My father was continously sedated

Rao subramanya asked...

Dear Doctor, My father , almost 87 years old, in good health had a black out. I admitted him to the nearest nursing home. There was no ER or preliminary assessment. He was placed in their ICU. A nasal tube was inserted and oxygen mask put on his nose (No assessment, but this treatment was started). CT scan was normal, no stroke or brain damage . 'age related atrophy". He as moving his limbs normally, unable to talk due to the tube in his nose. They put him on sedation which went on continuosly for 11 days (i got this info from one of the medical staff in an informal conversation). He was put on Meronet 4 gen injection 1 gram each time, twice a day. They said infection and Pneumonia , but with my questioning they said 'there is some congestion, but no Pneumonia symptoms, just wanted to play it safe. All parameters were normal (including blood test 11.5 hemoglobin, ECG normal, pulse normal,etc). This line of treatment went on for 11 days and finally he died when his pulse fell to 30. My question is 'was continuous sedation and use of heavy dose of Antibiotics the major contributor to his death?. Just want to know what could perhaps be the cause. I am his son (60 years old) just to put my mind at rest. Thanks for the clarification in advance. By the way I live in India.