Procedure volume is one determinant of centre effect in mechanically ventilated patients.

Survival rates vary significantly between intensive care units, most notably in patients requiring mechanical ventilation (MV). The present study sought to estimate the effect of hospital MV volume on hospital mortality. We included 179,197 consecutive patients who received mechanical ventilation in 294 hospitals. Multivariate logistic regression models with random intercepts were used to estimate the effect of annual MV volume in each hospital, adjusting for differences in severity of illness and case mix. Median annual MV volume was 162 patients (interquartile range 99-282). Hospital mortality in MV patients was 31.4% overall, 40.8% in the lowest annual volume quartile and 28.2% in the highest quartile. After adjustment for severity of illness, age, diagnosis and organ failure, higher MV volume was associated with significantly lower hospital mortality among MV patients (OR 0.9985 per 10 additional patients, 95% CI 0.9978-0.9992; p = 0.0001). A significant centre effect on hospital mortality persisted after adjustment for volume effect (p < 0.0001). Our study demonstrated higher hospital MV volume to be independently associated with increased survival among MV patients. Significant differences in outcomes persisted between centres after adjustment for hospital MV volume, supporting a role for other significant determinants of the centre effect.

Hypovolaemic shock with oedema due to increased capillary permeability.

A case of severe hypovolaemic shock related to idiopathic oedema was observed in a 37 year old woman. Large plasma volume expansion (nearly 12 1 over 9 hours) did not change the clinical status. Haemodynamic studies showed low cardiac index (1.1 1/min/m2), decreased left ventricular stroke work index (6.7 gm/m2), and high systemic arterial resistance (52 mmHg/1/min/m2). Dopamine infusion improved the haemodynamic condition which returned to normal 30 hours after the beginning of shock. After recovery, capillary permeability measured by a modification of Landis' method was markedly increased. A study of albumin metabolism showed a normal intravascular pool and a rapid exchange compartment with a twofold increase in slow exchange compartment. Hormonal levels and complement fractions were within normal limits. Serum protein immuno-electrophoresis showed an abnormal IgG. These results clearly demonstrate that hypovolaemia is related to increased capillary permeability and leakage of albumin out of the vascular space. When large infusions fail, inotropic agents, especially Dopamine, should be used in such cases.

Evaluation of the logistic organ dysfunction system for the assessment of organ dysfunction and mortality in critically ill patients.

OBJECTIVES: To evaluate the performance of the logistic organ dysfunction (LOD) system for the assessment of morbidity and mortality in multiple organ dysfunction/failure (MOD/F) in an independent database and to evaluate the use of sequential LOD measurements for the prediction of outcome. DESIGN AND SETTING: Prospective, multicentric cohort study in 13 adult medical, surgical, and mixed intensive care units (ICUs) in Austria. PATIENTS: A total of 2,893 consecutive admissions to the ICUs. MEASUREMENTS AND MAIN RESULTS: Patient vital status at ICU and hospital discharge was recorded. Univariate analysis showed that the LOD was able to distinguish between survivors and nonsurvivors (2 vs. 6 median score). Within organ systems, higher levels of the severity of organ dysfunction were consistently associated with higher mortality. For the prediction of hospital mortality, the original prognostic LOD model did not perform well in our patients, as indicated by the goodness-of-fit C statistic. Using multiple logistic regression we developed a prognostic model with a satisfactory fit in our patients. The integration of further measurements during the ICU stay increased discrimination but not calibration. CONCLUSIONS: The LOD system is well correlated well with the numbers and levels of organ dysfunctions and discriminates well between survivors and nonsurvivors. It can thus be used to quantify the baseline severity of organ dysfunction. Moreover, after customization of the predictive equation the LOD predicted hospital mortality in our patients with high precision. It thus provides a combined measure of morbidity and mortality for critically ill patients with MOD/F.

Ratios of observed to expected mortality are affected by differences in case mix and quality of care.

