Continuous peritoneal dialysis compared with daily hemodialysis in patients with acute kidney injury

Background: In some parts of the world, peritoneal dialysis is widely used for renal replacement therapy (RRT) in acute kidney injury (AKI), despite concerns about its inadequacy. It has been replaced in recent years by hemodialysis and, most recently, by continuous venovenous therapies. We performed a prospective study to determine the effect of continuous peritoneal dialysis (CPD), as compared with daily hemodialysis (dHD), on survival among patients with AKI.Methods: A total of 120 patients with acute tubular necrosis (ATN) were assigned to receive CPD or dHD in a tertiary-care university hospital. The primary endpoint was hospital survival rate; renal function recovery and metabolic, acid-base, and fluid controls were secondary endpoints.Results: of the 120 patients, 60 were treated with CPD (G1) and 60 with dHD (G2). The two groups were similar at the start of RRT with respect to age (64.2 +/- 19.8 years vs 62.5 +/- 21.2 years), sex (men: 72% vs 66%), sepsis (42% vs 47%), shock (61% vs 63%), severity of AKI [Acute Tubular Necrosis Individual Severity Score (ATNISS): 0.68 +/- 0.2 vs 0.66 +/- 0.22; Acute Physiology and Chronic Health Evaluation (APACHE) II: 26.9 +/- 8.9 vs 24.1 +/- 8.2], pre-dialysis blood urea nitrogen [BUN (116.4 +/- 33.6 mg/dL vs 112.6 +/- 36.8 mg/dL)], and creatinine (5.85 +/- 1.9 mg/dL vs 5.95 +/- 1.4 mg/dL). In G1, weekly delivered Kt/V was 3.59 +/- 0.61, and in G2, it was 4.76 +/- 0.65 (p < 0.01). The two groups were similar in metabolic and acid-base control (after 4 sessions, BUN < 55 mg/dL: 46 +/- 18.7 mg/dL vs 52 +/- 18.2 mg/dL; pH: 7.41 vs 7.38; bicarbonate: 22.8 +/- 8.9 mEq/L vs 22.2 +/- 7.1 mEq/L). Duration of therapy was longer in G2 (5.5 days vs 7.5 days; p = 0.02). Despite the delivery of different dialysis methods and doses, the survival rate did not differ between the groups (58% in G1 vs 52% in G2), and recovery of renal function was similar (28% vs 26%).Conclusion: High doses of CPD provided appropriate metabolic and pH control, with a rate of survival and recovery of renal function similar to that seen with dHD. Therefore, CPD can be considered an alternative to other forms of RRT in AKI.

TONOMETRY REVISITED: PERFUSION-RELATED, METABOLIC, AND RESPIRATORY COMPONENTS OF GASTRIC MUCOSAL ACIDOSIS IN ACUTE CARDIORESPIRATORY FAILURE

Mucosal pH (pHi) is influenced by local perfusion and metabolism (mucosal-arterial Pco2 gradient, DeltaPco2), systemic metabolic acidosis (arterial bicarbonate), and respiration (arterial Pco2). We determined these components of pHi and their relation to outcome during the first 24 h of intensive care. We studied 103 patients with acute respiratory or circulatory failure (age, 63 +/- 2 [mean +/- SEM]; Acute Physiology and Chronic Health Evaluation II score, 20 +/- 1; Sequential Organ Failure Assessment score, 8 +/- 0). pHi, and the effects of bicarbonate and arterial and mucosal Pco2 on pHi, were assessed at admission, 6, and 24 h. pHi was reduced (at admission, 7.27 +/- 0.01) due to low arterial bicarbonate and increased DeltaPco2. Low pHi (<7.32) at admission (n = 58; mortality, 29% vs. 13% in those with pHi >/=7.32 at admission; P = 0.061) was associated with an increased DeltaPco2 in 59% of patients (mortality, 47% vs. 4% for patients with low pHi and normal DeltaPco2; P = 0.0003). An increased versus normal DeltaPco2, regardless of pHi, was associated with increased mortality at admission (51% vs. 5%; P < 0.0001; n = 39) and at 6 h (34% vs. 13%; P = 0.016; n = 45). A delayed normalization or persistently low pHi (n = 47) or high DeltaPco2 (n = 25) was associated with high mortality (low pHi [34%] vs. high DeltaPco2 [60%]; P = 0.046). In nonsurvivors, hypocapnia increased pHi at baseline, 6, and 24 h (all P

Effects Of Therapeutic Approach On The Neonatal Evolution Of Very Low Birth Weight Infants With Patent Ductus Arteriosus.

