Eight days and four surgeries later, Zelin did return home, the fortunate survivor of a highly unusual cascade of events that could have cost him his arm - or even his life.
"I try not to be too reflective about the whole thing," said Zelin of the events of May 2018, "although when I tell people what happened, they freak out."
Lauren Zelin, media relations manager for a global environmental group, was downstairs at their home in Washington catching up on work after her children, then ages 5, 3 and 1, were asleep. Shortly after 10pm her cellphone pinged with a message: her husband asked her to come upstairs to their bedroom.
Michael had arrived home as usual at 7, following a stop at the gym. He'd eaten dinner, bathed the kids and then gone to bed.
Sending a text was odd. "I knew something was wrong," Lauren said. "Otherwise he'd have come down."
Michael told her he had been unable to fall asleep because the pain in his forearm, which he'd developed earlier that day, was getting worse. Lauren gave him an over-the-counter pain reliever, then an analgesic salve. When neither worked, she texted her longtime friend for advice.
Raizman, whose wife is also a surgeon, is accustomed to night-time missives. "One of us is usually on call," he said.
"My initial thought is that it's probably a bad muscle strain," Raizman recalled, "or that he might be getting a little rhabdo" from overuse. Rhabdo is slang for rhabdomyolysis, an uncommon and serious condition that causes muscle breakdown and requires medical attention. The disorder has a multitude of causes including injury, overexertion and the use of certain medications, including, rarely, cholesterol-lowering drugs.
Raizman and Lauren traded texts for another hour or so. Michael's pain intensified and Raizman said he asked Lauren, "Would you use 'rapidly progressing' to describe this? She said yes."
When she joked that she wished she had kept oxycodone from her last Caesarean section to give her husband, Raizman's advice was unequivocal: If the pain was bad enough to require narcotics, he told her, "you need to get eyes on it."
So Michael headed to Sibley Memorial Hospital, where Raizman is on staff. Lauren decided she should join him, arriving an hour later after arranging with her mother, who lives nearby, to stay with their children.
"They started running all these tests," Michael recalled. "Then it turned a corner and the pain got really bad."
Tests showed no signs of rhabdomyolysis. Michael's white blood cell count was normal, which seemed to point away from infection. One inflammatory marker was high, but another was normal. The working diagnosis was tendinitis, an inflammation of the tendon that often results from overuse. But tendinitis doesn't usually worsen so dramatically or so quickly. And Michael's forearm was becoming increasingly swollen.
An MRI scan performed about 3am was "torture," Michael recalled. "The pain was so bad that all I wanted to do was to curl it next to my body and shield it."
Obtaining decent images required that his arm be kept straight and that he remain motionless.
"I was sweating and crying and finally said, 'You have to stop this,' " he remembered telling the technician. "I had never been in so much pain in my life."
The scan seemed to confirm the tendinitis diagnosis.
Shortly before 5am, Lauren called Raizman. Michael had received double doses of morphine, which wasn't allaying the pain, and was disoriented.
Raizman got dressed and headed to the hospital. He said he was increasingly worried that Michael was showing signs of acute compartment syndrome. The problem, often caused by a crush injury, occurs when pressure inside muscles builds, cutting off blood flow to the affected limb.
Acute compartment syndrome is a medical emergency that requires prompt intervention, usually surgery, to relieve the pressure. (Chronic compartment syndrome is related to exertion, evolves more slowly and typically does not require emergency treatment.)
"With compartment syndrome," Raizman said, "time equals muscle." In 2014, PBS science correspondent Miles O'Brien developed acute compartment syndrome after heavy camera equipment fell on his arm during a reporting trip to the Philippines. O'Brien did not realise the injury was serious and continued working. A day or so later when he sought treatment, his arm had to be amputated just above the elbow.
When he arrived in the ER, Raizman performed a compartment pressure measurement test, in which a needle is inserted into a muscle. The result erased any doubt: Michael's pressure measured 70 mmHg, more than double the reading that indicates acute compartment syndrome. An emergency fasciotomy would be required to relieve the pressure, decrease the swelling and, hopefully, save his arm.
