MeconiumMeconium

Dr .Ashraf Fouda

Ob/Gyn. Consultant

Damietta General Hospital

E. mail : ashraffoda@hotmail.com

INTRODUCTIONINTRODUCTION

The detection of meconiumThe detection of meconium stained amniotic fluid during stained amniotic fluid during

labour often causes labour often causes anxiety in the delivery roomanxiety in the delivery room because of its association with because of its association with increased perinatal mortality increased perinatal mortality

and morbidity and morbidity..

Meconium is composed ofMeconium is composed of : :

1.1. Small dried amniotic fluid debris, Small dried amniotic fluid debris,

2.2. Bile pigment and Bile pigment and

3.3. The residue from intestinal The residue from intestinal secretionssecretions. .

It is a sterile compound made up It is a sterile compound made up primarily ofprimarily of water water ((75 %75 %)), with , with mucous glycoproteins, lipids and mucous glycoproteins, lipids and proteasesproteases. .

INTRODUCTIONINTRODUCTION

Although meconium is Although meconium is sterile, its passage into sterile, its passage into

amniotic fluid is important amniotic fluid is important because of the because of the

risk of risk of meconium aspiration meconium aspiration

syndrome syndrome ((MASMAS)) and its sequelae and its sequelae. .

INTRODUCTIONINTRODUCTION

Infants delivered through Infants delivered through meconiummeconium--stained amniotic stained amniotic fluid are more likely to be fluid are more likely to be

depressed at birthdepressed at birth and to require and to require resuscitation and resuscitation and neonatal intensive care neonatal intensive care..

INTRODUCTIONINTRODUCTION

INCIDENCEINCIDENCE

Meconium-stained liquor is rareMeconium-stained liquor is rare in in premature infants premature infants

(<5 % of preterm (<5 % of preterm pregnancies);pregnancies); if it does if it does occur, there is an association occur, there is an association

with with infection and infection and chorioamnionitis. chorioamnionitis.

Passage of meconium is Passage of meconium is increasinglyincreasingly common in infants common in infants >37 weeks>37 weeks' gestation and occurs ' gestation and occurs in up to in up to 50 %50 % of post-mature of post-mature infants infants ( >42 weeks).( >42 weeks).

The incidence of MAS varies The incidence of MAS varies between between 1 and 5 %1 and 5 % of of all deliveries where there has all deliveries where there has been meconium-stained liquor. been meconium-stained liquor.

INCIDENCEINCIDENCE

There are a number of factors associated with There are a number of factors associated with an increased risk of developing MAS; these an increased risk of developing MAS; these include ainclude a: :

1.1. LLack of antenatal care, ack of antenatal care, 2.2. BBlack race, lack race, 3.3. MMale fetus, ale fetus, 4.4. AAbnormal fetal heart rate monitoring, bnormal fetal heart rate monitoring, 5.5. TThick meconium, hick meconium, 6.6. OOligohydramnios, ligohydramnios, 7.7. OOperative delivery, perative delivery, 8.8. PPoor Apgar scores, oor Apgar scores, 9.9. NNo oropharyngeal suctioning and o oropharyngeal suctioning and 10.10.TThe presence of meconium in the trachea.he presence of meconium in the trachea.

INCIDENCEINCIDENCE

Many theories have been proposed to explain Many theories have been proposed to explain the passage of meconium in utero; however, the passage of meconium in utero; however, the the precise mechanisms remain unclearprecise mechanisms remain unclear. .

The The fetal bowelfetal bowel has has little peristaltic actionlittle peristaltic action and and the the anal sphincter is contractedanal sphincter is contracted. .

It is thought that It is thought that hypoxia and academiahypoxia and academia cause cause the the anal sphincter to relaxanal sphincter to relax, whilst at the same , whilst at the same time increasing the production of time increasing the production of motilinmotilin, , which promotes peristalsis. which promotes peristalsis.

