I had many sleepless nights last year when my grandson was in hospital for two weeks. In the next bed was a twenty month old toddler who also had a heart operation. One day when I arrived this particular tot was up and having his first walk after his operation and at the same time as my grandson. They were both crying, though the little boy's wasn't open heart surgery he must have still been in a lot of pain and he was little more than a baby. I was shocked when his father started saying, "stop it, stop it," to stop him crying. Well for a week this went on, if he cried either of the parents would growl at him, "stop it, stop it."
I was on edge and it got worse, the mother started smacking him if he cried. The nurses could see what was going on and we, my son, DIL and I weren't sure about saying something. I spoke to the mother in the parent's kitchen (we normally had the curtain closed between the boy's beds) saying they were in a lot of pain etc, but not outright telling her off. This woman told me her son's heart defect wasn't picked up until he was sixteen months old because he was quite heavy, normally babies with this problem fail to thrive. Every meal time after his operation she force fed this poor toddler, making him eat everything on his plate. The day before my GS was moved to another ward, I heard her telling someone on the phone they had found her son's stress levels were exceptionally high. 
Then to make matters worse I took over from my son one morning to sit with my GS and just after he left an older nurse rushed over to the little toddler's bed and told him off, telling him "mummy wouldn't help him out this time." I nearly choked and though again I didn't say anything my face must have said it all. Later when the same nurse came into the ward where my GS had been moved for his last few days at the hospital, she hesitated when she saw me and looked very uncomfortable.