Flexible Fibre-Optic Bronchoscopy in the Intensive- Care Unit

Flexible fibre-optic bronchoscopy and bronchoalveolar lavage have become important diagnostic tools for the evaluation and often for the treatment of infants and children with serious lung and airway problems causing respiratory insufficiency or failure. These patients are cared for in the paediatric or neonatal intensive-care units, and they usually require endotracheal intubation (or tracheostomy) and mechanical ventilation. Although the technique of the procedure and the equipment used do not differ from those used in the outpatient setting, the severity of illness and the lability of the patients pose unique challenges for the bronchoscopist. These challenges stem primarily from the fact that even the smallest bronchoscope causes significant obstruction of the artificial airway, which the patient may not be able to tolerate. The airway obstruction has various effects on the lung mechanics (especially on airway resistance), on the gas exchange (causing significant hypoxaemia and/or hypercapnia) and on the haemodynamic status of the patient. The following chapter discusses the range of possible problems as well as the precautions that should be taken in order to avoid severe adverse effects. Copyright © 2010 S. Karger AG, Basel In principle, flexible fibre-optic bronchoscopy (FFB) in the intensive-care unit (ICU) is not different from a bronchoscopy performed in an outpatient setting. The equipment as well as the basic technique are the same [1–5]. Yet, differences in the patient population and in the conditions under which the procedure is performed in the ICU demand very different considerations and precautions. The range of potential problems was very graphically summed up in the title of a recent editorial on the effects of FFB on mechanical ventilation: ‘How to cause chaos with a bronchoscope in the ICU’ [6]. The following chapter discusses the most common of these problems and provides tips on how to avoid ‘causing chaos’. Characteristics of the Critical-Care Setting Patient Population Patients undergoing an FFB in the ICU differ substantially from those who undergo the procedure in an outpatient setting (table 1). The latter tend to have a single condition or symptom involving the airways and/or the lung parenchyma (e.g. persistent wheezing or stridor, recurrent croup, persistent cough, recurrent pneumonia) but they are otherwise well or at least clinically stable. In contrast, patients in the ICU are either critically ill or at risk of becoming critically ill with conditions that often affect multiple organ systems. Their respiratory insufficiency or failure is often caused by the dysfunction or failure of organ systems other than the respiratory (e.g. cardiogenic or neurogenic pulmonary oedema, liver failure, major surgery or trauma). The vast majority of the ICU patients receive some form of mechanical ventilatory support either by non-invasive means such as continuous or biphasic positive airway pressure and more commonly via an endotracheal tube (ETT) or tracheostomy tube (T tube). Airway Size The insertion of a flexible fibre-optic bronchoscope into the trachea causes partial obstruction of its lumen, the degree of which depends on the diameter of the patient’s trachea in relation to the diameter of the bronchoscope. This