Is it permissible to pray with an imagined tayammum, without facing the Qibla, in a state of complete inability to perform tayammum or face the Qibla? And is qadaa' (making up the prayer) obligatory in this case?

A sick person who is unable to perform ablution (wudu') and cannot find anyone to help him perform it should perform tayammum (dry ablution) with pure earth. If he cannot find pure earth, he may perform tayammum on a wall or a bedspread if there is dust on them. Otherwise, the purification requirement is waived for him, and he should pray in his current state.

As for facing the Qibla, if he is able, it is obligatory for him. Otherwise, he should pray in his current state.

A wall made of pure earth, such as clay or stone, may be used for tayammum. However, if it is covered with wood or paint, it is not permissible unless there is dust on it.

Bedspreads may be used for tayammum if there is dust on them.

If a sick person is unable to purify himself with water or earth, he should pray in his current state. For istijmar (cleaning after relieving oneself), it is sufficient to wipe with tissues or a stone until the area is clean.

A sick person should pray standing. If he is unable, then sitting. If he is unable, then lying on his side.

If a sick person prays without ablution or tayammum or facing the Qibla due to his inability, his prayer is valid. However, if he neglected to seek assistance despite being able to do so, he must repeat the prayer.