To analyze the effects of treatment approach on the outcomes of newborns (birth weight [BW] < 1,000 g) with patent ductus arteriosus (PDA), from the Brazilian Neonatal Research Network (BNRN) on: death, bronchopulmonary dysplasia (BPD), severe intraventricular hemorrhage (IVH III/IV), retinopathy of prematurity requiring surgical (ROPsur), necrotizing enterocolitis requiring surgery (NECsur), and death/BPD. This was a multicentric, cohort study, retrospective data collection, including newborns (BW < 1000 g) with gestational age (GA) < 33 weeks and echocardiographic diagnosis of PDA, from 16 neonatal units of the BNRN from January 1, 2010 to Dec 31, 2011. Newborns who died or were transferred until the third day of life, and those with presence of congenital malformation or infection were excluded. Groups: G1 - conservative approach (without treatment), G2 - pharmacologic (indomethacin or ibuprofen), G3 - surgical ligation (independent of previous treatment). Factors analyzed: antenatal corticosteroid, cesarean section, BW, GA, 5 min. Apgar score < 4, male gender, Score for Neonatal Acute Physiology Perinatal Extension (SNAPPE II), respiratory distress syndrome (RDS), late sepsis (LS), mechanical ventilation (MV), surfactant (< 2 h of life), and time of MV. death, O2 dependence at 36 weeks (BPD36wks), IVH III/IV, ROPsur, NECsur, and death/BPD36wks. Student's t-test, chi-squared test, or Fisher's exact test; Odds ratio (95% CI); logistic binary regression and backward stepwise multiple regression. Software: MedCalc (Medical Calculator) software, version 12.1.4.0. p-values < 0.05 were considered statistically significant. 1,097 newborns were selected and 494 newborns were included: G1 - 187 (37.8%), G2 - 205 (41.5%), and G3 - 102 (20.6%). The highest mortality was observed in G1 (51.3%) and the lowest in G3 (14.7%). The highest frequencies of BPD36wks (70.6%) and ROPsur were observed in G3 (23.5%). The lowest occurrence of death/BPD36wks occurred in G2 (58.0%). Pharmacological (OR 0.29; 95% CI: 0.14-0.62) and conservative (OR 0.34; 95% CI: 0.14-0.79) treatments were protective for the outcome death/BPD36wks. The conservative approach of PDA was associated to high mortality, the surgical approach to the occurrence of BPD36wks and ROPsur, and the pharmacological treatment was protective for the outcome death/BPD36wks.

PROWESS-SHOCK TRIAL: A PROTOCOL OVERVIEW AND PERSPECTIVES

Sepsis remains a challenge for intensive care physicians, as it keeps up with high mortality rate in spite of the high costs associated with its treatment. Several studies indicate that the infusion of Drotrecogin-alpha activated (DrotAA) reduce mortality in patients at high risk of death when administered early and secured the appropriate initial treatment of sepsis as recommended by Surviving Sepsis Campaign. Europe and United States of America differ regarding the criteria of high risk of death in sepsis, two or more organ dysfunctions and Acute Physiology and Chronic Health Evaluation 25 or more, respectively. In addition to varied definitions of high risk of death for inclusion of patients in sepsis studies, the possibility of bleeding related to drug use and intrinsic limitations related to study design led the Company to develop a new randomized, multinational, placebo-controlled, double-blind study to assess the effectiveness of drug in patients with septic shock in adults.

Differences Between ""Classical"" Risk Factors for Infections Caused by Methicillin-Resistant Staphylococcus aureus (MRSA) and Risk Factors for Nosocomial Bloodstream Infections Caused by Multiple Clones of the Staphylococcal Cassette Chromosome mec Type IV MRSA Strain

