[Prognosis for acute exacerbation of chronic obstructive pulmonary disease in mechanically ventilated patients]. / Pronóstico de los enfermos con enfermedad pulmonar obstructiva crónica reagudizada que precisan ventilación mecánica.

OBJECTIVE: To determine the variables associated with prognosis for acute exacerbation of chronic obstructive pulmonary disease (AECOPD) in mechanically ventilated patients. DESIGN: Prospective cohort study with retrospective analysis. LOCATION: 361 Intensive Care Units (ICU) in 20 countries. PATIENTS AND METHODS: There were included in the study 522 patients who required mechanical ventilation for more than 12 hours due to an acute exacerbation of chronic obstructive pulmonary disease (AECOPD). In order to determine those variables associated with mortality, there was performed a recursive partition analysis in which the following variables were included: demographics, arterial blood gas prior to intubation, complications arising during mechanical ventilation (barotrauma, acute respiratory distress syndrome, ventilator-associated pneumonia, sepsis), organ dysfunction (cardiovascular, renal, liver, coagulation) and duration of ventilatory support. INTERVENTIONS: None. VARIABLES OF PRIME IMPORTANCE: ICU mortality. RESULTS: ICU and hospital mortality rates were 22% and 30%, respectively. Variables associated with mortality were cardiovascular dysfunction, renal dysfunction and duration of ventilatory support > 18 days. Median durations were as follows: mechanical ventilatory support, 4 days (P25: 2, P75: 6); weaning from ventilatory support, 2 days (P25: 1, P75: 5); stay in intensive care unit, 8 days (P25: 5, P75: 13); stay in hospital, 17 days (P25: 10, P75: 27). CONCLUSIONS: Mortality in the studied cohort of patients with AECOPD was associated with cardiovascular dysfunction, renal dysfunction and prolonged mechanical support.

Pronóstico de los enfermos con enfermedad pulmonar obstructiva crónica reagudizada que precisan ventilación mecánica / Prognosis for acute exacerbation of chronic obstructive pulmonary disease in mechanically ventilated patients

Objetivo. Determinar las variables asociadas con el pronóstico de los enfermos con agudización de la enfermedad pulmonar obstructiva crónica que requieren ventilación mecánica. Diseño. Estudio prospectivo de cohortes con análisis retrospectivo. Ámbito. Trescientas sesenta y una Unidades de Cuidados Intensivos (UCI) de 20 países. Pacientes y métodos. Se incluyeron en el estudio a 522 pacientes que precisan ventilación mecánica durante más de 12 horas debido a una agudización de la enfermedad pulmonar obstructiva crónica. Para la estimación de las variables asociadas a la mortalidad se realizó un análisis de particiones recursivas, donde se incluyeron las siguientes variables: demográficas, gases arteriales previos a la intubación, complicaciones aparecidas durante la ventilación mecánica (barotrauma, síndrome de distrés respiratorio agudo, neumonía asociada a la ventilación mecánica, sepsis), disfunción de órganos (cardiovascular, renal, hepático, coagulación) y duración del soporte ventilatorio. Intervenciones. Ninguna. Variables de interés principales. Mortalidad en la UCI. Resultados. La mortalidad en la UCI fue de un 22% y en el hospital de un 30%. Las variables asociadas a la mortalidad fueron la disfunción cardiovascular, la disfunción renal y una duración del soporte ventilatorio de más de 18 días. La mediana de la duración de la ventilación mecánica fue de 4 días (P25: 2, P75: 6), de desconexión de la ventilación mecánica de 2 días (P25: 1, P75: 5), de estancia en la UCI de 8 días (P25: 5, P75: 13) y de estancia en el hospital de 17 días (P25: 10, P75: 27). Conclusiones. En nuestra cohorte de enfermos con enfermedad pulmonar obstructiva crónica que requieren ventilación mecánica la mortalidad se asoció a disfunción cardiovascular, renal y necesidad de soporte ventilatorio prolongado

Objective. To determine the variables associated with prognosis for acute exacerbation of chronic obstructive pulmonary disease (AECOPD) in mechanically ventilated patients. Design. Prospective cohort study with retrospective analysis. Location. 361 Intensive Care Units (ICU) in 20 countries. Patients and methods. There were included in the study 522 patients who required mechanical ventilation for more than 12 hours due to an acute exacerbation of chronic obstructive pulmonary disease (AECOPD). In order to determine those variables associated with mortality, there was performed a recursive partition analysis in which the following variables were included: demographics, arterial blood gas prior to intubation, complications arising during mechanical ventilation (barotrauma, acute respiratory distress syndrome, ventilator-associated pneumonia, sepsis), organ dysfunction (cardiovascular, renal, liver, coagulation) and duration of ventilatory support. Interventions. None. Variables of prime importance. ICU mortality. Results. ICU and hospital mortality rates were 22% and 30%, respectively. Variables associated with mortality were cardiovascular dysfunction, renal dysfunction and duration of ventilatory support > 18 days. Median durations were as follows: mechanical ventilatory support, 4 days (P25: 2, P75: 6); weaning from ventilatory support, 2 days (P25: 1, P75: 5); stay in intensive care unit, 8 days (P25: 5, P75: 13); stay in hospital, 17 days (P25: 10, P75: 27). Conclusions. Mortality in the studied cohort of patients with AECOPD was associated with cardiovascular dysfunction, renal dysfunction and prolonged mechanical support

Increase in cardiac output and PEEP as mechanism of pulmonary optimization.

