Intra-abdominal pressure as a predictor of acute kidney injury in postoperative abdominal surgery.

OBJECTIVES: The purpose of this study was to determine if intra-abdominal pressure (IAP) could predict acute renal injury (AKI) in the postoperative period of abdominal surgeries, and which would be its cutoff value. PATIENTS AND METHODS: A prospective observational study was conducted in the period from January 2010 to March 2011 in the Intensive Care Units (ICUs) of the University Hospital of Botucatu Medical School, UNESP. Consecutive patients undergoing abdominal surgery were included in the study. Initial evaluation, at admission in ICU, was performed in order to obtain demographic, clinical surgical and therapeutic data. Evaluation of IAP was obtained by the intravesical method, four times per day, and renal function was evaluated during the patient's stay in the ICU until discharge, death or occurrence of AKI. RESULTS: A total of 60 patients were evaluated, 16 patients developed intra-abdominal hypertension (IAH), 45 developed an abnormal IAP (>7 mmHg) and 26 developed AKI. The first IAP at the time of admission to the ICU was able to predict the occurrence of AKI (area under the receiver-operating characteristic curve was 0.669; p=0.029) with the best cutoff point (by Youden index method) ≥ 7.68 mmHg, sensitivity of 87%, specificity of 46% at this point. The serial assessment of this parameter did not added prognostic value to initial evaluation. CONCLUSION: IAH was frequent in patients undergoing abdominal surgeries during ICU stay, and it predicted the occurrence of AKI. Serial assessments of IAP did not provided better discriminatory power than initial evaluation.

Injúria renal aguda em unidade de terapia intensiva: estudo prospectivo sobre a incidência, fatores de risco e mortalidade / Acute kidney injury in intensive care unit patients: a prospective study on incidence, risk factors and

OBJETIVO: Comparar características clínicas e evolução de pacientes com e sem injúria renal aguda adquirida em unidade de terapia intensiva geral de um hospital universitário terciário e identificar fatores de risco associados ao desenvolvimento de injúria renal aguda e à mortalidade. MÉTODOS: Estudo prospectivo observacional com 564 pacientes acompanhados diariamente durante a internação em unidade de terapia intensiva geral do Hospital das Clínicas da Faculdade de Medicina de Botucatu por 2 anos consecutivos (de maio de 2008 a maio de 2010), divididos em 2 grupos: com injúria renal aguda adquirida (G1) e sem injúria renal aguda adquirida (G2). RESULTADOS: A incidência de injúria renal aguda foi 25,5 por cento. Os grupos diferiram quanto à etiologia da admissão em unidade de terapia intensiva (sepse: G1:41,6 por cento x G2:24,1 por cento, p<0,0001 e pós operatório neurológico 13,8 por cento x 38,1 por cento, p<0,0001), idade (56,8±15,9 x 49,8± 17,8 anos, p< 0,0001), APACHE II (21,9±6,9 x 14,1±4,6, p<0,0001), ventilação mecânica (89,2 x 69,1 por cento, p<0,0001) e uso de drogas vasoativas (78,3 x 56,1 por cento, p<0,0001). Com relação aos fatores de risco e às comorbidades, os grupos foram diferentes quanto à presença de diabetes mellitus, insuficiência cardíaca congestiva, insuficiência renal crônica e uso de anti-inflamatórios não hormonais (28,2 x 19,7 por cento, p=0,03; 23,6 x 11,6 por cento, p=0,0002, 21,5 x 11,5 por cento, p< 0,0001 e 23,5 x 7,1 por cento, p<0,0001, respectivamente). O tempo de internação e a mortalidade foram superiores nos pacientes que adquiriram injúria renal aguda (6,6 ± 2,7 x 12,9± 5,6 dias p<0,0001 e 62,5 x 16,4 por cento, p<0,0001). À análise multivariada foram identificados como fatores de risco para injúria renal aguda, idade>55 anos, APACHE II>16, creatinina (cr) basal>1,2 e uso de anti-inflamatórios não hormonais (OR=1,36 IC:1,22-1,85, OR=1,2 IC:1,11-1,33, OR=5,2 IC:2,3-11,6 e OR=2,15 IC:1,1-4,2, respectivamente) e a injúria renal aguda esteve independentemente associada ao maior tempo de internação e à mortalidade (OR=1,18 IC:1,05-1,26 e OR=1,24 IC:1,09-1,99 respectivamente). À análise da curva de sobrevida, após 30 dias de internação, a mortalidade foi de 83,3 por cento no G1 e 45,2 por cento no G2 (p<0,0001). CONCLUSÃO: A incidência de injúria renal aguda é elevada em unidade de terapia intensiva, os fatores de riscos independentes para adquirir injúria renal aguda são idade >55 anos, APACHE II>16, Cr basal >1,2 e uso de anti-inflamatórios não hormonais e a injúria renal aguda é fator de risco independente para o maior tempo de permanência em unidade de terapia intensiva e mortalidade.

