anaesthesia for mediastinal masses presents a topic for debate as to the questionable advantages of general anaesthesia ( g.a . ) .
however , successful management with minimal complications is reported of late due to well - balanced g.a . in such surgeries .
the mediastinum is the most common site of chest masses in children . of the many intrathoracic sites where chest masses are seen ,
the anterior mediastinum poses a greater risk in terms of life - threatening complications arising from compression of airway and vascular structures .
we present two cases , one with an anterior mediastinal mass suspected to be a lymphangioma for excision by median sternotomy and another with a non - compressible mediastinal mass electively taken up for right lateral thoracotomy ; both procedures were performed under g.a .
an 8-year - old boy weighing 16 kg scheduled for median sternotomy for excision of anterior mediastinal mass had intermittent fever for 3 months and dry cough for 2 weeks associated with breathlessness on exertion .
chest x - ray , computer tomography ( ct ) scan , magnetic resonance imaging ( mri ) and echocardiogram were performed to assess the mass and its compression on vital structures .
the child was pre - medicated and induced with 5 mg / kg of thiopentone i.v .
anaesthesia was maintained with n2o : o2 ( 50:50 ) and sevoflurane 0.8 - 2.0% .
five hundred millilitres of ringer 's lactate was administered over 2 h. heart rate , systolic blood pressure , diastolic blood pressure , mean arterial pressure , oxygen saturation , end - tidal carbon - di - oxide ( etco2 ) and electrocardiography ( ecg ) with st segment analysis were recorded .
the patient was electively ventilated in a paediatric intensive care unit ( icu ) for 3 h , reversed and extubated .
a 16-year - old female weighing 37 kg , with dyspnoea on exertion that worsened in the supine position , had productive cough , intermittent fever and dysphagia for solid food for 1 month ; hence , she was referred to a pulmonologist for management of her condition . on treatment with antibiotics and bronchodilators ,
her haemoglobin improved from 7.3 gm% to 11.5 gm% after transfusion of 2 units of packed red blood cells ( prbcs ) .
her pulse rate was 110/min and her blood pressure was 110/60 mmhg . on examination , her trachea was central and the apical impulse was in the 5 left intercostal space in the mid - axillary line and there was reduced air entry in the right supraclavicular , infraclavicular , mammary and subscapular areas and dullness on percussion .
the chest x - ray showed mediastinal widening to the right of the midline obscuring the right cardiac border [ figure 1 ] .
obscured right heart border fibreoptic bronchoscopy ( fob ) performed pre - operatively by a pulmonologist with the aid of oral local anaesthetic gargle and spray showed no extrinsic compression on the airway .
ct scan of the thorax revealed a lobulated heterogeneous solid cystic mass on the right side of the superior mediastinum , extending from the inlet of the thorax to the level of the upper part of the right atrium .
spirometry showed severe restrictive and obstructive lung disease with peak expiratory flow rate of 26% .
inj ondansetron 0.1 mg / kg and inj glycopyrrolate 0.02 mg / kg were administered before induction .
pre - oxygenation with 100% oxygen for 3 min was followed by induction with sevoflurane 8% .
after confirmation of mask ventilation , the child was intubated with a 26fr left - sided double - lumen tube ( dlt ) .
the tube was then removed and the patient was ventilated using a face mask with 100% o2 .
three attempts of intubation with the 26fr left - sided dlt failed to achieve single lung ventilation . as the patient started desaturating , ventilation with 100% o2 and intubation with a 6.00 mm cuffed oral endotracheal tube was performed .
the patient responded to inj adrenaline ( 1 mg / kg ) i.v . and developed tachycardia ( 150 - 170 bpm ) . because of the non - availability of a reinforced tube , the 6.0 mm tube ( already in situ ) was removed as it had failed to establish air entry , and was reintroduced this time with a stylet .
this attempt with a stylet was successful at negotiating the compressive obstruction and establishing ventilation , although insufficiently .
while the immediate danger of desaturation was addressed , adequate ventilation was not achieved . to achieve adequate ventilation ,
the 6.0 mm tube was replaced with a 7.0 mm tube using a tube exchanger , after making sure that the existing tube tip was indeed at the mid - tracheal position with the aid of a flexible fob .
