Biomedical subjects
A Esteban
Publications and source records attributed to A Esteban.
An evaluation of extubation failure predictors in mechanically ventilated infants and children.
OBJECTIVE: To assess the accuracy of traditional weaning indices in predicting extubation failure, and to compare their accuracy when indices are measured at the onset of a breathing trial (SBT) and at the end of the SBT before extubation. DESIGN: Prospective study. SETTING: Medical-surgical intensive care unit at a tertiary care hospital. PATIENTS: Four hundred eighteen consecutive infants and children who received mechanical ventilation for at least 48 h and were deemed ready to undergo a SBT by their primary physician. INTERVENTIONS: Respiratory frequency (RR), tidal volume (V(T)), maximal inspiratory pressure (P(imax)) and frequency-to-tidal volume ratio (f/V(T)) were obtained within the first 5 min of breathing through a T-piece. The primary physicians were unaware of those measurements and the decision to extubate a patient was made by them. RR, V(T), f/V(T) were remeasured before extubation by the respiratory therapists. Extubation failure was defined as needing re intubation within 48 h after extubation. The area under the receiver operating characteristic (ROC) curve was calculated for each index as a measure of the accuracy in predicting extubation outcome. MEASUREMENTS AND MAIN RESULTS: Three hundred twenty-three patients successfully underwent the SBT and were extubated, but 48 of them (14%) required re-intubation. The ROC curve for V(T), RR, P(imax) and f/V(T) measured within the first 5 min of breathing were 0.54, 0.56, 0.57 and 0.57, respectively. The ROC curve did not increase significantly when the above indices were remeasured before extubation. CONCLUSIONS: In a population which had passed SBT, the ability of the traditional weaning indices to discriminate between children successfully extubated and children re-intubated is very poor.
Assessment of renal function during the postoperative period following liver xenotransplantation from transgenic pig to baboon.
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Long term follow up of a hemimasticatory spasm.
OBJECTIVES: To describe the clinical and neurophysiological findings in a case of hemimasticatory spasm (HMS) followed during 14 years of evolution. MATERIAL AND METHODS: A woman suffered from very frequent paroxysmal episodes of painful involuntary occlusion of the jaw. Neurophysiological studies were performed at the 3, 12 and 14 years after the onset of symptoms. They included a needle electromyographic (EMG) evaluation of the main jaw closing and opening muscles, the jaw reflex (JR), the masseteric silent period (MSP) and the masseteric inhibitory reflex (MIR). RESULTS: Clinical symptoms remained unchanged throughout the period of observation. Conventional EMG never disclosed neurogenic signs. Voluntary closure of the jaw systematically provoked an abnormal activity with muscle cramps characteristics, restricted to the left masseter muscle. Left JR response was normal in the first evaluation and became delayed and of reduced amplitude in the second. The MSP and MIR were abolished on the left side during the spasmodic episodes whereas they were strictly normal out of them. The MIR abnormalities showed the characteristic pattern of an efferent lesional type. CONCLUSIONS: Hemimasticatory spasm probably is the consequence of an abnormal trigeminal hyperexcitability likely induced by the demyelinating lesion of its peripheral motor pathway. The main neurophysiological abnormalities may persist unmodified over a long course of the disease and allow the differential diagnosis of HMS from oromandibular dystonia and temporomandibular dysfunction (TMD).
Withdrawing and withholding life support in the intensive care unit: a Spanish prospective multi-centre observational study.
OBJECTIVE: To determine how frequently life support is withheld or withdrawn from adult critically ill patients, and how physicians and patients families agree on the decision regarding the limitation of life support. DESIGN: Prospective multi-centre cohort study. SETTING: Six adult medical-surgical Spanish intensive care units (ICUs). PATIENTS AND PARTICIPANTS: Three thousand four hundred ninety-eight consecutive patients admitted to six ICUs were enrolled. MEASUREMENTS AND RESULTS: Data collected included age, sex, SAPS II score on admission and within 24 h of the decision to limit treatment, length of ICU stay, outcome at ICU discharge, cause and mode of death, time to death after the decision to withhold or withdraw life support, consultation and agreement with patient's family regarding withholding or withdrawal, and the modalities of therapies withdrawn or withheld. Two hundred twenty-six (6.6%) of 3,498 patients had therapy withheld or withdrawn and 221 of them died in the ICU. Age, SAPS II and length of ICU stay were significantly higher in patients dying patients who had therapy withheld or withdrawn than in patients dying despite active treatment. The proposal to withhold or withdraw life support was initiated by physicians in 210 (92.9%) of 226 patients and by the family in the remaining cases. The patient's family was not involved in the decision to withhold or withdraw life support therapy in 64 (28.3%) of 226 cases. Only 21 (9%) patients had expressed their wish to decline life-prolonging therapy prior to ICU admission. CONCLUSIONS: The withholding and withdrawing of treatment was frequent in critically ill patients and was initiated primarily by physicians.