The influence of cardiac output (CO) and PEEP on pulmonary shunt (Qs/Qt) has been the subjects of considerable investigation but findings are controversial. The role of CO and PEEP on 19 isolated rabbit lung preparations perfused with hypoxic mixture (6% CO2, 10% O2, and 84% N2), which resulted in a constant oxygen venous pressure (64 +/- 5.6 mmHg) has been studied. The first group of 11 preparations were used to study the influence of CO modifications with room air ventilation on the Qs/Qt when the CO rises in 48%; in the second group simultaneous modifications in CO and PEEP (0.5 and 10 cm H2O) were performed. A positive correlation (p < 0.01) in Qs/Qt (0.048 +/- 0.04 to 0.12933 +/- 0.09) was found when the CO increased in the first experimental group, the fluid filtration rate (FFR) also increased and the pulmonary vascular resistance (PVR) remained stable. In the second group an increase of 5 and 10 cm H2O of PEEP at constant CO reduced the Qs/Qt (0.0361 +/- 0.02 to 0.0184 +/- 0.006) while it increased the arterio-venous oxygen difference, PVR and FFR. During high CO conditions increase of 5 and 10 cm H2O of PEEP reduced the Qs/Qt (0.099 +/- 0.03 to 0.027 +/- 0.02) and FFR. These data suggest that when the Qs/Qt is increased, the use of PEEP can compensate the ventilation/perfusion alterations and restore pulmonary gas exchange.

Percutaneous balloon valvotomy for patients with severe mitral stenosis.

Thirty-five patients with severe mitral stenosis underwent percutaneous mitral valvotomy (PMV). There were 29 female and six male patients (mean age 49 +/- 3 years, range 13 to 87). After transseptal left heart catheterization, PMV was performed with either a single- (20 patients) or double- (14 patients) balloon dilating catheter. Hemodynamic and left ventriculographic findings were evaluated before and after PMV. There was one death. Mitral regurgitation developed or increased in severity in 15 patients (43%). One patient developed complete heart block requiring a permanent pacemaker. PMV resulted in a significant decrease in mitral gradient from 18 +/- 1 to 7 +/- 1 mm Hg (p less than .0001) and a significant increase in both cardiac output from 3.9 +/- 0.2 to 4.6 +/- 0.2 liters/min (p less than .001) and in mitral valve area from 0.8 +/- 0.1 to 1.7 +/- 0.2 cm2 (p less than .0001) Effective balloon dilating diameter per square meter of body surface area correlated significantly with the decrease in mitral gradient but did not correlate with the degree of mitral regurgitation. There was no correlation of age, prior mitral commissurotomy or mitral calcification with hemodynamic results. PMV is an effective nonsurgical procedure for patients with mitral stenosis, including those with pliable valves, those with previous commissurotomy, and even those with mitral calcification.

Effect of prethymectomy plasma exchange on postoperative respiratory function in myasthenia gravis.

The effect of prethymectomy plasma exchange on postoperative mechanical ventilation requirement and length of stay in the intensive care unit were studied retrospectively in 37 patients with myasthenia gravis. We found a significantly decreased time on mechanical ventilation (mean 1.02 +/- 0.40 versus 3.43 +/- 0.60 days) and a shorter stay in the intensive care unit (mean 3.09 +/- 0.99 versus 5.15 +/- 0.66 days) for 11 patients with respiratory weakness who were treated with preoperative plasma exchange compared with 26 patients who did not receive plasma exchange. Patients with respiratory weakness who received prethymectomy plasma exchange required less time on mechanical ventilation (mean 1.02 +/- 0.40 versus 2.73 +/- 0.88 days) and a shorter stay in the intensive care unit (mean 3.09 +/- 0.99 versus 4.46 +/- 1.08 days) than those patients without respiratory weakness who did not receive plasma exchange. Eleven patients met the criteria for plasma exchange but did not receive it. They required significantly more time on mechanical ventilation (mean 4.43 +/- 0.94 versus 1.02 +/- 0.40 days) and in the intensive care unit (mean 6.09 +/- 0.86 versus 3.09 +/- 0.99 days) than patients who received plasma exchange. Our results indicate that patients with severe forms of myasthenia gravis treated with prethymectomy plasma exchange require less mechanical ventilation and less time in the intensive care unit postoperatively.