Abandoning Salah during the period of receiving treatment at hospital
It is Wajib (obligatory)
on sick persons to offer Salah according to their condition. They must not abandon Salah as long as they have full mental capacity. A proof for this is Allah's statement:
So keep your duty to Allâh and fear Him as much as you can
You have thus to make up for the Salahs that you missed provided that you follow the right order of Salahs. It must be made up for at one and the same time and it is impermissible that you make up for one obligatory Salah with a current obligatory one. Nevertheless, the Salahs that you have already made up for are valid In sha’a-Allah (if Allah wills). On the other hand, people who are ill must be in a state of Taharah (ceremonial purification) as much as possible. Accordingly, if you can perform ablution using water; you have to do so. Otherwise, you may perform Tayammum using dust. Finally, if you are unable to purify yourself with water or dust, you are to pray without performing Wudu' (ablution) or Tayammum. (Part No. 6; Page No. 384) May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.