A comparison of two methods to perform a breathing trial before extubation in pediatric intensive care patients.
OBJECTIVE: To compare the percentage of infants and children successfully extubated after a trial of breathing performed with either pressure support or T-piece. DESIGN: Prospective and randomized study. SETTING: Three medical-surgical pediatric intensive care units (PICUs). PATIENTS: Two hundred fifty-seven consecutive infants and children who received mechanical ventilation for at least 48 h and were deemed ready to undergo a breathing trial by their primary physician. INTERVENTIONS: Patients were randomly assigned to undergo a trial of breathing in one of two ways: pressure support of 10 cmH2O or T-piece. Bedside measurements of respiratory function were obtained immediately before discontinuation of mechanical ventilation and within the first 5 min of breathing through a T-piece. The primary physicians were unaware of those measurements, and the decision to extubate a patient at the end of the breathing trial was made by them. MEASUREMENTS AND MAIN RESULTS: Of the 125 patients in the pressure support group, 99 (79.2%) completed the breathing trial and were extubated, but 15 of them (15.1%) required reintubation within 48 h. Of the 132 patients in the T-piece group, 102 (77.5%) completed the breathing trial and were extubated, but 13 of them (12.7%) required reintubation within 48 h. The percentage of patients who remained extubated for 48 h after the breathing trial did not differ in the pressure support and T-piece groups (67.2% versus 67.4%, p=0.97). CONCLUSIONS: In infants and children mechanically ventilated, successful extubation was achieved equally effectively after a first breathing trial performed with pressure support of 10 cmH2O or a T-piece.
Botulinum toxin in motor disorders: practical considerations with emphasis on interventional neurophysiology.
After a brief review of the pharmacological properties of the botulinum toxin (BT), its mechanism of action on the nerve endings of the neuromuscular junctions, and the general therapeutic principles and adverse side effects, we discuss the advantages of interventional neurophysiology for the treatment of focal motor disorders by means of botulinum toxin A (BTA) muscle infiltration. Electromyography (EMG) provides a valuable objective information in the diagnosis of many motor disturbances and enables the precise identification of the muscles that contribute to the abnormal movement or posture. The use of EMG guidance for BTA injection seems advisable in every muscle but it become indispensable in those difficult to access, deeply located or partially atrophied by previous toxin infiltrations. The EMG study also serves to localise the areas with the highest abnormal activity and the motor point of the muscle, where the injection of toxin exerts its maximal effect. Consequently, lower doses of BTA can be employed without decreasing the efficacy of treatment but reducing the potential risk of side effects, antibody production and the cost of treatment. Electrophysiological diagnosis and BTA treatment may be performed during the same exploration. Considerations on the particular aspects and lines of action are given referring to the main focal muscular hyperactivity motor disorders such as cervical, oromandibular and laryngeal dystonias, blepharospasm, writer's cramp, hemifacial and hemimasticatory spasms, infantile and adult forms of spasticity and some other focal disturbances such as strabismus, detrusor-sphincter dyssynergia and anismus.
Predicting success in weaning from mechanical ventilation.
