meconium aspiration syndrome

2.  MORNING MEETING
 NICU
 Dr Aijaz Ahmed
 Postfellow NICU

3. B.O Rehana
Age: 6 days old
Gender: female
DOB : 30 july 2023
DOA: 04-08-2023
resident of landhi
admitted in NICU with complain of:


4.  Presenting complains:
Respiratory distress since birth

5. HOPC

6.  Booked case
 Regular visits
 3 Ultrasound scans done, all normal.
 Tetanus vaccination done
 On supplementary multivitamins
 No history of GDM ,PIH ,Infection or any rash during pregnancy .
Birth history
Antenatal history:

7. Term Baby delivered by SVD at private hospital
Natal history

8.  Baby was cyanosed at birth
 Suctioning and PPV done, baby revived
 Admitted in NICU, for respiratory distress
 Feeding not started due to respiratory distress
Post natal history

9.  Family History
8th issue of non consangious marriage , other siblings
are alive and healthy
 Socioeconomic hx.
father is labourer , 9 family members live in rented
house

10.  sick looking tachypenic baby lying in incubator with respiratory
distress and obvious subcostal and intercostal recessions.
 Vitals :
SPO2 = 94% (on bubble cpap 3/3)
R/R = 76 breaths/mint
H/R = 155 beats/mint
Temp = Afebrile
Pre ductal and post ductal 02 saturation . ( 94%)
 A-, J-, C-, D-, Ed-
General Physical Examination

11.  FOC = 35 cm (at 50th centile)
 LENGTH= 51cm (at 50th centile)
 WEIGHT= 3.8 kg (at 75th centile)
Anthropometric measurements

12. HEAD: Anterior fontanelle was wide
and flat
EYES: Normal
NOSE: nasal flaring
MOUTH & PALATE: No cleft lip and palate
EARS: Normally placed, No deformation
LIMBS: Normal
NAILS: MECONIUM STAINED
BACK: Normal
UMBLICUS: MECONIUM STAINED
(YELLOW GREEN COLOR)
Genitals : normal male
HEAD TO TOE EXAMINATION

13. INSPECTION:
Shape of the chest is
symmetrical with no deformities
Equal chest movement on both
sides with subcostal and
intercostal recessions.
PALPATION:
Trachea central placed
Apex beat lies at 4th left
intercostal space – mid-clavicular
line
AUSCULTATION:
Bilateral crepts
Equal Bilateral air entry

14.  INSPECTION: non distended
 No scar or distended veins
 Umbilical cord centrally placed
 PALPATION:
 Soft, non-tender with no visceromegaly
 AUSCULTAION:
 Gut sounds audible
Abdomen

15. INSPECTION:
 Normal shape of precordium with no visible pulsation.
PALPATION:
 Apex beat palpable in left 4th intercoastal space slightly medial to mid clavicular line.
AUSCULTATION:
 Both S1 and S2 were audible with no added sounds.
CVS Examination

16. REFLEXES:
 MORO: Incomplete
 SUCKING: Fair
 ROOTING: good
 GRASPING: Good
ACTIVTY:
 Good
TONE:
 Normal
CNS Examination

17.  Pt was active.
 CN II:Pupils b/l equally reactive to light,blink reflex intact.
 CN III,IV,VI:Eye movements intact.
 CN V,VII,XII:Corneal,sucking,rooting reflex intact.
 CN VIII: responds to sound stimulus
 CN IX,X:Gag reflex present
 CN I,XI:NOT accessible
CNS EXAMINATION

18. AGA , TERM
 Meconium Aspiration Syndrome
 Congenital heart disease (TGA)
 Early onset Sepsis (Pneumonia)
 (PPHN)
Differential Diagnosis

19.  Baby admitted in NICU
 IV line maintained
 NPO
 OG passed
 kept on Bcpap 3/3
 IV antibiotics started
 IV fluids attached
Management

20. CXR

21. CBC 15-11-21
Hb 15.7gm/dl
TLC COUNT 17500
N 55%
L 40%
E 03
M 02
PLT 220000
HCT 25.2%
MCV 70 fl
 Peripheral smear
 Microcytic hypochromic.
21
Labs

