The prayer sign. The patient is unable to approximate the palmar surfaces of the phalangeal joints despite maximal effort.
Prayer Sign - If patient shows inability to place palms flat together, it suggests difficult intubation. It is a reflection of generalised joint and cartilage immobility and tight waxy skin, particularly in diabetic patients. About 33% of diabetic patients are prone to difficult intubations. One study from Istanbul, Turkey compared 80 diabetic patients (D) with 80 non-diabetic patients (ND) undergoing elective surgery under general anaesthesia. The incidence of difficult laryngoscopy was 18.75% in Group D and 2.5% in Group ND. The incidence of the prayer sign was 31.25% in Group D and 13.75% in Group ND.
Another version of prayer sign is "palm print" method in which grading of the ink impression made by the palm of the hand has been proposed as a means of screening diabetic patients in whom tracheal intubation may prove difficult. In one study, it was found to be superior to 3 other indices - Mallampati classification, thyromental distance and head extension.
- Relationship of difficult laryngoscopy to long-term non-insulin-dependent diabetes and hand abnormality detected using the ‘prayer sign’ - British Journal of Anaesthesia, 2003, Vol. 91, No. 1 159-1602.
- The palm print as a sensitive predictor of difficult laryngoscopy in diabetics - Acta Anaesthesiol Scand. 1998 Feb;42(2):199-203.