Raizman said he tried not to panic his friends, while trying to prepare them for the uncertainty of what lay ahead.
Michael said he was in too much pain to care that he needed emergency surgery and told Raizman to do whatever was necessary to get rid of the pain. Lauren said she felt "so so nervous" but was relieved that a reason for her husband's agony had been identified.
But what none of them knew then was that surgery alone would not solve the underlying problem, which posed an even greater risk than compartment syndrome.
The first operation, which involved making an incision that stretched from Michael's right palm to his elbow, went well. Raizman said he was hugely relieved to see that the muscle looked healthy. A repeat procedure was scheduled for the next day to clean out and inspect the wound, which would need to be closed.
But a key question lingered unanswered: What had caused the compartment syndrome in the first place? Doctors were puzzled and kept quizzing the couple about a possible recent injury.
A few hours after the first operation, while Michael was recovering in the intensive care unit, he developed a fever, which began to climb. Lauren said that an astute nurse, concerned that he looked pale and sick, alerted his doctors. Later that day, an infectious disease specialist was brought in an as a consultant.
The specialist said that Michael had developed an infection that would require high doses of several antibiotics to treat staphylococcus and streptococcus bacteria.
A few hours after meeting with the infectious disease specialist, Lauren sought out the ICU doctor to tell him something she had forgotten to mention. Several days before Michael's arm started to hurt, she had been diagnosed with strep throat, a bacterial infection caused by Group A strep. Could the events be related?
The doctor said it was possible.
The following day, tests revealed that the connection seemed likely.
Michael was suffering from necrotising fasciitis - popularly dubbed "flesh-eating bacteria."
The fast-moving infection, which kills about 30 per cent of those who develop it, is most often caused by Group A strep and less often, staph. It can lead to septic shock, which has an even higher fatality rate. In addition to high doses of intravenous antibiotics, multiple surgeries may be necessary to remove infected tissue.
After tests showed that Michael's infection was caused by strep, the couple's three children were tested. All were infected, although none showed symptoms.
Raizman said that doctors theorise that Michael overexerted himself playing golf, which probably caused slight muscle damage to his forearm. Group A strep was probably lurking somewhere in his nose or mouth and migrated to his arm, triggering necrotising fasciitis. The infection caused so much swelling that it led to acute compartment syndrome.
It is a very rare scenario, but one that has been reported previously. In 2008, Ohio doctors published a study of 13 cases over a 57-year-period involving men who developed acute compartment syndrome caused by strep following a nontraumatic injury. Most were previously healthy.
Doctors were initially concerned that Michael appeared to be showing signs of sepsis. By the fifth day of his hospitalisation, he had improved significantly and was moved out of the ICU.
"I didn't sleep for a week," Raizman said. "There's nothing comfortable about this situation. And you're never quite sure how it's going to go."
After a fourth operation performed by a plastic surgeon to close the wound, Michael went home, eight days after he had arrived in the ER. A catheter called a PICC line had been implanted in his chest to deliver the IV antibiotics he would need for the next six weeks.
Two months later, after physical therapy, Michael had regained nearly full use of his arm and hand.
The psychological aftereffects have taken longer to resolve.
"I replayed it many times," Lauren said. Raizman later told the couple that a delay of four to six hours would probably have cost Michael his arm.
She remains keenly aware of the what-ifs: What if this had happened when Michael was at the resort? What if he hadn't gone to the ER but decided to wait until morning? What if they didn't have a surgeon friend who served as their medical sherpa and was able to make things happen quickly? What if the ICU nurse hadn't acted on her suspicion that something serious was brewing?
She said the couple asked the infectious disease specialist what they could have done to prevent it. His reply? Nothing.
Raizman said he, too, has pondered the what-ifs, beginning with, "What if Lauren hadn't texted me?"
"This was the luckiest we could have gotten," he added. "I've never gotten to a case of nec(rotizing) fasc(iitis) so early and seen so little damage. It was truly just dumb luck. Any hand surgeon would do exactly what I did."
Raizman warned that any pain that seems out of proportion to an injury or that is worsening rapidly should prompt an immediate visit to an ER, not an urgent care centre. "This is exactly what you should be going to an ER for," he said.