OBJECTIVE. To identify risk factors associated with nosocomial bloodstream infections caused by multiple clones of the staphylococcal cassette chromosome mec (SCCmec) type IV strain of methicillin-resistant Staphylococcus aureus (MRSA). DESIGN. An unmatched case-control study (at a ratio of 1 : 2) performed during the period from October 2002 through September 2003. SETTING. A 2,000-bed tertiary care teaching hospital affiliated with the University of Sao Paulo in Sao Paulo, Brazil. METHODS. Case patients (n = 30) were defined either as patients who had a bloodstream infection due to SCCmec type IV strains of MRSA diagnosed at least 48 hours after hospital admission or as neonates with the infection who were born in the hospital. Control patients (n = 60) were defined as patients with SCCmec type III MRSA infection diagnosed at least 48 hours after hospital admission. Genes n = 60 encoding virulence factors were studied in the isolates recovered from case patients, and molecular typing of the SCCmec type IV MRSA isolates was also done by pulsed-field gel electrophoresis and multilocus sequence typing. RESULTS. In multivariate analysis, the following 3 variables were significantly associated with having a nosocomial bloodstream infection caused by SCCmec type IV strains of MRSA: an age of less than 1 year, less frequent use of a central venous catheter (odds ratio [OR], 0.07 [95% confidence interval {CI}, 0.02-0.28]; P = .001), and female sex. A second analysis was performed that excluded the case and Pp. 001 control patients from the neonatal unit, and, in multivariate analysis, the following variables were significantly associated with having a nosocomial bloodstream infection caused by SCCmec type IV strains of MRSA: less frequent use of a central venous catheter (OR, 0.12 [95% CI, 0.03-0.55]; P = .007), lower Acute Physiology and Chronic Health Evaluation II score on admission (OR, 0.14 [95% CI, 0.03-0.61];), less frequent surgery (OR, 0.21 [95% CI, 0.06-0.83];), and female sex (OR, 5.70 [95% CI, 1.32-24.66]; P =.020). P = .009 Pp. 025 Pp). Of the 29 SCCmec type IV MRSA isolates recovered from case patients, none contained the Panton-Valentine leukocidin, gamma-hemolysin, enterotoxin B or C, or toxic shock syndrome toxin-1. All of the isolates contained genes for the LukE-LukD leukocidin and alpha-hemolysin. Genes for enterotoxin A were present in 1 isolate, and genes for beta-hemolysin were present in 3 isolates. CONCLUSIONS. ""Classical"" risk factors do not apply to patients infected with the SCCmec type IV strain of MRSA, which is an important cause of nosocomial bacteremia. This strain infects a patient population that is less ill and has had less frequent invasive procedures than a patient population infected with the multidrug-resistant strain of SCCmec type III MRSA. We found that virulence factors were rare and that Panton-Valentine leukocidin was absent. There were multiple clones of the SCCmec type IV strain in our hospital. Children under 1 year of age were at a higher risk. There was a predominant clone ( sequence type 5) in this patient population.

Factors associated with mortality in patients with bloodstream infection and pneumonia due to Stenotrophomonas maltophilia

Severe infections caused by Stenotrophomonas maltophilia are associated with high mortality, and strategies to improve the clinical outcome for infected patients are needed. A retrospective cohort study of patients with bloodstream infection (BSIs) and pneumonia caused by S. maltophilia was conducted. Multivariate analysis was performed to access factors associated with 14-day mortality. A total of 60 infections were identified. Among these, eight (13%) were pneumonias and 52 were BSIs; 33.3% were primary, 13% were central venous catheter (CVC)-related and 40% were secondary BSIs. Fifty-seven (85%) patients had received previous antimicrobial therapy; 88% had CVC, 57% mechanical ventilation and 75% were in the intensive care unit at the onset of infection. Malignancy (45%) was the most frequent underlying disease. The mean of the Acute Physiology and Chronic Health Evaluation II (APACHE II) scores was 17 and for the Sepsis-related Organ Failure Assessment (SOFA) score, it was 7 points. The overall and 14-day mortality were, respectively, 75% and 48%. Forty-seven (78%) patients were treated and, of these, 74% received trimethoprim-sulfamethoxazole. Independent risk factors associated with mortality were SOFA index > 6 points (0.005) and septic shock (0.03). The Kaplan-Meier estimations curves showed that patients with APACHE II score > 20 and SOFA score > 10 had a survival chance of, respectively, less than 8% and less than 10% (P <= 0.001) at 21 days after the first positive S. maltophilia culture. Our results suggest that the independent factors associated with outcome in patients with infection caused by S. maltophilia are septic shock and higher SOFA index.

