Survival and long-term follow-up of tracheostomized patients with COPD treated by home mechanical ventilation. A multicenter French study in 259 patients. French Cooperative Study Group.

To define more clearly the value of home mechanical ventilation by tracheostomy (HMVT) in patients with advanced COPD, a retrospective French multicenter study group analyzed the prognostic factors and long-term survival of 259 patients with severe COPD, who were tracheostomized for at least 1 year. Seventy-eight percent of the patients died by the end of the observation period. The actuarial survival rate for the overall study population was, therefore, 70 percent at 2 years, 44 percent at 5 years, and 20 percent at 10 years. These results appear to be better than those of the major published series and compare to the prognosis of COPD patients treated by long-term oxygen therapy (LTO) 15 hr/24 hr. The parameters most closely correlated with a survival for more than 5 years were age < 65 years, use of an uncuffed cannula, and a PaO2 > 55 mm Hg in room air during the 3 months after tracheostomy (p < 0.01). This study, therefore, confirmed the feasibility of HMVT in COPD and should lead to a review of the place of permanent tracheostomy in the long-term prognosis of severe COPD patients.

Sequential use of noninvasive pressure support ventilation for acute exacerbations of COPD.

OBJECTIVES: To compare the efficacy of noninvasive pressure support ventilation (NIPSV) in acute decompensation in chronic obstructive pulmonary disease (COPD) by means of a bi-level positive airway pressure support system (BiPAP) in a sequential mode with medical therapy alone; to assess the short-term physiologic effects of the device on gas exchange; and to compare patients successfully ventilated with NIPSV with those in whom NIPSV failed. DESIGN: A prospective case series with historically matched control study. SETTING: A general intensive care unit (ICU) of a university hospital. PATIENTS: We evaluated the efficacy of administration of NIPSV in 42 COPD patients and compared this with standard treatment in 42 matched historical control COPD patients. INTERVENTIONS: NIPSV was performed in a sequential mode, i.e., BiPAP in the spontaneous mode was used for at least 30 min every 3 h. Between periods of ventilation, patients could be systematically returned to BiPAP when the arterial oxygen saturation was < 0.85 or when the respiratory rate was > 30 breaths/min. MEASUREMENTS AND RESULTS: Success rate, mortality, duration of ventilatory assistance, and length of ICU stay were recorded. Eleven of the 42 patients (26%) in the NIPSV group needed tracheal intubation compared with 30 of the 42 control patients (71%). The 31 patients in whom NIPSV was successful were ventilated for a mean of 6 +/- 3 days. In-hospital mortality was not significantly different in the treated versus the control group, but the duration of ventilatory assistance (7 +/- 4 days vs 15 +/- 10 days, p < 0.01) and the length of ICU stay (9 +/- 4 days vs 21 +/- 12, p < 0.01) were both shortened by NIPSV. BiPAP was effective in correcting gas exchange abnormalities. The pH values, measured after 45 min of BiPAP with optimal settings, in the success (7.38 +/- 0.04) and failure (7.28 +/- 0.04) patients were significantly different (p < 0.05). CONCLUSIONS: NIPSV, performed with a sequential mode, may be used in the management of patients with acute exacerbations of COPD.

Fulminant Guillain-Barré syndrome mimicking cerebral death: case report and literature review.

A 45-year-old woman was admitted to the intensive care unit (ICU) for respiratory arrest. One day prior to admission, she had been nauseated and in a state of total exhaustion. On the night of admission she was unresponsive and developed gasping respiration. The patient was comatose with absent brainstem reflexes and appeared brain dead. Blood chemistry findings and brain magnetic resonance imaging were normal. Electroencephalogram revealed an alpha rhythmical activity unresponsive to painful or visual stimuli. The cerebrospinal fluid showed an albuminocytological dissociation. Guillain-Barré syndrome (GBS) was suspected. The electrophysiological evaluation revealed an inexcitability of all nerves. The pathological findings of the sural nerve biopsy indicated an axonal degeneration secondary to severe demyelination. GBS can very rarely present with coma and absent brainstem reflexes. This case illustrates the importance of electrophysiological tests and laboratory and imaging studies in patients with suspected brain death where a cause is not clearly determined.

