How can a sick person do wudu?
Question

Is it permissible to help a sick person who cannot do tayammum (“dry ablution”) by himself because of medical equipment attached to his hands, and how is that to be done? If he wants to help him to do wudu, then how can he rinse his mouth and nose? Or how can he help him to do wudu?
Praise be to Allah.What is required of the healthy person is also required of the sick person in terms of purifying himself with water in the case of both minor and major impurity. So he should do wudu in the case of minor impurity and do ghusl in the case of major impurity. If he is not able to do wudu for himself, then someone else may help him to do wudu.
Al-Bahooti (may Allah have mercy on him) said in Kashshaaf al-Qinaa‘ (1/103): If the individual who is missing an arm, and the like – such as cases of paralysis, or a sick person who is not able to do wudu himself – has someone who can help him to do wudu, or to do ghusl, in return for an appropriate fee that he can afford to pay, then he must do that, because he is subject to the same ruling as one who is healthy. End quote.
If the sick person is not able to do wudu himself, and there is no one who can help him to do wudu, then he must do tayammum, even by placing his hands on the wall or on the bed, if there is dust on it, or he can keep some earth with him in a vessel or a bag with which to do tayammum. If he is not able to do tayammum either, then he must pray as he is.
Al-Bahooti (may Allah have mercy on him) said in Kashshaaf al-Qinaa‘ (1/103): If there is no one who can help him to do wudu or tayammum, because he cannot afford to pay someone to help him, or he is not able to find someone whom he can hire to do that, then he must pray as he is. End quote.
Based on that, it is permissible for you to help this sick person to do wudu, by pouring water on him, and he can wash his limbs, or you can wash his limbs if he is not able to do that himself.
With regard to rinsing the mouth and nose, if the sick person is not able to do that himself, and it is too difficult for him, then there is nothing wrong with omitting it, but after finishing wudu, he should do tayammum, because he is regarded as having omitted washing one of the parts that must be washed in wudu. In the answer to question no. 88066, we have explained that wudu and ghusl are not valid without rinsing of the mouth and nose.
With regard to tayammum, if he is not able to do tayammum himself, then you should place your hands on the dust, then wipe his face and hands with your hands.
And Allah knows best.