Assessment of pain may be carried out by normal methods and conventional numerical or graphical methods work well. However, impairment of higher intellectual functions may mean that observational techniques similar to those described earlier be needed. When analgesic drugs are given they may not be absorbed as well or metabolised as efficiently. In addition, since the metabolites of drugs such as morphine and pethidine are excreted by the kidneys, any decrease in renal function may lead to accumulation with repeated doses. Local anaesthetics .
Nerve blocks are a most effective way of giving postoperative pain relief.
Intercostal nerve block can aid pulmonary function after chest or upper abdominal surgery and pain below the waist can be abolished by epidural blockade aiding the return of gastrointestinal function after surgery. However, blocks spread more widely in the elderly and there may be compromise of respiratory function due to intercostal paralysis. In addition, a greater sympathetic block may occur with a consequent fall in blood pressure. With care, local anaesthetic blocks can be very useful in the elderly and give excellent pain relief whilst permitting mobilisation and rehabilitation. However, gastrointestinal disorders are more common and care should be taken in patients with compromised hepatic or renal function.