The Domino Effect: Hyperventilation, Hypocapnia, and Tetany in Airway Management

Airway management represents one of the most critical challenges in anaesthesiology, particularly in patients with history of head and neck surgeries due to altered anatomy. Routine procedures like tracheostomy can occasionally present with unforeseen challenges, demanding prompt adaptability. We describe a case involving a 60-year-old female with bilateral vocal cord palsy following thyroidectomy for Hashimoto’s thyroiditis four years ago. The patient had undergone a modified Dennis Kashima procedure, which involves injecting a bulking agent or placing a graft into the affected vocal cord to reposition it towards the midline, improving voice quality and airway protection in cases of vocal cord paralysis. The patient was tracheostomised for the first time under Local Anesthesia (LA) followed by Intensive Care Unit (ICU) stay for recovery two years ago and now came in for microlaryngoscopic biopsy under general anaesthesia in view of new onset persistent hoarseness of voice and progressive dyspnoea. The complication in our case arose due to repeated failed attempts in securing the airway, prompting anxiety and rapid breathing which in no time led to systemic complications like hyperventilation induced hypocapnia and hypocalcaemia which eventually landed patient to present with classical signs of tetany, supported by arterial blood gas analysis, confirmed hypocalcaemia (0.59 mmol/L). The condition was managed successfully with rebreathing using a Bain’s circuit and intravenous calcium gluconate, which restored patient stability. This case shows the importance of the anaesthesiologist in unpredictable airway management scenarios along with neutralising the systemic complications like hypocalcaemia a potentially life-threatening condition that can precipitate neuromuscular irritability, seizures, arrhythmias, and cardiac arrest, if left uncorrected at the same time. Preparation, teamwork, flexibility, and vigilant monitoring in such a difficult situation are far more elemental to the practice of true optimal patient care.