In the first 48-72 hours quitters may have increased secretions and more reactive airways. Acute cessation decreases carboxyhemoglobin and increases oxygenation to tissues (right shift of oxyhemoglobin curve), less carbon monoxide, less nicotine and associated tachycardia, and increased ciliary function. Other benefits take 2-4 weeks, such as decreased secretions and decreased airway reactivity.
4-6 weeks immune and metabolic function normalize, 12 weeks for an improvement in mucociliary transport and small airway function.
A study of 410 non-cardiac surgery VA patients showed that smoking cessation within 4 weeks of surgery actually increased pulmonary complications. Bluman et al. In CABG patients, reduced pulmonary complications require 8 weeks of cessation, and in thoracic surgery patients, at least 4 weeks. Warner et al.
Smoking Cessation: Acute Physiology
- 48 – 72 hours: increased secretions and more reactive airways. Decreased carboxyhemoglobin (normal < 1.5%, smokers 3-10%), increased tissue oxygenation
- 2 – 4 weeks: decreased secretions, decreased airway reactivity
- 8 weeks: decrease in overall post-op morbidity and mortality
M A Warner, M B Divertie, J H Tinker Preoperative cessation of smoking and pulmonary complications in coronary artery bypass patients. Anesthesiology: 1984, 60(4);380-3
L G Bluman, L Mosca, N Newman, D G Simon Preoperative smoking habits and postoperative pulmonary complications. Chest: 1998, 113(4);883-9