SALT LAKE CITY -- Hyperbaric oxygen therapy has been given credit for the dramatic recovery of Randal McCloy Jr., who was pulled unconscious from a mine in Sago, W.Va., 10 months ago, suffering from carbon monoxide poisoning.
SALT LAKE CITY, Oct. 25 -- Ten months after he was pulled unconscious from a mine in Sago, W.Va., Randal McCloy Jr. has made a dramatic recovery from carbon monoxide poisoning, probably because of the hyperbaric oxygen therapy he was given.
McCloy is "remarkably cognitively intact" despite spending 42 hours in the mine, where carbon monoxide reached 1,300 parts per million, more than three times the level that is rapidly fatal, said Anil Singh, M.D., of Allegheny General Hospital in Pittsburgh.
"He's at home, he's passed all his neurological tests, he's playing with his kids," Dr. Singh said, presenting a case report at CHEST 2006, the meeting of the American College of Chest Physicians.
Dr. Singh credited McCloy's treatment in his institution's hyperbaric chamber for his recovery. It is the first reported case of survival and recovery after such a long exposure to carbon monoxide, he said.
"When he arrived at our hospital, he was in multi-system organ failure," Dr. Singh said. "He was tremendously sick."
An electrocardiogram showed McCloy had an ejection fraction of 20% and global wall hypokinesis. A brain CT showed several areas of hemorrhage in the subcortical white matter, the largest of which measured 9 mm across.
McCloy, who had been on 100% oxygen at normal pressure since he was pulled from the mine, was given three hyperbaric treatments, consisting of three atmospheres for half an hour followed by 2.4 atmospheres for an hour.
After the hyperbaric therapy, Dr. Singh said, "he demonstrated significant improvement in all aspects of his care." Specifically, his ejection fraction improved to 35%, his heart wall movement became normal, and he was able to be transferred back to a tertiary care hospital in West Virginia.
Back in West Virginia, Dr. Singh said, McCloy's recovery continued, including resolution of the brain lesions.
What remains to be seen, Dr. Singh said in an interview, is whether McCloy will suffer from delayed neurological syndrome, in which carbon monoxide poisoning patients appear to make a full recovery, but later show widely varied neurological effects, including mood changes, memory lapses, problems with concentration, and even seizures.
The syndrome usually begins to appear between two and 47 days after exposure, Dr. Singh said, but there are so far no signs of it in McCloy. "The fact that he may not have (developed the syndrome) is potentially a credit to the hyperbaric oxygen therapy," he Dr. Singh said.
"Would he have gotten better without the hyperbaric oxygen? I don't know," Dr. Singh said, although there is evidence from a clinical trial, reported in 2002, that hyperbaric oxygen reduces the rate of delayed neurological syndrome better than normal pressure oxygen.
"This case shows that it's worth a shot."
The Sago Mine collapse trapped McCloy and 12 other miners when a lightning bolt set off a methane explosion on Jan. 2. McCloy, 26 at the time, was the youngest of the trapped miners, something that has been suggested as a reason why he survived and others did not.
Also, Dr. Singh said, he was found in a temporary shelter with several bottles of oxygen near him, suggesting he may have been deprived of oxygen for less time than the others.
When he was first tested for carboxyhemoglobin, a measure of how much carbon monoxide has been absorbed by the body, the levels were normal, but Dr. Singh said that was likely because the equipment at the local hospital was inaccurate.
Carbon monoxide binds oxygen at 240 times that of oxygen, consequently decreasing oxygen carrying capacity of blood. The severity of carbon monoxide poisoning is a function of the duration of exposure and the concentration of the gas.
The mechanisms of acute carbon monoxide poisoning include hypoxia, reduced cellular oxygen metabolism, oxidative injury, and damage to the vascular endothelium, Dr. Singh noted. Standard treatment includes supplemental oxygen and supportive care.
The half-life of carboxyhemoglobin is more than five hours with normal air, and between 40 and 80 minutes with normal pressure oxygen therapy, but 23 minutes with hyperbaric oxygen treatment, he said.