OBJECTIVES: To validate SAPS II-AM, a recently customized version of the Simplified Acute Physiology Score II (SAPS II) in a larger cohort of Austrian intensive care patients and to evaluate the effect of the customization process on the ratio of observed to expected mortality. DESIGN: Prospective, multicentric cohort study. PATIENTS AND SETTING: A total of 2,901 patients consecutively admitted to 13 adult medical, surgical, and mixed intensive care units (ICUs) in Austria. MEASUREMENTS AND RESULTS: After the database was divided randomly into a development sample (n = 1,450) and a validation sample (n = 1,451), logistic regression was used to develop a new model (SAPS II-AM2). The original SAPS II, the SAPS IIAM, and the newly developed SAPS II-AM2 were then compared by means of calibration, discrimination and O/E ratios. Differences in O/E ratios before and after customization (deltaO/E) were calculated. The Hosmer-Lemeshow goodness-of-fit H and C statistics revealed poor calibration of the original SAPS II on the database. The new model, SAPS II-AM2, performed better than the SAPS II-AM and excellent in the validation data set. However, mean O/E ratios varied widely among diagnostic categories (range 0.55-1.05 for the SAPS II). Moreover, the deltaO/E of the 13 ICUs ranged from -3.6 % to +25 %. CONCLUSIONS: Today's severity scoring systems, such as the SAPS II, are limited by not measuring (and adjusting for) a profound part of what constitutes case mix. Changes in the distribution of patient characteristics (known and unknown) therefore affect prognostic accuracy. First-level customization was not able to solve all these problems. Using O/E ratios for quality of care comparisons one must therefore be critical when using these data and should search for possible confounding factors. In the case of unsatisfactory calibration, customized severity of illness models may be useful as an adjunct for quality control.

Hyperkinetic shock in viral and pneumococcal pneumonias.

Ten patients, suffering from severe viral or bacterial pneumonia had circulatory shock, characterised haemodynamically by normal or high cardiac output (CI = 4.1 +/- 1.2 1/min/m2) and low systemic resistance (SVR = 14 +/- 3.7 mm Hg/1/min/m2). Existence of such a hyperkinetic state greatly complicates the management of patients. Plasma volume expansion, performed in five cases of initial hypovolaemia, and Dopamine infusion (five patients) increased markedly the intra-pulmonary shunting. High level PEEP ventilation was not tolerated, despite the improvement of blood gases it produced. Extra-corporeal membrane lung oxygenation (three cases), whilst giving an initial decrease of shunting and restoring SVR, produced no long term surviors. All ten patients died from intractable shock and severe hypoxaemia. Spontaneous ventilation with positive expiratory pressure (CPAP) is believed to be an attractive alternative, due to its absence of deleterious haemodynamic effects.

Influence of patients' age on survival, level of therapy and length of stay in intensive care units.

The influence of patients' age on survival, level of therapy and length of stay was analyzed from data collected in 792 consecutive admissions to eight intensive care units. Mortality rate increased progressively with age; over 65 years of age, it was more than double that of patients under 45 years (36.8% versus 14.8%). However, mortality rate in patients over 75 years was equal to that observed in the 55 to 59 years group. There was a significant relationship between age and acute physiology score (APS) and the influence of age upon outcome decreased when APS increased. The number of TISS (therapeutic intervention scoring system) points delivered to patients increased slightly but significantly with age (r = 0.14). Standard care was responsible for the main part of this increase. Both in survivors and in non-survivors the length of stay was not different comparing the stay of the oldest patient with that of the younger age groups. We conclude that, in ICU patients, age is an important factor of prognosis but not as important as the severity of illness, and that there is no major difference in outcome of patients over 65 years of age compared to the entire study group of ICU patients.

Computed tomography and post-laparotomy intra-abdominal abscesses.

Thirty-one patients were prospectively studied and had abdominal computed tomography for post laparotomy sepsis. Computed tomography is of particular interest in seriously ill post-operative patients, 15 of our patients were on ventilators, and it enabled diagnosis and localization of abscesses in 15 patients. Drainage could therefore be achieved via a limited surgical approach, and extensive laparotomy was avoided. Of 16 patients without abscess, the abdominal computed tomogram was negative in 14 cases and there were two false positives. The overall accuracy was 0.94 with a sensitivity of 1 and a specificity of 0.88. The ability to screen the whole abdomen and exactly localize the lesion are the advantages of this non-invasive method.