OBJECTIVE:To compare the clinical features and outcomes of patients with and without acute kidney injury in an intensive care unit of a tertiary university hospital and to identify acute kidney injury and mortality risk factors. METHODS: This was a prospective observational study of a cohort including 564 patients followed during their stay in the intensive care unit of Hospital das Clinicas da Faculdade de Medicina de Botucatu (Botucatu, São Paulo, Brazil) between May 2008 and May 2010. Patients were allocated to two different groups: with (G1) and without (G2) acute kidney injury. RESULTS: The incidence of acute kidney injury was 25.5 percent. The groups were different with respect to the reason for admission to the intensive care unit (sepsis, G1: 41.6 percent versus G2: 24.1 percent; P < 0.0001; neurosurgery, postoperative G1: 13.8 percent versus G2: 38.1 percent; P < 0.0001); age (G1: 56.8 ± 15.9 vs. G2: 49.8 ± 17.8 years; P < 0.0001); Acute Physiological Chronic Health Evaluation (APACHE) II score (G1: 21.9 ± 6.9 versus G2: 14.1 ± 4.6; P < 0.0001); use of mechanical ventilation (G1: 89.2 percent vs. G2: 69.1 percent; P < 0.0001) and use of vasoactive drugs (G1: 78.3 percent vs. G2: 56.1 percent; P < 0.0001). Higher rates of diabetes mellitus, congestive heart failure, chronic renal disease and use of non-steroidal anti-inflammatory drugs were more frequent in acute kidney injury patients (28.2 percent vs. 19.7 percent, P = 0.03; 23.6 vs. 11.6 percent, P = 0.0002; 21.5 percent vs. 11.5 percent, P < 0.0001 and 23.5 percent vs. 71. percent, P < 0.0001, for G1 versus G2, respectively). Length of hospital stay and mortality were also higher for acute kidney injury patients (G1: 6.6 ± 2.7 days versus G2: 12.9 ±5.6 days, P < 0.0001 and G1: 62.5 percent versus G2: 16.4 percent, P < 0.0001). Multivariate analysis identified the following as risk factors for acute kidney injury: age above 55 years, APACHE II score above 16, baseline creatinine above 1.2 and use of non-steroidal anti-inflammatory drugs (odds ratio (OR) = 1.36, 95 percent confidence interval (95 percentCI): 1.22 - 1.85; OR = 1.2, 95 percentCI: 1.11 - 1.33; OR = 5.2, 95 percentCI: 2.3 - 11.6 and OR = 2.15, 95 percentCI: 1.1 - 4.2, respectively). Acute kidney injury was independently associated with longer hospital stay and increased mortality (OR = 1.18, 95 percentCI: 1.05 - 1.26 and OR = 1.24, 95 percentCI: 1.09 - 1.99, respectively). Analysis of the survival curve 30 days after admission showed 83.3 percent mortality for acute kidney injury patients and 45.2 percent for non-acute kidney injury patients (P < 0.0001). CONCLUSION: The incidence of acute kidney injury was high in this intensive care unit; the independent risk factors associated with acute kidney injury were age > 55 years, APACHE II > 16, baseline serum creatinine > 1.2 and use of non-steroidal anti-inflammatory drugs. Acute kidney injury is an independent risk factor for longer intensive care unit stay and mortality.