Benefit of antiretroviral therapy on survival of human immunodeficiency virus-infected patients admitted to an intensive care unit

Objective: To evaluate the impact of antiretroviral therapy (ART) and the prognostic factors for in-intensive care unit (ICU) and 6-month mortality in human immunodeficiency virus (HIV)-infected patients. Design: A retrospective cohort study was conducted in patients admitted to the ICU from 1996 through 2006. The follow-up period extended for 6 months after ICU admission. Setting: The ICU of a tertiary-care teaching hospital at the Universidade de Sao Paulo, Brazil. Participants: A total of 278 HIV-infected patients admitted to the ICU were selected. We excluded ICU readmissions (37), ICU admissions who stayed less than 24 hours (44), and patients with unavailable medical charts (36). Outcome Measure: In-ICU and 6-month mortality. Main Results: Multivariate logistic regression analysis and Cox proportional hazards models demonstrated that the variables associated with in-ICU and 6-month mortality were sepsis as the cause of admission (odds ratio [OR] = 3.16 [95% confidence interval [CI] 1.65-6.06]); hazards ratio [HR] = 1.37 [95% Cl 1.01-1.88)), an Acute Physiology and Chronic Health Evaluation 11 score >19 [OR = 2.81 (95% CI 1.57-5.04); HR = 2.18 (95% CI 1.62-2.94)], mechanical ventilation during the first 24 hours [OR = 3.92 (95% CI 2.20-6.96); HR = 2.25 (95% CI 1.65-3.07)], and year of ICU admission [OR = 0.90 (95% CI 0.81-0.99); HR = 0.92 [95% CI 0.87-0.97)]. CD4 T-cell count <50 cells/mm(3) Was only associated with ICU mortality [OR = 2.10 (95% Cl 1.17-3.76)]. The use of ART in the ICU was negatively predictive of 6-month mortality in the Cox model [HR = 0.50 (95% CI 0.35-0.71)], especially if this therapy was introduced during the first 4 days of admission to the ICU [HR = 0.58 (95% CI 0.41-0.83)]. Regarding HIV-infected patients admitted to ICU without using ART, those who have started this treatment during ICU, stay presented a better prognosis when time and potential confounding factors were adjusted for [HR 0.55 (95% CI 0.31-0.98)]. Conclusions: The ICU outcome of HIV-infected patients seems to be dependent not only on acute illness severity, but also on the administration of antiretroviral treatment. (Crit Care Med 2009; 37: 1605-1611)

Evolutive physicochemical characterization of diabetic ketoacidosis in adult patients admitted to the intensive care unit

Purpose: The aim of this study was to characterize the first 48-hour evolution of metabolic acidosis of adult patients with diabetic ketoacidosis admitted to the intensive care unit. Materials and Methods: We studied 9 patients retrieved from our prospective collected database, using the physicochemical approach to acid-base disturbances. Results: Mean (SD) age was 34 (13) years; mean (SD) Acute Physiology and Chronic Health Evaluation II score was 16 (10); mean (SD) blood glucose level on admission was 480 (144) mg/dL; mean (SD) pH was 7.17 (0.18); and mean (SD) standard base excess was -16.8 (7.7) mEq/L. On admission, a great part of metabolic acidosis was attributed to unmeasured anions (strong ion gap [SIG], 20 +/- 10 mEq/L), with a wide range of strong ion difference (41 +/- 10 mEq/L). During the first 48 hours of treatment, 297 +/- 180 IU of insulin and 9240 +/- 6505 mL of fluids were used. Metabolic improvement was marked by the normalization of pH, partial correction of standard base excess, and a reduction of hyperglycemia. There was a significant improvement of SIG (7.6 +/- 6.2 mEq/L) and a worsening of strong ion difference acidosis (36 +/- 5 mEq/L) in the first 24 hours, with a trend toward recuperation between 24 and 48 hours (38 +/- 6 mEq/L). Conclusion: Initial metabolic acidosis was due to SIG, and the treatment was associated with a significant decrease of SIG with an elevation of serum chloride above the normal range. (C) 2011 Elsevier Inc. All rights reserved.

