Implications of low great toe pressures in clinical practice

The aim of this study was to observe the outcome of patients with a great toe pressure (GTP) reading of less than 40 mmHg.

Between 2002 and 2004, of 4,714 patients assessed in the Westmead Vascular Laboratory, 365 (7.7%) had GTP measurements for assessment of possible critical limb ischaemia. There were 56 limbs in 40 patients with a GTP measurement of less than 40 mmHg, and this group was studied to assess outcome factors of death, requirement for major or minor amputation, arterial reconstructive surgery, clinical stability, or documented improvement from the initial assessment.

Patients requiring a major amputation had an average GTP of 13 mmHg and a toe brachial index (TBI) of 0.08, whereas those not undergoing a major amputation had an average GTP of 23.6 mmHg and TBI of 0.15. This association was weaker when an initial single evaluation was used as opposed to two or more serial assessments. Patients with and without a major amputation had an average ankle brachial index of 0.16 and 0.53, respectively. Diabetes mellitus requiring insulin and cerebrovascular disease were risk factors for major amputations.

Low GTP was associated with a greater risk of major amputations. Two or more serial assessments were found to be of greater value than an initial single assessment.