Acute kidney injury in intensive care unit patients: a prospective study on incidence, risk factors and. / Injúria renal aguda em unidade de terapia intensiva: estudo prospectivo sobre a incidência, fatores de risco e mortalidade.

OBJECTIVE: To compare the clinical features and outcomes of patients with and without acute kidney injury in an intensive care unit of a tertiary university hospital and to identify acute kidney injury and mortality risk factors. METHODS: This was a prospective observational study of a cohort including 564 patients followed during their stay in the intensive care unit of Hospital das Clinicas da Faculdade de Medicina de Botucatu (Botucatu, São Paulo, Brazil) between May 2008 and May 2010. Patients were allocated to two different groups: with (G1) and without (G2) acute kidney injury. RESULTS: The incidence of acute kidney injury was 25.5%. The groups were different with respect to the reason for admission to the intensive care unit (sepsis, G1: 41.6% versus G2: 24.1%; P < 0.0001; neurosurgery, postoperative G1: 13.8% versus G2: 38.1%; P < 0.0001); age (G1: 56.8 ± 15.9 vs. G2: 49.8 ± 17.8 years; P < 0.0001); Acute Physiological Chronic Health Evaluation (APACHE) II score (G1: 21.9 ± 6.9 versus G2: 14.1 ± 4.6; P < 0.0001); use of mechanical ventilation (G1: 89.2% vs. G2: 69.1%; P < 0.0001) and use of vasoactive drugs (G1: 78.3% vs. G2: 56.1%; P < 0.0001). Higher rates of diabetes mellitus, congestive heart failure, chronic renal disease and use of non-steroidal anti-inflammatory drugs were more frequent in acute kidney injury patients (28.2% vs. 19.7%, P = 0.03; 23.6 vs. 11.6%, P = 0.0002; 21.5% vs. 11.5%, P < 0.0001 and 23.5% vs. 71.%, P < 0.0001, for G1 versus G2, respectively). Length of hospital stay and mortality were also higher for acute kidney injury patients (G1: 6.6 ± 2.7 days versus G2: 12.9 ±5.6 days, P < 0.0001 and G1: 62.5% versus G2: 16.4%, P < 0.0001). Multivariate analysis identified the following as risk factors for acute kidney injury: age above 55 years, APACHE II score above 16, baseline creatinine above 1.2 and use of non-steroidal anti-inflammatory drugs (odds ratio (OR) = 1.36, 95% confidence interval (95%CI): 1.22 - 1.85; OR = 1.2, 95%CI: 1.11 - 1.33; OR = 5.2, 95%CI: 2.3 - 11.6 and OR = 2.15, 95%CI: 1.1 - 4.2, respectively). Acute kidney injury was independently associated with longer hospital stay and increased mortality (OR = 1.18, 95%CI: 1.05 - 1.26 and OR = 1.24, 95%CI: 1.09 - 1.99, respectively). Analysis of the survival curve 30 days after admission showed 83.3% mortality for acute kidney injury patients and 45.2% for non-acute kidney injury patients (P < 0.0001). CONCLUSION: The incidence of acute kidney injury was high in this intensive care unit; the independent risk factors associated with acute kidney injury were age > 55 years, APACHE II > 16, baseline serum creatinine > 1.2 and use of non-steroidal anti-inflammatory drugs. Acute kidney injury is an independent risk factor for longer intensive care unit stay and mortality.

Evaluation of the diagnostic performance and cut-off value for the rapid shallow breathing index in predicting extubation failure.

