J. R. Le Gall

Predicting outcome in ICU patients

ConclusionsConsiderable time and energy has been invested in the conception, modelling and evaluation of sophisticated severity scoring systems for ICU patients. These systems are created to enhance the precise estimation of hospital mortality for large ICU patient populations. Their current low sensitivity precludes their use for predicting out-come for individual ICU patients. However, severity scores can already be valuable for predicting mortality in groups of general ICU patients, and are very useful in the clinical trial setting.Outcome of ICU therapy, however, should incorporate more than mortality. Morbidity, disability and quality of life should also be taken into account; these factors were not taken into consideration in the design of the currently available severity scoring systems.At present, the severity scores have a very limited or no role in clinical decision-making for an individual patient, because they are based on a number of physiological and disease-oriented variables collected during the first 24 h after ICU admission. Future developments and subsequent validation of the dynamic process of clinical, physiological and organ-specific variables could improve the sensitivity and the value of severity scoring. Further collaborative developmental work in this field should be encouraged and supported across Europe and North America.

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

Abstract 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.

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.

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 patients 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.

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-Hopitaux 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.

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

Abstract. 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 2893 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 Ĉ 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.

Description of various types of intensive and intermediate care units in France

The types of intensive care are multiple. The aim of this multicentric study was to describe activity of different ICUs using the same methods. 38 ICU were chosen by cooption, not randomization. Collected data concerned input age, previous health status (HS), Simplified Acute Physiology Score or SAPS, Intensive Care Group (ICG), processes (TISS points), percentage of ventilated patients and pulmonary arterial lines and outcome (ICU death rate). The 3 ICG were: M=medical: all the none surgical patients; S=surgical patients operated in emergency setting during the week preceding or following ICU admission; E=surgical patients whose admission to ICU was scheduled at least 24 h before because of elective surgery. 3687 patients were studied, classified as follows: M=2175; S=885; E=627. The first part of the results concerned the differences between the three ICG: inputs, processes and outcome were very diferent in the three groups M, S, E, particularly in the E (elective) group, where therapeutic level was higher for low SAPS and mortality lower for high SAPS. The second part of the results concerns the differences between the ICUs. Intermediate units had older, less severe, and mainly medical patients. Surgical patients had better previous health status, were younger and scheduled for 40%. TISS points were higher, mainly by a higher rate of ventilated patients and patients with pulmonary artery lines on the first day. Specialized units characteristics depended mainly on the ICG. For instance, patients of coronary units compared to post cardiac surgery patients were older, in better previous HS, had a low therapeutic level (13.5 TISS points versus 41.5) and a higher ICU death rate (10% versus 4%). We conclude that description of different units can be made by a limited number of criteria.

Haemodynamic study of prolonged deep accidental hypothermia

SummaryRight heart catheterisation was undertaken in six patients with accidental deep hypothermia. Studies were carried out before and after rapid blood volume expansion, with and without Isoproterenol infusion, and were repeated at normal body temperatures.The initial haemodynamic pattern indicated a marked hypovolemia with a simultaneous decrease of both cardiac output and ventricular filling pressures, and a decreased measured total blood volume. Rapid correction of the hypovolemia revealed cardiac insufficiency, in part due to the persisting bradycardia. Left ventricular function was depressed in patients with prolonged cold exposure and normal in patients with short exposure. These abnormalities disappeared after Isoproterenol infusion during hypothermia, and spontaneously after return to normothennia.No imbalance existed between the decreased cardiac output and oxygen uptake in hypothermia, arterio-venous oxygen difference being within normal limits.

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.

Hyperkinetic shock in viral and pneumococcal pneumonias

SummaryTen 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 survivors. All the 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.