A cough following surgery is a common experience for many patients, often causing discomfort during recovery. While the symptom can be startling, its causes range from simple, temporary irritation to more medically significant pulmonary issues. Understanding the reasons a cough develops after surgery helps distinguish a minor annoyance from a warning sign requiring medical attention.
Acute Irritation from Intubation and Anesthesia
One of the most frequent causes of a post-operative cough relates to general anesthesia procedures. If surgery required a breathing tube (endotracheal tube), its insertion and presence mechanically irritate the delicate lining of the throat and trachea. This irritation often results in a dry, scratchy throat sensation, triggering a cough reflex after the tube is removed.
Anesthetic gases also contribute by having a drying effect on the airway’s mucous membranes, which can lead to inflammation. The resulting cough is typically self-limiting, often resolving within 24 to 72 hours following the operation. This temporary response is generally not a sign of deep lung trouble but reflects the body’s protective mechanisms returning to normal function.
Pulmonary Complications Like Atelectasis and Pneumonia
A more significant cause of post-operative coughing involves changes within the lungs, primarily due to the effects of anesthesia and restricted breathing. General anesthesia alters the normal pattern of respiration, often leading to shallow breathing and decreased activity of the small air sacs (alveoli) deep within the lungs. This common condition is known as atelectasis, which is a partial collapse of lung tissue.
Atelectasis occurs when small airways become blocked with mucus or when pressure dynamics shift, causing the alveoli to deflate. The body responds by triggering a mild, persistent cough in an attempt to forcibly re-inflate the affected lung sections. While atelectasis is common after general anesthesia, it creates an environment where mucus and fluid can pool, raising the risk for infection.
If pooled secretions are not cleared, bacteria can flourish, leading to post-operative pneumonia. This infection is characterized by a productive cough, meaning it brings up thick phlegm that may be yellow or green. Unlike the initial dry cough, pneumonia symptoms are also typically accompanied by a fever, increased heart rate, and shortness of breath. This progression highlights why deep breathing exercises are encouraged immediately following surgery.
Systemic Causes and Drug Interactions
Sometimes the cough is not a direct result of surgery or anesthesia, but a side effect of medications or an underlying condition worsened by the procedure.
ACE Inhibitors
One common medication class known to cause a persistent dry cough is Angiotensin-Converting Enzyme (ACE) inhibitors, used to treat high blood pressure. These drugs can cause an accumulation of inflammatory substances in the respiratory tract, leading to a dry, tickly sensation that triggers coughing. If an ACE inhibitor was restarted after surgery, this drug interaction may be the source of the persistent, non-productive cough.
Gastroesophageal Reflux Disease (GERD)
Gastroesophageal Reflux Disease (GERD) is another common systemic cause, as surgical stress, dietary changes, and certain pain medications can trigger acid reflux. When stomach acid backs up into the esophagus and reaches the throat, it irritates sensitive tissues, provoking a cough often worse when lying down. The cough serves as a protective mechanism against this irritation, even if no food or liquid is aspirated.
Pulmonary Edema
In rare instances, overly aggressive administration of intravenous (IV) fluids during or after the procedure can contribute to a cough. Excessive fluid can overwhelm the body’s capacity to excrete it, leading to pulmonary edema, where fluid leaks into the lung tissues. This accumulation causes congestion, which the body attempts to clear with a cough, and may be accompanied by shortness of breath.
Managing the Cough and Recognizing Warning Signs
Managing a post-operative cough requires protecting the surgical site and clearing the airways effectively. If you have a chest or abdominal incision, the technique of “splinting” is effective for reducing pain during a cough. This involves holding a pillow or folded blanket firmly against the incision when coughing, providing support to the underlying tissues.
To address the cause, deep breathing exercises are effective tools for preventing atelectasis and clearing mucus. Taking several slow, deep breaths every hour helps re-expand the alveoli and move secretions upward for expulsion. Maintaining hydration by drinking plenty of fluids and using a humidifier can also help thin mucus, making the cough more productive and less harsh.
It is important to know when a cough signals a serious problem requiring immediate medical attention. Contact your surgical team promptly if the cough is accompanied by a temperature over 101°F, chest pain, or significant shortness of breath. The presence of thick, discolored phlegm (yellow, green, or rusty), or any instance of coughing up blood, are warning signs indicating a possible infection or complication.