hypocalcaemia can be an important cause for delayed recovery in the post - operative period and can significantly influence post - operative morbidity . we report a case of laminectomy and decompression of the spine with increased morbidity because of undetected pre - existing hypoparathyroidism . a 45-year - old male of 65 kg , presented with a history of low backache and weakness of both lower limbs for last 2 years , and urinary retention and constipation for the last 2 days . he had full power in the upper limb and grade 3 power in the lower limbs . a magnetic resonance image ( mri ) of the dorso - lumbar spine showed thickened ligamentum flavum indenting the thecal sac from d9 to d12 with cord oedema . pre - anaesthetic examination was normal except for distended , but soft abdomen without clinical evidence of ascites or organomegaly . standard monitoring , including invasive blood pressure and arterial blood gas ( abg ) was used intraoperatively . anaesthesia was induced with propofol 140 mg , fentanyl citrate 150 g and rocuronium bromide 50 mg and trachea wase intubated . anaesthesia was maintained with 2% sevoflurane in 50% o2 in air , propofol infusion at 25 g / kg / min and vecuronium bromide at 2 mg / h . the surgery lasted 5 h. intermittent fentanyl ( total 500 g ) was used for analgesia intraoperatively . hydration was maintained with intravenous ( iv ) 3.5 l 0.9% saline , 0.5 l colloid ( tetra starch ) . noradrenaline at 2 - 4 g / min was started in view of refractory hypotension . methylprednisolone was started as 30 mg / kg bolus followed by infusion at 5.4 mg / kg / h . at the end of surgery , insulin infusion was started , and the patient was shifted to intensive care unit for elective ventilation . a central venous line inserted showed a central venous pressure of 1 - 2 cm h2o . overnight serum sodium , potassium , and thyroid status was found normal . at this time , his upper limb power was almost normal while power in both lower limbs was 1/5 requiring continuation of methylprednisolone . due to inconclusive abdominal ultrasound report ( usg ) a computerized tomography of the abdomen was obtained which showed colonic gaseous distension without free fluid in the abdomen . ryle 's tube was inserted and injection neostigmine started at 2.5 mg / h for 2 h. on post - operative day ( pod ) 2 the patient re - developed deranged kft along with high - grade fever . blood , urine , and tracheal aspirate were sent for cultures and sensitivity and antibiotics upgraded as per culture reports . sepsis and  pancreatitis profile  revealed serum procalcitonin 4.4 ng / ml , hypocalcaemia ( serum calcium 4.1 mg% ) , hypoalbuminemia ( 2 g% ) , but normal serum amylase and lipase . , high doses of iv calcium ( 450 mg elemental calcium 4 h ) , was required along with oral calcitriol 0.5 g q8h . on pod 3 renal functions and acidosis started to resolve . despite 2 days trial of neostigmine , prokinetics and laxatives , his abdominal symptoms persisted . decompressive sigmoidoscopy was performed and total parenteral nutrition ( tpn ) was started . over next 2 days gastrointestinal ( gi ) symptoms , procalcitonin and total leucocyte count started to decrease . eighteen hours later , he was reintubated and ventilated due to severe tachypnoea and decreased consciousness . he was weaned off the ventilator fully conscious with good power in all limbs , normal calcium and albumin levels , and no gi symptoms . he was later decannulated and discharged with on - going treatment and advice for follow - up . the patient had been harbouring urinary tract infection ( uti ) which was missed in the absence of urine microscopic examination . hyperglycaemia in our non - diabetic patient was because of steroids and sepsis due to uti . the decreased urine output , and metabolic acidosis was the combined result of sepsis and intraoperative usage of noradrenaline . spasticity is a known clinical manifestation of hypocalcaemia , which in our case manifested as a tense abdomen . as calcium is an important mediator of excitation - contraction coupling , colonic distension and paralytic ileus is possible due to hypocalcaemia . the best - studied treatment of acute colonic pseudo - obstruction is iv neostigmine , which leads to prompt colon decompression in the majority of patients after a single infusion . however in our case , actual improvement started to occur only after normalisation of calcium levels . alkalosis and hypokalaemia aggravate the clinical manifestations of hypocalcaemia . in this patient , pain and discomfort of tense abdominal distension methylprednisolone , with predominantly glucocorticoid activity , decreases calcium absorption from the gut and increases its excretion in the urine . it also causes hypokalaemia and alkalosis by excretion of potassium and hydrogen ions through renal tubules . increased serum free fatty acids due to tpn lower serum ionized calcium . our patient was diagnosed as primary hypoparathyroidism , with severe hypocalcaemia , sepsis and acute renal failure . pancreatitis profile in view of fever , abdominal symptoms , and acute kidney injury ( aki ) , which revealed hypocalcaemia . a review into the literature of hypoparathyroidism revealed hyperostosis as a feature due to chronic hypocalcaemia . to the best of our knowledge , this is the first report correlating hypoparathyroidism , paralytic ileus and aki . hypocalcaemia though not an uncommon entity is frequently overlooked . its presence along with its etiological and aggravating factors should always be sought where recovery gets delayed .
routine investigation of serum calcium is not recommended in asa one and two patients unless abnormalities of calcium metabolism are clinically suspected . 
 the clinical features of hypocalcaemia can often be subtle and may manifest in the presence of associated factors . 
 hypoparathyroidism , an important cause of hypocalcaemia , often presents as soft tissue calcification ( ostosis ) . 
 ligamentum flavum ostosis can present with compressive myelopathy requiring laminectomy . 
 we report a case of ligamentum flavum ostosis and subclinical hypocalcaemia due to hypoparathyroidism , who went undetected pre - operatively resulting in significant post - operative morbidity .