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Chirurgia Del Piede 2005 August;29(2):79-84

Copyright © 2005 EDIZIONI MINERVA MEDICA

language: Italian

Haemodynamic effects of the tourniquet in surgery of the lower extremities

Napoli V., Napoli E.

In orthopaedic surgery of the extremities it is now established practice to use a haemostatic tourniquet which, in the case of the lower extremity, is preferably positioned at the root of the thigh. With the realisation and maintenance of ischaemia certain haemodynamic variations are observed at both extremity and systemic levels and these have to be managed adequately to keep them within physiological limits and prevent dangerous changes occurring. The variations at extremity level consist of the persistence of blood flow and postischaemic reactive hyperaemia. Systemic changes are represented by the change in blood volume, heart frequency, central venous pressure and systemic arterial pressure. In certain operations carried out under general anaesthetic the increase in systemic arterial pressure may become critical with peaks which, when they reach and exceed 200 mmHg, generate serious risks of cardiac decompensation and vascular lesions. The increase is rapid and there are no premonitory signs. Treatment should be equally rapid but not drastic, so as to prevent it resulting in dangerous hypotensive attacks. The aetiology of critical hypertension is not clear and suggests the presence of predisposing factors, some of them linked to the use of the tourniquet, others to the concomitance of ongoing or previous pathologies in the patient, which are activated by a triggering cause. Adequate knowledge of tourniquet-induced haemodynamic variations and predisposing factors with their preventive treatment are at the basis of the prevention of changes.