We identified 65 observational studies of weaning predictors that had been reported in 70 publications. After grouping predictors with similar names but different thresholds, the following predictors met our relevance criteria: heterogeneous populations, 51; COPD patients, 21; and cardiovascular ICU patients, 45. Many variables were of no use in predicting the results of weaning. Moreover, few variables had been studied in > 50 patients or had results presented to generate estimates of predictive power. For stepwise reductions in mechanical support, the most promising predictors were a rapid shallow breathing index (RSBI) < 65 breaths/min/L (measured using the ventilator settings that were in effect at the time that the prediction was made) and a pressure time product < 275 cm H2O/L/s. The pooled likelihood ratios (LRs) were 1.1 (95% confidence interval [CI], 0.95 to 1.28) for a respiratory rate [RR] of < 38 breaths/min and 0.32 (95% CI, 0.06 to 1.71) for an RR of > 38 breaths/min, which indicate that an RR of < 38 breaths/min leaves the probability of successful weaning virtually unchanged but that a value of > 38 breaths/min leads to a small reduction in the probability of success in weaning the level of mechanical support. For trials of unassisted breathing, the most promising weaning predictors include the following: RR; RSBI; a product of RSBI and occlusion pressure < 450 cm H2O breaths/min/L; maximal inspiratory pressure (PImax) < 20 cm H2O; and a knowledge-based system for adjusting pressure support. Pooled results for the power of a positive test result for both RR and RSBI were limited (highest LR, 2.23), while the power of a negative test result was substantial (ie, LR, 0.09 to 0.23). Summary data suggest a similar predictive power for RR and RSBI. In the prediction of successful extubation, an RR of < 38 breaths/min (sensitivity, 88%; specificity, 47%), an RSBI < 100 or 105 breaths/min/L (sensitivity, 65 to 96%; specificity, 0 to 73%), PImax, and APACHE (acute physiology and chronic health evaluation) II scores that are obtained at hospital admission appear to be the most promising. After pooling, two variables appeared to have some value. An RR of > 38 breaths/min and an RSBI of > 100 breaths/min/L appear to reduce the probability of successful extubation, and PImax < 0.3, for which the pooled LR is 2.23 (95% CI, 1.15 to 4.34), appears to marginally increase the likelihood of successful extubation. Judging by areas under the receiver operator curve for all variables, none of these variables demonstrate more than modest accuracy in predicting weaning outcome. Why do most of these tests perform so poorly? The likely explanation is that clinicians have already considered the results when they choose patients for trials of weaning.
Evolution in the utilization of the mechanical ventilation in the critical care unit.
Use of mechanical ventilation has increased in recent years and constitutes a major therapeutic modality in the intensive care unit (ICU). In the recent years, changes in the ventilatory modes, in the ventilatory strategies and in the weaning from mechanical ventilation have occurred. We have compared the data obtained from the Spanish ICUs in studies that were carried out in three periods of the nineties, with the aim to test whether the aforementioned innovations have modified the clinical practice. We analyzed demographic data, primary reason for mechanical ventilation, ventilatory parameters, mode of weaning and performance of tracheostomy. It was observed a decrease in the percentage of patients receiving mechanical ventilation. There was a significant trend to ventilate older patients over the course of the decade. In the mode of ventilation, we observed a significant decrease in the use of the synchronized intermittent mandatory ventilation with a increment in the use of assist-control ventilation. We did not find differences in the ventilatory settings. Concerning to weaning, over the course of the decade occurred an increase in use of pressure support ventilation and spontaneous breathing trial, being this method the most frequently used at the end of the decade. The performance of the tracheostomy has been lesser and earlier over the time. The results obtained suggest that findings from research on mechanical ventilation are incorporated into clinical practice at a very slow pace whereas the evidence obtained from the clinical trials about weaning has had a better reception.
Weaning from mechanical ventilation.
Practice guidelines on weaning should be based on the results of several well-designed randomized studies performed over the last decade. One of those studies demonstrated that immediate extubation after successful trials of spontaneous breathing expedites weaning and reduces the duration of mechanical ventilation as compared with a more gradual discontinuation of ventilatory support. Two other studies showed that the ability to breathe spontaneously can be adequately tested by performing a trial with either T-tube or pressure support of 7 cmH2O lasting either 30 or 120 min. In patients with unsuccessful weaning trials, a gradual withdrawal for mechanical ventilation can be attempted while factors responsible for the ventilatory dependence are corrected. Two randomized studies found that, in difficult-to-wean patients, synchronized intermittent mandatory ventilation (SIMV) is the most ineffective [corrected] method of weaning.
Hemodynamic, biochemical and morphological changes induced by aminoguanidine in normal and septic sheep.