while risks versus benefit of proceeding with the surgery ( in view of pulmonary oedema having occurred , although transiently and the possible need for elective ventilation  should the need arise ) were being deliberated by the surgical and the anaesthesiology teams , the patient was placed in a left lateral position for better ventilation .
intra - operatively , there was one episode of hypotension , which was managed with inj noradrenaline infusion .
etco2 was high ( 60 - 76 mmhg . ) until excision of the tumour .
after excision of the tumour , the heart rate and etco2 improved ( 36 - 48 mmhg ) .
the patient was ventilated in the icu for 24 h. inotropic support was tapered on the second day and patient was extubated on the third post - operative day .
an 8-year - old boy weighing 16 kg scheduled for median sternotomy for excision of anterior mediastinal mass had intermittent fever for 3 months and dry cough for 2 weeks associated with breathlessness on exertion .
chest x - ray , computer tomography ( ct ) scan , magnetic resonance imaging ( mri ) and echocardiogram were performed to assess the mass and its compression on vital structures .
the child was pre - medicated and induced with 5 mg / kg of thiopentone i.v .
anaesthesia was maintained with n2o : o2 ( 50:50 ) and sevoflurane 0.8 - 2.0% .
five hundred millilitres of ringer 's lactate was administered over 2 h. heart rate , systolic blood pressure , diastolic blood pressure , mean arterial pressure , oxygen saturation , end - tidal carbon - di - oxide ( etco2 ) and electrocardiography ( ecg ) with st segment analysis were recorded .
the patient was electively ventilated in a paediatric intensive care unit ( icu ) for 3 h , reversed and extubated .
a 16-year - old female weighing 37 kg , with dyspnoea on exertion that worsened in the supine position , had productive cough , intermittent fever and dysphagia for solid food for 1 month ; hence , she was referred to a pulmonologist for management of her condition . on treatment with antibiotics and bronchodilators ,
her haemoglobin improved from 7.3 gm% to 11.5 gm% after transfusion of 2 units of packed red blood cells ( prbcs ) .
her pulse rate was 110/min and her blood pressure was 110/60 mmhg . on examination , her trachea was central and the apical impulse was in the 5 left intercostal space in the mid - axillary line and there was reduced air entry in the right supraclavicular , infraclavicular , mammary and subscapular areas and dullness on percussion .
the chest x - ray showed mediastinal widening to the right of the midline obscuring the right cardiac border [ figure 1 ] .
obscured right heart border fibreoptic bronchoscopy ( fob ) performed pre - operatively by a pulmonologist with the aid of oral local anaesthetic gargle and spray showed no extrinsic compression on the airway .
ct scan of the thorax revealed a lobulated heterogeneous solid cystic mass on the right side of the superior mediastinum , extending from the inlet of the thorax to the level of the upper part of the right atrium .
spirometry showed severe restrictive and obstructive lung disease with peak expiratory flow rate of 26% .
inj ondansetron 0.1 mg / kg and inj glycopyrrolate 0.02 mg / kg were administered before induction .
pre - oxygenation with 100% oxygen for 3 min was followed by induction with sevoflurane 8% .
after confirmation of mask ventilation , the child was intubated with a 26fr left - sided double - lumen tube ( dlt ) .
the tube was then removed and the patient was ventilated using a face mask with 100% o2 .
three attempts of intubation with the 26fr left - sided dlt failed to achieve single lung ventilation .
as the patient started desaturating , ventilation with 100% o2 and intubation with a 6.00 mm cuffed oral endotracheal tube was performed .
the patient responded to inj adrenaline ( 1 mg / kg ) i.v . and developed tachycardia ( 150 - 170 bpm ) .
because of the non - availability of a reinforced tube , the 6.0 mm tube ( already in situ ) was removed as it had failed to establish air entry , and was reintroduced this time with a stylet .
this attempt with a stylet was successful at negotiating the compressive obstruction and establishing ventilation , although insufficiently .
while the immediate danger of desaturation was addressed , adequate ventilation was not achieved . to achieve adequate ventilation ,
the 6.0 mm tube was replaced with a 7.0 mm tube using a tube exchanger , after making sure that the existing tube tip was indeed at the mid - tracheal position with the aid of a flexible fob .
after 10 min , the patient developed pulmonary oedema for which inj furosemide 40 mg i.v .
