I am haemodialysis patient when time for Salaat comes I have either undo nor do I face Qiblah. Shall I wait and pray when I come home or shall I perform Tayammum with right hand that I have free and pray without facing Qiblah.

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.

First of all we ask Allaah, the Lord of the Mighty Throne to cure you from your disease. As regards your question, you have to know that Allaah does not burden a person more than he can bear, and the religion of Allaah is easy. If the dialysis of the blood ends before the end of the time of the prayer, then you are obliged to delay the prayer until the end of the haemodialysis so that you will be able to make ablution and turn yourself to the direction of the Qiblah and pray while standing. However, if the haemodialysis ends after the prayer time ends, then you have to pray according to your ability. If you can have ablution without the help of anyone or with the help of another woman or your husband or one of your Mahaarim (unmarriageable relatives) then do so. Otherwise you can make Tayammum (dry ablution) by putting one hand on the floor and then wipe over your face and over the other hand, and this is sufficient. The same thing applies to turning towards the Qiblah, if you can turn by yourself or with the help of somebody else then do so, otherwise you can pray as you are, standing, and if you are not able, pray sitting and if you are not able then pray leaning on one of your sides. 

Allaah knows best.