According to Whitaker (1989), elderly surgical patients appear to have a higher tendency to post-operative delirium in comparison to other age groups. Through countless researches (Lindesay, Macdonald & Starke, 1990; Mentes, Culp, Maas & Rantz, 1999) the determinant(s) contributing to this phenomenon remained a puzzle. Delirium is a state of temporary but acute mental confusion (Lewis Heitkemper & Dirksen, 2003).
Clinically, delirium is rarely caused by a single factor. It is often the result of the interaction of the patient’s underlying condition with a precipitating event. It may be the result of a combination of factors including anesthesia, major surgery, infection and prolonged sleep deprivation (Lewis et al, 2003). Delirium can also arise from hypoxia and water-electrolyte imbalances, which are caused by disruption to oxygenation and ventilation, metabolism and elimination, respectively. Since Mr Munro has had insomnia since 6 years ago after the death of his wife, him exhibiting signs of confusion post-operatively is expected.
Hypoxia, an inadequate amount of oxygen in body tissue cells can occur on anyone. However, post-operative patients are at an increased risk of being diagnosed with delirium after surgery. Hypoxia is caused by the reduction in partial pressure of oxygen, inadequate oxygen transport, or the inability of the tissues to use oxygen. The tissues of the brain, heart, pulmonary vessels and the liver are most sensitive to hypoxia. Hypoxia in the brain can cause confusion, dizziness and poor co-ordination of muscle movements. Breathing abnormality can also result from severe hypoxic brain tissues.
Preliminary signs of hypoxia on a patient include increased heart beat (>100 beats per minute), increased breathing rate, elevated blood pressure and cramps. Multiple treatments are available for Hypoxia. This may include cardiotonic, respiratory stimulant drugs, oxygen therapy, mechanical ventilation and frequent analysis of blood gases. If hypoxia continues and left untreated, heart and breathing failure can result which can lead to unconsciousness and death. Imbalances of body water-electrolytes, like sodium, calcium, potassium and chloride, can cause acute confusion, respiratory infections and constipation. Elderly people are more vulnerable to imbalances due to their reduced ability to reserve water and impaired kidney function. These elements contribute to their decreased ability to compensate for alterations to their body.
Disturbances to the body’s electrolyte and water balance can cause serious effects on people. The body is composed of 60% water and therefore even a slight change in water balance can cause major changes in body function. Altered water equilibrium has profound affects on the normal function of almost all body systems. Electrolyte imbalances affect the function of excitable tissues like nerves, cardiac muscle, smooth muscle and skeletal muscle. Changes in renal, cardiac, nervous, muscular function and skin tone form the basis for the clinical signs observed during water and electrolyte imbalances.
Water imbalances can be caused by dehydration, sodium retention by kidneys and imbalances of output and input values. Upon receiving Mr Munro on the ward, his observations including temperature, blood pressure, pulse rate and respiratory rate should be taken and recorded. Nursing management for the next 48 hours of Mr Munro should include close monitoring of his physical and psychological status. Due to the bowel resection, Mr Munro’s blood pressure, respiratory rate and temperature may be abnormal.
Although Mr Munro had ceased his smoking habit 16 years ago, the trauma caused to his lungs are irreversible and therefore would impact on his ability to breathe normally. Taking into account his past smoking history and his current hypoxic condition, commencement of early oxygen therapy is essential. To further assist patient in breathing, Mr Munro’s bed can be elevated to a 40 degree angle so he can sit slightly upright which can increase oxygen inhalation to the body (Nursing Tutorial Notes, 2004).
Visual observation like Mr Munro’s lips moist level, skin turgor and weight can help to determine his water balance. If patient is dehydrated, his lips would appear to be cracking and dry, skin turgor would be poor and would have lost weight. This can be treated by encouraging patient to drink more water and/or administering fluids through intravenous therapy. Imbalances of body electrolytes can be treated by replacing the missing ion(s). Sodium, chloride and potassium can be administered intravenously to Mr Munro to replenish his inadequate body fluids. Accurate and precise recording of a fluid balance chart is necessary. Patient may suffer pain from his abdominal incision, consult with doctor, if allowed, give patient pethidine to ease his pain.