Layton Tait was diagnosed with laryngomalacia when he was just a few months old, a condition known as floppy airway, which leaves him struggling to breathe.
At just two weeks old, he stopped breathing completely and had to be rushed to hospital.
Parents Libby Caldwell, 36, and her partner Calum Tait, 38, who have another son Calum, 12, say they live in constant fear Layton will stop breathing, particularly at night when his breaths are laboured and it can sound like he is choking.
Doctors at the Sick Kids Hospital discovered the 16-month-old also had a collapsed voicebox that was pressing on his windpipe after health visitors referred him for a check-up last year.
As the operation was so complex, the hospital decided Layton would need a bed in an intensive care unit (ICU) afterwards.
But despite the urgency, Layton has had a string of operations cancelled since November – once as the surgeon was sick and three times due to a lack of ICU beds. One procedure was called off just 20 minutes before it was due to take place.
NHS chiefs said operations are only cancelled in “unavoidable circumstance” as it can have a negative impact on both patients and doctors.
Mum Libby, of Muirhouse, said: “I can’t believe there are no beds in ICU for a wee boy. The surgeons said it was really important to get Layton into surgery as soon as possible. But the operations keep getting cancelled. I am just so fed up of this. My boy needs the operation and it is so hard waiting.
“It is always on the morning of the surgery, when I’ve had to make sure he fasts and everything beforehand. It’s so difficult for him.”
Layton’s parents have been told that his condition is so serious that he needs to go straight to the Sick Kids if he picks up a cold or a cough, rather than going to see his GP.
Libby, who works as a home help, said: “They know how serious this is. What’s it going to take to get the operation? Is he going to have to be blue in the face before they act?”
The family has been left at a loss after the most recent cancellation earlier this month and Libby is concerned that the wait is having a serious impact on Layton. Her little boy has failed to hit normal baby landmarks such as crawling and sitting up himself as he is so exhausted trying to breathe.
Patient groups branded the situation “outrageous” and called on NHS Lothian to sort out their capacity shortages before patients suffer.
Dr Jean Turner, patron of the Scotland Patients Association, said: “It is a horrible experience to go in for a procedure, especially if you are a child.
“This just shows the state of management in the NHS. It is outrageous to be postponed four times. It is bad enough it happening once but this is frankly ridiculous.
“This needs to be sorted out. It shows they don’t have enough beds or staff.
“I think it is unfair on this family and on this little boy. It would be dreadful if something did happen in the meantime.”
Conservative health spokesman Jackson Carlaw said: “For this to be cancelled four times is a disgrace, and it’s no wonder the parents are at their wits’ end.”
NHS Lothian said it had apologised for the distress caused and organised a date for surgery as soon as possible.
Dr Edward Doyle, associate medical director at NHS Lothian, said: “I know that rescheduled appointments can be upsetting, but I would stress it is a decision that is never taken lightly.
“There are unavoidable circumstances which can lead to an operation being rescheduled, including increased emergency admissions, which due to their severity require immediate access to our facilities.”