Incidence and outcome of weaning from mechanical ventilation according to new categories.

Weaning from mechanical ventilation was categorised as simple, difficult or prolonged by an international task force of the American Thoracic Society/European Respiratory Society/European Society of Intensive Care Medicine/Society of Critical Care Medicine/Sociéte de Réanimation de Langue Française in 2007. This new classification has not been tested in clinical practice. The objective of the present study was to determine the incidence and outcome of weaning according to the new categories. We included medical and surgical patients who required mechanical ventilation in a prospective, multicentre, 6-month cohort study. From an initial cohort of 510 patients, 257 intubated patients started weaning. Of these patients, the cumulative incidences of simple, difficult, and prolonged weaning were 152 (59%), 68 (26%) and 37 (14%), respectively. Hospital mortality was increased in patients with prolonged (32%) but not difficult (9%) weaning in comparison with those with simple weaning (13%), overall p = 0.0205. In a multivariate logistic regression model, prolonged but not difficult weaning was associated with an increased risk of death. Ventilator-free days and intensive care unit (ICU)-free days were decreased in both difficult and prolonged weaning. In conclusion, the new weaning category prolonged weaning is associated with increased mortality and morbidity in the ICU. The new category difficult to wean was associated with increased morbidity, but not mortality.

Effects of biphasic positive airway pressure in patients with chronic obstructive pulmonary disease.

Biphasic positive airway pressure (BiPAP) is a ventilatory mode in which two pressure levels (higher (Phigh) and lower (Plow)) acting as continuous positive airway pressure (CPAP) alternate at preset time intervals. BiPAP combines pressure-controlled ventilation with unrestricted spontaneous breathing. BiPAP has not yet been evaluated in patients with chronic obstructive pulmonary disease (COPD). Therefore, the effects of BiPAP (15 cmH2O Phigh and 5 cmH2O Plow) pressure support (PS; 15 cmH2O and positive end-expiratory pressure (PEEP) 5 cmH2O) and CPAP (5 cmH2O) on respiratory mechanics in COPD patients were compared. Twenty-one COPD patients were supported in randomized order with BiPAP, PS and CPAP. Pressure-time product (PTP), work of breathing (WOB), change in oesophageal pressure (deltaPoes), mouth occlusion pressure (P0.1), intrinsic PEEP (PEEPi), tension time index (TTI), respiratory frequency, and tidal volume (VT) were measured. During BiPAP, the COPD patients showed a significantly higher PTP, WOB, deltaPoes, P0.1, TTI and PEEPi than during PS. Comparing the Plow phases of BiPAP and CPAP, the breaths during the Plow phases of BiPAP had a lower VT and a greater WOB and PTP due to a higher PEEPi than on CPAP alone. In conclusion, biphasic positive airway pressure carries the risk of increased work of breathing in spontaneously breathing chronic obstructive pulmonary disease patients. Pressure support is superior for reducing their respiratory muscle effort.

[Noninvasive ventilation]. / Die nicht-invasive Beatmung.

Non invasive ventilation is defined as mechanical ventilation without the use of endotracheal intubation and has been increasingly established within intensive care units during the last decades. Negative pressure ventilation and non invasive positive pressure ventilation have been successfully applied, first in chronic respiratory failure (CRF) due to various causes and later in acute respiratory failure (ARF). In this review ventilation modes, indications, contraindications and side effects of non invasive ventilation are analysed and the impact of non invasive ventilation on the physiology, pathophysiology and outcome of CRF and ARF, and possible applications in CRF (restrictive chest and pulmonary diseases, neuromuscular diseases and COPD) and ARF are discussed. It is concluded that non invasive ventilation should be included in the routine management of respiratory failure at all intensive care units.

Successful lung transplantation in a long-term ventilator-dependent patient.

Ventilator dependence has been postulated to be a major contraindication for successful lung transplantation. We describe the case of a 44-year-old female patient mechanically ventilated for 10 months after adult respiratory distress syndrome. After a program of physical training the patient underwent successful bilateral sequential lung transplantation. Six months postoperatively she is in good physical condition and is able to carry out the activities of normal daily living. We conclude that in selected patients long-term mechanical ventilatory support is not a contraindication for lung transplantation.

[Effect of stress ulcer prevention on the incidence of ventilation pneumonia at a pulmologic intensive care unit]. / Der Einfluss der Stressulkusprophylaxe auf die Inzidenz von Beatmungspneumonien an einer pulmologischen Intensivstation.