22. UREA 20
CREATININE 0.7
SODIUM 138
POTASSIUM 3.9
CHLORIDE 103
H2C03 25
22
UCE

23.  CRP : <05
 Blood CS: Negative
 Urine CS : Negative
septic screening

24. ABGs
PH 7.58
PCO2 24
HCO3 24
PO2 148
BE -3
SO2 99%
24
ABGS

25. PFO seen on Echo
Echocardiography

26.  Baby kept on bubble cpap for 3 days
 respiratory distress improved
 OG feed started
 CPAP Tapered
 Plan shift to Tr on mother feed
Course of illness

28. FINAL DIAGNOSIS
Meconium Aspiration
Syndrome

44. DEFINITION
Meconium aspiration syndrome (MAS) is a
respiratory disorder caused by inhalation of amniotic
fluid contaminated with meconium into the
tracheobronchial tree.

45. EPID
E
M
I
O
LO
G
Y
• MSAF 10-15% of deliveries
3-4% Develop MAS
50% Require CPAP/mechanical
Ventilation
• Term & Post term

46. P
H
Y
S
I
O
L
O
G
Y
• Ph of meconium- 5.5 to 7.0
• Sterile, viscous, dark green, odourless substance
•COMPONENTS-
Water(72-80%),
Desquamated cells
Mucin, lanugo hair
Amniotic fluid & intestinal secretion
Blood group specific glycoprotein/ bile pigments

47. • Meconium is 1st found in fetal ileum between 10-
16th week of gestation
• In utero passage of meconium is uncommon due to
 Lack of strong peristalsis
 Good anal sphincter tone
 A cap of viscous meconium in the rectum
• Meconium passage uncommon < 34weeks

48. •Watery-
amniotic fluid that is thinly stained
•Moderately stained-
opaque fluid without particle
•Pea soup-
fluid with thick meconium & particle

49. E
F
F
E
C
T
SO
FMECONIUM
• Directly alters the amniotic fluid antibacterial activity
increase infection
erythema toxicum
• Irritant to fetal skin -------
• Meconium aspiration

50. Fetal distress
(hypoxia/acidosis/ infection)
post term
babies( motilin)
Vagal + due to
Head/cord
Compression
gasping before/during delivery
INU
T
E
R
O
P
A
S
S
A
G
E
O
F
MECONIUM

51. R
I
S
KF
A
C
T
O
R
S
• Maternal hypertension/DM
• Maternal chronic respiratory/cardiovascular disease
• Heavy cigarette smoking
• Post date pregnancy
• Pre-eclampsia/eclampsia
• Oligohydramnios
• Chorioamnionitis
• Abnormal fetal heart pattern

52. HYPOXIA
AIREWAY
OBSTRUCTION
PULMONARY
HYPERTENSION
CHEMICAL
PNEUMONITIS
SURFACTANT
DYSFUNCTION

53. AIRWAY OBSTRUCTION
COMPLETE PARTIAL
Atelectasis ball valve effect
CHEMICAL PNEUMONITIS –
• Enzymes, bile salts, FFA irritate the airway/ parenchyma
• Release of cytokines( IL1B, IL8, TNF )
• Direct lung damage/ vascular permeability

54. SURFACTANT DYSFUNCTION
• Damage to type 2 alveolar cells ------ surfactant proteinA&B
• Protein / FFA in meconium cause alteration in the phospholipid
structure of surfactant ----- ability to reduce surface tension

55.  + persistent hypoxia /acidosis
 Remodelling of pulmonary vasculature PPHN (1/3rd
cases of MAS )
Fetal compromise + inflammatory
mediators

57. H
I
S
T
O
R
Y
• Presence of meconium in amniotic fluid is required to
cause MAS
• Green urine may be observed in newborns with MAS less
than 24 hours of birth. Meconium pigments can be
absorbed by lungs & excreted in urine.
• Term/post term
• Depressed at birth

58. D
E
LI
V
E
R
YR
O
O
M
• Infants with MSAF present with poor muscle tone & breathing
efforts ----- initial steps done under radiant warmer
• PPV ------ not breathing/ HR<100
• Routine intubation for tracheal suctioning is no longer
suggested.
• Skilled personal in intubation needed during delivery.
• If infant does not improve with PPV/ intubation then go for
tracheal suctioning.