OBJECTIVE: To define the acute hemodynamic, metabolic, and morphological changes induced by aminoguanidine, a selective iNOS inhibitor, in septic sheep. DESIGN: Prospective, nonrandomized animal study. SETTING: Animal research facility in a University Hospital. INTERVENTIONS: Adult sheep, sedated and mechanically ventilated, were monitored with a pulmonary arterial catheter and an ultrasonic blood flow probe in the mesenteric artery, to measure the systemic (Q(TOT)I) and the mesenteric (Q(MES)I) blood flow indices, and an ileal tonometer. Four groups of sheep were studied: nonseptic, septic, nonseptic treated with aminoguanidine, and septic treated with aminoguanidine (100 mg kg(-1) h(-1)) (n = 6 for each group). Sepsis was induced by the intravenous administration of E. coli. Hemodynamic and biochemical parameters were measured during 300 min. Histological changes in the liver and small intestinal mucosa were analyzed at the end of the experiment. MEASUREMENTS AND MAIN RESULTS: In nonseptic animals, aminoguanidine slightly increased mean systemic arterial pressure (MAP), decreased Q(TOT)I, and increased vascular resistance index (SVRI) and pulmonary vascular resistance index. Q(MEs)I did not change and Q(MES)I/Q(ToT)I increased. Aminoguanidine also induced intestinal intramucosal hypercarbia, hyperlactatemia, acidemia, hypoglycemia, and morphological signs indicative of tissue ischemia in the small intestinal mucosa. In septic sheep, aminoguanidine increased SVRI and MAP only at 4 h after the septic challenge and thereafter, and worsened gas exchange. CONCLUSIONS: In this model, exogenous administration of aminoguanidine induces beneficial hemodynamic effects 4 h after the septic challenge. In normal animals, however, aminoguanidine was associated with hypoglycemia, acidosis, hyperlactatemia, and intestinal mucosal ischemia.
Peroxidase activity in Aloe barbadensis commercial gel: probable role in skin protection.
A basic peroxidase (EC 1.11.1.7) (pl around 9.0) has been identified in commercial gel of Aloe barbadensis. In vivo, the activity is localised in the vascular system of inner aqueous leaf parenchyma. Some relevant properties of this basic peroxidase of Aloe have been investigated in leaf extract and in commercial gel where it is notably stable. The acid optimum pH (5.0) for activity and the low KM for H2O2 (0.14 mM) suggest that, when topically applied, Aloe peroxidase may scavenge H2O2 in skin surface.
Accidental removal of endotracheal and nasogastric tubes and intravascular catheters.
OBJECTIVES: To characterize the rates of accidental removal of endotracheal tubes, nasogastric tubes, central venous catheters, and arterial catheters. To assess the efficacy of corrective measures aimed at reducing the accidental removal of these devices. DESIGN: Prospective, observational, and interventional study. SETTING: Eighteen-bed medical-surgical intensive care unit of a 650-bed tertiary care hospital. PATIENTS: Patients admitted to the intensive care unit who had any of the following devices in place for more than 24 hrs: endotracheal tube, nasogastric tube, central venous catheter, arterial catheter. MEASUREMENTS AND INTERVENTIONS: Data were collected on the date of placement of tubes and catheters, position of vascular catheters, date of removal, and reason for removal. The study involved three consecutive 6-month periods. At the end of the first and the second periods, information about rates of accidental removal was provided to the physicians and nurses. In addition, the personnel were instructed to be more vigilant and specific measures aimed at reducing the accidental removal were introduced. MAIN RESULTS: In the first period, 289 endotracheal tubes were placed and 13.1% (24.7 per 1000 days) were removed accidentally. In the second and third periods, 17.1% (25.5 per 1000 days) and 11.4% (15.1 per 1000 days) were removed accidentally, respectively. In the first period, 368 nasogastric tubes were placed and 41% (73.9 per 1000 days) were removed accidentally. In both the second and the third period, a significant reduction in the rate of accidental removal was observed (32.4% or 41.2 per 1000 days and 25.8% or 29.8 per 1000 days, respectively). A significant decrease was observed in the rates of accidental removal of central venous catheters from 7.5% (12.4 per 1000 days) in the first period to 3.6% (5.4 per 1000 days) in the second period. The rate of arterial catheters accidentally removed expressed according to the time at risk significantly decreased from 46.5 per 1000 days in the first period to 19.1 per 1000 days in the second period and 25.3 per 1000 days in the third period. CONCLUSIONS: The information provided by the rates of accidental removal expressed by patient-days is helpful to compare results obtained in populations with different times of follow-up. Education of medical personnel and limiting upper-extremity access to within 20 cm from any catheter or tube resulted in a significant reduction of patient-related removal of tubes and catheters.
