1. Prediction tools CXR Low yield in in patient without risk factors In a systematic review of 14 studies abnormal CXR lead to Rx change in 10% of cases without changing PPC rate. ABG Cardiac, thoracic, abdominal surgeries Pts who have SOB or smokers Pt with abnormal pulse oximetry

2. Prediction tools Cardiopulmonary Exercise Testing Purely lung resection surgery MVO2 maximum oxygen consumption MVO2 > 20ml/kg low risk MVO2 < 10 ml/kg very high risk Stair climbing Prospective study in 110 pts who underwent high risk procedures  thoracotomy, sternotomy or upper abd sx 7 Flights of stairs each flight consists of 18 steps Cardioplumonary complications & mortality Girisch et al Chest 2001

5. Lung Resection The risks associated with thoracotomy can be divided into 2 categories: I- short-term risk  perioperative morbidity and mortality II- long-term risk  activity limitation resulting from loss of lung reserve. Low Risk FEV1 (Forced Expiratory Volume in one second ) 1.2 L Predicted postoperative FEV1.8 L or 40% predicted MVV ( Maximum Voluntary Ventilation) 50% predicted High Risk PCO2 45 or PO2 50 Predicted Postoperative FEV1 0.7 L 40% predicted Poor exercise performance Rilley Chest 1999

6. American College Of Chest Physician Guidelines 2007

8. Preventive Measures Incentive spirometry & deep breathing exercises Meta-analysis of 14 studies of incentive spirometry & deep-breathing exercises Vs no intervention  odds ratios of 0.44 and 0.43 for PPC Preoperative education reduces PPC to a greater degree than instruction that begins after surgery Arch Phys Med Rehab 1985 & AmRev Respir Dis 1984

9. Preventive Measures Non invasive positive pressure ventilation Prospective study of 72 post abdominal Sx pts with acute hypoxic failure were treated with escalating PSV /PEEP to achieve target tidal volume of 8-10 ml/kg. 48/72 (67%) avoided intubation LOS was shorter 17 days Vs 34 days Mortality was less 6% Vs 29% 10/72 had esophageal & gastric surgery  no leak Jaber Chest oct 2005

10. To put everything together Sematana NEJM 2007

11. Take Home Message Conducting detailed history taking & physical examination should be the first screening tool Investigations selection had to tailored to detected abnormalities Risk factors for PPC are either patient or procedure related. It could be modifiable or non modifiable The variation in definition of PPC & patient population lead to different reported rate of PPC All prediction tools of PPC have not been validated after being derived  further studies is needed

12. Thanks The more you know the more you realize how much you don’t know