My sister (21) just suffered from cardiac arrest about 3 hours ago; she is an asthmatic and was experiencing difficulties breathing . She was taken to the ER and that is when her heart stopped. The doctors said they performed CPR for about 5-10 mins before the heart began beating again. She is now in ICU on a ventilator and being sedated. The doctor stated that there is a possibility of brain damage and I m scared. What extent of damages should be expected? Was 5-10 mins too long of a time period?
Thanks for coming to Chat Doctor for your query.  When there is cardiac arrest, there is cessation of blood supply to different organs in the body including brain. If the duration of cardiac arrest is sufficiently prolonged (>20 mins)- there is very high chance of brain injury. For shorter duration of cardiac arrest, outcome is difficult to predict. From the description given, she had cardiac arrest in ER (and thankfully not on the way to hospital). In-hospital cardiac arrest has better outcome than out-of-hospital cardiac arrest, as prompt treatment was given. In your sisters case - the next step over next 48-72 hours will be tried and get her off the ventilator and sedation and assess her brain function. Your doctor may ask for an MRI Brain/EEG to get some idea about any neurological damage. I hope I've able to answer most of your queries. Wish your sister good luck for complete recovery. Regards Chat Doctor.