluid. Cardiac arrest was induced by a transthoracic direct current shock. CPR was begun immediately by artificial ventilation and simultaneous external chest compressions. Epinephrine was administered after 8 min of CPR. One group (n = 5) of animals received no buffer treatment while another (n = 5) received an infusion of 75 mmol sodium bicarbonate and a third group (n = 5) received an equivalent amount of tris-buffer mixture. The results of these experiments, as well as previously described circulatory variables during CPR, were analyzed using a computer model describing the CO2kinetics of the pig. Our main finding was that Paco2was positively correlated to cardiac output during CPR; improved cardiac output during CPR resulted in more efficient tissue CO2elimination and was associated with increased survival rates. Paco2was also somewhat reduced by efficient alveolar hyperventilation. The arterial Pco2and pH did not reflect the acidbase balance in peripheral tissues. During CPR, bicarbonate and tris-buffer mixture both quickly passed through the blood-brain barrier. When buffer treatment is indicated during CPR, a buffer which does not increase tissue Pco2may be the drug of choice.

ISSN:0090-3493    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

Oxygen consumption (Vo2), CO2production, respiratory quotient, resting metabolic expenditure (RME), and urine catecholamine levels were measured in 52 patients with acute cerebrovascular disease. RME correlated positively with urinary norepinephrine and epinephrine excretion; its maximum value was 187% higher than expected for an uninjured resting person of equivalent age, sex, and size. Vo2correlated positively with the urinary catecholamine excretion. These facts imply that the sympathetic nervous system might directly influence Vo2and RME. Moreover, the hyper-metabolic state should be taken into consideration when caring for patients with cerebrovascular disease, as malnutrition might cause weight loss and a decrease in immunity.

ISSN:0090-3493    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

The ICU records of 31 patients with the acquired immunodeficiency syndrome were reviewed. Of 23 (74%) patients admitted for respiratory failure requiring intubation and mechanical ventilation, 20 (87%) patients hadPneumocystis cariniiand/or cytomegalovirus pneumonia. Of the eight patients admitted without respiratory failure, five (63%) were monitored after brain biopsy. Respiratory failure patients remained in the ICU for 10 ± 1 days, compared to 5 ± 1 days for those without respiratory failure (p< .05). Overall mortality was 24 patients (77%); 21 (91%) of 23 respiratory failure patients died, compared to three (38%) of the eight without respiratory failure (p< .01). All seven ICU survivors lived to hospital discharge.

ISSN:0090-3493    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

The ability to breathe spontaneously through an endotracheal tube is a usual prerequisite before an intubated patient can have it removed. Other researchers have measured air flow resistance through endotracheal tubes. In this study, we evaluated work of breathing in joules per min and tension-time index while three normal volunteers breathed through different sized endotracheal tubes. Four 27.5-cm endotracheal tubes were used. Subjects breathed with a constant tidal volume of 500 ml. By increasing respiratory frequency, minute ventilation was increased from 5 to 30 L/min. As tube diameter decreased, work and the tension-time index increased. Changes were magnified at higher minute ventilations through the 6− and 7-mm endotracheal tubes, and the tension-time index critical fatigue level of 0.15 was approached or exceeded.

ISSN:0090-3493    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

The effects of dobutamine on hemodynamic and oxygen transport were evaluated in 43 studies on 34 critically ill general (noncardiac) surgical patients. Dobutamine, beginning at a low dose (2.5 μg/kgċmin) significantly increased cardiac index (CI), oxygen delivery (Do2), and oxygen consumption (Vo2), while decreasing mean arterial pressure, pulmonary artery and wedge pressures, and systemic and pulmonary vascular resistances; blood gases, pH, and pulmonary shunt were not significantly changed. These effects were seen in postoperative and septic patients, as well as in patients with normal, low, and high control CI. These responses were poor in terminally ill and hypovolemic patients; however, when the latter were given additional fluids, their responses were markedly improved. The hemodynamic effects of dobutamine are well known, but the Do2and Vo2effects, which suggest improved tissue perfusion, have not been appreciated.

ISSN:0090-3493    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

Cardiac output was measured 120 times in 27 critically ill patients using the thermodilution and transthoracic electrical impedance methods. Both the minimum and mean values for the distance between the inner electrodes, and a variety of values for the resistivity of blood (p) were substituted in the Kubicek's empiric formula for calculating cardiac output by transthoracic electrical impedance. Using the mean distance between the inner electrodes and ap-value of 150 ohmċcm gave the best agreement between the methods (mean difference 0.17 ± 2.4 L/min). Ventilation alone or with positive end-expiratory pressure did not significantly affect the bias of the estimate, but both affected its precision when compared with measurements in spontaneously breathing patients (SD of mean difference 2.4 and 3.2 L/min, respectively, vs. 1.5 L/min). The pulmonary artery wedge pressure was significantly higher in patients with an abnormal diastolic impedance waveform (zero-wave), but there was no relationship between wedge pressure and base impedance per unit length between the measuring electrodes.

ISSN:0090-3493    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

To achieve adequate arterial BP, adequate capillary filling time, and adequate peripheral pulses, hypotensive newborn infants often require higher doses of dopamine that reportedly reduce urine output in adults. Whether these larger doses of dopamine also reduce urine output in newborns is not known. Therefore, we determined the effects of administering high-dose dopamine (more than 20 μg/kgċmin) on the urine output of 15 newborn infants. Five infants were studied prospectively and ten retrospectively. In the prospective study, urine output was determined as the dose of dopamine was increased; in the retrospective study, urine output was determined as the infants were being weaned from high doses of dopamine. Both data sets demonstrate that administering high-dosage dopamine does not reduce the urine output of sick new born infants. Therefore, we conclude that doses of dopamine previously reported to decrease urine output in adults do not do so in sick newborn infants. Consequently, when necessary, high doses of dopamine may be used in sick newborn infants to achieve cardiovascular stability without reducing urine output.

ISSN:0090-3493    

出版商:OVID    

年代:1986

数据来源: OVID