a 35-year - old man who had a history of rp ( 66 kg and 168 cm ) was scheduled for rigid bronchoscopy to relieve of his worsening dyspnea . preoperative fiberoptic bronchoscopy revealed subglottic stenosis ( 6 mm in diameter , 70% narrowing ) ( fig . preoperative chest tomography showed diffuse narrowing of the trachea ( 9.4 mm in diameter ) and main bronchi ( 7.6 mm in diameter ) , in addition to right lower lobe partial atelectasis ( fig . general anesthesia was induced with propofol ( target plasma concentration 5 ug / ml ) and remifentanil ( target plasma concentration 4 ng / ml ) , using a target controlled infusion pump ( orchestra is3 , fresenius vial , breezins , france ) after injection of lidocaine 40 mg . ninety seconds after injection of succinylcholine 100 mg , a rigid bronchoscope was inserted by a pulmonologist . in addition to subglottic stenosis , cartilage loss in the entire trachea and airway narrowing , due to luminal collapse , was observed ( fig . 4 ) and i d 7.5 tube was intubated and placed right above the carina . although the patient 's spontaneous respiration was returned right after the end of the procedure , it was very weak and ineffective . the tidal volume was detected as less than 50 ml and assisted ventilation could not augment expiratory tidal volume significantly ( 50 - 100 ml ) . we encouraged the patient to breathe deeply , but there was no improvement of the tidal volume and minute ventilation , and eventually 20 minutes after the return of spontaneous ventilation , end - tidal carbon dioxide ( etco2 ) level increased gradually from 60 mmhg to 110 mmhg . he became irritable with jerky movement of the four limbs , and facial flushing accompanied . his blood pressure ( bp ) and heart rate ( hr ) increased to 180/110 mmhg and 110/min , respectively . presuming that the patient 's excessive respiratory effort and anxiety could interfere with the effective ventilation assistance , we restarted the infusion of propofol ( 2 ug / ml ) to sedate the patient . we concluded that the patient was in a state of respiratory failure and recommended the pulmonologist for mechanical ventilation . waiting for the preparation of icu bed , the pulmonologist wanted to encourage the patient to breathe in a sitting position after extubation , but the trial was not successful and his spo2 decreased to 90% . the patient was reintubated with i d 6.5 tube with stylet after an injection of 3 mg of midazolam . tube was fixed at 24 cm and breathing sound was generally coarse , and in the right lower lung field , breathing sound decreased more prominently . after injection of additional 100 mg of succinylcholine , we started hyperventilation to reduce etco2 level . in pressure controlled mode ( pcv ) , the setting was pressure above positive end - expiratory pressure ( peep ) 28 cmh2o , peep 5 cmh2o , peak inspiratory pressure 33 cmh2o , rr 20 /min , i : e ratio 1 : 1.5 and tidal volume was measured as 250 ml . etco2 decreased from 110 mmhg to 60 mmhg over 20 minutes and spo2 was well maintained as 100% at fio2 0.5 . after 20 minutes of mechanical ventilation , hr increased from 110 /min to 150 /min , and bp decreased from 120/70 mmhg to 80/40 mmhg abruptly . on the presumption of near tampon status from dynamic hyperinflation ( dhi ) , we immediately changed the mechanical ventilation into manual ventilation , decreased rr into half , and permitted abundant expiration time after several seconds of apnea period . we could not feel any build - up of high pressure through the reservoir bag . few minutes after manual ventilation , the patient 's hemodynamic status was stabilized ( bp 120/70 mmhg , hr 110 /min ) . mechanical ventilation was resumed at different settings to avoid dhi . in pcv mode , the setting was pressure above peep 28 cmh2o , no peep , rr 13 /min , i : e ratio 1 : 2 , fio2 1.0 and tidal volume was measured as 230 ml . ten minutes after resuming mechanical ventilation , arterial blood gas showed ph 7.25 , paco2 75 mmhg , pao2 356 mmhg , and hco3 33 meq / l . thirty minutes after icu admission , arterial blood gas revealed ph 7.28 , paco2 66 mmhg , pao2 104 mmhg , and hco3 31 meq / l under the same setting of mechanical ventilation as in the operating room . during the repeated weaning and extubation failure , he received tracheostomy at postoperative 16th day and on ventilator support for 27 days , postoperatively . in fiberoptic bronchoscopy taken at postoperative 27th day , generalized tracheobronchomalacia and edematous change were present in the entire trachea and main stem bronchi , and total luminal collapse was observed during coughing or suctioning . he was recommended with y stent insertion , but refused , and is taking supportive care on the ward . rp is a rare autoimmune disease that is characterized by inflammation and destruction of cartilaginous structures . the most commonly involved organs in rp include the ears ( 85% ) , nose ( 62% ) , eyes ( 54% ) , joints ( 50 - 75% ) , and airways ( 50% ) . this patient had flabby ears and nose because of cartilage destruction , but no saddle nose deformity . other involved organs in this patient were eyes ( scleritis ) , joints ( rib fracture , sternal fracture , and achilles tendon rupture ) , and tracheobronchial tree ( dyspnea ) . in this patient , symptoms include hoarseness , a nonproductive cough , and tenderness over the larynx and proximal trachea . mucosal edema , strictures , and/or cartilage collapse may cause stridor and life - threatening airway obstruction necessitating tracheostomy . when the involvement extends into the lower airways , it will result in tracheobronchomalacia , which requires stenting . when this patient had visited our hospital , due to hoarseness and cough 8 years