摘要:

ObjectiveTo determine pulmonary mechanical characteristics in neonates after cardiac surgery.DesignA prospective study.SettingA 23-bed, pediatric ICU in a 280-bed children's hospital.PatientsTwenty-six infants on the first post-operative day after cardiac surgery.MethodsPulmonary mechanics measurements were made during spontaneous breathing, using the esophageal balloon technique and a pneumotachometer. The least mean square method of analysis was used to calculate mechanics. Infants who tolerated withdrawal of mechanical ventilation (group 1) were compared with those infants with respiratory failure (group 2).ResultsSpontaneous respiratory rate, tidal volume, and minute ventilation were similar in groups 1 and 2. Lung compliance was decreased, with no difference between groups. Total lung resistance (34.3 ± 21.6 cm H2O/L·sec in group 1 vs. 136.8 ± 105.8 cm H2O/L·sec in group 2,p= .002) and resistive work of breathing (33.4 ± 29.9 g·cm/kg in group 1 vs. 212.9 ± 173.8 g·cm/kg in group 2,p= .001) were significantly higher in group 2. All infants with a total lung resistance >75 cm H2O/L·sec exhibited respiratory failure (resistance >75 cm H2O/L·sec correlated with respiratory failure, r2= .73, odds ratio of 70 [confidence interval, 4.4 to 3240],p< .001).ConclusionsIncreased lung resistance identifies neonates with respiratory failure after cardiac surgery. Pulmonary mechanics testing may be useful in timing withdrawal of mechanical ventilation. (Crit Care Med 1992; 20:22)

ISSN:0090-3493    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ObjectiveTo determine the feasibility of utilizing a scintigraphic technique to differentiate patients with adult respiratory distress syndrome due to sepsis syndrome from control volunteers and patients with congestive heart failure. Gamma scintigraphy was compared with chest roentgenograms to predict mortality rate and morbidity in adult respiratory distress syndrome (ARDS) patients.DesignProspective study.SettingUniversity hospital ICUs.PatientsThirty-five control volunteers, 19 patients with congestive heart failure, 30 patients with a diagnosis of sepsis.Measurements and Main ResultsAll patients were infused iv with technetium 99m-labeled albumin and underwent computerized gamma-scintigraphic analysis with a portable gamma camera. Lung-to-heart ratio of tracer was calculated and expressed as the slope index. Increase in slope index indicated increased pulmonary albumin flux. Slope index was no different in controls compared with congestive heart failure patients, unless the pulmonary artery occlusion pressure (PAOP) was >30 mm Hg. Patients with a diagnosis of sepsis had an overall increased slope index compared with the other groups. A subgroup of patients in the septic group had a normal slope index. Septic patients with an increased slope index had a significantly (p< .01) longer duration of mechanical ventilation (36 ± 5 vs. 7 ± 1 days), spent longer in the ICU (67 ± 9 vs. 11 ± 1 days), and had a longer hospital stay (113 ± 20 vs. 35 ± 5 days) than septic patients with a normal slope index.ConclusionsGamma scintigraphy successfully differentiated between control volunteers and patients with congestive heart failure with PAOP <30 mm Hg from patients with sepsis-induced ARDS. Although all of the patients with a clinical diagnosis of septic ARDS had similar impairments in oxygenation and chest roentgenograms, those patients with a significantly increased pulmonary albumin flux (>2 SD above control mean) had a markedly increased morbidity. (Crit Care Med 1992; 20:28)

ISSN:0090-3493    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ObjectiveTo determine the frequency of upper gastrointestinal (GI) bleeding in pediatric ICUs.DesignProspective, descriptive study.SettingPediatric ICU in a university hospital.PatientsAll children admitted to a pediatric ICU over a 55-wk period.InterventionNone.Measurements and Main ResultsUpper GI bleeding was considered to be present if there was an episode of hematemesis or if any amount of blood was seen in drainage from a nasogastric tube. Sixty-three (6.4%) upper GI bleeds were detected among 984 patients: 5.2% in 698 patients who did not receive upper GI bleeding prophylaxis, and 9.4% in 286 patients who did receive some prophylaxis. Density was defined as the number of events/1000 days patient. The mean density was 10.8 GI bleeding episodes/1000 days patient in a pediatric ICU. A multivariate analysis detected four independent risk factors or risk markers for upper GI bleeding: high Pediatric Risk of Mortality score, coagulopathy, pneumonia, and multitrauma. Age, sex, hepatic and respiratory failures were identified as confounding variables. An upper GI bleeding episode was defined as being clinically important if hypotension, death, or transfusion occurred within 24 hrs after the bleeding. There were four clinically important GI bleeding epidodes. All were caused, at least in part, by a coagulopathy. The GI bleeding was associated with a need for transfusion in four children, and with hypotension in two.ConclusionsThe frequency of upper GI bleeding is substantial, but the rate of occurrence of clinically important upper GI bleeding is low, even in a pediatric ICU where most patients do not receive any prophylaxis. (Crit Care Med 1992; 20:35)

