摘要:

ObjectivesTo identify a method for predicting the success or failure of a defibrillatory shock such as to avoid potentially detrimental interruptions of cardiopulmonary resuscitation (CPR). Such a method would also guide more optimal programming of automated external defibrillators.DesignProspective, observational animal study.SettingMedical research laboratory in a university-affiliated research and educational foundation.SubjectsDomestic pigs.InterventionsVentricular fibrillation (VF) was electrically induced in 66 domestic pigs. After an interval of between 3 and 5 mins of untreated VF, precordial compression was begun. Electrocardiographic lead 2 was monitored and artifacts produced during precordial compression were removed by digital filtering.Measurements and Main ResultsIn the derivation study, electrical defibrillation restored spontaneous circulation in 30 of the 66 animals. Successfully resuscitated animals had significantly greater coronary perfusion pressure, maximum VF amplitude, mean VF amplitude, and dominant VF frequency. No animals were resuscitated if the coronary perfusion pressure was <8 mm Hg, maximum amplitude was <0.48 mV, mean amplitude was <0.25 mV, or dominant frequency <9.9 Hz independently of the duration of untreated VF. When mean amplitude and dominant frequency were combined, the predictability was further improved. In an additional validation study of 14 animals, consecutive defibrillations were uniformly unsuccessful if the combination of mean amplitude and dominant frequency did not exceed the threshold values obtained in derivation study.ConclusionMean VF amplitude alone or in combination with dominant frequency of VF was expressed as a numerical score. It served as an objective noninvasive measurement on a par with that of coronary perfusion pressure for predicting the success of defibrillation. As such, it minimizes the detriment of repetitively interrupting mechanical interventions during CPR for electrical defibrillation when an electrical shock predictably fails to restore an effective rhythm. (Crit Care Med 1999; 27:708-714)

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

ObjectiveTo investigate, in restrictive patients, the influence of pressure ramp slope values on the efficacy of pressure support ventilation.DesignProspective study.SettingA university hospital medical intensive care unit.PatientsTwelve intubated restrictive patients.InterventionsPatients were randomly assigned to four sequences in which the values of the slope of the pressure ramp increase were modulated so that the plateau pressure was reached within a predetermined time: 0.1, 0.50, 1, or 1.50 secs. The more rapidly the pressure plateau was achieved, the higher was the initial flow rate. For convenience, these four different ventilatory settings were termed T 0.1, T 0.5, T 1, and T 1.5.Measurements and Main ResultsWe measured the following parameters 10 mins after application of each pressure ramp slope: inspiratory work of breathing, breathing pattern, and intrinsic PEEP (PEEPi). Work of breathing was evaluated using Campbell's diagram, and expressed as a percentage of the values observed under spontaneous ventilation. A marked interindividual variation of the values for work of breathing was observed under spontaneous ventilation; the mean value for work of breathing was 1.97 +/- 0.82 joule/L, with a range of 1.22 to 4.10 joule/L. Comparison between the means for each sequence and each variable measured was performed by two-way analysis of variance with internal comparisons between sequences by Duncan's test. Between the first (T 0.1) and the last (T 1.5) sequence, the reduction of values of the pressure ramp slope induced a progressive increase in the values for work of breathing, regardless of the mode of expression (in joule, joule/L, or joule/min). The values for work of breathing (joule/L), expressed as a percentage of the values observed under spontaneous ventilation, increased from 44.2 +/- 14.4% to 78.3 +/- 17.8% (p < .001). In contrast, the reduction of the pressure ramp slope values and initial flow rate did not induce any significant change in tidal volume, respiratory frequency, and PEEPi.ConclusionAmong the four tested slope values, the steepest was that which induced the lowest possible work of breathing in restrictive patients ventilated by pressure support ventilation. In this type of patient, we therefore suggest that the programmed pressure value should be reached by using a steep pressure ramp slope. (Crit Care Med 1999; 27:715-722)