AETIOIOGYAETIOIOGY

PATHOPHYSIOLOGYPATHOPHYSIOLOGY

Meconium aspiration syndrome is a Meconium aspiration syndrome is a disease of term and postdisease of term and post--term infantsterm infants and its severity is linked to coand its severity is linked to co--existing existing fetal asphyxiafetal asphyxia. .

Aspiration of meconium into Aspiration of meconium into the distal airways can occur either the distal airways can occur either antenatally or postnatallyantenatally or postnatally, , but in the majority of but in the majority of affected infants affected infants the exact timing is not clear.the exact timing is not clear.

Aspiration is known to occur Aspiration is known to occur prior to deliveryprior to delivery, as meconium , as meconium has been found in the lungs of has been found in the lungs of

stillbirths and in infants stillbirths and in infants delivered pre-labour by delivered pre-labour by

caesarean sectioncaesarean section without without evidence of fetal distress. evidence of fetal distress.

PATHOPHYSIOLOGYPATHOPHYSIOLOGY

Postnatal inhalationPostnatal inhalation can occur can occur

late in the second stage or late in the second stage or immediately after deliveryimmediately after delivery if the infant if the infant

gasps or makes breathing gasps or makes breathing movementsmovements while the while the

oropharynx, oropharynx, nasopharynx or tracheanasopharynx or trachea

contains meconium-stained liquor.contains meconium-stained liquor.

PATHOPHYSIOLOGYPATHOPHYSIOLOGY

Meconium has a number of Meconium has a number of adverse effects on adverse effects on the neonatal lung the neonatal lung, ,

which may which may ultimately lead to ultimately lead to the the

respiratory failure (and respiratory failure (and hypoxaemia)hypoxaemia) which characterizes MAS.which characterizes MAS.

PATHOPHYSIOLOGYPATHOPHYSIOLOGY

Meconium:Meconium:1.1. Causes Causes mechanical blockagemechanical blockage of the of the

airwayairway, ,

2.2. Acts as a Acts as a chemical irritantchemical irritant causing causing pneumonitis, alveolar collapse and pneumonitis, alveolar collapse and cell necrosiscell necrosis

3.3. Although initially sterile, Although initially sterile, predisposes to predisposes to secondary bacterial secondary bacterial infectioninfection

PATHOPHYSIOLOGYPATHOPHYSIOLOGY

PREVENTION OF MECONIUM PREVENTION OF MECONIUM ASPIRATION SYNDROMEASPIRATION SYNDROME

Because of potential morbidity Because of potential morbidity and mortality from MAS, and mortality from MAS, prevention would prevention would

clearly be beneficial.clearly be beneficial. This has led to a number of This has led to a number of

antenatal, intrapartum and antenatal, intrapartum and postnatal preventative therapiespostnatal preventative therapies, ,

with a varying with a varying degree of success. degree of success.

1.1. AmnioinfusionAmnioinfusion

2.2. Delivery by caesarean Delivery by caesarean sectionsection

3.3. Maternal sedationMaternal sedation

Antenatal therapiesAntenatal therapies

The idea behind amnioinfusion The idea behind amnioinfusion is that by increasing the liquor is that by increasing the liquor volume, volume, meconium will be diluted.meconium will be diluted.

In addition, in cases of oligohydramnios, In addition, in cases of oligohydramnios, the increased volume will the increased volume will preventprevent : :

1.1. cord compression, cord compression,

2.2. subsequent hypoxia, subsequent hypoxia,

3.3. fetal gasping and fetal gasping and

4.4. passage of meconiumpassage of meconium. .

AmnioinfusionAmnioinfusion

AmnioinfusionAmnioinfusionA meta-analysis of amnioinfusion A meta-analysis of amnioinfusion

trials showed that this therapy has trials showed that this therapy has a a role in the prevention role in the prevention of MAS. of MAS.

However, the use of amnioinfusion However, the use of amnioinfusion requires further evaluation, as the requires further evaluation, as the therapy is associated with a number therapy is associated with a number of complications, including a of complications, including a higher incidence of instrumental higher incidence of instrumental delivery and endometritisdelivery and endometritis..

