McKenna's Pharmacology for Nursing, 2e

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P A R T 4  Drugs acting on the central and peripheral nervous systems

KEY POINTS

■ ■ Monitor for adverse effects (respiratory depression, hypotension, bronchospasm, GI slowdown, skin breakdown, fear related to helplessness and inability to communicate). ■ ■ Evaluate effectiveness of the teaching plan (the person can relate anticipated effects of the drug and the recovery process). ■ ■ Monitor the effectiveness of comfort measures and compliance with the regimen.

■■ Non-depolarising NMJ blockers prevent ACh from exciting the muscle, and paralysis ensues because the muscle cannot respond. ■■ Depolarising NMJ blockers cause muscle paralysis by acting like ACh. They excite (depolarise) the muscle and prevent repolarisation and further stimulation. There is only one drug available in this class.

CRITICAL THINKING SCENARIO Using suxamethonium in an elderly person

THE SITUATION S.N., an 82-year-old Caucasian woman in very good health, has been admitted to the hospital for an exploratory laparotomy to evaluate a probable abdominal mass. On admission, healthcare practitioners learned that she had a history of mild hypertension that was well regulated by diuretic therapy. She received a baseline physical examination and preoperative instruction. On the morning of the surgery, it was noted that the anaesthesiologist CRITICAL THINKING What areas must be considered for S.N.? Consider the woman’s age and associated chronic problems that often occur with ageing. Also consider the support that she has available and potential physical and emotional support that she might need before and after this procedure. Use of a NMJ blocker in the elderly presents some care challenges that may not be seen with younger people. What particular care activities should be considered with S.N.? Because S.N. has been maintained on long- term diuretic therapy, she is at special risk for electrolyte imbalance. What, if any, complications could arise if S.N. has electrolyte disturbances before surgery? DISCUSSION Before surgery, the preoperative teaching protocol should be reviewed with the woman. S.N. should be advised that she may experience back and neck pain secondary to the muscle contractions caused by suxamethonium and throat pain after the procedure. Reassure her that this is normal and that medication will be made available to alleviate the discomfort. Review deep breathing and coughing; she may need encouragement to clear secretions from her lungs and ensure full inflation. This is usually easier to do if it is a familiar activity. S.N.’s serum electrolytes should be planned to give her a general anaesthetic and suxamethonium to ensure muscle paralysis.

evaluated before surgery because potassium imbalance can cause unexpected effects with suxamethonium. Renal and hepatic function tests also should be performed to ensure that the dose of the NMJ blocker is not excessive. During the procedure, S.N.’s cardiac and respiratory status should be monitored carefully for any potential problems; such effects are more common in people with underlying physical problems. Because of S.N.’s age and potential circulatory problems, she should receive meticulous skin care and turning as soon as the procedure allows this kind of movement. She should be turned frequently during the recovery period, and her skin should be checked for any breakdown. Clinical staff must remain close by until she has regained muscle control and the ability to communicate. She should be evaluated for the need for pain medication and position adjustments. S.N. will require additional teaching about her diagnosis and potential treatment. This should wait until she has regained her full ability to communicate and is able to respond and participate in any discussion that may be held. At that time, she may require emotional support and encouragement. It may be necessary to contact available family or social service agencies regarding her physical and medical needs. CARE GUIDE FOR S.N.: SUXAMETHONIUM Assessment: History and examination Assess allergies to the drug, and assess for history of respiratory or cardiac disorders, myasthenia gravis, hepatic or renal dysfunction, fractures, and glaucoma. Concurrent use of aminoglycosides or calcium-channel blockers. Focus the physical examination on the following: CV: Blood pressure, pulse rate, peripheral perfusion and ECG

CNS: orientation, affect, reflexes and vision Skin: colour, lesions, texture and sweating GU: urinary output and bladder tone GI: abdominal examination Respiratory: respirations and adventitious sounds