ago , a diagnosis of rp had been made on the basis of the typical clinical features , such as diffuse airway narrowing on computed tomography ( ct ) , scleritis , and vestibular neuritis . neck ct demonstrated significant concentric wall thickening in the entire tracheal airway and luminal narrowing in laryngeal airway . ct scanning is a good tool to evaluate the thickness of the airway wall and can point where the flow - limiting site is occurring , providing help in the choice of therapy . rp patients with airway involvement have ventilation impairment and abnormal pulmonary function test . in this patient , forced expiratory volume in 1 second is 2.23 l ( 57% of predicted value ) , forced vital capacity is 4.58 l ( 94% ) and the ratio is 49% , showing moderate obstructive pattern . usually , the dyspnea may be caused by subglottic or regional fixed narrowing , dynamic obstruction , or any combination of these . later , as the inflammation subsides , the cartilage structure is lost and the airway collapses . hence , the fixed pattern might occur early in the disease and the variable patterns later . without adequate treatment , respiratory tract involvement can be complicated by airway collapse , which is the main cause of death in rp , accounting for almost 30% of mortality . this patient had combinations of fixed narrowing due to subglottic stenosis , and dynamic obstruction due to airway collapse . therefore , widening of subglottic stenosis alone could not improve his dyspnea , and the remaining malacia component might cause postoperative respiratory insufficiency . however , the pulmonologist decided not to insert a stent at this time , after considering the risk - benefit ratio . major complications with stent placement are migration , pneumothorax , persistent cough , retained secretions , infection , hemorrhage , and formation of granulation tissues . most important thing in stent placement is choosing the location at which the stents will do the most good . however , in case of diffuse involvement , as in this patient , the effect of stenting would not outweigh the risk of complications . therefore , this patient tried to encourage breathing with sitting position , but not effective in this case . when extreme tachycardia and hypotension occurred abruptly , we auscultated the lung sound to eliminate the possibility of tension pneumothorax . there was no change of breathing sound , compared to that of the previous auscultation after intubation , and subcutaneous emphysema was not observed . the sudden hemodynamic change was coincided with injection of 50 mg of rocuronium , suggesting the possibility of anaphylactic reaction . however , there were no urticaria or erythema on inspection and increase of airway pressure , and desaturation did not happen . therefore , we presumed that the near - tampon status was provoked from dynamic hyperinflation ( dhi ) by expiratory air trapping due to high inspiratory pressure , luminal collapse , rapid rr , and decreased i : e ratio . primary concern in central airway obstruction is not the limitation of inspiratory air flow , but rather dhi with hypercarbia and hemodynamic collapse . flow - volume loop and bronchoscopy can be useful in demonstrating the presence of a severe fixed stenosis and illustrating dynamic airway closure on inspiration and expiration . we observed dhi in a rp patient , but usually , dhi can be occurred in copd ( such as asthma or emphysema ) patients when they are not allowed sufficient expiratory time during controlled ventilation . hyper - inflated lungs due to air trapping result in tamponading constrictive force to the right heart . in this situation , signs of bulging of the external jugular vein and pulsus paradoxus , in addition to the hemodynamic instability can be observed . if there is an immediate improvement of hemodynamics , o2 saturation , and airway pressure after disconnecting the ventilator , diagnosis of dhi if there is not any other explanation , except dhi , then disconnecting the ventilator or stopping ventilation may be life - saving . in resuming ventilator setting after crisis resolving , the key factor is to maximize expiratory time by increasing i : e ratio and lowering respiratory rate . generally , peep is not recommended in patients with severe airflow obstruction . in conclusion , rigid bronchoscopy of rp patient with airway involvement can be complicated with dhi and post - procedure respiratory insufficiency . therefore , close communications with pulmonologist and a clear understanding of the degree and type of airway involvement are essential to safe anesthetic management .
relapsing polychondritis ( rp ) is an uncommon disease that is characterized by inflammation and destruction of cartilaginous structures . when tracheobronchial tree is involved 
 , respiratory obstructive symptoms can occur . a 35-year - old man , with a previous diagnosis of rp , 
 was scheduled for rigid bronchoscopy to relieve dyspnea , caused by subglottic stenosis . 
 after laser splitting of the subglottic web , the spontaneous respiration of the patient was insufficient , and hypercarbia developed progressively even with assisted ventilation . 
 after 20 minutes of aggressive hyperventilation to reduce end - tidal co2 level , sudden extreme tachycardia and hypotension developed . ventilation rate was reduced and prolonged expiration time was allowed to alleviate a near - tampon status from dynamic hyperinflation . after the hemodynamic status was stabilized , the patient was transferred to the icu for mechanical ventilation . 
 he received icu care for 30 days , and now , he was on supportive care on a ward , considering y stent insertion to prevent luminal collapse from tracheobronchomalacia .