Systematic approach for severe respiratory failure due to novel A (H1N1) influenza.

AIM: In April 2009, a novel influenza A (H1N1) virus appeared in Mexico. It rapidly acquired the characteristics of a pandemic disease. Our objective is to present a case series of mechanically ventilated patients with severe influenza, treated with a systematic approach. METHODS: Prospective, observational, single-center study in a University Hospital. A (H1N1) virus was confirmed by rRT-PCR. In this report, we only considered patients that required mechanical ventilation (MV). All patients received antibiotics, steroids and oseltamivir from the time of admission. The main strategies incorporated in the systematic approach were a lung-protective strategy, PEEP adjusted for each patient, protocol-guided sedoanalgesia, restrictive fluid management, weaning protocol, and prolonged prone ventilation and extracorporeal membrane oxygenation (ECMO) as rescue therapies. RESULTS: We studied 19 patients: age 41 ± 13 years old, APACHE II 16 ± 7 and SOFA 8 ± 4. All patients presented PaO2/FiO2 ≤ 200 before connection to MV. Their worst values within the first 24 hours for oxygenation index, PaO2/FiO2, and PaCO2 on MV were 21.8 ± 13, 98 ± 39, and 48 ± 16 mmHg, respectively. Sixteen patients achieved ARDS; three exhibited acute lung injury criteria. Ten required a prone position, and two required ECMO (one patient required both therapies). Time on MV was 16 ± 13 days. Length of stay in the ICU and in hospital was 18 ± 12 and 28 ± 17 days, respectively. Mortality was 21%. CONCLUSION: Severe hypoxemia and a high rate of rescue therapies were observed among our patients. Nevertheless, mortality was lower than previously reported in comparable populations, which may be related to the management by a critical care team and the use of a systematic approach for ventilatory and non-ventilatory therapeutic strategies.

Efectos de la ventilación en posición prono extendida en SDRA secundario a influenza A(H1N1) / Impact of extended prone position ventilation in patients with severe ARDS secondary to influenza A(H1N1)

Introducción: Durante la pandemia por influenza A(H1N1), Chile alcanzó una de las tasas de casos más alta del mundo. Nuestro hospital recibió numerosos afectados el 2009 y 2010. Evaluamos el impacto de ventilación en posición prono (VPP) extendida, en las variables respiratorias de pacientes con SDRA grave secundario a influenza, y comparamos estos resultados con los obtenidos en otras series de VPP. Métodos: Estudio prospectivo, intervencional en UCI. Los pacientes recibieron oseltamivir y antibióticos y fueron manejados según protocolos (ventilatorio y no ventilatorio). Aquellos con criterios de SDRA grave fueron pronados hasta un índice de oxigenación <10. Se registraron parámetros de intercambio gaseoso, ventilatorios y desenlaces clínicos. Resultados: 12 pacientes con SDRA grave (edad 46+/-12 años, 7 hombres, APACHE II 17+/-6, SOFA 9+/-3) requirieron VPP, que se instauró a las 14(7-39) horas de ventilación mecánica (VM) y se mantuvo por 72(54-96) horas. Ningún paciente experimentó complicaciones mayores. La PaO2:FiO2 mejoró de 82(63-101) mmHg a 145(138-223) mmHg, (p<0.001). El tiempo en VM fue 20+/-13 días y en UCI 22+/-13 días. La mortalidad hospitalaria fue 25 por ciento y no cambió en el seguimiento de más de 8 meses. Este comportamiento con VPP fue similar al observado en otras series de SDRA grave. Conclusión: Los resultados obtenidos sugieren que la VPP resultó segura y se asoció a mejoría del intercambio gaseoso en pacientes con SDRA por influenza A(H1N1). Aunque el número reducido de pacientes no permite sacar mayores conclusiones, la VPP extendida podría ser de utilidad en los casos más graves causados por esta nueva influenza.

Introduction: During pandemic for influenza A(H1N1), Chile achieved one of the highest rates of infection worldwide. On 2009 and 2010, our hospital received a large number of infected patients. We evaluated the impact of extended prone position ventilation (PPV) on respiratory variables from severe ARDS patients secondary to this influenza. We also compared these results with those obtained with PPV in other series. Methods: Prospective, interventional study, performed in a mixed-ICU. Patients received oseltamivir and antibiotics, and were treated according to protocols (ventilatory and non-ventilatory). Severe ARDS patients were proned until oxygenation index was < 10. Oxygen exchange, ventilatory parameters and clinical outcomes were registered. Results: 12 severe ARDS patients (46+/-12 y.o., 7 men, APACHE II 17+/-6, SOFA 9+/-3) required PPV, which was started 14(7-39) hours after mechanical ventilation (MV) initiation, and it was maintained for 72(54-96) straight hours. No major complication was described. Three patients needed two periods of PPV. PaO2:FiO2 improved significantly with PPV from 82(63-101) mmHg to 145(138-223) mmHg, (p<0.001). Time on MV was 20+/-13 days, and LOS in UCI was 22+/-13 days. Hospital mortality was25 percent and remained unchanged for at least 8 month of follow-up. PPV had the same effect than in other severe ARDS series. Conclusion: Our results suggest PPV is safe and it was associated with improvement in oxygen exchange in ARDS secondary to A(H1N1) influenza. Although the small number of patients does not allow drawing any major conclusion, we believe PPV can be useful to treat severe ARDS cases due to influenza infection.