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

ObjectiveTo investigate the effects of stress doses of hydrocortisone on the duration of vasopressor therapy in human septic shock.DesignProspective, randomized, double-blind, single-center study.SettingTwenty-bed multidiscipllnary intensive care unit in a 1400-bed university hospital.Patients4 L/min/m2or=to6 [micro sign]g/kg/min). Secondary study end points were the evolution of hemodynamics and the multiple organ dysfunction syndrome (MODS). The severity of illness at recruitment was graded using the Acute Physiology and Chronic Health Evaluation II and the Simplified Acute Physiology Score II scoring systems. MODS was described by the Sepsis-related Organ Failure Assessment score.Interventions155 mmol/L, the hydrocortisone infusion was tapered in steps of 24 mg/day. Physiologic saline solution was the placebo.Measurements and Main ResultsHemodynamic and oxygen-derived variables were measured at previously defined time points over a study period of 5 days. Relevant clinical and laboratory measurements were registered for a study period of 14 days to assess the evolution of organ dysfunction. Baseline data at recruitment did not differ between the two groups. Shock reversal was achieved in 18 of the 20 patients treated with hydrocortisone vs. 16 of the 20 patients treated with placebo. Hydrocortisone significantly reduced the time to cessation of vasopressor support. The median time of vasopressor support was 2 days (1stand 3rdQuartiles, 1 and 6 days) in the hydrocortisone-treated group and 7 days (1stand 3rdQuartiles, 3 and 19 days) in the placebo group (p = .005 Breslow test). There was a trend to earlier resolution of the organ dysfunction syndrome in the hydrocortisone group.ConclusionsInfusion of stress doses of hydrocortisone reduced the time to cessation of vasopressor therapy in human septic shock. This was associated with a trend to earlier resolution of sepsis-induced organ dysfunctions. Overall shock reversal and mortality were not significantly different between the groups in this low-sized single-center study. (Crit Care Med 1999; 27:723-732)

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

ObjectiveTo study the frequency of several lymphocyte subsets, circulating cytokines, and prostaglandin plasma values at their time course over a period of 14 days in severely injured trauma patients in relation to the development of sepsis and multiple organ failure (MOF).DesignProspective study.SettingAn operative intensive care unit (ICU) of a university hospital.PatientsSixty-eight consecutive severely injured trauma patients.InterventionsPatients were separated into patients without sepsis and MOF (group 1, n = 51), and patients who developed sepsis and MOF (group 2, n = 17) during their stay in the ICU. Therapy was adjusted to the standards of modern intensive care management by physicians who were not involved in the study.Measurements and Main ResultsIn arterial blood samples, the profile of lymphocyte subset frequencies was performed by flow cytometry and, together with interleukin (IL)-1, IL-10, tumor necrosis factor (TNF)-alpha, soluble TNF-alpha receptor 1 (sTNF-alpha r1 [p55]), and prostaglandin E2(PGE2alpha)-alpha, serially measured after arrival in the ICU (baseline value) and during the next 14 days.Mean plasma IL-1 (29.3 +/- 5.8 [SD] pg/mL), TNF-alpha (138.5 +/- 22.4 pg/mL), and soluble TNF-alpha r1 (6.1 +/- 0.3 ng/mL) values were significantly higher in group 2 patients before clinical evidence of sepsis and MOF. With the onset of severe infections in group 2 patients, IL-1, TNF-alpha, and sTNF-alpha r1 values decreased, while immunosuppressive IL-10 (191.7 +/- 29.1 p g/mL) and PGE2alpha (87.7 +/- 20.4 pg/mL) values further increased and remained elevated during the time course. Analysis of lymphocyte subsets revealed a fall in total lymphocyte levels, in CD4+ T lymphocytes, and natural killer (NK) cells, but no change in CD8+ T lymphocyte subset. Despite a marked change in the T helper (CD4+) to T suppressor (CD8+) ratio (from 1:1.72 to 1:1.10), patients without MOF (group 1) had no significant difference in any of the markers tested compared with baseline values. In addition to the inverse CD4+/C D8+ T cell ratio (from 1:1.75 to 1:0.91) and increased activated T cells, each of these markers was significantly elevated and peaked before the onset of MOF in group 2 patients.ConclusionsA severely depressed cellular immune response associated with increased suppressive mediators might be closely related to the development of severe sepsis and MOF in trauma patients. Therefore, an in-depth understanding of the deficits in host defense following multiple trauma-will provide the basis for therapeutic interventions. (Crit Care Med 1999; 27:733-740)