Predictors of short-term mortality in critically ill patients with solid malignancies.

UNLABELLED: Admission of cancer patients with serious medical complications to the ICU remains controversial primarily because of the high short-term mortality rates in these patients. However, the cancer patient population is heterogeneous regarding age, underlying conditions, and curability of their disease, suggesting that large variations may occur in the effectiveness of intensive care within this subgroup of critically ill patients. OBJECTIVES: To identify factors predicting 30-day mortality in patients with solid tumors admitted to a medical ICU. PATIENTS AND METHODS: We conducted a retrospective study in 120 consecutive cancer patients (excluding patients with hematological malignancies) admitted to the medical ICU of a 650-bed university hospital between January 1990 and July 1997. Medical history, physical and laboratory test findings at admission, and therapeutic interventions within the first 24 h in the ICU were recorded. The study endpoint was vital status 30 days after ICU admission. Stepwise logistic regression was used to identify independent prognostic factors. RESULTS: The observed 30-day mortality rate was 58.7 % (n = 68), with most deaths (92 %) occurring in the ICU. Univariate predictors of 30-day mortality were either protective [prior surgery for the cancer (p = 0.01) and complete remission (p = 0.01)] or associated with higher mortality [Knaus scale C or D (p = 0.02), shock (p = 0.04), need for vasopressors (p = 0.0006) or for mechanical ventilation (p = 0.0001), SAPS II score greater than 36 (p = 0.0001), LOD score greater than 6 (p = 0.0001), and ODIN score > 2 (p = 0.0001)]. Three variables were independent predictors: previous surgery for the cancer (OR 0.20, 95 % CI 0.07-0.58), LOD score > 6 (OR 1.26, 95 % CI 1.09-1.44), and need for mechanical ventilation (OR 3.55, 95 % CI; 1.26-6.7). Variables previously thought to be indicative of a poor prognosis (i. e., advanced age, metastatic or progressive disease, neutropenia or bone marrow transplantation) were not predictive of outcome. CONCLUSION: When transfer to an ICU is considered an option by patients and physicians, 30-day mortality is better estimated by an evaluation of acute organ dysfunction than by the characteristics of the underlying malignancy.

Estimation of direct cost and resource allocation in intensive care: correlation with Omega system.

OBJECTIVE: An instrument able to estimate the direct costs of stays in Intensive Care Units (ICUs) simply would be very useful for resource allocation inside a hospital, through a global budget system. The aim of this study was to propose such a tool. DESIGN: Since 1991, a region-wide common data base has collected standard data of intensive care such as the Omega Score, Simplified Acute Physiologic Score, length of stay, length of ventilation, main diagnosis and procedures. The Omega Score, developed in France in 1986 and proved to be related to the workload, was recorded on each patient of the study. SETTING: Eighteen ICUs of Assistance Publique-Hôpitaux de Paris (AP-HP) and suburbs. PATIENTS: 1) Hundred twenty-one randomly selected ICU patients; 2) 12,000 consecutive ICU stays collected in the common data base in 1993. MEASUREMENTS: 1) On the sample of 121 patients, medical expenditure and nursing time associated with interventions were measured through a prospective study. The correlation between Omega points and direct costs was calculated, and regression equations were applied to the 12,000 stays of the data base, leading to estimated costs. 2) From the analytic accounting of AP-HP, the mean direct cost per stay and per unit was calculated, and compared with the mean associated Omega score from the data base. In both methods a comparison of actual and estimated costs was made. RESULTS: The Omega Score is strongly correlated to total direct costs, medical direct costs and nursing requirements. This correlation is observed both in the random sample of 121 stays and on the data base' stays. The discrepancy of estimated costs through Omega Score and actual costs may result from drugs, blood product underestimation and therapeutic procedures not involved in the Omega Score. CONCLUSIONS: The Omega system appears to be a simple and relevant indicator with which to estimate the direct costs of each stay, and then to organise nursing requirements and resource allocation.

Changing use of intensive care for hematological patients: the example of multiple myeloma.