Systemic hemodynamics, gastric intramucosal PCO2 changes, and outcome in critically ill burn patients.
OBJECTIVES: To define the hemodynamic and gastric intramucosal PCO2 (PiCO2) changes during the first 48 hrs after burn trauma and to analyze their relationship with outcome. DESIGN: Prospective, observational study in a cohort of consecutively admitted critically ill burn patients. SETTING: Intensive care burn unit in a university hospital. PATIENTS: Forty-two patients with burns covering >20% of body surface area or inhalation injury. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Patients were monitored with an oximetric pulmonary arterial catheter and a gastric tonometer to measure PiCO2. The difference between arterial and gastric mucosal PCO2 (P[i-a]CO2) was considered indicative of gastric mucosal hypoxia. Hemodynamic and PiCO2 measurements were performed during the first 48 hrs after admission. Patients suffered burns covering 36.1% +/- 14.3% (mean +/- SD) and 45.3% +/- 21.9% of body surface area (survivors and nonsurvivors, respectively). All patients were successfully resuscitated by conventional standards. Nonsurvivors (n = 16) died a median of 17 days after admission. In univariate analysis, the presence of shock during the resuscitation phase, age, mixed venous pH, P[i-a]CO2, right atrial pressure, pulmonary arterial pressure, pulmonary arterial occlusion pressure, cardiac index, systemic and pulmonary vascular resistance, left ventricular stroke work index, mixed venous oxygen saturation, and systemic oxygen delivery, consumption, and extraction ratio, measured over the first 12 hrs after admission, were significantly (p < .05) different between survivors and nonsurvivors. These differences disappeared after 12 hrs after admission. Multivariate analysis identified age, percentage body surface area burned, and oxygen delivery index (6 hrs after admission) as factors independently associated with a poor outcome. P[i-a]CO2 (12 hrs after admission) was significantly greater in patients with than in those without inhalation injury (17 +/- 13 torr [2.26 +/- 1.73 kPa] vs. 6 +/- 10 torr [0.79 +/- 1.33 kPa]; p = .005). Patients with a P[i-a]CO2 difference (6 hrs after admission) > or =10 torr (1.33 kPa) had a mortality rate of 56% vs. 25% of those patients with <10 torr (p = .044). CONCLUSIONS: Our data indicate that there are hemodynamic and biochemical changes that occur early after burn trauma that are associated with prognosis after an apparently successful resuscitation. Particularly, a hemodynamic profile characterized by systemic acidosis, low systemic blood flow, and systemic and pulmonary vasoconstriction early after trauma is associated with a poor outcome. Additionally, intestinal mucosal acidosis occurs after burn trauma, is influenced by inhalation injury, and is a variable related to outcome.
How is mechanical ventilation employed in the intensive care unit? An international utilization review.
A 1-d point-prevalence study was performed with the aim of describing the characteristics of conventional mechanical ventilation in intensive care units ICUs from North America, South America, Spain, and Portugal. The study involved 412 medical-surgical ICUs and 1,638 patients receiving mechanical ventilation at the moment of the study. The main outcome measures were characterization of the indications for initiation of mechanical ventilation, the artificial airways used to deliver mechanical ventilation, the ventilator modes and settings, and the methods of weaning. The median age of the study patients was 61 yr, and the median duration of mechanical ventilation at the time of the study was 7 d. Common indications for the initiation of mechanical ventilation included acute respiratory failure (66%), acute exacerbation of chronic obstructive pulmonary disease (13%), coma (10%), and neuromuscular disorders (10%). Mechanical ventilation was delivered via an endotracheal tube in 75% of patients, a tracheostomy in 24%, and a facial mask in 1%. Ventilator modes consisted of assist/control ventilation in 47% of patients and 46% were ventilated with synchronized intermittent mandatory ventilation, pressure support, or the combination of both. The median tidal volume setting was 9 ml/kg in patients receiving assist/control and the median setting of pressure support was 18 cm H(2)O. Positive end-expiratory pressure was not employed in 31% of patients. Method of weaning varied considerably from country to country, and even within a country several methods were in use. We conclude that the primary indications for mechanical ventilation and the ventilator settings were remarkably similar across countries, but the selection of modes of mechanical ventilation and methods of weaning varied considerably from country to country.
Thienothiadiazine 2,2-dioxide acyclonucleosides: synthesis and antiviral activity.
