Mecconium Flashcards
What is the definition for meconium?
Green viscous fluid that forms in the fetal ilium at around 11-14 weeks. It is known as the first excrement that gets passed at around 24-48 hours post-partum. It consists of water, cellular debris, vernix, lanugo, bile acids, mucus, salts, and lipids.
However,
Fetus can pass the meconium in utero. This occurs in roughly in 20 % of pregnancies and increases with fetal maturation. The incidence is around 30- 40 % in postdates pregnancies. Around 5 % of neonates will go on and develop meconium aspiration syndrome.
Speak through the physiology and pathophysiology
Physiology:
Increased gestational age causes maturation of the fetal intestinal myelination and ganglion cells. Additionally, mature fetus has a higher level of motilin, which is a polypeptide that stimulates the peristalsis of the intestinal smooth muscle. As the meconium moves closer to the distal colon and rectum, the maturing parasympathetic nervous system triggers bowel movement, relaxes the anal sphincter and releases the faecal matter.
It is important to determine whether the passage of meconium was due to the normal physiological maturation of the fetal gut or due to an underlying acute or chronic hypoxic event.
Some of the conditions associated with meconium passage in-utero include placental insufficiency, preeclampsia, oligohydramnios, infections, and certain maternal drugs such as cocaine. Additionally in acute hypoxia it could be caused by cord compression or hyperstimulation.
Reduction of oxygen in the hypoxic event causes a distribution of oxygenated blood to essential organs, such as heart and brain and reduces the supply to less vital organs such as intestine. This causes the parasympathetic nervous system to contract the bowel and relax the anal sphincter, releasing the meconium into the amniotic fluid.
During delivery 5% of neonates with meconium will aspirate meconium and develop Meconium aspiration syndrome.
Meconium aspiration happens when the amniotic fluid stained with meconium moves in and out of the lungs. Additionally, a hypoxia causes gasping reflex and further inhalation of the meconium.
Meconium is acidic and aspiration then leads to further complications such as:
Upper Airway obstruction, where the sticky substance creates a complete obstruction of the airway and can lead to acute hypoxia.
Lower airway obstruction by diffusion of meconium particles that can cause complete or partial obstruction depending on consistency of the fluid and can lead to air trapping, hyperinflation, and pneumothorax.
Inflammation of the alveoli and larger airways can cause airway oedema and inactivation of the surfactant which is a substance that reduces surface tension within the alveoli. This leads to increase of the tension, prevents the alveoli from opening and impairs oxygenation.
Differentiation of two categories:
1. Light/thin/non-significant meconium
2. Dark/thick/significant meconium (also exclude breach presentation)
Speak through the intrapartum care plan
Introduction to the woman and birth partner
Making sure that dignity is always protected
Woman comfortable and informed of the care and plan
Birth plan discussed
Informed consent obtained prior any care
Check the resuscitaire and the room temperature
Documentation
Monitoring:
Ask for Dr review with any meconium/
If augmentation of labour with Oxytocin followed by Meconium, consider stopping the infusion
In case of significant meconium or thin meconium and signs of distress, identified risk factors such as IUGR, hypertension, signs of infection, continuous CTG. If in birth centre, transfer to labour ward.
Inform MDT team: midwife in charge, obstetrician, anaesthetist, neonatologist. Escalate if any negative changes in CTG and take intrauterine resuscitation measures such as IV fluids, changing maternal position
In case of thin meconium specially in postdates pregnancies and no risk factors for fetal hypoxia present we can use intermittent monitoring every 15 minutes in 1st stage and every 5 min or after every contraction in 2nd stage. However, change to CTG if any risks arise, susceptible fetal distress or increase of the meconium.
Hourly observations to make sure there is no signs of infection, as higher risk due to meconium passage. If any signs, such increased respiration, pyrexia, low BP do Septic screen and escalate
CTG classification…if any tachycardia, rising baseline, late decelerations, low variability escalate to doctors
Hourly fresh eyes and documenting on the ctg every half an hour.
Vaginal examination every 4 hours to assess the progress, expecting 2cm in 4 hours
Checking the colour of amniotic fluid to see if any change in meconium or any excessive bleeding
Bladder care every 4 hours to help with descent and prevent damage, urinalysis to check for ketones, leucocytes, protein
Mobilising- throne position to help, preventing pressure sores
Teds stockings to prevent blood cots
Hydration
Pain relief
2nd stage: If thick meconium the neonatologist to be present
If thin mec and not reassuring CTG the neonatologist to be present
If Thin and reassuring CTG the no need for neonatologist
Support perineum to prevent tears, following the birth assess baby for colour, tone, breathing…if baby is vigorous support skin to skin. Clamp and cut the cord. Facilitate the 3rd stage.
If baby is not vigorous and shows signs of respiratory distress
Pull the emergency buzzer/Ask for help of the trained person
We shouldn`t stimulate the baby as this can increase the meconium aspiration
Inspect the airway and suction and begin the resuscitation with 5 inflation breaths and ventilation.
Keep the baby warm as in hypoxic event this can led to further complications such as hypoglycaemia.
Trained person should consider using laryngoscope to visualise the oropharynx and laryngopharynx, intubate and suction any visible meconium, inflate immediately
Call 2222 neonatal cardiac arrest if baby not responding and further help anticipated.
Cord bloods from the umbilical vein and artery should be taken to if the baby is at risk of being compromised to help assess the level of acidosis.
Speak though postnatal care in meconium
Baby:
Transfer the baby to NICU if baby showing signs of a respiratory distress or meconium aspiration
Support the airways or needed prolonged resuscitation for treatment with Antibiotics, ventilation etc…. Give parents emotional support and organise visit as soon as possible, support expressing
If baby well and stays with mother:
Initial postnatal checks, weight, HC, Vit K with consent
Support skin to skin and feeding
Observation According to trust guidelines:
Initial neonatal check, weight, HC, Vit K with consent according to weight to
Thick Mec 1 hour old, 2 hours old then 2 hourly for 12 hours
Thin Mec 1 hour old, 2 hours old and discontinue if all well
Observe for colour, circulatory impairment, HR, tone, RR, signs of respiratory distress, cyanosis, temperature
Support feeding
Discharge with information for parents how to recognise signs of unwell baby and how to seek help
Mother:
Initial postnatal assessment
Vital signs
Assess and repair perineum
Offer analgesia
Emotional support and debrief as she might be distressed
Monitor lochia/ uterus contracted
Help to mobilise/ signs of dvt/ preeclampsia
Monitor passing urine within 6 hours
Hydration/ diet
Feeding/ Espressing specially if baby is in NNU
Discharge talk and leaflets
How to recognise unwell baby and how to seek help
Follow up in community.