ISSN:0090-3493    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ObjectivesTo determine patients' preferences for intensive care and to evaluate the influence of a recent ICU experience on preferences for future ICU treatment.DesignSurvey of nonrandomized patient sample using structured interviews.SettingLarge, urban, tertiary academic medical center.PatientsEighty-four adult inpatients discharged from the medical ICU between June and August 1990.MeasurementsAgreement with life-supportive care under each of four potential outcome scenarios was assessed on a 5-point scale. An overall preference score was created by summing scores for the four items. Patients were also asked about their recent experiences in the ICU.ResultsPatients identified sources of stress associated with their ICU stay, yet most (76%) rated their ICU experience positively. Preferences for future intensive care varied with perceived outcome, and were strongest for health restoration and weakest for persistent vegetative states. No significant relationships were found between ICU preferences and any demographic or clinical variable except race.ConclusionsPatients tolerate intensive care well and desire it to restore health. Most patients modify their desire for intensive care if less favorable outcomes are likely. Patients' preferences for intensive care cannot be predicted from demographic features or previous ICU experiences. (Crit Care Med 1992; 20:43)

ISSN:0090-3493    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ObjectiveTo determine if there was a difference between reflection and transmission pulse oximeters in their ability to regain data display after hypothermia in patients recovering from open-heart surgery.DesignProspective, randomized, controlled study.PatientsNineteen adult patients scheduled for open-heart surgery were studied immediately after surgery in the ICU.InterventionsTransmission and reflection sensors were used in random order in two simultaneously monitoring identical oximeters and probes. The time difference at the start of display between the oximeters was measured and the skin temperatures in the region of the probes, cardiac index, systolic BP, pulse pressure, and systemic vascular resistance index were recorded.ResultsThe mean skin temperatures at the probe sites differed significantly (p= .001) at the moment of data acquisition. The mean fore-head, ear lobe, and fingertip temperatures (simultaneously measured) were 33.9°C, 31.8°C, and 28.8°C, respectively. The hemodynamic variables were comparable at the moment when the oximeters resumed display. The reflection probe was the first to resume function in 12 patients and the transmission probe was the first to resume function in four patients (p < .02). The bias of the reflection probe was 1.4% (SD 2.2) and that of the transmission probe was −0.4% (SD 2.7). All the patients were normoxic throughout the study.ConclusionThe forehead reflection probe regained signal detection earlier than the transmission probe on the ear lobe in patients with compromised peripheral blood flow and cool periphery. This finding may be due to higher skin temperature at the reflection probe site, since the systemic hemodynamic conditions were equal at the time of the data acquisition of both sensors. (Crit Care Med 1992; 20:48)

ISSN:0090-3493    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ObjectivesTo evaluate the changes in the anion gap and their relation to hyperlactatemia and alterations in plasma proteins after cardiopulmonary bypass.DesignProspective study.SettingCardiothoracic intensive therapy unit.PatientsOne hundred eleven consecutive patients after cardiopulmonary bypass.Measurements and Main ResultsData were collected before cardiopulmonary bypass and every 6 hrs for 24 hrs after cardiopulmonary bypass. Results were analyzed for the entire cohort and for hyperlactatemic subgroups. The major finding of this study was that the anion gap decreased significantly at all sampling periods relative to precardiopulmonary bypass values, despite the presence of clinically important hyperlactatemia. No correlation between the decrease in plasma protein concentrations and the decrease in anion gap could be demonstrated.ConclusionsThe decrease in anion gap after cardiopulmonary bypass appears to represent a balance between the influences of increased serum chloride and lactate concentrations and reduced plasma protein concentrations. This analysis demonstrates the limitations of the anion gap in the evaluation of a metabolic acidosis after cardiopulmonary bypass. (Crit Care Med 1992; 20:52)

ISSN:0090-3493    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ObjectivesTo investigate the relationship of thrombotic thrombocytopenic purpura to adult respiratory distress syndrome (ARDS) and study the responses of thrombotic thrombocytopenic purpura patients to early plasmapheresis.DesignCase series.SettingICU of a university hospital.PatientsTwenty-four consecutive patients with thrombotic thrombocytopenic purpura, with various periods of time (1 to 18 days) having elapsed since the onset of this condition. Patients ranged in age from 17 to 66 yrs.InterventionsPlasmapheresis, using intermittent flow separators, was instituted soon after the patients' ICU admission. The retinoscopic findings on admission and the relationship of Pao2to platelet counts before and after plasmapheresis therapy were recorded. Antiplatelet agents were given to the survivors to prevent relapses.Measurements and Main ResultsEighteen patients survived and six died. Plasmapheresis was administered for a range of 1 to 5 days (mean 3) and 3 to 18 days (mean 9.8) in survivors and nonsurvivors, respectively (p< .001). Four patients with confluent fundus hemorrhages died and seven without these fundoscopic findings had easily controlled disease. Increases in Pao2paralleled increases in platelet counts after plasmapheresis (p< .001) in this small series of patients. Three of 18 discharged survivors relapsed over a period of 3 to 56 months of follow-up.ConclusionsEarly introduction of plasma pheresis in thrombotic thrombocytopenic purpura seems to increase the survival rate and to halt the development of ARDS. Fundus findings may be a prognostic factor in thrombotic thrombocytopenic purpura. The antiplatelet agents seem to be efficacious in the prevention of relapses. (Crit Care Med 1992; 20:57)

