RESUMO
Following on from Part 1 of the series (regional nerve blocks for the face and scalp), we guide the clinician through the anatomy and cutaneous innervation of the digits, wrist and ankle, providing a practical step-by-step guide to regional nerve blockade of these areas.
Assuntos
Anestesia Local/métodos , Anestésicos Locais/administração & dosagem , Tornozelo , Dedos , Bloqueio Nervoso/métodos , Dedos do Pé , Punho , Tornozelo/inervação , Dermatologia/métodos , Dedos/inervação , Humanos , Guias de Prática Clínica como Assunto , Dedos do Pé/inervação , Punho/inervaçãoRESUMO
The aim of this two-part series is to provide an up-to-date review of essential regional nerve blocks for dermatological practice. In Part 1, we give a concise overview of local anaesthetics and their potential complications, as well as the relevant anatomy and cutaneous innervation of the face and scalp. This culminates in a step-by-step practical guide to performing each nerve block.
Assuntos
Anestesia Local/métodos , Anestésicos Locais/administração & dosagem , Face , Bloqueio Nervoso/métodos , Couro Cabeludo , Dermatologia/métodos , Face/inervação , Humanos , Couro Cabeludo/inervaçãoRESUMO
The relative order of potency of anaesthetic agents on the hypoxic ventilatory response has been tested in humans, but animal data are sparse. We examined the effects of 1.4, 1.6, 1.8, and 2.0 MAC halothane, isoflurane, and sevoflurane on phrenic nerve activity in euoxia (baseline) and during acute normocapnic hypoxia (inspired oxygen fraction 0.09) in adult male Sprague-Dawley rats. With halothane, all animals became apnoeic even in euoxia, and the hypoxic response was completely abolished at all anaesthetic levels. With isoflurane, 5 of 14 animals exhibited phrenic nerve activity in euoxia at 1.4 MAC and demonstrated a hypoxic response (302% of baseline activity), but all became apnoeic and lost the hypoxic response at higher doses. With sevoflurane, phrenic nerve activity and a hypoxic response was preserved in at least some animals at all doses (i.e. even the highest dose of 2.0 MAC). Similar to the rank order of potency previously observed in humans, the relative order of potency of depression of the hypoxic ventilatory response in rats was halothane (most depressive) > isoflurane > sevoflurane (p = 0.01 for differences between agents).