As weaning or weaning (English wean to - wean), and weaning called the phase of weaning is a mechanically ventilated patient from the ventilator designated, a mechanical breathing assistance, mostly in the context of intensive care on an intensive care unit takes place.
The weaning process takes a short time if the ventilation duration was short and the lung function did not change significantly. This is the case with operations . After anesthesia with respiratory support for about 30 minutes to a few hours, depending on the respective procedure, the patient is looked after in the operating room or in the recovery room by competent nursing staff until he has regained full breath control and alertness. The extubation , so the removal of the endotracheal tube , then usually proceeds without difficulty.
In the case of a somewhat longer ventilation duration (1 to 3 days), weaning from the respirator is also often problem-free if the ventilation did not result from a disorder that primarily affected the lungs.
After long-term ventilation (longer than a week) in the case of severe illnesses , weaning of the patient is often difficult. Sometimes it takes a long time, in individual cases up to several weeks, before the work of breathing can be completely taken over again. Assisted spontaneous breathing is an essential part of weaning: The ventilation support provided by the ventilator can be gradually reduced by changing the settings on the device. When weaning from the device, the ventilation modes BIPAP and later CPAP are often used. There are many reasons for making ventilatory weaning difficult. Clinically, there is often a muscular weakness of the respiratory muscles, which leads to ventilation failure with hypercapnic lung failure. Extracorporeal systems for CO 2 removal (extracorporeal CO 2 elimination "E-CO 2 -E"; iLA membrane ventilator from Novalung ) are increasingly used to support ventilation lifting , since they can be used to stimulate the respiratory muscles by modifying their gas flow to relieve the patient and to train again in a targeted manner, without having to worry about overexertion of the patient. The use of iLA (Interventional Lung Assist, an artificial lung) also leads to a reduction in the need for analgesics and sedation and increases the proportion of spontaneous breathing significantly within a few hours, so that the weaning time can be shortened.
The percutaneous tracheotomy also makes weaning significantly easier .
With the resumption of respiratory function, the patient must also become more alert. In this context it becomes necessary to reduce the patient's sedation as well .
The prerequisites for starting weaning include, for example, existing bowel activity, regular self-breathing without extreme tachypnea, stable circulatory conditions, sufficient inspiratory strength and minimum values for the arterial oxygen partial pressure and for the pH value.
A main goal when weaning from the respirator is to reduce ventilatory invasiveness, for example by systematically reducing the inspiratory oxygen concentration, shortening the ratio of inspiration to expiration, reducing PEEP, promoting spontaneous breathing and reducing airway pressure. The ventilation hose can be removed if the oxygen concentration to be supplied is around 40%, the respiratory support (CPAP) is around 5 cm of water and the oxygen partial pressure in the arterial blood is at least 60 mm of mercury.
- H. Benzer: Therapy of respiratory failure. In: J. Kilian, H. Benzer, FW Ahnefeld (ed.): Basic principles of ventilation. Springer, Berlin a. a. 1991, ISBN 3-540-53078-9 , 2nd, unchanged edition, ibid 1994, ISBN 3-540-57904-4 , pp. 215-278; here: pp. 269–275: Weaning from the respirator (weaning) .
- André Gerdes: Weaning. In: Intensive Care Unit. May 16, 2001 .
- L. Gattinoni, A. Pesenti, D. Mascheroni et al .: Low-frequency positive-pressure ventilation with extracorporeal CO2 removal in severe acute respiratory failure. In: JAMA. 256, 1986, pp. 881-886. PMID 3090285 .
- H. Benzer: Therapy of respiratory failure. In: J. Kilian, H. Benzer, FW Ahnefeld (ed.): Basic principles of ventilation. Springer, Berlin a. a. 1991, ISBN 3-540-53078-9 , 2nd, unchanged edition, ibid 1994, ISBN 3-540-57904-4 , pp. 215-278; here: p. 268 f.
- S. Weber-Carstens et al .: Hypercapnia in late-phase ALI / ARDS: providing spontaneous breathing using pumpless extracorporeal lung assist. In: Intensive Care Medicine , 2009, 35, pp. 1100-1105.
- H. Benzer: Therapy of respiratory failure. 1991 (1994), pp. 269-271.
- H. Benzer: Therapy of respiratory failure. 1991 (1994), pp. 271-275.