OBJECTIVE: To evaluate the diagnostic performance of the rapid shallow breathing index (RSBI) in predicting extubation failure among adult patients in the intensive care unit and to determine the appropriateness of the classical RSBI cut-off value. METHODS: This was a prospective study conducted in the adult intensive care unit of the Botucatu School of Medicine Hospital das Clínicas. The RSBI was evaluated in 73 consecutive patients considered clinically ready for extubation. RESULTS: The classical RSBI cut-off value (105 breaths/min/L) presented a sensitivity of 20% and a specificity of 95% (sum = 115%). Analysis of the receiver operator characteristic (ROC) curve revealed a better cut-off value (76.5 breaths/min/L), which presented a sensitivity of 66% and a specificity of 74% (sum = 140%). The area under the ROC curve for the RSBI was 0.78. CONCLUSIONS: The classical RSBI cut-off value proved inappropriate, predicting only 20% of the cases of extubation failure in our sample. The new cut-off value provided substantial improvement in sensitivity, with an acceptable loss of specificity. The area under the ROC curve indicated that the discriminative power of the RSBI is satisfactory, which justifies the validation of this index for use.

Avaliação do desempenho diagnóstico e do valor de corte para o índice de respiração rápida e superficial na predição do insucesso da extubação / Evaluation of the diagnostic performance and cut-off value for the rapid shallow breathing index in predicting extubation failure

OBJETIVO: Avaliar o desempenho diagnóstico do índice de respiração rápida e superficial (IRRS) na predição do insucesso da extubação de pacientes adultos em terapia intensiva e verificar a adequação do valor de corte clássico para esse índice. MÉTODOS: Estudo prospectivo realizado na unidade de terapia intensiva de adultos do Hospital das Clínicas da Faculdade de Medicina de Botucatu, através da avaliação do IRRS em 73 pacientes consecutivos considerados clinicamente prontos para extubação. RESULTADOS: O IRRS com valor de corte clássico (105 ciclos/min/L) apresentou sensibilidade de 20 por cento e especificidade de 95 por cento (soma = 115 por cento). A análise da curva receiver operator characteristic (ROC) demonstrou melhor valor de corte (76,5 ciclos/min/L), o qual forneceu sensibilidade de 66 por cento e especificidade de 74 por cento (soma = 140 por cento), e a área sob a curva ROC para o IRRS foi de 0,78. CONCLUSÕES: O valor de corte clássico do IRRS se mostrou inadequado nesta casuística, prevendo apenas 20 por cento dos pacientes com falha na extubação. A obtenção do novo valor de corte permitiu um acréscimo substancial de sensibilidade, com aceitável redução da especificidade. O valor da área sob a curva ROC indicou satisfatório poder discriminativo do índice, justificando a validação de sua aplicação.

OBJECTIVE: To evaluate the diagnostic performance of the rapid shallow breathing index (RSBI) in predicting extubation failure among adult patients in the intensive care unit and to determine the appropriateness of the classical RSBI cut-off value. METHODS: This was a prospective study conducted in the adult intensive care unit of the Botucatu School of Medicine Hospital das Clínicas. The RSBI was evaluated in 73 consecutive patients considered clinically ready for extubation. RESULTS: The classical RSBI cut-off value (105 breaths/min/L) presented a sensitivity of 20 percent and a specificity of 95 percent (sum = 115 percent). Analysis of the receiver operator characteristic (ROC) curve revealed a better cut-off value (76.5 breaths/min/L), which presented a sensitivity of 66 percent and a specificity of 74 percent (sum = 140 percent). The area under the ROC curve for the RSBI was 0.78. CONCLUSIONS: The classical RSBI cut-off value proved inappropriate, predicting only 20 percent of the cases of extubation failure in our sample. The new cut-off value provided substantial improvement in sensitivity, with an acceptable loss of specificity. The area under the ROC curve indicated that the discriminative power of the RSBI is satisfactory, which justifies the validation of this index for use.