it is usually the result of leakage from the thoracic duct or one of its main draining lymphatic vessels .
the most common causes of chylothorax in children are lymphoma and trauma caused by thoracic surgery .
the effusion can be identified by its white and milky appearance which is due to its high levels of triglycerides and lymphocytes .
postoperative chylothorax occurs in less than 1% of thoracic procedures with a prevalence ranging from 0.5% to 2% .
postoperative chylothorax is a serious complication with a high mortality , which can approach 50% in untreated patients .
it causes nutritional deficiencies , respiratory dysfunction , dehydration , immunosuppression , and increased vulnerability to infections .
the initial management consists of indwelling pleural drainage and feeding with a milk formula rich in medium chain triglyceride ( mct ) along with total parenteral nutrition if required .
in resistant cases , ligation of thoracic duct or placement of pleuroperitoneal shunts may be considered .
somatostatin , or its analog octeriotide , has recently been used with success in a number of pediatric cases of postoperative and iatrogenic chylothorax . in pediatric patients
the reported effective doses of intravenous somatostatin ranges from 3.5 to 12 mcg / kg / h .
we report two cases of successful management of postoperative chylothorax , following surgery for congenital diaphragmatic hernia , both in full - term newborn babies , using an escalating regimen of octeriotide infusion .
a term female 3.5-kg infant , diagnosed with left diaphragmatic hernia on antenatal ultrasound scan done at 19 week of gestation , was born by spontaneous vaginal delivery in a very good condition .
she was electively intubated and stabilized for surgical repair of diaphragmatic hernia which was done uneventfully on third day of life [ figures 1 and 2 ] . during surgery
left diaphragm was found to be very vascular , which is a known risk factor for postoperative chylothorax .
she developed left pleural effusion on third postoperative day requiring ongoing ventilation and an indwelling chest drain .
the amount of fluid drained was high ( 130 ml / day).the initial pleural fluid was serosanguinous with a protein content of 26 g / dl and normal triglyceride level ( during this time the baby was only on tpn with no oral feeds ) .
the oral feeds were gradually built up over the next 8 days . by the age of 13 days the pleural fluid developed classic consistency of chylothorax : milky appearance with high lymphocyte and triglyceride ( protein 28 g / dl and wbc 8000 with 98% lymphocyte ) .
the condition was initially managed with enteral feeding with medium chain triglyceride formula ( monogen ) and total parenteral nutrition .
there was no reduction in the amount of chylothorax drainage over a period of 1 week ( day 20 of life ) [ figure 3 ] . on day 21 of life
intravenous octeriotide infusion was started at a dose of 3 mcg / kg / hr . the enteral feeds were stopped because of reports of high risk of necrotizing enterocolitis with octeriotide infusion .
the dose of octeriotide was gradually increased by 1 mcg / kg / hr everyday till we reached a dose of 9 mcg / kg / hour after 8 days .
there was a sudden drop in the chylothorax output once the dose octeriotide dose reached 9 mcg / kg / hr . the infusion was maintained at the same level ( 9 mcg / kg / hr ) for 11 days . during this period ,
the chyle drainage per 24 hours reduced gradually to a minimal amount with significant response noted 2 days after reaching 216 mcg / kg / day ( 9 mcg / kg / hr ) .
the infant was extubated successfully to nasal cannula and then to room air within 3 days after administration of octeriotide infusion ( day 20 postsurgical repair ) .
this resulted in transient increase in chylothorax drain which resolved spontaneously [ figure 4 ] .
the octeriotide infusion was weaned over 5 days by decreasing the dose at a rate of 2 mcg / kg / hr everyday till the infusion was discontinued . during octeriotide therapy
the baby was monitored closely , on daily basis , for any evidence of glucose intolerance , liver and renal impairment .
no side effects were noted . left diaphragmatic hernia before surgery chest x - ray of our patient immediately after surgery left chylothorax with chest tube drainage chylothorax drainage ( pink line ) , octeriotide
dose mcg / kg / hr ( blue line ) , gray zone reflect days of enteral feed , white zone reflects days of exclusive tpn with no oral feeds the infant was discharged home self - ventilating in room air after 1 week on monogen formula .
medium chain triglyceride ( mct ) oil and oral polycose were added to the feed to increase her caloric intake and promote weight gain .
on postdischarge follow - up in neonatal and dietetic clinics she had symptomatic of massive gastroesophageal reflux which required antireflux medication .
a term male 3.5 kg infant was born by spontaneous vaginal delivery in a good condition .
the chest drain placed during surgery - drained blood - stained fluid which decreased gradually and chest tube was removed on 7 post - op day .
oral feeding with breast milk was started on 9 post - op day . the next day baby developed respiratory distress requiring reintubation and ventilation .
the initial pleural fluid was serosanguinous with a protein of 26 g / dl and normal triglyceride level . during this time
the baby was only on tpn with expressed breast milk feeds . over the next few days
the contents became typical of chylothorax with triglyceride level of 4 mmol / l and lymphocytes count of > 91% .
management with formula feed containing medium chain triglycerides ( monogen ) and total parenteral nutrition did not reduce the amount of chylothorax drainage .
