The state Board of Medicine reprimanded a Keene physician for allegedly providing substandard care to a 75-year-old man who suffered kidney failure after developing sepsis, a potentially life-threatening infection.

According to a settlement agreement reached with the state Board of Medicine dated Oct. 5, Dr. Gerard N. Kiernan did not admit or deny the allegations but reached the settlement to avoid the delay and expense of further proceedings and to promote the best interests of the public and the practice of medicine. He was fined $2,000 and must take 25 hours of continuing education classes in infectious diseases or critical medical care.

A call to Dr. Kiernan for comment Thursday was not immediately returned.

The board, in summarizing the allegations, said the patient had a history of congestive heart failure and chronic obstructive pulmonary disease. He arrived at the emergency room at Cheshire Medical Center early on the morning of Aug. 16, 2009, complaining of pain in his left shoulder.

He had a fever, low oxygen level, high acid levels, which can cause kidney failure, and was hypoxic — his body was deprived of oxygen. About six hours after his arrival, he was transferred to the care of Dr. Kiernan, who is board certified in family medicine and employed at Dartmouth-Hitchcock, Keene.

Kiernan later learned from laboratory tests that the man had group A streptococcal sepsis and ordered IV Levaquin, a drug for treating bronchitis, pneumonia and other infections.

The next day, Aug. 17, Kiernan examined the patient, performed a lung examination, and noted he no longer had a fever. He discharged him with oral Levaquin.

Seven hours later, the man was back in the emergency room with kidney failure. His oxygen levels had dropped to 77 percent — normal is from 95 to 100 percent — and his blood pressure had plummeted, requiring intubation.

The board contended that before discharging the patient, Dr. Kiernan did not re-check the man’s oxygen level, his blood gases to assess acidosis (to see if too much acid was being produced, which can lead to renal failure) or order a follow-up complete blood count. The state said Kiernan’s actions, if proved, constituted substandard care and professional misconduct.