A. Antecedent events / associated diseases
• Acute infectious disease: Campylobacter jejuni, viral (viral exanthems, CMV, EBV, HIV), myocoplasma
• Surgery.
• Immunization.
• Hodgkin's lymphomas.
• Systemic lupus erythematosus.
• Thrombolytic agents (rare).
B. Clinical features
• Usually preceded by acute illness, as mentioned above.
• Mainly motor polyneuropathy, often progressive and ascending over 3 days to 4 weeks but it may come on rapidly and affect all 4 limbs simultaneously. Proximal muscle may be more affected.
• Trunk, respiration and cranial nerves (especially VII) may be affected.
• Areflexia occurs early and is generalized.
• Bladder or bowel dysfunction at the onset or persisting during the disease is rare.
• Autonomic dysfunction can cause cardiac arrhythmias.
C. Investigations
• The increase in CSF protein with less than 10 cells/ml strongly supports the diagnosis when found after the first week of symptoms or when a
progressive rise of protein content is demonstrated from several lumbar punctures.
• Nerve conduction studies usually show a demyelinating pattern but may occasionally show primary axonal pattern.
D. Management
1. General management:
• Monitor vital capacity (not peak expiratory flow): intubation and ventilation if breathless or vital capacity <20ml/kg or VC drops to 25-30%
of normal (Normal vital capacity in males = 25cc X height in cm; females = 20cc X height in cm).
N.B. There should be a low threshold for ventilation. Remember, pharyngeal paralysis without respiratory muscle weakness must be excluded. The treatment here is a tracheostomy with a protected cuffed portex tube.
• Monitor ECG & BP - Tachycardia with loss of sinus arrhythmia are usual, rapid fluctuations of pulse and BP may occur. Tracheal suction may cause bradycardia and asystole - this can be prevented by hyperoxygenation beforehand but if it persists it may be necessary to use atropine.
• ABG should be done periodically.
• Subcutaneous heparin 5000U bd daily in paralyzed patients.
• Chest physiotherapy.
• Prevent contractures: passive movements, ankle splints, hand-wrist finger splint.
• Hydration/nutrition via nasogastric tube.
• Urinary catheter.
• Analgesia: including amitriptyline, carbamazepine, NSAIDs, opiates.
2. IV immunoglobulin:
• It is now consider the first choice of therapy for most patients. It should be offered to all patients who have severe disease that they are unable to walk or requiring respiratory support.
• The rate of recovery is similar in patients treated with IV Ig compared to those treated with PE.
• Although IV Ig is expensive, it is not usually more expensive than PE and it
• IV Ig is given either as 0.4g/kg daily for 5 days or 1g/kg daily for 2 days.
• IV Ig should be used with extreme caution or avoided in patients with pre-existing renal failure which it may exacerbate. Other adverse effects are headache, chills, myalgia, chest discomfort, fatigue, exhaustion, fever, skin reactions, aseptic meningitis, severe anaphylactic reaction in those patients with absent or severely decificient IgA and thromboembolic events.
3. Plasma exchange/Plasmapheresis:
• Plasma exchange can be of ferred to patients with GBS who have severe disease that they are unable to walk or requiring respiratory support but have relative contraindications to the use of IV Ig.
• It should be given as early as possible although so long as the disease is still progressing it would be worth using PE.
• The usual course is 5 exchanges every other day over a period of 8-10 days.
4. Corticosteroids:
• Oral prednisolone or IV methylprednisolone has not been demonstrated to be beneficial in GBS.
6. ENDOCRINOLOGY AND METABOLIC DISEASE
_ HYPOGLYCAEMIA
# Symptoms usually occur when blood glucose <2.8mmol/L (50 mg/dL) for patients with normal initial blood glucose. The nature of symptoms depend on the absolute level of glucose and the rate of fall to this level.
A. Predisposing factors
1. Insulin or oral hypoglycaemic agent (OHA) “overdose”.
2. Changes in content or timing of meals.
3. Increased physical activity.
4. Renal failure with decreased clearance of insulin and OHA.
5. Onset of certain disorders eg. Addison’s disease, hypopituitarism, liver cirrhosis/failure and malabsorption.
B. Symptoms and Signs
• Early:
Shaking, trembling, sweating, palpitations, hunger, pins and needles in lips and tongue.
• Neuroglycopenia:
Difficulty in concentrating, change of behaviour, confusion, seizure, stupor, coma or focal neurological signs simulating cerebrovascular accidents or transient ischaemic attacks.
C. Management
1. Treatment of hypoglycaemic episodes: Prevention is better than cure, and correction should be as quick as possible.
a. Fully conscious patients:
• Oral glucose, sucrose, or sugar-containing fluids eg. 1-2 tablets of glucose/sweets, 1-2 cups of milk, orange juice, piece of fruit, cheese etc.
Ensure adequate subsequent food intake to prevent relapses.
b. When mental function is impaired:
• IV 50% dextrose 25-50ml, or as much as possible until mental functional recovery or blood glucose estimation shows a normal level, followed by infusion of 5-10% D/W or a glucose drink, if the patient recovers full consciousness.
• When hypoglycaemia is due to an overdose of long-acting insulins or OHA, 10% dextrose drip should be continued for 24-48 hrs to maintain satisfactory blood glucose level.
• Blood glucose should be maintained between 90-120 mg/dL (5-6.7mmol/L).
• Glucagon, 1mg IM or SC can be given to treat severe hypoglycaemia when IV access is difficult. This treatment option can also be taught to relatives of patients on insulin, with episodes of severe hypoglycaemia. As soon as the patient regains consciousness after glucagon, they are advised to eat/drink something as the hyperglycaemic action of glucagon lasts only 10-15 minutes.
• Patients who remain unconscious after prolonged hypoglycaemia may need to be given treatment for cerebral oedema with IV dexamethasone 4mg 6hrly or IV mannitol.
2. Adjustments of drug therapy, diet and physical activity:
• If hypoglycaemia recurs at a particular time of day- change the distribution and timing of insulin injections.
• If hypoglycaemia is severe, prolonged, or unpredictable, reduce total dose.
• Increased carbohydrate intake prior to increased or prolonged activity/exercise.
3. When the crisis is over, deal with the cause to prevent a recurrence.