The synthesis of acyclonucleosides derived from thieno[3,2-c] and thieno[2,3-c][1,2,6]thiadiazine 2,2-dioxides was achieved following the silylation method. Lipase-mediated methodology was employed for deprotection of the acyclic moieties. The antiviral effects were determined against a broad spectrum of viruses, including cytomegalovirus (CMV) and varicella zoster virus (VZV). Only minor antiviral activity against VZV was observed for those acyclonucleosides carrying a benzyl group.
Effect of different doses of S-adenosyl-L-methionine on paracetamol hepatotoxicity in a mouse model.
This study investigated the hepatoprotective effects of N-acetylcysteine and different doses of S-adenosyl-L-methionine after a single intraperitoneal overdose of paracetamol in mice. Plasma concentrations of paracetamol metabolites were also determined. Female mice (Souris OFl strain) 16 weeks old and weighing 30 g were fasted for 18 h prior to intraperitoneal (i.p.) administration of 375 mg/kg (2.5 mmol/kg) of paracetamol. Experimental subgroups included mice administered paracetamol only (control group), those given of N-acetylcysteine 1 g/kg (6.13 mmol/kg) i.p. immediately after paracetamol overdose (T0) and 6 h after dosing (T6) and those administered S-adenosyl-L-methionine at doses of 20 mg/kg (0.05 mmol/kg) and 1 g/kg (2.5 mmol/kg) i.p. at T0 and T6. Twenty-four hours after paracetamol overdose, mortality and liver necrosis were significantly lower (p < 0.01) in mice treated with 2.5 mmol/kg of S-adenosyl-L-methionine and N-acetylcysteine at T0 as compared with the remaining subgroups. Plasma ALT concentrations were significantly lower (p < 0.01) in mice treated with 2.5 mmol/kg of S-adenosyl-L-methionine than in those given N-acetylcysteine. Plasma concentrations of paracetamol metabolites showed an increase in the glucuronide conjugate and a decrease in the mercapturic acid conjugate in N-acetylcysteine-treated mice and an overall decrease in the conjugation pathway without changes in the oxidative pathway in S-adenosyl-L-methionine-treated animals. We conclude that S-adenosyl-L-methionine at doses of 1 g/kg (2.5 mmol/kg) i.p. was equally effective as 1 g/kg (6.13 mmol/kg) N-acetylcysteine for preventing hepatotoxicity after paracetamol overdose in mice. S-adenosyl-L-methionine may be a therapeutic alternative to N-acetylcysteine as an antidote for poisoning with paracetamol.
Prospective randomized trial comparing pressure-controlled ventilation and volume-controlled ventilation in ARDS. For the Spanish Lung Failure Collaborative Group.
STUDY OBJECTIVES: To compare in-hospital mortality of patients with ARDS ventilated with either pressure-controlled ventilation (PCV) or volume-controlled ventilation (VCV) with a square-wave inspiratory flow. DESIGN: : Multicenter and randomized trial. SETTING: Twelve medical-surgical ICUs located in tertiary-care hospitals. PATIENTS: Seventy-nine patients having ARDS, as defined by the American-European Consensus Conference. INTERVENTIONS: Patients were randomly assigned to be ventilated with either PCV (n = 37) or VCV (n = 42). In both instances, inspiratory plateau pressure was limited to < or = 35 cm H(2)O. MEASUREMENTS AND RESULTS: There were no significant differences among the studied groups at the moment of randomization, although there was a trend toward greater renal failure in patients assigned to VCV. Ventilatory settings and blood gases did not significantly differ over time between the two groups. Patients in the VCV group had both a significantly higher in-hospital mortality rate than those in the PCV group (78% vs 51%, respectively) and a higher number of extrapulmonary organ failures (median, 4 vs 2, respectively). The development of renal failure during the study period was also significantly more frequent among VCV patients (64% vs 32%, respectively). Multivariate analysis showed that factors independently associated with an increased mortality rate were the presence of two or more extrapulmonary organ failures (odds ratio [OR], 4.61; 95% confidence interval [CI], 1.38 to 15.40) and acute renal failure (OR, 3.96; 95% CI, 1.10 to 14.28) but not the ventilatory mode used. CONCLUSIONS: The increased number of extrapulmonary organ failures developed in patients of the VCV group was strongly associated with a higher mortality rate. The development of organ failures was probably not related to the ventilatory mode.