ISSN:0090-3493    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ObjectivesTo analyze the impact of the position of the thoracic external electrodes on the values of cardiac output measured by electrical bioimpedance and to compare the results obtained by bioimpedance with those values determined by thermodilution in critically ill patients.DesignOpen, prospective, comparative trial.SettingICU of a teaching hospital.PatientsTwenty healthy volunteers and ten critically ill patients.InterventionsMeasurements of cardiac output by bioimpedance at rest and after physical activity in normal volunteers and after changing the neck or xiphoid electrodes. Comparisons of cardiac output obtained by thermodilution and bioimpedance with internal and external electrodes in patients.Measurements and Main ResultsMean ± SD values are presented. Cardiac output values at rest and after exercise were 6.7 ± 1.3 and 10.8 ± 2.6 L/min at rest and after exercise, respectively (p< .001). Displacement of the xiphoid electrodes 3 cm in the caudal direction was accompanied by a decrease of the mean cardiac output from 7.1 ± 1.2 to 5.8 ± 1.3 L/min (p< .001) and displacement 3 and 6 cm cranially was accompanied by increases in cardiac output from 7.1 ± 1.2 to 8.1 ± 1.4 L/min (p< .001) and 8.6 ± 1.5 L/min (p< .001), respectively. In the ten patients, cardiac output measurements were virtually identical when results obtained by thermodilution (6.7 ± 3.1 L/ min) were compared with those results obtained by bioimpedance using internal esophageal (6.6 ± 3.1 L/min), but not external (4.7 ± 1.6 L/min) electrodes.Conclusionsa) The values of cardiac output derived from measurements obtained by bioimpedance using internal electrodes were comparable with those values derived from thermodilution. b) Values of cardiac output from bioimpedance studies with external electrodes were dependent on the position of the xiphoid electrodes. (Crit Care Med 1992; 20:62)

ISSN:0090-3493    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ObjectivesTo review the pathophysiology, diagnosis, and treatment of the syndromes of diabetes insipidus with an emphasis on those situations likely to be encountered in the critical care setting.Data SourcesExtensive clinical experience and relevant publications from the English literature identified via MEDLINE search, citation in reviews, publications of original data, and endocrine texts.Study Selection and Data ExtractionLand-mark papers pertaining to all aspects of diabetes insipidus were selected. Reviews, primary articles, and case reports pertaining to diabetes insipidus in the critical care setting were identified and selected according to their content of clinically useful information.Data Synthesis and ConclusionsDiabetes insipidus may result from impaired synthesis and release of vasopressin from the hypothalamic-pituitary unit (neurogenic) or renal insensitivity to circulating vasopressin (nephrogenic). A number of interventions, diseases, and drugs commonly encountered in the critical care setting may result in the development or exacerbation of diabetes insipidus. The diagnosis of diabetes insipidus requires the exclusion of other causes of polyuria and a systematic demonstration of the response of homeostatic mechanisms to controlled dehydration. The treatment of diabetes insipidus depends on many factors, including the clinical setting, degree and pathophysiologic classification, ability of the patient to compensate for free water losses, and expected duration of the abnormality. Underlying disorders should be treated appropriately whenever possible. (Grit Care Med 1992; 20:69)

ISSN:0090-3493    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

PurposeThis article reviews the current body of knowledge regarding lactic acidosis in critically ill patients. The classification of disordered lactate metabolism and its pathogenesis are examined. The utility of lactate as a metabolic monitor of shock is examined and current therapeutic strategies in the treatment of patients suffering from lactic acidosis are extensively reviewed. The paper is designed to integrate basic concepts with a current approach to lactate in critical illness that the clinician can use at the bedside.Data SourcesComprehensive review of the available, basic science, medical, surgical, and critical care literature.ConclusionsThe severity of lactic acidosis in critically ill patients correlates with overall oxygen debt and survival. Lactate determinations may be useful as an ongoing monitor of perfusion as resuscitation proceeds. Therapy of critically ill patients with lactic acidosis is designed to maximize oxygen delivery in order to reduce tissue hypoxia by increasing cardiac index, while maintaining hemoglobin concentration. Buffering agents have not been shown to materially affect outcome from lactic acidosis caused by shock. The benefits of other specific therapies designed to reduce the severity of lactic acidosis remain unproven. (Crit Care Med 1992; 20:80)

ISSN:0090-3493    

出版商:OVID    

年代:1992

数据来源: OVID