OBJECTIVE: Intensivists generally view patients with hematological malignancies as poor candidates for intensive care. Nevertheless, hematologists have recently developed more aggressive treatment protocols capable of achieving prolonged complete remissions in many of these patients. This change mandates a reappraisal of indications for ICU admission in each type of hematological disease. Improved knowledge of the prognosis is of assistance in making treatment decisions. PATIENTS AND METHODS: The records of 75 myeloma patients consecutively admitted to our ICU between 1992 and 1998 were reviewed retrospectively and predictors of 30-day mortality were identified using stepwise logistic regression. RESULTS: The median age was 56 years (37-84). Chronic health status (Knaus scale) was C or D in 39 cases. Fifty-five patients (73%) had stage III disease and 17 had a complete or partial remission. Autologous bone marrow transplantation had been performed in 28 patients (37%). ICU admission occurred between 1992 and 1995 in 41 patients (54.7%), and between 1996 and 1998 in 34 patients (45.3%). The median SAPS II and LOD scores were 60 (23-107) and 7 (0-21), respectively. Reasons for ICU admission were acute respiratory failure in 39 patients (52%) and shock in 31 (41%). Forty-six patients (61%) required mechanical ventilation. Fifty patients (66%) received vasopressors and 24 dialysis. Thirty-day mortality was 57%. Only five parameters were independently associated with 30-day mortality in the multivariate model: female gender (OR = 5.12), mechanical ventilation (OR = 16.7) and use of vasopressor agents (OR = 5.67) were associated with a higher mortality rate, whereas disease remission (OR = 0.16) and ICU admission between 1996 and 1998 (OR = 0.09) were associated with a lower one. CONCLUSION: The prognosis for myeloma patients in the ICU is improving over time. This may reflect either recent therapeutic changes in hematological departments and ICUs or changes in patient selection for ICU admission. Hematologists and intensivists should work closely together to select hematological patients likely to benefit from ICU admission.

Hemodynamic effects of dopamine in septic shock with and without acute renal failure.

Hemodynamic response to dopamine hydrochloride in septic shock with myocardial dysfunction was studied in ten patients with normal renal function (group 1) and in ten patients with acute renal failure (group 2). The control hemodynamic data were similar in the two groups. Dopamine in groups 1 and 2 induced significant (P less than .01) and similar increases in cardiac index and mean aortic pressure. Group 1 had a smaller increase in heart rate (+ 16%), than group 2 (+ 24%), but this difference was not significant. Stroke volume index had a significant increase in group 1 (+ 18%), whereas it did not increase significantly in group 2 (+ 4%); this difference of changes in stroke volume index between the two groups was significant (P less than .01). This phenomenon suggests an increased chronotropic effect and/or a reduced inotropic effect of dopamine in patients with septic shock and acute renal failure.

Prognosis for recovery from multiple organ system failure: the accuracy of objective estimates of chances for survival. The French Multicentric Group of ICU Research.

This study evaluated the accuracy and reliability of predictions for recovery from multiple organ system failure (OSF). A previous analysis had provided estimates of the probabilities of recovery from various combinations of OSF for 2,843 intensive care unit (ICU) patients treated in 13 U.S. hospitals. These estimates were applied prospectively to 2,405 ICU admissions in 27 French hospitals. Despite variations in the incidences of underlying disease and the distributions of OSF between the two countries, clinical outcomes were similar for the 5,248 total patients. In both countries, two OSFs persisting for more than one day resulted in a hospital death rate of 60%. Hospital mortality rates for patients with three or more OSFs persisting after one day consistently exceeded 90%. Isolated neurologic failure had the poorest overall prognosis, but various other combinations of OSFs did not result in significantly different outcomes. The stability of the prognostic estimates in the two countries suggests that, despite pathogenetic variations, persistent multiple OSF results in consistent clinical outcomes. These mortality projections provide firm reference data for assessing efficacy of new treatments within institutions with similar standards of care. The narrow confidence intervals associated with these estimates also provide objectively defined opportunities to review future treatment plans for individual patients.

Do objective estimates of chances for survival influence decisions to withhold or withdraw treatment? The French Multicentric Group of ICU Research.

