Anesthesia and COPD - An Insight

Introduction:

Patients with chronic obstructive pulmonary disease (COPD) are more likely to experience perioperative complications and face higher mortality rates. Anesthetic management focuses on preoperative preparation and prioritizes regional techniques when applicable. When general anesthesia is necessary, managing artificial ventilation becomes difficult due to the development of intrinsic positive end-expiratory pressure.

What Is the Pathophysiology of COPD?

• Chronic obstructive pulmonary disease (COPD) is a progressive inflammatory condition affecting the airways, lung tissue, and blood vessels in the lungs. This leads to persistent narrowing of the airways, changes in airway structure, increased mucus production, and pulmonary hypertension.

• Cigarette smoking is widely recognized as the primary cause of COPD. However, recent studies suggest that genetic factors, such as a specific gene variant (FAM13A), also play a role in the development of COPD.

• COPD is characterized by restricted airflow during exhalation due to inflammation in the small airways (obstructive bronchiolitis) and damage to lung tissue (emphysema). In obstructive bronchiolitis, inflammation causes airway blockage and trapping of air, leading to increased lung volume during exhalation, which impairs oxygen exchange and respiratory muscle function. Emphysema involves the breakdown of lung tissue, reducing the gas exchange surface area and worsening oxygen transfer. Both processes contribute to airflow limitation.

• Patients with COPD often have other health conditions that complicate anesthesia management. Many COPD patients are smokers, increasing their risk of developing lung cancer. Pulmonary hypertension (blood vessels in the lungs are affected) is common and linked to poor long-term outcomes. Lung inflammation in COPD can also trigger systemic inflammation, leading to weight loss, muscle weakness (affecting breathing muscles), heart problems, depression, and bone loss. Significant weight loss in severe COPD indicates a poor prognosis.

Can Anesthesia Be Administered in COPD Patients?

Whether one can undergo anesthesia with COPD depends on several factors:

• Severity of COPD: The risk increases with severe COPD, whereas mild cases have fewer complications.

• Type of Anesthesia: Some procedures do not require a breathing tube, reducing lung strain. Options include spinal, epidural, or regional anesthesia, where they breathe on their own.

• Surgical Requirements: Certain surgeries necessitate a breathing tube, like coronary artery bypass grafting, demanding healthier lungs.

• Surgery Urgency: Emergency surgeries are unavoidable, while elective ones enhance the quality of life by considering lung capability and urgency.

For COPD patients needing surgery, the surgeon prioritizes favorable outcomes, especially in severe cases, focusing on lung response and recovery.

What Are the Complications of Anesthesia in COPD Patients?

The most significant dangers faced by individuals with COPD following surgery include:

• Postoperative respiratory failure.

• Extended need for mechanical ventilation.

• Increased likelihood of developing other associated medical complications.

• Risk of mortality.

• For those with COPD, undergoing surgery involving the heart and chest poses a higher risk of poor outcomes.

Additional heightened risks during surgery for individuals with COPD include:

• Cardiac arrest.

• Increased chances of needing re-intubation.

• Myocardial infarction (heart attack).

• Sepsis.

• Postoperative pneumonia(lung infection).

• Kidney dysfunction necessitating dialysis.

• Knowing that one has COPD and requires surgery can also lead to heightened preoperative anxiety, which not only impacts mental well-being but can also affect the body's response to surgery due to increased stress.

How Should COPD Patients Prepare for Anesthesia?

• Patients have moderate to severe COPD; the surgeon may advise consulting with a pulmonologist (a specialist in lung conditions).

• The medical team might suggest adjusting their treatment plan, like incorporating bronchodilator medications or corticosteroids during a COPD exacerbation—a worsening of symptoms.

• Pulmonary function testing (PFT) may be recommended by the doctor to assess lung function, though it is not always necessary for everyone with COPD.

• If they have had a recent COPD exacerbation or are currently experiencing one, the surgery may be postponed to allow the lungs time to recover.

Preparation Tips:

• S = Stop smoking, ideally several weeks before surgery, to improve outcomes.

• P = Practice breathing exercises to strengthen respiratory muscles; a pulmonary rehab specialist can guide them.

• A = Manage anxiety to reduce strain on the heart and lungs.

• C = Consult a cardiologist if they have heart issues to ensure readiness for surgery.

• E = Engage in pulmonary rehabilitation and exercises like using an incentive spirometer to enhance lung function.

• Consult the doctor for tailored advice based on the health and specific conditions.

Before undergoing surgery, the healthcare provider may request various tests to assess the COPD status:

• A chest X-ray to detect lung infections or other lung issues.

• An electrocardiogram (EKG) to detect heart problems that could affect surgery risk.

• Spirometry to diagnose and assess the severity of COPD.

• Lung diffusion testing to evaluate oxygen transfer efficiency from alveoli to the bloodstream.

• A six-minute walk test to gauge exercise tolerance.

• Arterial blood gas analysis to assess preoperative oxygen and carbon dioxide levels in the blood.

What Are Post-operative Complications in COPD Patients After Administration of Anesthesia?

• Recovery typically takes several days (or even weeks following major surgery) after remaining immobile and undergoing an incision, regardless of whether general anesthesia was used.

• COPD can prolong recovery and may lead to complications emerging days or weeks after surgery. An increased risk of postoperative complications is associated with COPD.

• Complications that may arise from lung infections like pneumonia include sepsis, collapsed lung (pneumothorax), and respiratory failure. Other risks involve impaired wound healing, hypoxia leading to tissue and brain cell damage, and potential blood clots or pulmonary embolism (clot formation in lungs) if prolonged inactivity is required post-surgery. Full recovery is essential before resuming normal activities, as demonstrated by the ability to perform basic tasks like walking, eating, and using the restroom without difficulty.

Conclusion:

Having COPD raises the likelihood of experiencing additional health problems and complications during surgery. To address these risks, medical professionals can conduct specific tests to evaluate respiratory function and recommend measures to minimize complications during and after the procedure. After surgery, it is crucial to stay vigilant about monitoring lung health to ensure timely medication and lifestyle adjustments that can help slow down the progression of COPD.