He’s adamant about it.

Every time his mother Kate goes to bed at night, she silently prays she will be able to see her son alive when she wakes up.

Every time his father, Mark, has to leave for his job with an office design firm, he is gripped with fear that Kyle will be gone before he returns home.

Kyle’s siblings — Alexis, 11, and Jack, 6 — have on more than one occasion drawn the resolve to say their final “goodbyes” to brother Kyle. Just in case.

“Every single time I leave, I have that extra bit of stress in the pit of my stomach,” Mark St. Clair said. “As a dad, you often feel like it’s your job to fix things. And I can’t fix this little boy.”

Nobody can.

“[Doctors] told us the only chance we had to save his life was a multiple organ transplant,” Kate said. “He was denied for that last year.

“Some days … when he’s having good days, I think, ‘He’s going to see Christmas — he’s going to see 9,’” she continued. “Then I’ll see him struggling to breathe and I’ll know that may not be the case.”

But even in their darkest moments, the boy’s parents take some comfort in knowing that Kyle has touched more lives than some people who live much longer.

In less than a decade on this planet, Kyle St. Clair has gathered thousands of supporters from all around the world. Some are battling crippling ailments who say his story gives them inspiration. Some just promise to buy a coffee for the person in line behind them one morning or another.

Kyle St. Clair doesn’t have long, but he’s fighting to make a difference with every second he has.

‘It’s been a mystery’

Kyle St. Clair was born prematurely on Oct. 27, 2004, after just 33 weeks of gestation.

“He was born really sick,” Kate recalled. “Far sicker than any 33-week baby would normally be.”

First, his difficulty breathing alarmed doctors. But that wasn’t where the problems ended.

“We just thought, ‘Well, we’ll just do [a medical procedure to help inflate his lungs], and he’ll get better,’” recalled Merydeth Charlton, a Maine Medical Center nurse who first encountered Kyle in the hospital’s neonatal intensive care unit, and now spends her off hours visiting and caring for the boy in his Scarborough home.

“Then we said, ‘We’ll just do this and he’ll get better,’ or ‘We’ll just do that and he’ll get better.’ But he didn’t. It’s been a mystery. It’s baffled everybody.”

For reasons no doctor has been able to figure out, Kyle St. Clair’s digestive motility twisted in reverse, forcing acidic bile painfully up through his organs, flooding and burning his lungs and tearing through his esophagus.

He spent his first nine months in the Portland facility, and immediately after being released began what has become a life of travel and long hospital stays. He has stayed in Boston Children’s Hospital and Nationwide Children’s Hospital in Columbus, Ohio. He has endured more than 50 surgeries, many of them major procedures, in which his ravaged organs, one-by-one, were replaced by tubes and sacks hanging out of his torso.

Today, most of Kyle’s organs are external and made out of medical plastics.

“Each new tube was a process,” Kate said.

Kyle’s esophagus is no longer connected to his digestive tract. He gets nutrients through a feeding tube, and if he sips water, it immediately runs out of a tube exiting his body. Kyle has never in his life been able to eat a morsel of solid food.

He lives with intense pain, and is given powerful painkillers every hour or so, 24 hours a day.

Kyle needs a new set of lungs, stomach, bowel, intestines, liver and esophagus, and the Pittsburgh-based specialists finally declared last year his body just isn’t well enough for such a dangerous surgical overhaul.

“When they called to tell us that, it was crushing,” Kate recalled. “We had been holding on to that last sliver of hope that we were going to be able to fix him, that he was going to go on and have a normal, happy life and graduate from school.”

When the St. Clairs left Columbus early this year, after spending the better part of six months in the hospital there, they were returning to Scarborough for the rest of Kyle’s life.

“We brought him home in February on hospice care and they gave him four days,” Kate said.

Happy birthday

During the warm summer months, Kyle told his older sister Alexis he didn’t think he would make it to his eighth birthday.

“We’ve had to talk about heaven,” Kate said. “He’s told us he’s not going until mommy goes with him. That’s not a conversation you should have to have with a 7-year-old. How do you explain that to a little boy?”

But on Saturday, Oct. 27, Kyle celebrated his eighth birthday, a Mighty Morphin Power Rangers-themed affair featuring toys from his favorite video games, Super Mario Bros. and Sonic the Hedgehog.