Airway occlusion pressure at 0.1 s (P0.1) after extubation: an early indicator of postextubation hypercapnic respiratory insufficiency.

OBJECTIVE: To examine variables associated with postextubation respiratory distress in chronic obstructive pulmonary disease (COPD) patients. DESIGN: Prospective, clinical investigation. SETTING: Intensive care unit of a university hospital. PATIENTS: Forty COPD patients, considered ready for extubation. MEASUREMENTS AND MAIN RESULTS: We recorded, from the digital display of a standard ventilator, breathing frequency (f), tidal volume (VT) and f/VT for the respiratory pattern, airway occlusion pressure at 0.1 s (P0.1) for the respiratory drive and measured blood gases: i) before extubation, following 30 min of a 6 cm H2O pressure support (PS) ventilation trial, ii) 1 h after extubation, at the 30th min of a face mask 4 cm H2O PS ventilation trial. According to the weaning outcome, the patients were divided into two groups: respiratory distress, and non-respiratory distress within 72 h of the discontinuation of mechanical ventilation. The respiratory distress was defined as the combination of f more than 25 breaths/min, an increase in PaCO2 of at least 20% compared with the value measured after extubation, and pH lower than 7.35. We determined whether those patients who developed respiratory distress after extubation differed from those who did not. Respiratory pattern data and arterial blood gases recorded, either before or after extubation, and P0.1 recorded before extubation, were inadequate to differentiate the two groups. Only P0.1 recorded 1 h after the discontinuation of mechanical ventilation differentiated the patients who developed respiratory distress from those who did not (4.2+/-0.9 vs 1.8+/-0.8, p < 0.01). CONCLUSIONS: P0.1 recorded after extubation may be a good indicator of postextubation respiratory distress. Measuring P0.1 and/or the analysis of the evolution of this parameter could facilitate decisions during the period following extubation.

Optimal pressure support level for beginning weaning in patients with COPD: measurement of diaphragmatic activity with step-by-step decreasing pressure support level.

PURPOSE: The study objective was to determine an "optimal" individual pressure support (PS) level for beginning weaning with PS ventilation in patients with chronic obstructive pulmonary disease (COPD). MATERIALS AND METHODS: Eleven COPD patients intubated and ventilated for acute respiratory failure and judged ready for weaning were studied. The technique consisted of lowering the PS level from a point that was characteristic for each patient and measurable under controlled mechanical ventilation, after setting the ventilator as recommended for COPD patients judged ready for weaning, that is, peak inflation pressure (PIP). This determination was based mainly on exploring the diaphragm with an electromyographic technique by defining the optimal PS level as the lowest PS level associated with no EMG evidence of diaphragmatic stress. Diaphragmatic electromyographic activity (diEMG) was recorded by a bipolar esophageal electrode (Disa-Denmark), and the high-frequency electrical component/low-frequency ratio (H/L) was calculated. The reference H/L was determined during a few spontaneous ventilatory cycles. Muscle stress was defined as a greater than 20% reduction in H/L compared with the reference value. RESULTS: Optimal PS levels ranged from 4 to 24 cm H2O with a mean of 14+/-6 cm H2O. Two patients with optimal PS level at 4 cm H2O did not require weaning and were quickly extubated. For the nine other patients, optimal PS levels were found to be 70% of PIP; in none was it necessary during weaning to use PS levels higher than individual optimal PS levels. CONCLUSIONS: Optimal PS level established with diEMG monitoring seems to be a useful index for beginning weaning in the PS ventilation mode in COPD patients. The hypothesis of beginning weaning with a PS level equal to 70% of PIP needs to be tested.

Guillain-Barré syndrome: an ultrastructural study of peripheral nerve in 65 patients.

65 biopsies of peripheral nerve from patients suffering from Guillain-Barré syndrome were studied by electron microscopy. In 48 cases there was macrophagic invasion of the Schwann cells of certain myelinated fibers, and in 32 of these cases some myelin sheaths were stripped away by an elongated macrophagic process. Vesicular disruption of the myelin sheath was observed in only 8 cases and in less than 1% of the myelinated fibers. Uncompacted myelin lamellae were observed in a few myelinated fibers. These ultrastructural lesions are analysed and commented on with a view to selecting patients who are to undergo plasma exchange.

