Perioperative lung protective ventilation in obese patients

BMC Anesthesiology

Table 1 Changes of respiratory mechanics and functions in obese patients

Physiological changes	Challenges for respiratory management
Excessive oro-pharyngeal adiposity	Upper airway obstruction
Increased risk of pharyngeal collapse during sleep	Frequent sleep apnea/obesity hypoventilation syndrome
Decreased compliance (chest wall > lung)	Decreased compliance during mechanical ventilation
Increased airway resistance
Increased work of breathing
Increase in resting VO₂	Frequent hypoxemic events
Decrease in FRC and EELV	Atelectasis
FRC < closing capacity	Rapid oxygen desaturation
Small airway closure
Alveolar collapse
Ventilation–perfusion (V/Q) mismatch
Increased PA-aO2, Decreased PaO2

(EELV = End-expiratory lung volume; FRC = Functional residual capacity; PaO₂ = Arterial partial pressure of oxygen; PA-aO2 = Alveolar to arterial partial pressure of oxygen; VO₂ = Oxygen consumption; V/Q = Ventilation/perfusion).

ISSN: 1471-2253