Age-related changes in physiology of blood circulation, breath and appropriate anaesthetic considerations in patients older than 60 years
The presence of co-existing diseases and age-related physiological changes in blood circulation and breath are the main reasons for the increase in postoperative complications and 30 days mortality in patients over 60 years of age. A gradual increase in arterial blood pressure (ABP) usually begins in people older than 50 years. According to recommendations of the most anaesthesiologist societies, ABP above 180/110 mm Hg is the reason for canceling a scheduled surgical operation. However, no convincing evidences have yet been presented that high preoperative ABP as an isolated factor without some organ failures can lead to an increase in the amount of postoperative complications and early mortality. Meanwhile, low ABP both before surgery and/or during anaesthesia is a reliable proven factor in increasing the amount of postoperative complications and 30 days mortality. Surgery, which in itself carries out a high risk of the rapid development of arterial hypotension, such as for example vascular interventions with a high risk of bleeding, requires the use of an invasive measurement of ABP, which covers those temporary time pauses between measurements of non-invasive ABP. A clear advantage of one anaesthetic technique over another in reducing peri-operative arterial hypotension (PAH) and postoperative pulmonary complications in patients over 60 years of age has not been demonstrated. Based on pathogenesis of PAH for normovolemic patients, it makes no sense to correct PAH caused by vasodilation of arterioles and venules, by intravenous fluid administration, when there is a need to compensate for the missing norepinephrine. In patients at high risk of developing PAH, it is necessary to start the infusion of norepinephrine directly during induction of anaesthesia. In patients who received muscle relaxants during anaesthesia, the risk of developing postoperative pneumonia increases by 1.79 times, and in patients who received muscle relaxants without reversal with an acetylcholinesterase inhibitors the risk of developing postoperative pneumonia increases by 2.26 times. Early mobilization of elderly patients after surgery can help to prevent almost all postoperative complications.