Delivery by caesarean Delivery by caesarean sectionsection

Although most studies suggest Although most studies suggest that infants with MAS are more that infants with MAS are more

likely to be delivered by likely to be delivered by caesarean section than by caesarean section than by

vaginal delivery, this is largely vaginal delivery, this is largely due to the due to the suspicion or suspicion or

confirmation of fetal confirmation of fetal distress. distress.

There is currently There is currently no evidence to no evidence to suggest that MAS would be prevented by suggest that MAS would be prevented by elective delivery by caesarean sectionelective delivery by caesarean section of of infants with meconium-stained liquor; infants with meconium-stained liquor;

Perhaps this is not surprising, as neither Perhaps this is not surprising, as neither

1.1. The conditions for The conditions for nornor

2.2. The timing of aspiration The timing of aspiration can be predicted can be predicted..

Delivery by caesarean Delivery by caesarean sectionsection

Maternal sedationMaternal sedation It has been suggested that the It has been suggested that the

administration of narcotics to laboring administration of narcotics to laboring women will women will prevent fetal gasping in prevent fetal gasping in utero by suppressing fetal breathingutero by suppressing fetal breathing. .

Although there has been success in Although there has been success in the prevention of MAS in the prevention of MAS in animal animal modelsmodels, there are no data to , there are no data to support this therapy support this therapy in humansin humans. .

Moreover, the likely Moreover, the likely maternal and neonatal maternal and neonatal complicationscomplications would preclude its use .would preclude its use .

Intrapartum/Intrapartum/postpartum postpartum

managementmanagement

1.1. Oropharyngeal Oropharyngeal suctioningsuctioning

2.2. Physical manoeuvresPhysical manoeuvres

Oropharyngeal Oropharyngeal suctioningsuctioning

Suction of the oropharynx Suction of the oropharynx and nasopharynx before and nasopharynx before

delivery of the shoulders delivery of the shoulders and trunk is a and trunk is a

well-established well-established practicepractice that has been used that has been used

since the 1970s. since the 1970s.

It seems reasonable that It seems reasonable that suctioning in this way would suctioning in this way would

minimize the amount of minimize the amount of meconium in the upper airwaymeconium in the upper airway

and thus reduce and thus reduce the amount aspirated the amount aspirated

during the onset of during the onset of respiration.respiration.

Oropharyngeal Oropharyngeal suctioningsuctioning

The evidence relating to The evidence relating to routine routine suctioning of the oropharynxsuctioning of the oropharynx as a as a preventative measure is preventative measure is conflicting.conflicting.

What is clear, is that What is clear, is that meticulous meticulous cleaning of the upper airway cleaning of the upper airway after delivery is beneficial in after delivery is beneficial in reducing MASreducing MAS

Oropharyngeal suctioningOropharyngeal suctioning

EVIDENCE l aEVIDENCE l a

Physical manoeuvresPhysical manoeuvres

It has been suggested It has been suggested that MAS may be that MAS may be

prevented if prevented if the infant is the infant is prevented from breathing prevented from breathing

after deliveryafter delivery. .

Methods advocated include:Methods advocated include:

1.1.Thoracic compressionThoracic compression, in which the , in which the thoracic cage of the infant is thoracic cage of the infant is compressed by a healthcare compressed by a healthcare professional in order to prevent professional in order to prevent respiration and subsequent aspiration respiration and subsequent aspiration of the contents of the upper airway, and of the contents of the upper airway, and

2.2.Cricoid pressureCricoid pressure, in which external , in which external pressure is applied to the cricoid, thus pressure is applied to the cricoid, thus preventing aspiration. preventing aspiration.

Physical manoeuvresPhysical manoeuvres

It is suggested that if used, these It is suggested that if used, these interventions be continued until interventions be continued until a second resuscitator a second resuscitator undertakes oral and/or undertakes oral and/or endotracheal suctioning. endotracheal suctioning.

There is no evidence supporting There is no evidence supporting the use of either of these the use of either of these methods in preventing MAS. methods in preventing MAS.

