摘要:

Reduced levels of complement fractions C3and C4and total hemolytic complement (CH50) are usually attributed to classical complement pathway activation. However, studies in 26 patients undergoing severe anaphylactoid reactions during general anesthesia suggest that these changes may equally reflect plasma dilution and protein redistribution. Twelve patients showed a dramatic fall in complement complexes which tended to resolve after 24 h; however, this fall was not usually associated with the detection of C3breakdown products or antigen-antibody complexes. Measurement of complement levels is not a reliable index of activation or cleavage when there are dynamic shifts in plasma volume.

ISSN:0090-3493    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

Carlen's tubes were modified by introducing a manometer line into each lumen to allow both bronchi to be insufflated continuously. During such continuousflow ventilation (CFV) with a gas flow of 1 L/kg body weight min in 6 anesthetized dogs, both CO2and O2homeostasis were maintained. By contrast, during apneic oxygenation the mean Paco2rose by approximately 6 torr/min. After 12 min of apneic oxygenation the introduction of CFV at 1 L/kg min reduced the mean Paco2from 120 to 38 torr within 6 to 9 min; by 15 to 30 min the Paco2was stable at 33 torr. The mean Pao2was stable at 80 torr and 451 torr using air and oxygen, respectively, as the insufflating gas. When the CFV was reduced to 0.75 L/kg ± min, there was a rise in mean Paco2from 34 to 53 torr in 12 min; Paco2was then reduced to 40 torr when 4 breath/min was introduced with a mean tidal volume of 375 ml.

ISSN:0090-3493    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

The diagnosis of brain death requires absence of respiratory effort. Various protocols for apnea testing in adults have been reported; however, similar protocols have not been established for children. The technique of apneic oxygenation was used on 10 brain-dead children, PaO2remained over 200 torr in all patients, and the mean Paco2increase was 4 torr/min. Five min of apneic oxygenation is a safe and effective means of evaluating respiratory activity in initially normocapnic children thought to be brain-dead.

ISSN:0090-3493    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

Arterial hypoxemia occurs frequently during hemodialysis. Proposed mechanisms for this phenomenon have included hypoventilation and embolism of granulocyte aggregates. We studied 18 patients with endstage renal failure who required chronic hemodialysis, and measured arterial blood gases, pulmonary gas exchange, and dialyzer gas exchange. During use of acetate as a dialysate buffer, Pao2decreased to 80 ± 6.8 torr, whereas during use of the bicarbonate buffer oxygen tension remained at 92 ± 4.9 torr or greater. Hypoventilation and microembolism were not sufficient to explain the degree of hypoxemia during acetate dialysis. Hypoxemia occurred only after the 1st exposure to acetate; neither an instantaneous change to bicarbonate nor stopping dialysis restored oxygen tension to normal. We conclude that a pharmacologic action of acetate adversely affects lung function, aggravating the decreased alveolar oxygen tension (PAO2) due to hypoventilation. Hypoxemia was not present when bicarbonate was used. Acetate buffer should not be used for dialysis in patients with unstable cardiovascular or respiratory systems.

ISSN:0090-3493    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

An endobronchial tube was used to separately ventilate each lung in anesthetized dogs, and absorption atelectasis was then induced in the left lung and maintained for 3 1/2 h. The left lung was partially re-expanded by ventilation at normal tidal volumes for 10 min, and then completely re-expanded by manual hyperinflation. This delayed re-expansion was associated with an extravascular water content significantly greater than that of the right lung. A previous study demonstrated no increase in the ratio of left to right lung water content after 3 h of atelectasis alone and a significant increase after immediate hyperinflation. Delayed re-expansion produces significantly different results, and it is therefore concluded that the method of lung re-expansion influences the development of pulmonary edema after atelectasis

