Life support to newborn: Apgar score,methods and materials of resuscitation

Neonatal resuscitation is a very important exercise which should be performed immediately after delivery when the baby is struggling for survival.

The general condition of the baby is assessed by ‘Apgar score’ immediately after delivery, and according to it resuscitation should take place. Which is invented by  dr. Apgar, an anesthetist.

APGAR score:

                                          

Apgar score   quantifies  & summarizes   the response of newly  born  infant to  the extra uterine   environment & resuscitation.

Apgar score should be assigned at 1 min & 5mts   after birth. Score after 5 min is more important in predicting the success of resuscitation.

After   birth normally about 10% of new born require some assistance to begin breathing at birth,  and about 1%need extensive resuscitative measures to survive.

Form antepartum record of the mother we can guess to some extent that which newborn is going to need resuscitation.

Among the antepartum maternal complications which may lead to need of neonatal resuscitation are,

•    Gestational hypertension, pre-eclampsia, eclampsia.
•    Gestational diabetes or mothers with pre existing diabetes.
•    Mother with anaemia
•    Isoimmunisation as in Rh-ve pregnancy
•   Previous intra uterine death
• Prolonged pregnancy
•   Multiple gestation
•   Antepartum hemorrhage, as in placenta previa or abruptio placenta.
•    PROM: pre mature rupture of membranes
•    Poly & oligohydramnios.           

    Some intrapartum factors also can lead to the necessity of neonatal resuscitation, like

•   Instrumental delivery, causing injury to baby or because of factors leading to instrumental delivery.
•   Prolonged labor, may lead to fetal cardiac and respiratory problems.
•   Abnormal presentations , which will delay the labor and may lead to instrumental or operative delivery.
•   Premature labor, in this case baby may not be mature enough to sustain the stress of labor.
•    Precipitous labor, will not give much time to baby to adopt to delivery circumstances.
•    Chorioamnionitis  may occur because of premature rupture of membranes or prolonged labor or unhygienic surroundings which will affect baby’s general health.
•   Fetal bradycardia which may be due to prolonged labor may indicate compromised fetus.
•   Non-reassuring fetal heart rate patterns may occur because of intra uterine fetal insult or prolonged labor leading to decreased supply of oxygen to the fetus.
•    Meconium stained liquor, may occur because of prolonged labor leading to fetal hypoxia, which may lead to meconium aspiration syndrome.
•   Cord prolapse may occur in some cases which needs immediate delivery of the baby, delay will lead to hampered oxygen supply to baby leading to fetal death.

The babies faced all the above intrapartum conditions may need resuscitation immediately after birth.

The main steps in the resuscitation are,

•   Evaluation : of the baby’s condition
•  Decision : to be taken immediately
•   Action : should be prompt  
• Evaluation is based on ‘respirations , heart rate &  color’.   
•  The’ ABC s’   of resuscitation are,
•   airway  (position &clear )
•   breathing  ( stimulate to breath )
•   circulation  ( asses heart rate &color)

Airway:

• The  baby should be positioned on the back  or to the side with the neck slightly extended.
•   Have to bring the posterior pharynx, larynx   and trachea in line   facilitating   unrestricted air way.
•  Have to provide warmth either by using   radiant warmer or if unavailable with electric bulb.
• Have to clear meconium from the airway :  with bulb syringe or suction catheter.  
• If the heart rate is good > 100   suction by bulb can be used or syringe  or large bore suction catheter  ( 12f or 14f) can be used. If heart rate is < 100 laryngoscope is to be used.

Stimulate to breath:

•    Have to dry the baby and stimulate to breath & reposition.  
•   The safe methods of stimulation are : slapping or flicking soles or gently rubbing newborns back, trunk or extremities .
•  We should not rub vigorously.  The consequences of vigorous stimulation are,

Harmful actions                                        Consequences

             Slapping back                             -          bruising

Squeezing rib cage                       -     fractures, pneumothorax, respiratory distress, death

Forcing thighs into abdomen        -         rupture of liver &spleen

Dialating anal sphincter                -            tearing sphincter

Using hot compresses                 -             hyperthermia , burns

Using cold compresses               -              hypothermia

Shaking                                      -            brain damage  

Free flow of oxygen:

• Oxygen can be given either by flow inflating bag &mask 
•   Or  oxygen tubing 
•   Or oxygen mask

Bag &mask ventilation:

 This is the single most important &most effective step in the cardiopulmonary resuscitation of the compromised newborn most of the times.

General characteristics of bag & mask ventilation:

•  Size : 200 -750ml ;  passage of air is 15 to 25ml with each ventilation (5to 8ml /kg).
•   Oxygen capability  is 90 to 100%
•   Safety features  are there to avoid high ventilation pressures.
•   Size  to be choosed carefully  as it should cover chin, mouth &nose  but not the eyes.

Resuscitation bags:

•   Flow inflating bag ( anesthesia bag) oxygen from compressed source flows into it.
•   Self inflating bag:  fills spontaneously after squeezing  pulling oxygen or air into the bag.
•   Other devices :  laryngeal mask air way can be used in term babies.
•   Contra indications:  meconium aspiration syndrome,   when chest compression required, very low birth weight babies, when  delivery of medications is needed.

Self inflating bag:

•   Which is commonly used will have seven basic parts :
•   Air inlet & attachment site for oxygen reservoir
•    Oxygen inlet
•    Patient outlet
•    Valve assembly
•   Oxygen reservoir 
•    Pressure release ( pop -off) valve
•    Pressure manometer attachment site (optional)

Orogastric tube:

•   It is a 8f feeding tube.
•   Length  will be measured as the distance from bridge of the nose to the ear  lobe & from earlobe to xiphoid process.
•   Better to  insert through the mouth than nose  as nose should be left open for ventilation.

Chest compressions:

•  Are needed when the heart rate is <60,
•  Two persons are required one for chest compressions and for maintaining ventilation.
•  The thumb technique is  preferred  but  two finger  technique  is also acceptable.
•   Pressure should be applied to the lower third of sternum  which lies between xiphoid &line drawn between nipples.

Endo tracheal tube intubation:

Indications:

•   When tracheal suction is required.
•   When prolonged  positive pressure ventilation is  required.
•   When bag &mask ventilation is ineffective.
•   When baby presents with diaphragmatic hernia, as bag &mask ventilation should not be given.
•  Laryngo scope should be used with straight blades for endo tracheal intubation, for preterm - size 0 and for term- size 1.
•  Types of endo tracheal tube:

Tube size                   wt of the baby          gestational age                                   

              2.5mm              < 1000 g                                           <28 wks

             3.0mm               <1.5 -2 kg                                           28-34 wks

             3.5mm                 <2- 3 kg                                            34 -38 wks

             4.0mm                   >3 kg                                               >38 wks

Drugs: 

sometimes along with mechanical measures some drugs are required.

Epinephrine:

•   Epinephrine  can be used in case of asystole   0.1-0.3ml /kg  1 in 10000 dilutions.
• Can be repeated   3to 5mts if indicated.

Volume expansion:

•   Volume expansion   should be given when baby is in shock or  response to resuscitative   measures is inadequate.
•   Crystalloids either normal saline or ringer lactate or when needed blood 10ml/kg in  5-10mts can be given.

Sodium bicarbonate:

•   sodium bicarbonate  usage is controversial it can be used  only after establishment of adequate ventilation  & circulation.

 Naloxone:

•   naloxone can be used for reversal of  respiratory depression  in babies whose mother received  narcotics within 4hrs  of delivery.
•   0.1 mg/ kg of 1mg /ml solution should be used.