Physical manoeuvresPhysical manoeuvres

In fact, both In fact, both Thoracic compression Thoracic compression

and and Cricoid Cricoid pressurepressure are are

potentially dangerous potentially dangerous and cannot be and cannot be recommendedrecommendedEVIDENCEEVIDENCE IVIV

Physical manoeuvresPhysical manoeuvres

Postnatal Postnatal interventionintervention

Intratracheal Intratracheal suctioningsuctioning

Intratracheal suctioningIntratracheal suctioning

Until relatively recently,Until relatively recently, all infants with meconium all infants with meconium--

stainedstained amniotic fluid underwent amniotic fluid underwent endotracheal intubation endotracheal intubation and suctionand suction, ,

as this was known to as this was known to reduce the incidence of MASreduce the incidence of MAS. .

More recently, evidence More recently, evidence has suggested a has suggested a

change in practicechange in practice depending on whether depending on whether

or not an infant is or not an infant is deemeddeemed vigorousvigorous..

Intratracheal suctioningIntratracheal suctioning

A recent metaA recent meta--analysis analysis suggests that suggests that

routine intubation of routine intubation of vigorous term infants in vigorous term infants in

order to aspirate the lungs order to aspirate the lungs should be abandonedshould be abandoned

EVIDENCE l aEVIDENCE l a

Intratracheal suctioningIntratracheal suctioning

Suctioning of the oropharynx Suctioning of the oropharynx may be beneficial, but may be beneficial, but

endotracheal suctioning should endotracheal suctioning should be reserved forbe reserved for: :

1.1. Depressed Depressed oror

2.2. Non-vigorous infants Non-vigorous infants or or

3.3. Those who deteriorate following Those who deteriorate following initial assessment.initial assessment.

Intratracheal suctioningIntratracheal suctioning

Aspiration of gastric contents to remove Aspiration of gastric contents to remove swallowed meconium is still done in swallowed meconium is still done in many centers. many centers.

The passage of an The passage of an orogastric tubeorogastric tube is is likely to cause likely to cause apnoea and/or apnoea and/or bradycardia and is potentially harmful. bradycardia and is potentially harmful.

This practice should be abandonedThis practice should be abandoned

EVIDENCEEVIDENCE IVIV

Aspiration of gastric Aspiration of gastric contentscontents

Saline lavage is Saline lavage is used in order to loosen used in order to loosen meconium. meconium.

Saline lavage is potentially harmfulSaline lavage is potentially harmful, , as saline will displace endogenous as saline will displace endogenous surfactant, which could in turn surfactant, which could in turn worsen the respiratory illnessworsen the respiratory illness. .

In cases where saline lavage has been In cases where saline lavage has been used, infants developed respiratory used, infants developed respiratory distress secondary to distress secondary to 'wet lung'.'wet lung'.

Saline lavageSaline lavage

It is important that a It is important that a person experienced in person experienced in neonatal resuscitationneonatal resuscitation attends the delivery of all attends the delivery of all infants in whom infants in whom thick meconium-thick meconium-

stained liquor is notedstained liquor is noted, , particularly if accompanied by particularly if accompanied by suspected fetal compromise.suspected fetal compromise.

DELIVERY ROOM MANAGEMENT OF DELIVERY ROOM MANAGEMENT OF INFANTS BORN WITH MECONIUM-STAINED INFANTS BORN WITH MECONIUM-STAINED

LIQUORLIQUOR

The Neonatal Resuscitation Program of the The Neonatal Resuscitation Program of the American Academy of PediatricsAmerican Academy of Pediatrics incorporates incorporates guidelines for the management of these guidelines for the management of these infants infants

If an infant is vigorous after delivery:If an infant is vigorous after delivery:

1.1. No tracheal suctioning should be undertaken,No tracheal suctioning should be undertaken,

2.2. Secretions should be cleared from the mouth Secretions should be cleared from the mouth and nose using a wide-bore suction catheter, and nose using a wide-bore suction catheter,