Comparação entre diferentes escores de risco de mortalidade em unidade de tratamento intensivo neonatal

OBJETIVO: Avaliar peso de nascimento e os escores como preditores de mortalidade neonatal em unidade de terapia intensiva neonatal, comparando os seus resultados. MÉTODOS: Foram avaliados 494 recém-nascidos admitidos em uma unidade de terapia intensiva neonatal (UTIN) de um hospital geral de Porto Alegre, RS, logo após o nascimento, entre março de 1997 e junho de 1998. Foram avaliados o peso de nascimento e os escores considerando a variável óbito durante a internação na UTI. Os critérios de exclusão foram: alta ou óbito da UTIN com menos de 24 horas de internação, recém-nascidos cuja internação não ocorreu logo após o nascimento, protocolo de estudo incompleto e malformações congênitas incompatíveis com a vida. Para avaliação do CRIB (Clinical Risk Index for Babies) foram considerados somente os pacientes com peso de nascimento inferior a 1.500 g. Foram calculadas as curvas ROC (Receiver Operating Characteristics Curve) para SNAP (Score for Neonatal Acute), SNAP-PE (Score for Neonatal Acute Physiology Perinatal Extension), SNAP II, SNAP-PE II, CRIB e peso de nascimento. RESULTADOS: Dos 494 pacientes, 44 faleceram (8,9% de mortalidade). Dos 102 recém-nascidos com peso de até 1.500 g, 32 (31,3%) faleceram. As áreas abaixo da curva ROC variaram de 0,81 a 0,94. Todos os escores avaliados mostraram áreas abaixo da curva ROC sem diferenças estatisticamente significativas. Os escores de risco de mortalidade estudados apresentaram um melhor desempenho que o peso de nascimento, especialmente em recém-nascidos com peso de nascimento igual ou menor que 1.500 g. CONCLUSÕES: Todos os escores de mortalidade neonatal apresentaram melhor desempenho e foram superiores ao peso de nascimento como medidores de risco de óbito hospitalar para recém-nascidos internados em UTIN.

Avaliação do desempenho de indicadores com base na metodologia ROC (Receiver Operating Characteristic)

Dissertação de mestrado em Bioinformática

Aplicação da metodologia ROC na avaliação de desempenho de índices de gravidade clínica em unidades de neonatologia de Portugal

Tese de Doutoramento em Engenharia Industrial e de Sistemas

Are initial radiographic and clinical scales associated with subsequent intracranial pressure and brain oxygen levels after severe traumatic brain injury?

BACKGROUND: Prediction of clinical course and outcome after severe traumatic brain injury (TBI) is important. OBJECTIVE: To examine whether clinical scales (Glasgow Coma Scale [GCS], Injury Severity Score [ISS], and Acute Physiology and Chronic Health Evaluation II [APACHE II]) or radiographic scales based on admission computed tomography (Marshall and Rotterdam) were associated with intensive care unit (ICU) physiology (intracranial pressure [ICP], brain tissue oxygen tension [PbtO2]), and clinical outcome after severe TBI. METHODS: One hundred one patients (median age, 41.0 years; interquartile range [26-55]) with severe TBI who had ICP and PbtO2 monitoring were identified. The relationship between admission GCS, ISS, APACHE II, Marshall and Rotterdam scores and ICP, PbtO2, and outcome was examined by using mixed-effects models and logistic regression. RESULTS: Median (25%-75% interquartile range) admission GCS and APACHE II without GCS scores were 3.0 (3-7) and 11.0 (8-13), respectively. Marshall and Rotterdam scores were 3.0 (3-5) and 4.0 (4-5). Mean ICP and PbtO2 during the patients' ICU course were 15.5 ± 10.7 mm Hg and 29.9 ± 10.8 mm Hg, respectively. Three-month mortality was 37.6%. Admission GCS was not associated with mortality. APACHE II (P = .003), APACHE-non-GCS (P = .004), Marshall (P < .001), and Rotterdam scores (P < .001) were associated with mortality. No relationship between GCS, ISS, Marshall, or Rotterdam scores and subsequent ICP or PbtO2 was observed. The APACHE II score was inversely associated with median PbtO2 (P = .03) and minimum PbtO2 (P = .008) and had a stronger correlation with amount of time of reduced PbtO2. CONCLUSION: Following severe TBI, factors associated with outcome may not always predict a patient's ICU course and, in particular, intracranial physiology.

Timing of adequate antibiotic therapy is a greater determinant of outcome than are TNF and IL-10 polymorphisms in patients with sepsis.