Evaluation of bronchoalveolar lavage for the diagnosis of bacterial pneumonia in ventilated patients.

Fourty-six patients requiring mechanical ventilation and suspected of bacterial pneumonia were examined by fiberoptic bronchoscopy. Specimens recovered by bronchoalveolar lavage (BAL) and using a protected specimen brush (PSB) were quantitatively cultured and the results compared. An assessment of the percentage of cells with intracellular organisms present on cytocentrifuged preparations made from lavage fluid was made to evaluate the utility of this method in early diagnosis of pneumonia. BAL cultures made a correct diagnosis in 43 out of 46 patients and detected 10 false-negative cultures of the PSB. With a threshold of more than 3% of cells with intracellular bacteria, direct microscopic examination diagnosed bacterial pneumonia in 36 out of 46 patients and allowed appropriate antibiotherapy to be instituted earlier. These results demonstrate the ability of BAL to diagnose bacterial pneumonia in ventilated patients.

[Outcome of patients with chronic respiratory insufficiency treated at home with tracheotomy and assisted ventilation]. / Devenir des insuffisants respiratoires chroniques traités à domicile par trachéotomie et ventilation assistée.

60 patients were studied with severe chronic respiratory failure (IRC) and a permanent tracheostomy treated with domiciliary ventilation (VADT). The study commenced from the time of the tracheostomy and included length of survival (by the actuarial method) quality of life, subjectively and objectively (progress of blood gases in a stable clinical state and cumulative length of periods in hospital). Factors influencing the decision for tracheostomy and VADT were examined. Restrictive cases benefitted from the technique as much from the improved quality of life as from the duration of survival (77% at 5 years). Patients with an obstructive or mixed pattern had a 5 years survival of 73% after the first episode of acute or chronic respiratory failure which was 73% better than comparable patients given neither a tracheostomy nor oxygen therapy. The five years survival of 42% on VADT in our series compares favourably with the main series published. In our opinion the improved survival in these patients (which tends to rejoin that of the general population) and the improved quality of life justifies the use of this treatment in severe obstructive IRC, despite a greater demand and cost of this treatment than those with a restrictive defect.

[Non-invasive ventilation in immunosuppressed patients]. / La ventilation non invasive chez le patient immunodéprimé

INTRODUCTION: In immunosuppressed patients with acute respiratory insufficiency (ARI) mechanical ventilation is associated with a high mortality. Therefore, in this situation, avoidance of intubation could be an important objective. However, experience of non-invasive ventilation (NIV) in the immunosuppressed remains limited. STATE OF ART: The first descriptive studies have shown that NIV could be an alternative to intubation, particularly in patients with malignant haematological disorders. In a prospective randomised controlled study Antonelli et al. showed that the use of NIV significantly improved the prognosis of patients with ARI following organ transplantation. We have carried out a prospective randomised controlled trial in 52 immunosuppressed patients to determine whether NIV improved the prognosis in patients admitted to intensive care with pulmonary infiltrates, fever and ARI. The use of NIV was associated with significant reductions in the intubation rate, serious complications and ICU and hospital mortality. PERSPECTIVES: Further studies are needed in order to better define the patients susceptible to benefit from NIV, and to establish variables predictive of the success or the failure of the method. CONCLUSIONS: NIV leads to an improvement in the prognosis of some immunosuppressed patients admitted to intensive care.

[Association of type 1 neurofibromatosis and primary hyperparathyroidism]. / Association neurofibromatose de type I et hyperparathyroïdie primitive.

INTRODUCTION: The combination of neurofibromatosis type I with hyperparathyroidism is classical but rare. OBSERVATION: Our report is on the original observation of a patient affected with Von Recklinghausen's disease complicated by chronic restrictive breathing deficiency. After an intense breathing decompensation and a spreading convulsive attack, hyperparathyroidism was diagnosed. DISCUSSION: The similarity of the bone lesions seen in type I neurofibromatosis and in hyperparathyroidism strongly suggests a genetic link between these two pathologies. Hence, hyperparathyroidism should be searched for in all patients affected with Von Recklinghausen's disease, since the adjustment of hypercalcemia can lead to partial reversibility of the bone abnormalities.