59. PH
Y
S
I
C
A
LEXAMINATION
• EVIDENCE OF POST MATURITY: Peeling skin, long
fingernails, and decreased vernix.
• Nails will become stained after 6 hours and vernix after
12 to 14 hours of exposure .
• Umbilical cord staining

60. • Present at birth
• Initial apnea respiratory distress
• Tachypnea , marked cyanosis
• Use of accessory muscles of respiration
• Barrel shaped chest
• Crepts/wheeze
• Sign of cerebral irritation from cerebral edema or hypoxia
: jitteriness, seizures

61. CLASSIFICATIONO
FR
E
S
P
I
R
A
T
O
R
YD
I
S
T
R
E
S
S
• MILD MAS –
Disease requiring <40% o2 for <48hours
• MODERATE MAS-
Disease requiring >40% o2 for >48 hours without air leak
• SEVERE MAS-
Disease requiring assisted ventilation for >48 hours often
associated with PPHN

62. DIA
G
N
O
S
I
S
• MAS must be considered in any infant born through
MSAF who develops symptoms of RD with typical chest
Xray finding
• A chest radiographs - hyperinflation of the lung field and
flatten diaphragms
• Coarse irregular patchy infiltrates
• A pneumothorax and pneumomediastinum may be
present

64. left lung demonstrating
the streaky lucencies of
the air in the interstitium
(red arrows)
complicated by by a
pneumothorax
( yellow arrow )

65. • Arterial blood gas measurements typically show hypoxemia
and hypercarbia.
• Infants with pulmonary hypertension and right-to-left
shunting may have a gradient right-to-left shunting may
have a gradient in oxygenation between preductal and
postductal samples.
• Echocardiogram for evaluation of PPHN.

66. M
A
N
A
G
E
M
E
N
T
• Monitor the respiratory distress/ O2 saturation
• Optimal thermoneutral environment
• Minimal handling
• Blood glucose/ calcium monitoring
• ABG in severely depressed babies
• Circulatory support ----- NS/ inotropes/ PRBC
• Avoid chest physiotherapy

67. •OXYGEN THERAPY- for hypoxemia.
Serial monitoring of blood gases/ PH
If FiO2 >0.40
trial of CPAP ( caution : air trapping/ hyperinflation)
severe RD, PaC02 >60mm of Hg/ PaO2 <50mm of Hg
Mechanical ventilation

68. • High inspiratory pressure (30-35cm of water)
• Short inspiratory time
• Adequate expiratory time to prevent air trapping
• Low PEEP- 4-5 cm of water ---- splinting partially obstructed
airway & equalizing V/Q mismatch.
• Inspiratory time- 0.4-0.5sec.

69. • Severe MAS – high frequency ventilation with jet or
oscillatory ventilator.
It reduces barotrauma and air leak syndrome.
• ECMO- for infants with refractory respiratory failure.
survival rate >94% & reduces the duration of
mechanical ventilation

70. • ANTIBIOTICS:
Indicated if infiltrate on chest Xray
Broad spectrum antibiotics
Blood c/s – determine the duration
• CORTICOSTEROID:
Not routinely used
Reduce meconium induced inflammation & PG mediated
pulmonary vasoconstriction
Improves oxygenation and decreases length of NICU stay

71. • SURFACTANT THERAPY-
Considered in more severe cases of mas
Improves oxygenation & lung compliance
Reduces the need of ECMO

72. Decrease length of NICU stay, improve
Oxygenation
• SEDATIVE – Mechanical ventilation
• ANTIOXIDANTS – N acetylcysteine
• Inhalational NO for PPHN
reduces the need of ECMO

73. P
R
E
V
E
N
T
I
O
NO
F
M
A
S
• Careful monitoring during pregnancy
• AMNIOINFUSION - For treatment of variable fetal HR
deceleration by relieving umbilical cord compression.
• TIME OF DELIVERY- induce as early as 41weeks
• MODE OF DELIVERY- not significant.

74. C
O
M
P
L
I
C
A
T
I
O
N
S
•AIR LEAK – Pneumothorax & pneumomediastinum – 15 to 33%.
More with mechanical ventilation due to air trapping
• PPHN
• PULMONARY SEQUELAE- 5% require supplemental O2 at
1month .
Airway reactivity, higher incidence of pneumonia & abnormal
pulmonary function.

75. THANK
Y
O
U

76. Acute/chronic
hypoxia/infection
Passage of meconium in utero
Fetal distress / gasping
Meconium aspiration