undiagnosed subglottic stenosis ( sgs ) is a nightmare for the anaesthesiologist as the conventional preoperative predictors of difficult airway may not raise an alert . conditions that may increase airway oedema can worsen the sgs , which can manifest as wheezing or breathlessness . often , this may be the only telltale sign of sgs which can easily be misdiagnosed and treated as bronchial asthma with poor response to bronchodilators.[13 ] when such patients with undiagnosed sgs undergo general anaesthesia ( ga ) , a catastrophic series of events may occur following induction . multiple attempts at intubation by an unsuspecting team of anaesthesiologists , enamoured by an easy laryngoscopic view , can result in a life - threatening  can not ventilate , can not intubate  scenario , while forceful attempts may even lead to the damage of the laryngeal cartilages or perforation of the trachea . in this article , we present the management of a case of unrecognised sgs with pre - eclampsia and foetal distress scheduled for emergency lower segment caesarean section ( lscs ) . a 28-year - old lady with term gestation presented to emergency department with pre - eclampsia and a vague history of occasional breathing difficulty in the past for which she was on irregular bronchodilator therapy ; with no history of admission . her vitals were as follows : blood pressure , 158/94 mmhg ; heart rate , 83/min with respiratory rate 20/min . she was scheduled for category 1 lscs ( immediate ) in view of foetal distress . with unknown coagulation status and a normal appearing airway , the anaesthetic induction details are as follows : preoxygenation , propofol - 2 mg / kg with cricoid pressure in situ , suxamethonium - 1.5 mg / kg . direct laryngoscopy and intubation attempted following 60 seconds of apnoeic oxygenation revealed generalised oropharyngeal and glottic oedema . however , despite a cormack - lehane grade 1 view , it was not possible to insert a 7.0 size or subsequently a 6.0 size styleted cuffed tracheal tube in two attempts . a size 3 proseal laryngeal mask airway ( plma ) was inserted with cricoid pressure maintained , while a senior anaesthesiologist was called for help . considerable upsloping of capnogram , etco2 - 55 mmhg and tidal volumes of 70 to 80 ml despite 30 cm h2o peak inflation pressure were noticed . reinsertion of the plma did not improve the situation . in view of the compromised foetal status , after the delivery of a healthy child , the patient regained spontaneous breathing efforts but the tidal volumes were 100 to 130 ml with etco2 - 90 mmhg . at this stage , in consultation with the otorhinolaryngologist , it was decided to attempt intubation with a styleted 4.0 size cuffed microlaryngeal surgery tube after deepening with propofol , while tracheostomy was reserved as only an emergent option in view of unknown coagulation status . subsequent attempts to inspect the subglottic area with fiberscope were futile as it was impossible to pass it between the tracheal tube and vocal cords . a trial of extubation was given 48 hours later after cuff leak test showed enough peritubal leak . however , the patient required re - intubation within 15 minutes of extubation , following which she was tracheostomised and evaluated for the underlying pathology . x - ray neck , lateral view , showed no air shadow around the tracheal tube [ figure 1 ] suggesting possibility of sgs . this was confirmed subsequently by a computed tomography ( ct ) scan that also showed asymmetric calcification of the left arytenoid cartilage and sclerosis of the cricoid cartilage [ figures 2 and 3 ] . further evaluation of the airway under anaesthesia confirmed significant sgs with granulation tissue [ figure 4 ] , the biopsy of which was not suggestive of neoplasm or wegener 's granulomatosis . eight weeks later , she underwent laser excision of the granulation tissue and a silastic keel placement . x - ray neck , lateral view , showing absent air column around the endotracheal tube and calcified laryngeal cartilage ct scan of the neck . anteroposterior view , showing severe subglottic narrowing and left arytenoid asymmetric calcification ct scan of the neck . cross sectional view , show subglottic stenosis with asymmetric arytenoid calcification direct laryngoscopic view showing oedematous vocal cords with severe subglottic narrowing trauma , prolonged tracheal intubation , gastroesophageal reflux disease and wegener 's granulomatosis are reported causes for sgs . however , idiopathic sgs commonly occurs in women , which is believed to be related to hormonal factors . its occurrence during pregnancy is rare and very few cases have been reported in the literature.[1257 ] sgs of pregnancy is probably a misnomer . conditions that promote airway oedema may result in asymptomatic sgs to manifest with breathlessness . in this case , pregnancy and pre - eclampsia might have contributed to airway oedema , although she remained sub - symptomatic till the last stage of pregnancy . unfortunately , ability to mask ventilate could not be checked prior to laryngoscopy ; thus , it is difficult to ascertain if intubation attempts contributed to worsening of the situation . despite anti - oedema measures , the patient failed an extubation trial and the presence of granulation tissue noticed during tracheostomy , just 48 hours after initial intubation , indicates the possibility of severe sgs prior to admission itself . the asymmetric calcification or sclerosis of laryngeal cartilages may be a possible predictive marker for underlying neoplastic invasion , especially with calcification of the cricoid cartilage . however , the sensitivity and specificity of this in isolation has been reported to be low . whether sclerosis of the tissue , in proximity to the laryngeal cartilages , contributed to the unyielding nature of the subglottic tissue is not definitely known . supraglottic airway devices or smaller tracheal tubes have been used successfully to manage sgs . however , in our case , although supraglottic airway was life saving , a need for effective airway resulted in the use of a smaller size tube . although it is tempting to continue attempts at intubation when a full view of the glottis is visible , initial failure to intubate should lead to suspicion of sgs . in suspicious cases , oxygenation can be maintained with a supraglottic device , while a fiberscope can be passed through this to evaluate the airway below the glottis , which can help formulate a further airway management plan .
a 28-year - old lady with term gestation , pre - eclampsia and a vague history of occasional breathing difficulty , on irregular bronchodilator therapy , was scheduled for category 1 lower segment caesarean section in view of foetal distress . 
 a cormack - lehane grade 1 direct laryngoscopic view was obtained following rapid sequence induction . 
 however , it was not possible to insert a 7.0 or 6.0 size styleted cuffed tracheal tube in two attempts . 
 ventilation with a supraglottic device was inadequate . 
 airway was secured with a 4.0 size microlaryngeal surgery tube with difficulty . computed 
 tomography scan of the neck following tracheostomy for failed extubation revealed subglottic stenosis ( sgs ) with asymmetric arytenoid calcification . 
 this report describes the management of a rare case of unrecognised idiopathic sgs in pregnancy .