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

ObjectiveTo demonstrate if daily Multiple Organ Dysfunction scoring could describe outcome groups in septic shock better than daily Acute Physiology and Chronic Health Evaluation (APACHE) II and Organ Failure scores.DesignA prospective cohort study.SettingA medical and surgical adult intensive care unit (ICU) at a tertiary referral center.Measurements and Main ResultsDaily data collection over a 14-month period was performed on 368 ICU patients, 39 of whom developed septic shock while in the ICU. These data were entered into a computer programmed to calculate APACHE II, Organ Failure, and Multiple Organ Dysfunction scores. The admission Multiple Organ Dysfunction scores for nonsurvivors and survivors of septic shock in the ICU was 6.5 +/- 2.7 and 6.6 +/- 2.8 (SD), respectively. These patients deteriorated due to the development of septic shock during their ICU stay resulting in a maximum Multiple Organ Dysfunction score of 12.2 +/- 3.7 in nonsurvivors and 9.4 +/- 2.7 in survivors (p < .05). The difference between the maximum and initial Multiple Organ Dysfunction scores (delta score) was also significantly greater in nonsurvivors than in survivors (5.6 +/- 4.7 vs. 2.8 +/- 3.0) (p < .05). There were no significant differences between the maximum and delta scores in the outcome groups using the APACHE II and Organ Failure scoring systems. These results were mirrored by 2.3 +/- 0.7 and 1.7 +/- 0.5 organ failures in nonsurvivors and survivors, respectively (p < .01). For all 368 patients, the initial and maximum Multiple Organ Dysfunction scores were 3.5 +/- 2.5 and 10.5 +/- 3.6, respectively.ConclusionMaximum and delta Multiple Organ Dysfunction scores mirrored organ dysfunction and could accurately describe the outcome groups, whereas daily APACHE II and Organ Failure scores could not. (Crit Care Med 1999;27:741-744)

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

ObjectiveThe left lateral decubitus position is generally accepted as the position of choice to protect against aspiration pneumonia in comatose poisoned patients. We studied the relationship between initial body position during coma and subsequent development of suspected aspiration pneumonia (SAP).DesignObservational, descriptive study.SettingToxicology intensive care unit in a university hospital.PatientsAcutely poisoned comatose patients admitted to our intensive care unit.InterventionsNone.Measurements and Main ResultsGlasgow Coma Scale score (GCS) and body position were recorded in poisoned patients on discovery. Chest radiographs were examined for infiltrates suggesting SAP within 24 hrs of hospitalization.The prone positioned patients had a lower incidence of SAP than patients in the lateral decubitus and supine positions, despite similar GCS scores.Patients in the semi-recumbent position had an incidence of SAP similar to prone patients, but with higher GCS values.ConclusionsThe prone position appears to be associated with a lower incidence of SAP than the lateral decubitus position in comatose poisoned patients. (Crit Care Med 1999; 27:745-748)

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

ObjectivesTo define the pro- and anti-inflammatory cytokine response during acute severe pancreatitis and to evaluate its predictive value on hospital mortality.DesignProspective, multicenter study.SettingNine multidisciplinary intensive care units (ICUs).PatientsFifty patients with a diagnosis of acute pancreatitis who were admitted to the ICUs during a 14-month period were prospectively enrolled.InterventionsNone.Measurements and Main ResultsPlasma concentrations of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1 beta, IL-6, IL-10, IL-1 receptor antagonist (IL-1ra) were determined at the inclusion and during the ICU stay at Days 1, 3, 8, and 15. The patient population was analyzed by age, gender, previous health status, preexisting organ dysfunction, and type of acute pancreatitis. Physiologic variables were measured at inclusion and during ICU stay to calculate the new Simplified Acute Physiology Score II, the Acute Physiology and Chronic Health Evaluation II (APACHE II) score, and the number of organ system failures. Prognostic factors were determined by univariate methods and stepwise logistic regression analysis. Fifty patients were included, among whom 34 at the time of the ICU admission. Preinclusion symptom history was <or=to48 hrs in 78% of the patients. Eleven patients (22%) died during their hospital stay. At inclusion, 46 of 50 patients had elevated IL-6 serum levels (1512 +/- 635 pg/mL; normal value < 10 pg/mL), 36% of the patients had raised TNF-alpha concentrations, and all patients had an anti-inflammatory response (IL-10, 92 +/- 15 pg/mL [normal value < 10 pg/mL]; and/or IL-1ra, 7271 +/- 2530 pg/mL [normal value < 200 mg/mL]). During the follow-up period, pro- and anti-inflammatory cytokines remained elevated in at least 75% of the population. Positive correlations were found between inclusion pro- (IL-6) and anti-inflammatory cytokine concentrations at Day 1 (IL-10, IL-1ra; p < .0001) and between cytokines levels and the Simplified Acute Physiology Score II. While hospital mortality was linked to six factors in univariate analysis (age, cirrhosis, delay between hospitalization and ICU admission, severity of illness, and IL-10 and IL-6 plasma levels) when using stepwise logistic regression, only severity scoring indexes were predictive of death.ConclusionsDuring acute severe pancreatitis, the pro- and anti-inflammatory cytokine response occurred early and persisted in the systemic circulation for several days. Although associated with the patient's severity at inclusion and outcome, cytokine plasma concentrations were unable to predict death accurately in individual patients. If confirmed, these results should be taken into consideration when selecting patients who are apt to benefit from new therapies aimed at modifying the immune inflammatory response. (Crit Care Med 1999; 27:749-755)

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0090-3493    

出版商:OVID    

年代:1999

数据来源: OVID