You might want to figure out if that is a private hospital or a public one.

I know that provincial hospitals can be dicey. Poor ones require you to come up with cash for your own medicine and everything as you go. Private ones are expensive by local standards. $700 is 30,000 pesos which is like a month salary for a professional in the province. It sounds like you might be dealing with a private, "expensive" hospital.

At 75, you and or your parents would hopefully have considered their likely need for advanced care and would have discussed a plan in advance. I hope that others who read this will consider what it might mean for their children to have to deal with a situation like this without a plan or guidance. Continuing to reside in a province far from top tier care and far from relatives with means to assist is a choice with implications for situations like this. It sounds like a nightmare and I am sorry to hear about it.

As far as Philhealth goes I have no idea about care for elderly and what is covered. They likely do not normally go to the extremes that the US system does to extend life by a year or even months or weeks. A poor hospital may look at a US citizen in this situation and realize there is a good chance that someone will show up and pay a bill that locals normally would not or could not pay.

I do know that my wife filled out some paperwork and received a small reimbursement from Philhealth that covered around 20% of the cost of delivering our baby via CS. We were at St. Lukes Global though so consider that is one of the most expensive/best hospitals. It was nice but no where near enough to cover top tier private care. It might have covered a good portion of the bill at a cheaper public hospital.

You might also reach out the US Embassy in Manila for advice. Look on their website for information. Philippine government documents and forms are in English so you might find material on Philhealth's website.

 

I suffered a stroke myself and spent 3 days and 2 nights in Angeles University hospital in Angeles. I paid about 40,000 pesos bill. $4,000 (170,000 pesos) does seem high! I know others that spent about the same time in a hospital as I did and paid 20,000 pesos. I do not have Phil Health but my understanding is they pay 20%. I have heard if the hospital is not a government hospital they want full payment before discharging the patient.
Things do get confusing here and the rules changes fast and not applied the same. I know of a man that signed a promissory document to pay his bill and was release. Another an arm guard keeps him in the hospital till paid.
Living in the Philippines requires one to know a good doctor and the best hospital before disaster strikes.