PULMONARY RISK ASSESSMENT AND MANAGEMENT

Preoperative evaluation
Assessment:

Risk factors: (Ref 1) COPD Age >60 ASA class II+ Functionally dependent CHF	Note that obesity and mild-moderate asthma were not found to be risk factors for postoperative pulmonary complications. (Ref 1)
Obstructive Sleep Apnea	See “Obstructive Sleep Apnea”
Consider:  Serum albumin if suspected hypoalbuminemia. (Ref 1)	Albumin (<3.6 g/dl) predicts postoperative complications However, this finding may not change management with regard purely to pulmonary complications.  Surgeons are usually highly attentive to nutritional status for other reasons (overall morbidity, mortality, wound healing, etc.) and will delay surgery for those reasons.
Advise smoking cessation	Smoking cessation was previously thought to have benefit if done 6-8 weeks or greater prior to surgery, with concern for harm if cessation occurred too close to surgery.  However, a systematic review concluded that existing evidence does not support an increased risk of complications due to stopping smoking prior to surgery.2

 

Diagnostic tests:

Chest x-ray	Routine preop chest x-rays are NOT indicated.  No consensus—guidelines differ.  ACP guidelines: “may be helpful” in patients >50 year of age who are undergoing upper abdominal, thoracic, AAA surgery, or in patients with cardiac or pulmonary disease.1 Rarely changes management dramatically, but may be very useful in these select populations.
Pulmonary function tests (PFTs)	Routine PFTs NOT indicated except for certain surgeries (e.g. thoracic surgery—usually defer this testing to the surgeon) Known COPD:  assess by symptoms and exam Consider for patient with suspected but previously undiagnosed obstructive lung disease.
Arterial Blood Gas (ABG)	Consider for patients with elevated serum HCO3, O2 dependence, moderate to severe COPD, or suspected obesity-hypoventilation syndrome.

 

Postoperative management

Lung expansion maneuvers (e.g. incentive spirometry)	Recommended in ACP guidelines1 Cochrane Review found no evidence of incentive spirometry reducing pulmonary complications in upper abdominal surgery, but was limited by few quality studies.3
Nasogastric (NG) tube	ACP guidelines recommend “Selective use of NG tubes for decompression for nausea, vomiting, abdominal distension.” (Ref 1) In practice, we defer this to the surgery team.  For many patients, a new anastomosis (e.g. esophageal surgery) makes NG tube placement potentially dangerous—always discuss with the surgical team.
Pulse oximetry	Recovery room pulse oximetry is routine and managed by anesthesia. Consider for patients with sleep apnea or high risk of hypoxemia.  (see “Obstructive Sleep Apnea”)

 

Discussion
Risk stratification:  Despite attention paid to cardiovascular risk stratification and complications, pulmonary complications likely exceed those of cardiovascular complications.  Cardiovascular risk stratification, however, has benefited from easy to use, well validated risk tools such as the Revised Cardiac Risk Index (see “Cardiovascular Risk Stratification”).  Risk models for postoperative pulmonary complications have identified age, preoperative O2 sat, recent respiratory infection, preoperative anemia, upper abdominal or thoracic surgical site, duration of surgery, and emergent procedures as risk factors—however the scoring system requires adding up weight scores for each risk factor.4

Other pulmonary conditions:  Other conditions have had increasing evidence for risks of postoperative complications, including obstructive sleep apnea and pulmonary hypertension.  These are discussed separately—see “Obstructive Sleep Apnea,” “Asthma and COPD,” “Pulmonary Hypertension” “Venous Thromboembolic Disease.”

References

• 1.  Qaseem A, Snow V, Fitterman N, et al.  Risk Assessment for and Strategies to Reduce Perioperative Pulmonary Complications for Patients Undergoing Noncardiothoracic Surgery:  A Guideline from the American College of Physicians.  Annals of Internal Medicine.2006;144:575-580.
• 2.  Myers K, Hajek P, Hinds C, et al.  Stopping Smoking Shortly Before Surgery and Postoperative Complications.  Arch Intern Med.  Published online March 14, 2011.
• 3.  Guimaraes MMF, El Dib RP, Smith AF, et al.  Incentive Spirometry for Prevention of Postoperative Pulmonary Complications in Upper Abdominal Surgery.  Cochrane Database of Systematic Reviews.  2009;3: CD006058. (updated 2011).
• 4. Canet J, Gallart L, Gomar C, et al.  Prediction of Postoperative Pulmonary Complications in a Population-based Surgical Cohort.  Anesthesiology 2010; 113: 1338-1350.

 

 

Updated May 2011