The Royal Marsden Hospital Manual of Clinical Nursing Procedures - Lisa Dougherty [605]
Hyponatraemia (serum sodium <135 mmol/L) may be indicated in fluid retention (oedema)
Potassium 3.5–5.2 mmol/L Potassium plays a major role in nerve conduction, muscle function, acid/base balance and osmotic pressure. It has a direct effect on cardiac muscle, influencing cardiac output by helping to control the rate and force of each contraction
The most common cause of hyperkalaemia (serum potassium >5.2 mmol/L) is chronic renal failure. The kidneys are unable to excrete potassium. The level may be elevated due to an increased intake of potassium supplements during treatment. Tissue cell destruction caused by trauma/cytotoxic therapy may cause a release of potassium from the cells and an elevation in the potassium plasma level. It may also be observed in untreated diabetic ketoacidosis
Urgent treatment is required as hyperkalaemia may lead to changes in cardiac muscle contraction and cause subsequent cardiac arrest
The main cause of hypokalaemia (serum potassium <3.5 mmol/L) is the loss of potassium via the kidneys during treatment with thiazide diuretics. Excessive/chronic diarrhoea may also cause a decreased potassium level
Urea 2.5–6.5 mmol/L Urea is a waste product of metabolism that is transported to the kidneys and excreted as urine. Elevated levels of urea may indicate poor kidney function
Creatinine 55–105 μmol/L Creatinine is a waste product of metabolism that is transported to the kidneys and excreted as urine. Elevated levels of creatinine may indicate poor kidney function
Calcium 2.20–2.60 mmol/L Most of the calcium in the body is stored in the bone but ionized calcium, which circulates in the blood plasma, plays an important role in the transmission of nerve impulses and for the functioning of cardiac and skeletal muscle. It is also vital for blood coagulation
High calcium levels (hypercalcaemia >2.6 mmol/L) can be due to hyperthyroidism, hyperparathyroidism or malignancy. Elevation in calcium levels may cause cardiac arrhythmia, potentially leading to cardiac arrest
Tumour cells can cause excessive production of a protein called parathormone-related polypeptide (PTHrp) which causes a loss of calcium from the bone and an increase in blood calcium levels. This is a major reason for hypercalcaemia in cancer patients (Higgins 2009)
Hypocalcaemia (<2.20 mmol/L) is often associated with vitamin D deficiency due to inadequate intake or increased loss due to GI disease. Mild hypocalcaemia may be symptomless but severe disease may cause increased neuromuscular excitability and cardiac arrhythmias. It is also a common feature of chronic renal failure (Higgins 2009)
C-reactive protein (CRP) <10 mg/L Elevation in the CRP level can be a useful indication of bacterial infection. CRP is monitored after surgery and for patients who have a high risk of infection. The CRP level can help monitor the severity of inflammation and assist in the diagnosis of conditions such as systemic lupus erythematous (SLE), ulcerative colitis and Crohn’s disease (Higgins 2009)
Albumin 35–50 g/L Albumin is a protein found in blood plasma which assists in the transport of water-soluble substances and the maintenance of blood plasma volume
Bilirubin (total) <17 μmol/L Bilirubin is produced from the breakdown of haemoglobin; it is transported to the liver for excretion in bile. Elevated levels of bilirubin may cause jaundice
Procedure guideline 14.1 Antiembolic stockings: assessment, fitting and wearing
Essential equipment
Tape measure
Antiembolic stockings (calf or thigh length)
Apron
Patient records/documentation
Preprocedure
Action Rationale
1 Assess and record in the patient’s documentation the patient’s risk factors for VTE, that is, DVT and PE. See Box 14.2. All patients admitted to hospital should undergo a risk assessment for venous thrombosis to determine the most appropriate preventive measures, that is thromboprophylaxis (HoCHC 2005, C; NICE 2010,