A sudden drop in oxygen levels (SPO?) after surgery may indicate a lung complication such as pneumonia, fluid in the lungs, or a blood clot. You must seek immediate medical help from hospital staff, as this is a medical emergency requiring urgent oxygen therapy and other treatments.

Even with normal potassium levels, these symptoms can have many causes, such as heart rhythm problems, medications, dehydration, or, less commonly, a pulmonary embolism (a blood clot in the lung arteries). You should consult your doctor promptly to determine the underlying cause and have your heart and lungs examined.