[Confusion Assessment Method for diagnosing delirium in ICU patients (CAM-ICU): cultural adaptation and validation of the Spanish version]. / Método para la evaluación de la confusión en la unidad de cuidados intensivos para el diagnóstico de delírium: adaptación cultural y validación de la versión en idioma español.

OBJECTIVE: To adapt the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) for the diagnosis of delirium to the language and culture of Spain and to validate the adapted version. DESIGN: Population validation. SETTING: Intensive care units in a 600-bed university hospital. PATIENTS: We studied 29 critical patients undergoing mechanical ventilation. Mean age was 70 years (range 58-77 years), mean APACHE II score 16 (range 13-21), and mean SOFA score 7 (range 4-8). INTERVENTION: Two independent operators applied the Spanish version of the CAM-ICU and a psychiatrist applied the Diagnostic and Statistical Manual of Mental Disorders Fourth Edition-Revised (DSM IV TR). MAIN OUTCOME VARIABLES: Concordance (kappa index), internal consistency (Cronbach's alpha), and validity (sensitivity and specificity) of the Spanish version of the CAM-ICU were compared to the DSM IV TR, which is considered the current gold standard. RESULTS: The translation and cultural adaptation was carried out in accordance with current international guidelines. A total of 65 assessments were performed in 29 patients. The interobserver concordance was high: kappa statistic 0.91 (95% CI: 0.86-0.96). The internal consistence was adequate: Cronbach's alpha=0.84 (unilateral 95% CI: 0.77). For observer A (a physician), the sensitivity of the Spanish version of the CAM-ICU was 80% and the specificity was 96%. For observer B, (a nurse) the sensitivity was 83% and the specificity was 96%. CONCLUSIONS: The Spanish version of the CAM-ICU is a valid, reliable, and reproducible instrument that can be satisfactorily applied to diagnose delirium in Spanish-speaking ICU patients.

[Characteristics and impact of sedation, analgesia, and neuromuscular blockage in critical patients undergoing prolonged mechanical ventilation]. / Características e impacto de la sedación, la analgesia y el bloqueo neuromuscular en los pacientes críticos que recibieron ventilación mecánica prolongada.

AIM: To describe use of sedatives, analgesics, and neuromuscular blockers (NMB) in patients undergoing long-term mechanical ventilation and to assess factors associated with their use and their association with mortality at 28 days. DESIGN: Prospective observational multicenter cohort study. SETTING: Thirteen intensive care units (ICU) in Chile. PATIENTS: Patients undergoing mechanical ventilation for more than 48h. We excluded patients with neurological disorders, cirrhosis of the liver, chronic renal failure, suspected drug addiction, and early no resuscitation orders. INTERVENTION: None. MAIN MEASUREMENTS: Proportion of use and dosage of sedatives, analgesics, and NMB. Level of sedation observed (SAS). Variables associated with the Sedation Agitation Scale (SAS), use of sedatives, analgesics, and NMB. Multivariate logistic regression of variables associated to mortality at 28 days. RESULTS: A total of 155 patients participated (60+/-18 years, 57% male, SOFA 7 [6-10], APACHE II 18 [15-22], 63% with sepsis, and 47% with acute lung injury/adult respiratory distress syndrome. The drugs most frequently used were midazolam (85%, 4 [1.9-6.8]mg/hr) and fentanyl (81%, 76 [39-140]microg/hr). NMB were administered at least 1 day in 30% of patients. SAS score was 1 or 2 in 55% of patients. There was an association between NMB use and mortality at 28 days, but it was not consistent in all the models of NMB evaluated. CONCLUSIONS: Sedatives were frequently employed and deep sedation was common. Midazolam and fentanyl were the most frequently administered drugs. The use of NMB might be independently associated to greater mortality.

[Cholecystectomy in young women from the south-oriental area of Santiago: comparison between 2 periods]. / Colecistectomía en mujeres jovenes del area suroriente de Santiago: comparación entre dos períodos.

The aim of this study was to know if cholecystectomy rates have decreased in young women, considering that these rates have decreased in the last years in the general chilean population. The frequency of previous cholecystectomy was compared in 1582 women aged 23.9 +/- 5.8 years admitted to a maternity for delivery between 1985 and 1986 and 4943 women aged 24.6 +/- 5.9 years admitted between 1989 and 1990 for the same reason. There was a reduction in cholecystectomy frequency from 4.7 to 2.5% specially among women 21 to 35 years old. Cholecystectomy was performed at a mean age of 23 years in both groups and 42.6% of the procedures were done before the first pregnancy. An unexpected finding was a lower body weight among women studied in the second period (62.5 +/- 9.1 vs 67.7 +/- 8.4 k).