Members of the Scarborough High School football team, who come by Kyle’s house every week or two to provide the ailing boy company and play games with him, brought a life-size cutout of the Red Ranger.

And he received more than 500 birthday cards in the mail from all over the place — Texas, Iowa, New Jersey, England, Japan and many others.

“One of the cards was written in Vietnamese,” Kate said. “We couldn’t understand it, but it was really neat. It had all these air mail stamps on it from all over the world.”

The cards are really the tip of the iceberg that is what’s known as Team Kyle. More than 8,000 people and counting are fans of the Team Kyle Facebook page, and posts on Kate’s blogchronicling the family’s highs and lows frequently attract tens of thousands of readers.

Many sent Kate or Kyle letters saying the boy’s struggle puts their lives in perspective, Kate said, or that his perseverance helps inspire them through painful medical treatments of their own.

“He’s truly my hero,” Mark said, “and the hero of a lot of people.”

The family began selling Team Kyle T-shirts and bracelets, in part to help defray the considerable medical costs associated with the boy’s constant care, but also to generate donation money for some of the organizations the St. Clairs felt so indebted to for their help along the way, including the March of Dimes; Barbara Bush Children’s Hospital at Maine Medical Center; Angel Flight Northeast, which flew the St. Clairs to and from Columbus more than they could have afforded or withstood on commercial flights; and Make-A-Wish Foundation, which granted the St. Clairs a trip to Disney World in Florida in 2011.

The family and its chosen charities also have benefited from numerous fundraisers around the Scarborough community, from concerts by local bands to motorcycle rides to an auction event hosted at the local restaurant Anjon’s.

“People have done such incredible things for him because they love him,” Kate said. “And we try to pay that forward.”

Perhaps Kyle’s biggest “pay-it-forward” effort comes in the form of hundreds of small cards, designed and decorated by a small group of local Scarborough school students. More than 400 have been scattered across the country by friends and supporters. On the fronts of the cards, it reads “Live for today,” and on the back it urges the finder to do something nice and brighten somebody’s day, then pass the card along.

Emails started rolling in from kids who’d started lemonade stands to benefit local charities, or adults who simply picked up the tab for the people behind them at tollbooths or coffee counters.

Hundreds of strangers all over the country are doing nice things as an extension of Kyle, who rarely leaves his bedroom, where he’s tethered to cumbersome tanks and equipment by IVs, and feeding and oxygen tubes.

“I like to do good things,” Kyle said. “Because I like to make my friends and family happy.”

Many parents start daydreaming about sending their children to law school or into professional sports someday. These cards — this current ripple effect of goodwill and charity — is the only “future” for Kyle that Mark and Kate St. Clair can let themselves have.

“Most parents dream about their kids growing up to be a doctor or fly a plane or be president,” Kate said. “Parents whose kids have shortened lives worry that nobody will ever know their children [existed].”

Good days, bad days

On Kyle’s good days, he seems a lot like any 8-year-old boy. Thursday was one of those days. He played video games, watched cartoons and helped his father assemble a toy race track.

On his bad days, he gets frustrated, struggles to breathe and cannot muster the strength to cross his bedroom. Those are the days that really torture his mother, who replays every medical decision she and Mark ever made and wonders if they somehow failed their son.

“The nights are the worst,” she said. “That’s when the mind games start. What if we hadn’t done this surgery or that surgery? Is that what really caused this? What if we did that differently? Did the first surgery on his lungs cause everything to spiral out of control?”

And when Kate can’t hold back the tears any longer, Kyle, of all people, can be counted on to comfort her.

“He’ll rub my face and say, ‘I’m OK, mommy,’” Kate said. “And meanwhile, he’ll be crying because of his pain. … If he has a bad day, he’ll say, ‘It’s OK, because tomorrow is a new day, right?’”

And on every new day, Kate St. Clair prays it won’t be her last with Kyle. And Mark St. Clair’s stomach turns when he has to leave for work.

Someday too soon, Kyle will get his last new day.

When that day comes, there likely will be hundreds of little cards being passed from hand to hand with his name on them urging strangers to do nice things for each other.

When Kyle dies, his last words to nearly everyone who has ever met him will have been, “I love you,” followed by a blown kiss.

Many who live much longer will not have such a legacy.