Modeling in-Hospital Patient Survival During the First 28 Days After Intensive Care Unit Admission: a Prognostic Model for Clinical Trials in General Critically Ill Patients

OBJECTIVE: The objective of the study was to develop a model for estimating patient 28-day in-hospital mortality using 2 different statistical approaches. DESIGN: The study was designed to develop an outcome prediction model for 28-day in-hospital mortality using (a) logistic regression with random effects and (b) a multilevel Cox proportional hazards model. SETTING: The study involved 305 intensive care units (ICUs) from the basic Simplified Acute Physiology Score (SAPS) 3 cohort. PATIENTS AND PARTICIPANTS: Patients (n = 17138) were from the SAPS 3 database with follow-up data pertaining to the first 28 days in hospital after ICU admission. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: The database was divided randomly into 5 roughly equal-sized parts (at the ICU level). It was thus possible to run the model-building procedure 5 times, each time taking four fifths of the sample as a development set and the remaining fifth as the validation set. At 28 days after ICU admission, 19.98% of the patients were still in the hospital. Because of the different sampling space and outcome variables, both models presented a better fit in this sample than did the SAPS 3 admission score calibrated to vital status at hospital discharge, both on the general population and in major subgroups. CONCLUSIONS: Both statistical methods can be used to model the 28-day in-hospital mortality better than the SAPS 3 admission model. However, because the logistic regression approach is specifically designed to forecast 28-day mortality, and given the high uncertainty associated with the assumption of the proportionality of risks in the Cox model, the logistic regression approach proved to be superior.

Ventilação Mecânica numa Unidade de Cuidados Intensivos Pediátricos

Os autores fazem a análise dos doentes submetidos a ventilação mecânica na Unidade de Cuidados Intensivos Pediátricos do Hospital de Dona Estefânia, num período de 33 meses, desde a sua abertura em Abril de 1991 até ao final de Dezembro de 1993. Neste período foram internadas na Unidade 1513 crianças, das quais 264 (17.4%) foram ventiladas. A idade dos doentes ventilados variou entre os 28 dias e os 15 anos (média = 2.9 anos). De acordo com o Sistema de Classificação Clínica (CCS), 44 (16.7%) dos doentes pertenciam à classe III e 220 (83.3%) à classe IV. Os índices médios de Intervenção Terapêutica (TISS) e do Risco Pediátrico de Mortalidade (PRISM), no primeiro dia, foram respectivamente de 29.5 (min. = 9; max. = 75) e de 13.6 (min. = 0; max. = 50) pontos. A insuficiência respiratória constituiu o principal motivo de ventilação e a modalidade preferida foi a pressão controlada, utilizada em 201 doentes — 76.1%. A duração média da ventilação foi de 123.7 horas (min. = 30 minutos; max. = 9624 horas). A taxa de ocupação dos ventiladores nos anos de 1991, 1992 e 1993, foi respectivamente de 47.8%, 36.4% e de 53.2%. Registaram-se complicações relacionadas com a ventilação em 52 crianças (19.7%), sendo a atelectasia a mais frequentemente observada. A mortalidade foi de 31.1%, não se tendo relacionado nenhum óbito directamente com a ventilação mecânica.

Spectrum and Frequency of GJB2 Mutations in a Cohort of 264 Portuguese Nonsyndromic Sensorineural Hearing Loss Patients

OBJECTIVE: To assess the spectrum and prevalence of mutations in the GJB2 gene in Portuguese nonsyndromic sensorineural hearing loss (NSSHL) patients. DESIGN: Sequencing of the coding region, basal promoter, exon 1, and donor splice site of the GJB2 gene; screening for the presence of the two common GJB6 deletions. STUDY SAMPLE: A cohort of 264 Portuguese NSSHL patients. RESULTS: At least one out of 21 different GJB2 variants was identified in 80 (30.2%) of the 264 patients analysed. Two mutant alleles were found in 53 (20%) of these probands, of which 83% (44/53) harboured at least one c.35delG allele. Twenty-seven (10.2%) of the probands harboured only one mutant allele. Subsequent analysis revealed that the GJB6 deletion del(GJB6-D13S1854) was present in at least 7.4% (2/27) of the patients carrying only one mutant GJB2 allele. Overall, one in five (55/264) of the patients were diagnosed as having DFNB1-related NSSHL, of which the vast majority (53/55) harboured only GJB2 mutations. CONCLUSIONS: This study provides clear demonstration that mutations in the GJB2 gene are an important cause of NSSHL in Portugal, thus representing a valuable indicator as regards therapeutical and rehabilitation options, as well as genetic counseling of these patients and their families.