The authors studied the impact on clinical decision making of providing feedback of objective prognostic information describing the probability of survival for ICU patients with multiple organ system failure (OSF). The prognostic estimates, derived from a control period (1), were to be provided on a daily basis to physicians providing treatment in 25 French ICUs during a subsequent experimental period (2). The types of, frequencies of, and reasons for decisions to limit or stop treatment in the two periods were compared. In the experimental period 2, 17 ICUs participated in the feedback study. Within these 17 units, there was a small but significant (p less than 0.05) increase in decisions to stop active treatment and provide comfort care that was limited to patients with three or more OSFs. There was no change in decision making in the eight units that did not participate in the feedback study. Although these results suggest a direct causal relationship between the provision of objective prognostic data and changes in physician decision making, the small increase in comfort care decisions (n = 14) between period 1 and period 2 and the fact that only 17 of the 25 original units participated in the feedback study make it difficult to eliminate other influences. There was no indication in this study, however, that explicit provision of prognostic data led to a sense of therapeutic futility.

Initial international use of APACHE. An acute severity of disease measure.

We need objective and reliable ways of measuring the severity of disease of hospitalized patients. This paper demonstrates the international predictive accuracy of a severity of disease measure on 1504 consecutive, unscheduled intensive care admissions to 14 hospitals in the United States, France, Spain, and Finland. Using laboratory data gathered within 24 hours of ICU admission, the Acute Physiology Score of APACHE (Acute Physiology and Chronic Health Evaluation) was a strong and stable predictor of hospital survival and concurrent therapeutic effort. In ordinary least squares and logistic multiple regression analysis, the impact of the Acute Physiology Score (APS) was highly significant (p less than 0.001) and of virtually identical magnitude in the United States and European hospitals. The use of this severity of disease measure should help researchers gain insights concerning the efficacy of medical services and the characteristics of physician decision making by permitting more precise prognostic stratification of severely ill patients.

Routine exploratory thoracentesis in ICU patients with pleural effusions: results of a French questionnaire study.

PURPOSE: The purpose of this study was to report the opinions of intensivists regarding pleural effusions in patients in the intensive care unit (ICU). MATERIALS AND METHODS: Questionnaires were sent to 1,032 intensivists, who were members of the French Society of Critical Care. RESULTS: Four hundred thirty-one questionnaires (41.7%) were returned. Overall, the respondents' estimated the incidence of pleural effusion in ICU patients to be 22.19 +/- 17%, whereas 37 +/- 27% considered that exploratory thoracentesis was likely to determine the cause of the effusion, and 17.36 +/- 16% considered that its results were likely to result in a change in their therapeutic attitude. Sixty-five (15%) physicians, chiefly pulmonologists, performed exploratory thoracentesis routinely (Group 1). Compared with those who did not perform routine thoracentesis (Group 2), they ascribed a higher proportion of pleural effusions to infection (31.3% vs. 13.5%) and were more likely to consider that exploratory thoracentesis had a diagnostic and therapeutic contribution (51.2% vs. 34% and 23% vs. 16%, respectively). In addition to the respiratory medicine subspecialty, the practice of routine exploratory thoracentesis was significantly related to seniority, to the frequency of the suspicion of an infectious cause in the physician's practice, and to his or her appreciation of the risks associated with exploratory thoracentesis. Physicians from Group 1 were also more likely to describe exploratory thoracentesis as a noninvasive procedure. CONCLUSIONS: The beliefs and attitudes of intensivists regarding pleural effusions and exploratory thoracentesis are divergent. This may be due to the lack of precise guidelines on the topic and prompt the design of further studies to establish precisely the epidemiology and causes of pleural effusions in ICU patients.

Absence of enhancement of spontaneous echocardiographic contrast by thrombocytosis in a patient with left ventricular aneurysm, primary thrombocythemia, and von Recklinghausen neurofibromatosis: a case report.

