Mechanical ventilation in patients with chronic obstructive pulmonary disease and bronchial asthma

Abstract

Chronic obstructive pulmonary disease (COPD) and bronchial asthma often complicate the surgical patients, leading to post-operative morbidity and mortality. Many authors have tried to predict post-operative pulmonary complications but not specifically in COPD. The aim of this review is to provide recent evidence-based guidelines regarding predictors and ventilatory strategies for mechanical ventilation in COPD and bronchial asthma patients. Using Google search for indexing databases, a search for articles published was performed using various combinations of the following search terms: 'Predictors'; 'mechanical ventilation'; COPD'; 'COPD'; 'bronchial asthma'; 'recent strategies'. Additional sources were also identified by exploring the primary reference list.

Keywords: Bronchial asthma; chronic obstructive pulmonary disease; heliox; mechanical ventilation; risk.

Figure 1

Waterfall phenomenon and its relation with critical pressure

Figure 2

Expiratory hold manoeuvre to estimate auto-positive end-expiratory pressure

Figure 3

Generation of auto-positive end-expiratory pressure

Figure 4

Air trapping in flow-volume loop

Figure 5

(a) Waterfall phenomenon-negative pressure required to trigger the ventilator breath is reduced on application of external positive end-expiratory pressure, (b) effect of applied positive end-expiratory pressure on triggering-extrinsic positive end-expiratory pressure of 5 cm H₂O reduces the work of breathing from level A to level B by offsetting the auto-positive end-expiratory pressure in this chronic obstructive pulmonary disease patient with trigger sensitivity of 2 cm H₂O

Figure 6

Pressure-time curve indicating increased airway resistance. Peak inspiratory pressure increases whereas Pplat remains same