3.3. Routine care should be given.Routine care should be given.

DELIVERY ROOM MANAGEMENT OF DELIVERY ROOM MANAGEMENT OF INFANTS BORN WITH MECONIUM-INFANTS BORN WITH MECONIUM-

STAINED LIQUORSTAINED LIQUOR

DELIVERY ROOM MANAGEMENT OF INFANTS DELIVERY ROOM MANAGEMENT OF INFANTS BORN WITH MECONIUM-STAINED LIQUORBORN WITH MECONIUM-STAINED LIQUOR

However, if an infant is However, if an infant is not vigorousnot vigorous afterbirth afterbirth (defined as :(defined as :

depressed respirations, depressed respirations, decreased muscle tone and/or decreased muscle tone and/or

heart rate < 100 beats per minute):heart rate < 100 beats per minute):

1.1. Direct endotracheal suctioningDirect endotracheal suctioning should be should be undertaken as soon as possible,undertaken as soon as possible,

2.2. Suction should be applied for Suction should be applied for no more no more than 5 seconds and the tube withdrawnthan 5 seconds and the tube withdrawn..

If meconium is aspirated from below If meconium is aspirated from below the cords, the cords, the infant should be the infant should be reintubated and the process repeatedreintubated and the process repeated, ,

Unless the infant has a profound Unless the infant has a profound bradycardia, in which case:bradycardia, in which case:

1.1. Resuscitation should proceed with Resuscitation should proceed with intermittent positive pressure intermittent positive pressure ventilation ventilation (IPPV)(IPPV) without suctioning, without suctioning,

2.2. Further suctioning can be attempted Further suctioning can be attempted at a later stage.at a later stage.

DELIVERY ROOM MANAGEMENT OF INFANTS DELIVERY ROOM MANAGEMENT OF INFANTS BORN WITH MECONIUM-STAINED LIQUORBORN WITH MECONIUM-STAINED LIQUOR

If after the first suctioning If after the first suctioning no meconium is no meconium is aspirated : aspirated :

1.1. No further suctioning should be No further suctioning should be attempted and attempted and

2.2. The infant should be The infant should be resuscitated using IPPV via an resuscitated using IPPV via an endotracheal tube.endotracheal tube.

DELIVERY ROOM MANAGEMENT OF DELIVERY ROOM MANAGEMENT OF INFANTS BORN WITH MECONIUM-STAINED INFANTS BORN WITH MECONIUM-STAINED

LIQUORLIQUOR

IS MENONIUM PRESENTYESNO

SUCTION MOUTH,NOSE AND POSTERIOR PHARYNX AFTER DELIVERY OF HEAD

BUT BEFORE DELIVERY OF SHOULDERS

IS THE BABY VIGOROUS?

SUCTION MOUTH AND

TRACHEA

CONTINUE WITH RESUSCITATION

CLEAR MOUTH AND NOSE FROM SECRETIONS

DRY,STIMULATE AND REPOSITION

GIVE OXYGEN AS NECESSARY

NOYES

KEY POINTSKEY POINTS

Meconium-stained liquor is Meconium-stained liquor is associated with associated with increased increased morbidity and mortalitymorbidity and mortality in babies. in babies.

MAS is MAS is linked to perinatal linked to perinatal asphyxiaasphyxia. .

Good neonatal resuscitation skills Good neonatal resuscitation skills reduce the incidence of MAS reduce the incidence of MAS

In the prevention of MAS , there In the prevention of MAS , there is is no evidence supportingno evidence supporting

the use of: the use of:

1.1. Saline lavage, Saline lavage,

2.2. Gastric aspiration or Gastric aspiration or

3.3. Thoracic compressionThoracic compression

KEY POINTSKEY POINTS

The evidence relating to The evidence relating to routine suctioning of the routine suctioning of the oropharynxoropharynx as a preventative as a preventative measure is conflicting.measure is conflicting.

Intratracheal suctioningIntratracheal suctioning should be reserved for the should be reserved for the non-vigorous babynon-vigorous baby..

KEY POINTSKEY POINTS