Which of the following statements accurately reflects the relationship between obesity and surgical risk?

A. Murmurs are usually related to valve dysfunctions, such as tricuspid or pulmonic valve issues, which may or may not be present in right-sided heart failure.
B. Crackles (or rales) are more commonly associated with left-sided heart failure. They result from fluid accumulation in the lungs (pulmonary congestion) due to the heart's inability to handle the blood returning from the lungs.

C. Chest pain can occur in various cardiac conditions but is not a hallmark symptom of right-sided heart failure. It might be present if there are underlying coronary artery disease issues or other conditions, but it is not directly indicative of right-sided heart failure.
D. Peripheral edema is a classic finding in right-sided heart failure. It results from fluid accumulation in the lower extremities due to the heart's inability to effectively pump blood to the lungs and systemic circulation, causing increased venous pressure and fluid leakage into the tissues.

A. Metabolic acidosis is characterized by a primary decrease in bicarbonate (HCO₃⁻) levels, which is not typically a direct result of COPD. However, if a patient with COPD has an additional condition like kidney failure or severe sepsis, they could potentially develop metabolic acidosis. But, this is not the primary concern in COPD.
B. Respiratory alkalosis is caused by hyperventilation, where there is excessive loss of CO₂ leading to an increase in blood pH. This is less common in COPD patients, as they typically have difficulty exhaling CO₂ rather than hyperventilating.
C. Metabolic alkalosis involves an increase in blood pH due to elevated bicarbonate levels or loss of acid. This is not typically associated with COPD, unless there is an unrelated condition causing metabolic alkalosis.
D. COPD is characterized by impaired airflow and reduced ability to expel carbon dioxide (CO₂) effectively. As CO₂ accumulates in the blood, it combines with water to form carbonic acid, which lowers the blood pH, leading to respiratory acidosis.