was given and pulmonary oedema was seen to resolve . while risks versus benefit of proceeding with the surgery ( in view of pulmonary oedema having occurred , although transiently and the possible need for elective ventilation  should the need arise ) were being deliberated by the surgical and the anaesthesiology teams , the patient was placed in a left lateral position for better ventilation .
intra - operatively , there was one episode of hypotension , which was managed with inj noradrenaline infusion .
etco2 was high ( 60 - 76 mmhg . ) until excision of the tumour .
after excision of the tumour , the heart rate and etco2 improved ( 36 - 48 mmhg ) .
the patient was ventilated in the icu for 24 h. inotropic support was tapered on the second day and patient was extubated on the third post - operative day .
mediastinal masses assume significance due to the anaesthetic complications arising secondary to compression on the surrounding vital structures . as opposed to an adult average of 16% germ cell tumours , paediatric patients present with 19% germ cell tumours .
there is a significant higher incidence of neurogenic tumours and a lower incidence of thymomas and thyroid tumours in children than in adults .
the incidence of serious life - threatening respiratory and cardiovascular events in the paediatric population is approximately 7 - 20% intra - operatively and post - operatively . while it is difficult to extrapolate the same in adults , caution is advised .
general anaesthesia for median sternotomy is associated with hazards , many of which are well documented .
these risks are due to reduced functional residual capacity ( frc ) because of an increased abdominal muscle tone , decreased inspiratory muscle tone , loss of transpleural pressure gradient secondary to paralysed diaphragm , increased compressibility of the airways because of relaxation of the tracheobronchial tree under anaesthesia and supine position contributing to an increase in mass size secondary to increased central blood volume .
factors such as younger age , smaller size of mass and soft compressible nature ( lymphangioma ) evidently contributed to an absence of complications . in case 2 , although pre - operative fob failed to reveal compression on airway , compression nonetheless manifested .
this is probably explained by time lapse that ensued forth during repeated attempts at securing the airway , first with a dlt , then with a single lumen tube ( slt ) of 6 mm without and with the aid of a stylet and eventually with an slt of 7 mm .
this was further compounded by relaxation of the airway under g.a . , which made the airway vulnerable to the compressive effect of the mass .
although increased compressibility of the airways secondary to muscle relaxants can be countered by intermittent positive - pressure ventilation , it is of little help in the face of a non - compressible mass .
the fact that on the third attempt a cuffed tube with stylet was successfully negotiated beyond the point of compression serves to illustrate the undeniable value in adequate preparation for such cases .
in fact , had a reinforced tube been available , it would have further complemented the useful role of the stylet in a conventional tube . however ,
if all else fails , use of a microlaryngeal tube or rigid bronchoscope can be used under extraneous circumstances .
in addition , measures such as change of position to lateral or semi - prone , emergency thoracotomy and tumour debulking , femoro  femoral cardiopulmonary bypass , use of helium  oxygen mixture and direct laryngoscopy must be available to address contingencies .
the need for exhaustive pre - operative evaluation , meticulous preparation , perioperative anticipation of complications and equipping oneself to meet these requirements is paramount .
spontaneous ventilation should be preferred during induction to preclude the possibility of airway collapse under influence of relaxants , especially while dealing with non - compressible masses .
the use of reinforced tubes and stylets serve to negotiate near - fatal airway obstructions intra - operatively .
last but not the least , asymptomaticity in the pre - operative period in no way precludes the possibility of disastrous eventualities like airway compromise or cardiopulmonary arrest intra - operatively .
 we report the management of two paediatric cases undergoing median sternotomy and right lateral thoracotomy for mediastinal mass . 
 an 8-year - old boy presented with a history of intermittent fever and episodes of respiratory illness since 3 years and a 16-year - old girl presented with dyspnoea , cough , fever and dysphagia for solid foods . radiological investigation confirmed the diagnoses . 
 absence of pressure symptoms pointed towards a compressible mass in the boy and indicated a non - compressible mass in the girl . 
 we discuss the anaesthetic management of the younger patient with an uneventful course as opposed to the older patient where airway obstruction ensued soon after induction and led to near - cardiopulmonary arrest necessitating rescue measures . 
 swift measures at securing airway while simultaneously resuscitating the patient served to successfully revert an otherwise fateful eventuality . 
INTRODUCTION
CASE REPORTS
Case 1
Case 2
DISCUSSION
CONCLUSION