INTRODUCTION Genetic variations may influence clinical outcomes in patients with sepsis. The present study was conducted to evaluate the impact on mortality of three polymorphisms after adjusting for confounding variables, and to assess the factors involved in progression of the inflammatory response in septic patients. METHOD The inception cohort study included all Caucasian adults admitted to the hospital with sepsis. Sepsis severity, microbiological information and clinical variables were recorded. Three polymorphisms were identified in all patients by PCR: the tumour necrosis factor (TNF)-alpha 308 promoter polymorphism; the polymorphism in the first intron of the TNF-beta gene; and the IL-10-1082 promoter polymorphism. Patients included in the study were followed up for 90 days after hospital admission. RESULTS A group of 224 patients was enrolled in the present study. We did not find a significant association among any of the three polymorphisms and mortality or worsening inflammatory response. By multivariate logistic regression analysis, only two factors were independently associated with mortality, namely Acute Physiology and Chronic Health Evaluation (APACHE) II score and delayed initiation of adequate antibiotic therapy. In septic shock patients (n = 114), the delay in initiation of adequate antibiotic therapy was the only independent predictor of mortality. Risk factors for impairment in inflammatory response were APACHE II score, positive blood culture and delayed initiation of adequate antibiotic therapy. CONCLUSION This study emphasizes that prompt and adequate antibiotic therapy is the cornerstone of therapy in sepsis. The three polymorphisms evaluated in the present study appear not to influence the outcome of patients admitted to the hospital with sepsis.

Do standard burn mortality formulae work on a population of severely burned children and adults?

Accurate prediction of mortality following burns is useful as an audit tool, and for providing treatment plan and resource allocation criteria. Common burn formulae (Ryan Score, Abbreviated Burn Severity Index (ABSI), classic and revised Baux) have not been compared with the standard Acute Physiology and Chronic Health Evaluation II (APACHEII) or re-validated in a severely (≥20% total burn surface area) burned population. Furthermore, the revised Baux (R-Baux) has been externally validated thoroughly only once and the pediatric Baux (P-Baux) has yet to be. Using 522 severely burned patients, we show that burn formulae (ABSI, Baux, revised Baux) outperform APACHEII among adults (AUROC increase p<0.001 adults; p>0.5 children). The Ryan Score performs well especially among the most at-risk populations (estimated mortality [90% CI] original versus current study: 33% [26-41%] versus 30.18% [24.25-36.86%] for Ryan Score 2; 87% [78-93%] versus 66.48% [51.31-78.87%] for Ryan Score 3). The R-Baux shows accurate discrimination (AUROC 0.908 [0.869-0.947]) and is well-calibrated. However, the ABSI and P-Baux, although showing high measures of discrimination (AUROC 0.826 [0.737-0.916] and 0.848 [0.758-0.938]) in children), exceedingly overestimates mortality, indicating poor calibration. We highlight challenges in designing and employing scores that are applicable to a wide range of populations.

Umbilical cord blood and neonatal endothelin-1 levels in preterm newborns with and without respiratory distress syndrome

Increased pulmonary vascular resistance in preterm newborn infants with respiratory distress syndrome is suggested, and endothelin-1 plays an important role in pulmonary vascular reactivity in newborns. We determined umbilical cord blood and neonatal (second sample) levels of endothelin-1 in 18 preterm newborns with respiratory distress syndrome who had no clinical or echocardiographic diagnosis of pulmonary hypertension and 22 without respiratory distress syndrome (gestational ages: 31.4 ± 1.6 and 29.3 ± 2.3 weeks, respectively). Umbilical cord blood and a second blood sample taken 18 to 40 h after birth were used for endothelin-1 determination by enzyme immunoassay. Median umbilical cord blood endothelin-1 levels were similar in both groups (control: 10.9 and respiratory distress syndrome: 11.4 pg/mL) and were significantly higher than in the second sample (control: 1.7 pg/mL and respiratory distress syndrome: 3.5 pg/mL, P < 0.001 for both groups). Median endothelin-1 levels in the second sample were significantly higher in children with respiratory distress syndrome than in control infants (P < 0.001). There were significant positive correlations between second sample endothelin-1 and Score for Neonatal Acute Physiology and Perinatal Extension II (r = 0.36, P = 0.02), and duration of mechanical ventilation (r = 0.64, P = 0.02). A slower decline of endothelin-1 from birth to 40 h of life was observed in newborns with respiratory distress syndrome when compared to controls. A significant correlation between neonatal endothelin-1 levels and some illness-severity signs suggests that endothelin-1 plays a role in the natural course of respiratory distress syndrome in preterm newborns.