Blokada nerwowo-mięśniowa u osób w podeszłym wieku

Abstract

The aim of the presented review is to highlight the clinical problem of postoperative residual curarization (PORC) following general anaesthesia in the elderly. Possible complications of PORC are described along with age-induced changes in pharmacokinetics of long and intermediate-acting neuromuscular blocking agents. This is intended to facilitate the selection and to promote appropriate intraoperative use of muscle relaxants in patients over the age of 65 years.Key words: elderly patients; neuromuscular block, muscle relaxants; neuromuscular block, reversal; postoperative residual curarization Anaesthesiology Intensive Therapy 2016, vol. 48, no 4, 257-260 Anaesthesiologists are regularly involved in the treatment of elderly patients due to the increasing life expectancy and rising number of surgeries in the aging population [1]. General anaesthesia comprises four crucial components: unconsciousness, analgesia, immobilization and haemodynamic stability [2]. Neuromuscular block serves the two latter purposes. As it maintains good surgical conditions as well as facilitating airway management, doses of both volatile and intravenous anaesthetics can be considerably reduced. This is of importance in patients over 65 years of age, particularly those older than 75. This group of patients is most susceptible to the adverse effects of anaesthetics [3], including decreased heart muscle contractility and hypotension, which pose a risk of cardiac and central nervous system ischaemia [4].Unfortunately, advanced age is accompanied by an increasing risk of postoperative residual curarization (PORC) [5] which, along with intraoperative awareness [6], is one of the most clinically significant complications of the use of muscle relaxants. Residual blockade is currently defined by the train of four ratio (TOFR) < 0.9, although previous reports mentioned TOFR < 0.7. It may lead to severe respiratory complications in the post-operative period [7], and thus prolong hospitalization. Awareness of the specific issues of neuromuscular blocking agents use in the elderly is therefore crucial in daily anaesthesiological practice. CliniCal aspeCts of the pharmaCokinetiCs of neuromusCular bloCking agents in the elderlyDoses of both steroid and benzylisoquinoline-derived non-depolarising muscle relaxants necessary to reach maximal block, i.e. 95% reduction of muscle response to a stimulus (effective dose 95 , ED 95 ), do not vary significantly between elderly persons and younger subjects [8,9]. This suggests that the physiology of the neuromuscular junction and the pharmacodynamics of neuromuscular blocking agents are not markedly altered in advanced age. It is the pharmacokinetics of these agents that is responsible for their altered clinical effects in the elderly.Decreased cardiac output is accompanied by reduced skeletal muscle perfusion [3] and, consequently, one should expect a prolonged time to maximum blockade following drug administration [10,11]. However, doses of muscle relaxants used for intubation are two to three, or ...