الفهرس 
Anatomy of lower airways
ANESTHESIA OF PATIENTS WITH COPD AND COMPLICATIONSOnly 14 pages are availabe for public view
 |  | from | 104 |  |  |
| | | from | 104 | | |
Abstract
Respiratory diseases are one of the most frequently encountered problems in anesthetic practice, which may add to the risk of the operation. This includes some of the commonest respiratory diseases like: COPD and bronchial asthma.
COPD is a title which is used mainly to refer to patients with chronic bronchitis and emphysema characterised by the development of respiratory obstruction.
Bronchial asthma is chronic inflammatory disorder of the airways leading to recurrent episodes of wheezing, breathlessness, chest tightness and coughing in response to variable stimuli. These episodes are usually associated with variable widspread airways obstruction, that is often reversible.
A review of normal anatomy and physiology of respiratory system, and pathophysiology of COPD and
bronchial asthma were discussed with some detail in this essay.
Preoperative assessment of the patient’s condition was discussed to help in reducing the expected complications and their management. A good assessment can be achieved by carefull history, examination and investigation including pulmonary function tests in detail.
Proper preoperative preparation is mandatory intending to improve the respiratory condition through, eradication of infection, cessation of smoking treatment of bronchospasm and chest physiotherapy.
Premedication using narcotics and sedatives should be avoided in patients with preoperative hypercapnea (PaCO2 <
51 mmHg) or with hypoxia (PaO2>61 mmHg). Regional anesthesia is much preferable than general anesthesia as it avoids trachea! Intubation and general aneathetic agents that may initiate bronchospasm.
Regarding general anesthesia, different induction agent are discussed as methohexitone, etomidate, profol and ketamine. Thiopentone could be used with caution as it causes bronchospasm. Maintenance inhalational anesthetic agents discussed including halothane, enflurance, isoglurane, and the most recent, desflurane and sevoflorane. The bronchodilator effects of halothane must be weighed against its cardiovascular depressant effect. The newer inhalational agents such as enflurane and isoflurane produce
bronchodiatation but without the risk of cardiovascular depression, so, they are better alternative.
Concerning muscle relaxation the safest muscle relaxants are pancuronium and vecuronium being free from histamine release and cardiovasculr side effects.
Reversal of muscle relaxation is done by atropine followed by neostigmine to avoid precipitation of bronchospasm. Controlled ventilation of the lungs during intraoperative period is essential, in COPD especially emphysema, the use of slight positive pressure during expiration helps keeping the bronchi and alveoli uncollapsed and to avoid barotrauma.
A brief review of intraoperative monitoring was also discussed. Postoperative management was also discussed regarding recovery duration and satisfactory ventilation.
The use of elective postoperative artificial ventilation may be required for supporting patients with pre-existing COPD under certain circumstances. Postoperative pulmonary complications includes hypoxaernia, hypoventilation, atelectasis and pneumonia all of which can be minimized by good preoperative preparation, proper management intraoperatively and carful attendance to the patients in the early postoperative period.