ISSN:0090-3493    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

Three pediatric patients with generalized status epilepticus unresponsive to therapy with conventional anticonvulsants were successfully treated with moderate hypothermia (30± to 31±C) and barbiturate coma with thiopental. All 3 patients were treated with thiopental at doses producing burst suppression or an isoelectric tracing on the EEG and thiopental and barbiturate levels were followed sequentially in the plasma. Continuous thiopental infusion rates of 5 to 55 mg/kg ± h maintained burst suppression and correlated with plasma thiopental levels of 25 to 40 mg/dl. Total doses of thiopental used to obtain and maintain burst suppression ranged from 15 to 50 g over 48 to 120 h. In all 3 patients, control of the status epilepticus was obtained. Moderate hypothermia and thiopental barbiturate coma are indicated in patients with generalized tonic-clonic status epilepticus which cannot be controlled with standard anticonvulsant drug therapy. This regimen has the advantage that the patient can be managed in an ICU without the need for general anesthesia with volatile anesthetic agents.

ISSN:0090-3493    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

Aggressive pharmacotherapy for the treatment of patients with severe status asthmaticus includes theophylline and beta-adrenergic agonists such as isoproterenol. We found that the measured theophylline level decreased when an isoproterenol infusion was started, and this decrease persisted throughout the entire exposure to isoproterenol. When the isoproterenol infusion was discontinued, the theophylline level increased. The etiology of this observed effect is unknown.

ISSN:0090-3493    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

A total of 294 Clinical Classification System (CCS) Classes III and IV patients in a pediatric ICU (PICU) were evaluated in terms of severity of illness and quantity of care. The group was comprised of patients from 3 services: medicine, cardiovascular surgery, and other surgery. Severity of illness was measured by the Physiologic Stability Index (PSI) and quantity of care was measured by the Therapeutic Intervention Scoring System (TISS). Comparisons were made between survivors and nonsurvivors and among the 3 services.Nonsurvivors had significantly higher (p< .01) PSI and TISS scores than survivors. Medical patients had the highest PSI scores while cardiovascular surgery patients had the highest TISS scores. Analysis of 7-day regression slopes for all survivor groups and medicine and other surgery nonsurvivor groups demonstrated slopes consistent with the expected clinical course. Cardiovascular surgery nonsurvivor slopes were unique and demonstrated increasing stability with stable amounts of care.The PSI/TISS ratio was used to relate levels of physiologic instability to the amount of therapy. Medical patients had the highest ratios and cardiovascular surgery patients had the lowest ratios. Comparisons of survivors and nonsurvivors for the PSI/TISS ratios and regression slopes demonstrated differences that were not evident through comparison of PSI and TISS scores alone.

ISSN:0090-3493    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

Corticosteroid-induced metabolic alkalemia is an important ICU problem because many of these patients may compensate by alveolar hypoventilation. The effects of 3 commonly used steroids on arterial pH, Paco2, and serum bicarbonate concentrations were studied in 24 healthy male baboons randomly divided into 3 groups. Each group of 8 animals received 7-day dose-equivalent courses of either hydrocortisone (300 mg daily), methylprednisolone (60 mg daily), or dexamethasone (15 mg daily). Treatment with either hydrocortisone or methylprednisolone increased arterial pH (p< .05) and serum bicarbonate levels (p< .01) and the animals receiving hydrocortisone showed significant (p< .05) compensatory alveolar hypoventilation. Dexamethasone therapy did not cause any of these steroidinduced changes.

ISSN:0090-3493    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

PEEP may decrease regional perfusion to nondependent lung regions, thereby creating different zones of thermal dissipation in dependent and nondependent zones of the lung. Under these conditions, the measurement of cardiac output by thermodilution may, thus, be influenced by the vertical position of the pulmonary artery catheter in the lung. We investigated this hypothesis in 7 healthy, anesthetized pigs by comparing cardiac output measurements from thermistors located in dependent and nondependent lung regions at varying levels of PEEP. Our data from thermistors in these 2 positions were similar, suggesting that the measurement of cardiac output by thermodilution is not influenced by the vertical position of the thermal sensor with respect to the left atrium.

ISSN:0090-3493    

出版商:OVID    

年代:1984

数据来源: OVID