Metabolic disturbances – 1. hypocalcaemia, 2. hypoglycaemia, 3. hyperglycaemia

1. Hypocalcaemia

Immediate intern management

Suspect diagnosis.

Obtain IV access and basic blood tests (including serum calcium).
Administer 20 ml of 10% calcium gluconate.
May need to administer magnesium together with calcium.
Recheck serum calcium levels in four hours or if symptoms return.

Clinical features

History

Recent neck surgery, causes listed below
Tingling around hands, feet, mouth

Examination

Trousseau’s sign
- Carpal spasm within three minutes by BP cuff > systolic blood pressure around arm
Chovsteks’ sign
- Twitching of facial muscles by tapping over branches of facial nerve

Causes

Acute pancreatitis
Hypoparathyroidism (post thyroidectomy)
Hypoalbuminaemia
Vitamin D deficiency
Chronic renal failure

Other

Causes increasing nervous excitability leading to tetany

Further management

Investigations

Check renal function
PTH level
Amylase +/- Ranson’s criteria if in setting of pancreatitis, notify surgical registrar as could be a sign of worsening pancreatitis

Management

Notify appropriate medical staff (registrar)
Consider ICU review if pancreatitis
Medical referral if in setting of renal failure or non-surgical cause

2. Hypoglycaemia

Common in diabetic patients

Common causes:

Fasting status
Incorrect insulin dosage

Immediate intern management

If conscious

Check BSL – finger prick.
If alert and not fasting, administer oral glucose solution and Lucozade.

If unconscious

Airway/breathing/circulation (ABC).
Check BSL – finger prick.
Obtain IV access and send off basic blood tests.
Administer 25 g of 50% Dextrose. Patient should wake up on end of needle.
Consider continuing with 10 per cent Dextrose infusion.

Check BSLs frequently (30 minutely, then hourly if stabilising).

Clinical features

History

Diabetic, insulinoma
Recent change to insulin regimen
Fasting
Anxiety, tremor
Palpitations
Fatigue

Examination

Tachycardia
Sweaty
Confused
Pallor
Seizure
Loss of consciousness

Further management

Endocrine referral
Check HbA1c
Organise diabetic educator
Liaise with anaesthetist if fasting for surgery

3. Hyperglycaemia

Hyperglycaemia can be divided into:

Diabetic ketoacidosis (DKA)
Hyperosmolar non-ketotic-coma (HONKC)

i) DKA

Occurs in Type I diabetes mellitus
Results in insulin deficiency with absolute or relative increase in glucagon

Immediate intern management – DKA

If conscious:

Check BSL – finger prick.
Obtain IV access and send off basic blood tests
- (U&E, glucose, ketones, FBE).

ABG
- Metabolic acidosis
- Anion gap (HCO3- <10 mmol/L).

Dipstick urine
- Ketonuria.

IV fluids
- 1 L N saline over 30 minutes
- 1 L N. saline over one hour
- Then reassess fluid status.

Strict fluid balance chart
- +/- IDC (catheter) to monitor urine output.

Once the diagnosis of DKA has been established, seek advice from senior medical staff, including endocrinology team.

Start insulin infusion
- (Actrapid – short acting)
- 100 units Insulin in 100 mls N. Saline (one unit = 1 ml).

Infusion protocol

Once BSL <15.0 start 5% dextrose IV at 10/24 rate.
Potassium replacement.
Repeat U&E or venous gases to assess potassium.

Further replacement may be needed.

If unconscious:

Do above plus ABC.
Notify ICU.
Management may include bicarbonate replacement in ICU for severe acidosis.

Clinical features – DKA

History

Diabetic, past history, recent stress
Compliance, last insulin dose
Polyuria, polydipsia, LOW
Nausea, vomiting
Blurred vision, cramps
Abdominal pain

Examination

Dehydration
Acetone breath
Kussmaul breathing
Hypothermia
Confusion, comatose

Precipitating factors include:

Cessation of insulin
Infection
Surgery
Alcohol
Emotional stress

Issues are

Metabolic acidosis
Absolute potassium deficiency
Dehydration
Osmotic shifts

Further management

Cease insulin infusion when:
- pH normal
- pH normal
- BSL normal, <7.0
- Normal bicarbonate
- Conscious and able to resume normal diet and insulin (Ketones may still be present in urine for 48 hours)
Find precipitating factors
Diabetic education
Refer to appropriate medical staff – endocrinology unit

ii) HONKC

Occurs in elderly Type II diabetics
Causes sustained osmotic diuresis causing profound dehydration when patients are unable to drink sufficient water to replace urinary losses

Immediate intern management – HONKC

If conscious

Check BSL – finger prick.
Obtain IV access and send off basic blood tests
(U&E, glucose, FBE).
IV fluids need to be administered with care due to age and concurrent cardiac illness.
- Aim for 2–3 L’s in first two hours if able to tolerate volume.

Inform medical team and ICU early because patient may need invasive monitoring.

Strict fluid balance chart +/- IDC (catheter) to monitor urine output.
Start insulin infusion
- (Actrapid – short acting)
- 100 units Insulin in 100 mls N. Saline (one unit = 1 ml).

If unconscious:

Do above plus ABC.
Notify ICU.

Common causes

Intercurrent illness; for example, stroke or infection which worsens hyperglycaemia and prevents oral intake
Tube feeding high protein diets
Peritoneal dialysis
High carbohydrate intake
Osmotic agents (mannitol, urea)

Mortality is higher than DKA due to elderly population and co-morbidities (>50%)

Issues are

Profound dehydration
Mild acidosis may be present
Plasma glucose is very high >50 mmol/L
Serum osmolality is high

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