1 mcg / kg / hr everyday till we reached 10 mcg / kg / hr on post - op day 24 [ figure 5 ] . a dramatic response in terms of reduction of pleural drainage was noted once a dose of 10 mcg / kg / hr was reached .
the baby was extubated successfully to nasal cannula and then room air within 3 days .
the octeriotide infusion was kept at the same dose ( 10 mcg / kg / hr ) for 5 days and then gradually reduced at a rate of 2 mcg / kg / hr every day over the next 5 days . within three days the baby was discharged home self - ventilating in room air and on full enteral feeding with monogen formula . during the phase of high pleural drainage the baby was also supported with i.v .
the baby was monitored closely for any evidence of glucose intolerance , liver and renal impairment .
a term female 3.5-kg infant , diagnosed with left diaphragmatic hernia on antenatal ultrasound scan done at 19 week of gestation , was born by spontaneous vaginal delivery in a very good condition .
she was electively intubated and stabilized for surgical repair of diaphragmatic hernia which was done uneventfully on third day of life [ figures 1 and 2 ] . during surgery
left diaphragm was found to be very vascular , which is a known risk factor for postoperative chylothorax .
she developed left pleural effusion on third postoperative day requiring ongoing ventilation and an indwelling chest drain .
the amount of fluid drained was high ( 130 ml / day).the initial pleural fluid was serosanguinous with a protein content of 26 g / dl and normal triglyceride level ( during this time the baby was only on tpn with no oral feeds ) .
the oral feeds were gradually built up over the next 8 days . by the age of 13 days the pleural fluid developed classic consistency of chylothorax : milky appearance with high lymphocyte and triglyceride ( protein 28 g / dl and wbc 8000 with 98% lymphocyte ) .
the condition was initially managed with enteral feeding with medium chain triglyceride formula ( monogen ) and total parenteral nutrition .
there was no reduction in the amount of chylothorax drainage over a period of 1 week ( day 20 of life ) [ figure 3 ] . on day 21 of life
intravenous octeriotide infusion was started at a dose of 3 mcg / kg / hr . the enteral feeds were stopped because of reports of high risk of necrotizing enterocolitis with octeriotide infusion .
the dose of octeriotide was gradually increased by 1 mcg / kg / hr everyday till we reached a dose of 9 mcg / kg / hour after 8 days .
there was a sudden drop in the chylothorax output once the dose octeriotide dose reached 9 mcg / kg / hr . the infusion was maintained at the same level ( 9 mcg / kg / hr ) for 11 days . during this period ,
the chyle drainage per 24 hours reduced gradually to a minimal amount with significant response noted 2 days after reaching 216 mcg / kg / day ( 9 mcg / kg / hr ) .
the infant was extubated successfully to nasal cannula and then to room air within 3 days after administration of octeriotide infusion ( day 20 postsurgical repair ) .
this resulted in transient increase in chylothorax drain which resolved spontaneously [ figure 4 ] .
the octeriotide infusion was weaned over 5 days by decreasing the dose at a rate of 2 mcg / kg / hr everyday till the infusion was discontinued . during octeriotide therapy
the baby was monitored closely , on daily basis , for any evidence of glucose intolerance , liver and renal impairment .
no side effects were noted . left diaphragmatic hernia before surgery chest x - ray of our patient immediately after surgery left chylothorax with chest tube drainage chylothorax drainage ( pink line ) , octeriotide
dose mcg / kg / hr ( blue line ) , gray zone reflect days of enteral feed , white zone reflects days of exclusive tpn with no oral feeds the infant was discharged home self - ventilating in room air after 1 week on monogen formula .
medium chain triglyceride ( mct ) oil and oral polycose were added to the feed to increase her caloric intake and promote weight gain .
on postdischarge follow - up in neonatal and dietetic clinics she had symptomatic of massive gastroesophageal reflux which required antireflux medication .
a term male 3.5 kg infant was born by spontaneous vaginal delivery in a good condition .
the chest drain placed during surgery - drained blood - stained fluid which decreased gradually and chest tube was removed on 7 post - op day .
the initial pleural fluid was serosanguinous with a protein of 26 g / dl and normal triglyceride level . during this time
the baby was only on tpn with expressed breast milk feeds . over the next few days
the contents became typical of chylothorax with triglyceride level of 4 mmol / l and lymphocytes count of > 91% .
management with formula feed containing medium chain triglycerides ( monogen ) and total parenteral nutrition did not reduce the amount of chylothorax drainage .
