The reason I used code 519.9 (Unspecified disease of respitatory system) is because the meaning of this code is so broad and I was looking at what would be the cause of rhonchi which directed me to a number of respiratory diseases as follows:
Rhonchi: Medical causes
(Signs & Symptoms: A 2-in-1 Reference for Nurses)
Acute respiratory distress syndrome Fluid accumulation with acute respiratory distress syndrome (ARDS) — a life-threatening disorder — produces rhonchi and crackles. Initial features include rapid, shallow respirations and dyspnea, sometimes after the patient's condition appears stable. Developing hypoxemia leads to intercostal and suprasternal retractions, diaphoresis, and fluid accumulation. As hypoxemia worsens, the patient displays increased difficulty breathing, restlessness, apprehension, decreased level of consciousness, cyanosis, motor dysfunction and, possibly, tachycardia.
Aspiration of a foreign body A retained foreign body in the bronchi can cause inspiratory and expiratory rhonchi and wheezing due to increased secretions. Diminished breath sounds may be auscultated over the obstructed area. Fever, pain, and cough may also occur.
Asthma An asthma attack can cause rhonchi, crackles and, commonly, wheezing. Other features include apprehension, a dry cough that later becomes productive, prolonged expirations, and intercostal and supraclavicular retractions on inspiration. The patient may also exhibit increased accessory muscle use, nasal flaring, tachypnea, tachycardia, diaphoresis, and flushing or cyanosis.
Bronchiectasis Bronchiectasis causes lower-lobe rhonchi and crackles, which coughing may help relieve. Its classic sign is a cough that produces mucopurulent, foul-smelling and, possibly, bloody sputum. Other findings include fever, weight loss, exertional dyspnea, fatigue, malaise, halitosis, weakness, and late-stage clubbing.
Bronchitis Acute tracheobronchitis produces sonorous rhonchi and wheezing due to bronchospasm or increased mucus in the airways. Related findings include chills, sore throat, a low-grade fever (rising up to 102° F [38.9° C] in those with severe illness), muscle and back pain, and substernal tightness. A cough becomes productive as secretions increase.
With chronic bronchitis, auscultation may reveal scattered rhonchi, coarse crackles, wheezing, high-pitched piping sounds, and prolonged expirations. An early hacking cough later becomes productive. The patient also displays exertional dyspnea, increased accessory muscle use, barrel chest, cyanosis, tachypnea, and clubbing (a late sign).
Emphysema Emphysema may cause sonorous rhonchi, but faint, high-pitched wheezing is more typical, together with weight loss, exertional dyspnea, accessory muscle use on inspiration, tachypnea, grunting expirations, and a mild, chronic, productive cough with scant sputum. Other features include anorexia, malaise, barrel chest, peripheral cyanosis, and late-stage clubbing.
Pneumonia Bacterial pneumonias can cause rhonchi and a dry cough that later becomes productive. Related signs and symptoms — shaking chills, high fever, myalgias, headache, pleuritic chest pain, tachypnea, tachycardia, dyspnea, cyanosis, diaphoresis, decreased breath sounds, and fine crackles — develop suddenly.
I do agree that it is a symptom of a respiratory disorder which still brings me to code 519.9.