Hypocalcemia symptoms may vary from asymptomatic to life threatening. The following case demonstrates difficult intubation for a patient who suffered tetany and need to be intubated for respiratory distress.
A 60-year-old lady with underlying hypertension and end stage renal failure was brought to Red Zone on 16th February 2016; presented with sudden onset of dyspnea. On arrival, she is was drowsy, tachypneic and hypersalivating. Her blood pressure was normal. Lungs auscultation noted generalised crepitation till up to upper zone. Saturation was 100% on highflow mask oxygenation. However it was noted that patient suffering she has severe muscle spasm over the neck and back with bilateral upper limb in flexed position. She was in a bent forward position and also having lock jaw. In view of severe metabolic acidosis (ph 7.0, HC03 of 7.0, pC02 18, p02 259) and patient was tachypneic, she was planned for intubation. Patient was given few bolus of intravenous valium for muscle relaxation to lie her flat but failed. Anaesthesiologist was called in for difficult airway and surgical airway equipment is prepared in case of failed airway. Patient was then successfully intubated in the operation theatre by anaesthesiologist. Noted The corrected calcium is was 0.71mmol/L and potassium level of was 6.8mmol/L. Calcium gluconate, sodium bicarbonate and lytic cocktail for hyperkalaemia was were given before patient went for urgent hemodialysis. Patient also had one episode of unstable AF where patient was synchronized cardioverted. Prolonged QT interval was also noted on ECG.
In the neuromuscular system, ionized calcium facilitates nerve conduction, muscle contraction and relaxation. Since calcium blocks sodium channels and inhibits depolarization of nerve and muscle fibers, diminished
calcium will lowers the threshold for depolarization. As result, carpopedal and generalized tetany might be observed. Alkalemia induces tetany due to a decrease in ionized calcium, whereas acidemia is protective. This is important in patients with renal failure who have hypocalcemia because rapid correction of acidemia or development of alkalemia may trigger or worsen tetany.
Most hypocalcemic emergencies are mild and require only supportive treatment. However rapid correction must be done in severe hypocalcemia in those with seizures, tetany, refractory hypotension, or arrhythmias.