A thirty-eight-year-old man with primary thrombocythemia, von Recklinghausen neurofibromatosis, and myocardial-infarction-related left ventricular aneurysm with spontaneous echocardiographic contrast was followed up, suggesting that: 1. Neurofibromatosis may promote silent myocardial infarction or ischemia. Whether involvement of cardiac sensory nerves is a possible underlying mechanism remains nevertheless uncertain. 2. Platelets, whose role in the genesis of spontaneous echocardiographic contrast has been advocated, are probably not involved in this phenomenon, even in large numbers.

Life expectancy in hospitalized patients with AIDS: prognostic factors on admission.

In the course of the inevitable hospitalizations of AIDS patients, many difficult questions concerning curative and palliative approaches to care have to be answered. In order to guide these strategies, we conducted a prospective study to identify those variables which can be easily quantified on admission which might be predictive of patient outcomes. Between 1 June 1990 and 25 April 1991, 140 consecutive hospitalizations of 83 AIDS patients were recorded. Demographic, clinical, and biological data were collected within 48 hours of admission. Probable (p <0.10) or definite (p <0.05) factors contributing to a higher mortality included type of opportunistic infections, serum albumin level, total lymphocyte count, weight, CD4 cell count, and neurological manifestations. In the multivariate proportional hazards model, two factors were significantly and independently predictive of lower survival: body weight less than 90% of ideal body weight and neurologic manifestations. The probability of survival was significantly affected by the number of predictive factors present on admission, and patients were significantly more likely to die when these latter two factors were present concomitantly. These factors might be useful to define the optimal mode of care for hospitalized AIDS patients, considering both patients' wishes and an objective assessment of the prognosis.

[Pheochromocytoma mimicking septic shock]. / Phéochromocytome simulant un choc septique.

A tumour arising from chromaffin cells, the pheochromocytoma may be associated or present with hypotension and result in a lethal shock. The authors report a rare case of pheochromocytoma simulating septic shock. They review the mechanisms by which hypersecretion of catecholamines may cause shock. The detection of pheochromocytoma in its atypical presentation is essential for early diagnosis and the reduction of mortality related to this condition.

[Organization and quality control of a clinical database on intensive care medicine in central and suburban Paris]. / Mise en oeuvre et évaluation d'une base de données commune aux services de réanimation d'Ile-de-France.

BACKGROUND: Epidemiology and medical care appraisal of intensive care medicine relies on the homogeneity of information systems. This work is about a collaborative database related to intensive care units in Paris and its suburb. METHODS: A college of intensivists defined a standard dataset about stays, outcomes, severity of illness, diagnoses and work load, which are collected and analysed by a data management center. A quality control of the database was performed on a random sample of 199 stays. RESULTS: In 1996, 25 intensive care units participated in the database which encompassed more than 35,000 stays. The control of data quality showed a good reliability of data about stays, severity and workload but reproducibility of diagnosis coding has to be improved by means of more accurate coding guidelines. CONCLUSION: This database of case-mix and outcome information allows comparison and medical care appraisal of intensive care units.

[Prognostic factors in resuscitation]. / Facteurs pronostiques en réanimation.

The outcome from intensive care is known to be influenced by such factors as age, previous health status, severity of the disease and diagnosis. In order to assess the influence of each individual factor, 3,687 patients from 38 French intensive care units were studied. For each patient were recorded: age, simplified acute physiological score (SAPS), previous health status, diagnosis, type of intensive care unit (medicine, scheduled or elective surgery) and immediate outcome. Each of these factors was found to influence the immediate survival rate. A multivariate analysis ranked the factors in the following order: SAPS, age, type of intensive care unit and previous health status. Diagnosis played a role in the prognosis since with a 10-15 points SAPS mortality was nil for drug overdose, 12 per cent for chronic obstructive pulmonary disease and 38 per cent for cardiogenic shock. However, a single diagnosis was made in only 37 per cent of the patients, as against 3 diagnoses in 17 per cent and 4 diagnoses or more in 7 per cent. When the type of intensive care unit was considered, the mean death rate was 20 per cent in medicine, 27 per cent in scheduled surgery and 5 per cent in elective surgery (P less than 0.001). Since this study showed a definite influence of each of the four factors on immediate survival, intensive care patients can be described and classified according to this system. However, it must be stressed that individual prognoses are extremely vague.