In a retrospective analysis, the influence of stress ulcer prophylaxis on the incidence of ventilation pneumonia (VP) was investigated. In VP, we were able to isolate enterobacteria from the tracheal aspirate or bronchial secretion significantly (p = 0.015) more frequently than in the case of environmentally acquired and nosocomial pneumonia which were treated in the intensive care unit but did not comply with the criteria for VP. The detection of intestinal bacteria in the respiratory tract in VP patients supports the hypothesis that the "gastro-pulmonary" colonisation pathway represents a decisive factor in the development of VP. Patients undergoing long-term ventilation who had received ranitidine for prophylaxis of stress ulcer, developed VP statistically significantly more frequently (p = 0.044) than did patients with sucralfat cover. The non-physiologically high acid juice pH associated with the use of H2-antagonists leads to an increase in intestinal organisms within the stomach. By ascending the upper GI tract, the bacteria finally colonise the respiratory tract. Through the application of sucralfat, whose ulcerprotective action is not achieved by the inhibition of acid in the stomach, the incidence of VP in a pulmological intensive care unit was reduced.

[Anesthesia procedures for bronchoscopic intubation in a comparative study]. / Anästhesieverfahren zur bronchoskopischen Intubation im Vergleich.

In 94 patients intubation by means of the fibre-optic bronchoscope was effected in various indication. Three different methods of anaesthesia were used: local anaesthesia + mild sedation; general anaesthesia + relaxation; sedation + analgesia. The experiences made with these methods--based on clinical observation and interrogation of the patients--reveal the special usefulness of local anesthesia for bronchoscopic intubation; this is probably the method of choice in practice.

[The assessment of cardiorespiratory performance in pulmonary emphysema (author's transl)]. / Zur kardiorespiratorischen Leistungsbeurteilung bei obstruktiven Emphysem.

In patients with pulmonary emphysema the course of PO2 and of pulmonary and systemic circulation is analysed under exercise up to the performance limit and to PO2 reduction. By alterations of breathing mechanics frequent emphysematous persons and associated with bronchial obstructions under increased intrapulmonary pressure by forced ventilation a group of patients may be found with a quick limitation of performance by hindering the intrathoracic circulation followed by reduction of the systemic blood pressure. A pulmonary arterial hypertension cannot be seen in these cases. The registration of the parameters of breathing mechanics during exercise testing is recommended.

[Hemodynamics of pulmonary circulation during pulmonary resection (author's transl)]. / Zur Hämodynamik des kleinen Kreislautes während der Lungenresektion.

In 22 patients continuous measurement of the pulmonary artery pressure was performed during pulmonary resection. A remarkable elevation of the pulmonary artery pressure was observed: a) at the introduction of anesthesia, b) when the lung was compressed during the preparation of the hilus-vessels, c) when the pulmonary artery was ligated, d) at probatory inflation of the lungs. The factors causing the elevation of the pulmonary artery pressure during pulmonary resection are discussed.

[Can chloramphenicol be combined with beta-lactam antibiotics? (author's transl)]. / Kann Chloramphenicol mit Beta-Lactam-Antibiotika kombiniert werden?

The effect was studied of combinations of chloramphenicol with beta-lactam antibiotics, such as penicillin, ampicillin, cefotiam and cefotaxime, on 20 strains each of Haemophilus influenzae, Streptococcus pneumoniae and Neisseria meningitidis. No antagonism was observed using the checkerboard titration method. In most cases no interaction could be established. An evaluation by the fractional inhibitory concentration index was discussed: only values above 2 were interpreted as antagonism. The minimal bactericidal concentrations of chloramphenicol were identical with the minimal inhibitory concentrations (MIC) - i. e. the antibiotic acted bactericidally on the species tested. Further investigations on the killing kinetics have shown that chloramphenicol in low concentrations can cause a delay in the bactericidal action of the antibiotic with which it is combined in the first few hours. At higher concentrations (more than double the MIC) the killing kinetics approximate those of the individual antibiotics. It is improbable that the minor delays in killing are of clinical significance. The combination is almost as effective as chloramphenicol.

[Early bronchiolar-alveolar cell cicatricial carcinoma; a case report with 2 illustrations]. / "Early" bronchiolo-alveolarzelliges Narbenkarzinom; Ein Fallbericht mit zwei Abbildungen.

Only the solitary type of bronchiolo-alveolar cell carcinoma has a chance of being healed if surgery is performed in time. This type of tumor is often found as a cicatricial carcinoma in the periphery of the lung. Small tumors do not exhibit any clinical symptoms, they are either detected by mere chance or during radiological check-up or routine medical check-up of healthy persons. In the present case a small posttuberculous scar in the lung had been known to exist for ten years. Only a repeated routine medical check-up including X-ray examination and subsequent tomographic X-ray gave an indication for the performance of thoracotomy. While surgery was being performed the malignancy and the tumor type where cytologically determined and verified by histological examination of the excised tumor.