octeriotide infusion was started at 2 mcg / kg / hr and increased gradually by 1 mcg / kg / hr everyday till we reached 10 mcg / kg / hr on post - op day 24 [ figure 5 ] . a dramatic response in terms of reduction of pleural drainage
the baby was extubated successfully to nasal cannula and then room air within 3 days .
the octeriotide infusion was kept at the same dose ( 10 mcg / kg / hr ) for 5 days and then gradually reduced at a rate of 2 mcg / kg / hr every day over the next 5 days . within three days
the baby was discharged home self - ventilating in room air and on full enteral feeding with monogen formula . during the phase of high pleural drainage the baby was also supported with i.v .
the baby was monitored closely for any evidence of glucose intolerance , liver and renal impairment .
chylothorax may occur spontaneously in the neonatal population e.g. , due to abnormal congenital lymphatic malformations or in the postoperative setting after thoracic duct injury or disruption of lymphatic channels .
the incidence of chylothorax following surgery for congenital diaphragmatic hernia ranges from 7 to 28% .
a number of therapeutic interventions have been used to reduce chyle production and promote resolution of chylothorax .
milk feeds , high in medium - chain triglycerides ( mct ) , or parenteral nutrition may be used .
mct is transported directly into the portal system , bypassing the lymphatic pathways , thus diminishing lymphatic flow through the thoracic duct .
mct formulas have been shown to produce resolution of chylothorax in approximately one - third of patients after two weeks , while parenteral nutrition typically results in resolution in 75 - 80% of cases by that time .
in resistant cases , pleurodesis , ligation of thoracic duct , or placement of drains and pleuroperitoneal shunts may be considered .
however , the failure rate with these options is high and only pleurodesis works in severe cases .
recently , octreotide has emerged as an alternative option for management of patients with chylothorax resistant to conventional therapies .
, it is a potent inhibitor of growth hormone , glucagon , insulin and thyroid stimulating hormone .
moreover , by increasing splanchnic arteriolar resistance and decreasing gastrointestinal blood flow , octeriotide indirectly reduces lymphatic duct flow .
some authors have mentioned another mechanism : octeriotide blocks pancreatic and biliary secretion by inhibition of serotonin and other gastrointestinal peptides .
potential adverse effects of octeriotide therapy are bradycardia , stomachache , headache , hypo or hyperglycemia , hypothyroidism , nausea and vomiting .
one published report mentions an association between the use of octeriotide and necrotizing enterocolitis in a baby who had postoperative chylothorax .
although infusions of octreotide appear physically stable when mixed with parenteral nutrition solutions , the mixture may result in the formation of a glycosyl octreotide conjugate , resulting in reduced efficacy .
combined tpn and octeriotide increase the speed of chylothorax resolution in children and avoid later surgical intervention , which can have up to 10% perioperative mortality rate .
it is almost always used as a second line therapy following failure of initial management with no oral feeds , tpn and or mct feeds .
there is significant heterogeneity in dosing regimens , therapeutic duration , and time to start octeriotide .
most authors began treatment with a lower dose and progressively raised it to achieve a response .
the exact maximum dose at which significant reduction of chylous drainage can be achieved has been variable . in our two cases ,
we started octeriotide infusion at a rate of 2 mcg / kg / hr which was gradually increased by 1 mcg / kg / hr every day till we reached a maximum dose of 10 mcg / kg / hr . after being at this dose for 48 hours , we observed a dramatic reduction of chylous drainage which kept on decreasing gradually over the next few days .
similarly there is no established protocol for weaning the octeriotide infusion once chylothorax has resolved . in our two cases we weaned octeriotide by reducing the infusion at a rate 2 mcg / kg / hr every day .
we reviewed the literature to find out the most effective dose or regimen of octeriotide infusion in the management of chylothorax following repair of congenital diaphragmatic hernia .
the results , as expected , were very variable . based on these studies we constructed table 1 which shows a summary of therapeutic regimens of octeriotide in postoperative chylothorax following surgery for congenital diaphragmatic hernia .
the chyle drainage was significantly reduced within 48 - 72 hours once a maximum dose was reached .
previously published studies on the use of octeriotide in postoperative chylothorax following repair of 
 diaphragmatic hernia
octeriotide is a relatively safe second line therapy in the management of chylothorax secondary to surgery for congenital diaphragmatic hernia .
a trial of octeriotide therapy can prevent potential permanent surgical procedures like pleurodesis or pleuroperitoneal shunts .
 chylothorax , a known complication of surgery for congenital diaphragmatic hernia , can sometimes be resistant to treat . octeriotide ( somatostatin analogue ) can be useful in this situation . 
 however , the dose and schedule of octeriotide therapy in neonates is not well established . 
 we report two cases of resistant chylothorax following surgery for congenital diaphragmatic hernia which were successfully managed by using an escalating infusion of octeriotide . the literature on the subject is also reviewed . 