Wednesday 15 October 2014

Neonatal hypoglycaemia

Cause:
Maternal diabetes mellitus
Large or small for gestational age
Prematurity
fetal stress

Symptoms

Jitteriness
Lethargy
Poor feeding
Apnoea


Screening tests done in labour room

G6PD and TSH from cord blood.

Tuesday 14 October 2014

Neonatal resuscitation

Aim: prevention of birth asphyxia and brain damage resulting in failure to initiate and sustain breathing

Anticipate
Adequate preparation
Timely recognition
Quick and correct action


Prerequisite

Trained in neonatal rescitation
Prepare appropriate equipments
close communication between obstetrician and paediatricinan to identify high risk women before labour if possible or high risk newborn during delivery


High risk delivery

Maternal

Antenatal:
 Pre-eclampsia, Maternal diabetes, PPROM, Preterm, maternal substance abuse, lack of ANC, Multiple pregnancy, anemia in pregnancy
Rh isoimmunisation
Oligo and polyhydramios
cchronic maternal illness
Teenage pregnancy <18,
Elderly primi >35
Post term pregnancy

Intrapartum

Prolonged labour
Prolonged rupture of membrane delivery interval
Precipitous labour
Cord prolapse
Placental abruption or praevia
Instrumental delivery
Emergency C section
Fetal bradycardia-- hypoxia, acidosis, local anaesthetics, epidural, pethidine to mother, propanolol, MgSo4, fetal heart conduction defect
Meconium stained liquour
Narcotics to mother 4 hours before delivery
General anaesthesia
Chorioamnionitis


Fetal

IUGR
Prematurity
Postmaturity
Congenital anomalies
Multiple pregnancy

Delivery complications
Transverse lie or breech presentation
Chorioamnionitis
foul smelling or meconium stained liqour
antenatal asphyxia with abnormal fetal heart rate pattern, maternal administration of a narcotic within four hours of birth or delivery instrumentation eg forceps vacuum or caesarean

Asphyxia in a neonate can be due to to types of apnoea
Primary: Blue, heart rate increase, rescuscitate easily
Secondary: white floppy, heart rate decreased, BP decrease, require active rescuscitation like intermittent positive pressure ventilation.

APGAR score

Appearance -        Blue or pale                Pink centrally blue extremities            completely pink
Pulse                     Absent                        <100bpm                                              >100bpm
Grimace                No response                grimace on painful stimulus               cry, cough, sneeze
Activity                Limp                            some flexion                                       active movement
Respiration           absent                          slow irregular cry                               vigorous cry

Apgar score 1 minute signanls need for immediate resuscitation
5 minute apgar score indicates response to resuscitation rough prognostic indicator
If <7 at 5 min, repeat every 5 minutes up to 20 minutes to note progress
APGAR score at 20min is a good prognostic indicator for neurological outcome


Physiology of the newborn

There is basically a transition from fetal to Extrauterine life

Initial respiration inflates the lings and fluid in the lungs is absorbed
Clamping of umbilical arteries and veins removes low resistance placenta circulation and increase systemic BP

Lung expands and increases oxygenation so decreasing pulmonary vascular resistanc and increase pulmonary blood flow
Ductuus arteriosus and foramen ovale closes




MANAGEMENT OF NEWBORN


Birth

Term gestation?
Meconium stained liquour?                 Yes                           Routine care:
Breathing or crying?                                                              Provide warmth,
Good muscle tone?                                                            Dry: remove wet towel, replace with dry
Colour pink?                                                                      Clear aiway- suck nose and mouth
                                                                                            Position

NO

Provide warmth
Neutral position
Clear airway if necessary
Dry stimulate reposition
Give oxygen if necessary


Evaluate breathing heart rate colour and tone


Apnoeic or HR <100bpm- assess heart rate with stethoscope


Give PPV ( mask ventilation, O2 5L/min
Intubate when mask ventilation inadequate to oxygenate or ventilate


HR <60bpm (count by palpate the umbilicus)

PPV plus chest compression

HR less than 60bpm

Consider epinephrine with or without volume
administered through umbilical vein


If heart rate does not increase and adequate lung inflation not achieved consider DOPE

D- displaced tube (esophagus or right bronchus)
O- Obstructed tube (meconium)
P- patient--- lung disorder eg pneumothorax, shock, birth asphyxia, upper airway obstruction
E- equipment failure- exhausted gas supply


1 minute- 60-65%
2min- 65-70%
3min- 70-75%
4min - 75-80
5min- 80-85%
10min- 85-95


Breathing (ventilation): PPV by bag and mask ventilation required: infant gasping or apnoeic
HR <100

ET intubation if:

Tracheal suctioning for meconium is required
BMV is ineffective or prolonged
Chest compressions are being performed

Chest compressionsa re initiated if the infants heart rate remains <60 beats per minute despite adequate ventilation for 30 seconds

Administration of drugs such as epinephrine and or volume expansion
If the heart rate remains less than 60 beats per minute despite adequate ventilation and chest compressions administration of epinephrine is indicated
Rarely volume expansion or a narcotic antagonist eg naloxone may be useful

THe decision to progress from one step to the nect is determined by the time dependent response of the infant to the applied resuscitiative effort based upon his or her respiration and heart rate
A time allocation of 30 seconds is given to apply the resuscitative procedure evaluate and decide whether to proceed to the nect intervention
Monitoring of oxygen satyration by using pulse oximetry should be performed in infants who are gasoing apnoeic have laboured breathing persistent cyanosis or a heart rate less than 100 beats per minute. No further rescuscitative efforts are needed if he responds with spontaneous respirations and a heart rate of above 100 beats per miute




Equipment

Radiant warmer
Warm towel and blankets kept in the warmer
2 infant masks normal size and small size
A suction device- mucus extractor
Resuscitation bag and mask- self inflating bag

Oxygen source and tubing
suction source and tubing
drugs and fluid
syringes, needles, cannula and IV lines
Endotracheal tubes
Laryngoscopes
Stethoscope



  1. Place child in radiant warmer- prevent cold stress
  2. In neutral position- nose to the ceiling, towel under the neck to support. Maintains airway open.
  3. Clear airway by suction of FIRST MOUTH the nose.
  4. Wipe baby dry 
  5. Stimulate the baby by gentle tap on the foot flick in heel or rubbing back briefly
  6. Repositioned and heart rate is evaluated along with respiration and colour.
  7. Oxygen if necessary-
  8. A- head in neutral position and bulb suction in mouth and nose.  
  9. B- tactile stimulation. BMVPosition mask so no air can escape, give 5 inflation breaths to inflate the lungs . Squeeze bag, count 1 2 3, observe for chest wall rising. If it doesnt adjust baby position and repeat 5 inflation breaths
  10. Then ET tube connected to 100% O2
  11. C- circulation-- heart rate by listening to apical pulse wih steth, pulse in umbilius or brachial pulse
  12. Compressions if- cyanotic, increased work of breathing, nasal flaring, tachypnoea, grunting
  13. D- drugs- depends. Can be Epinephrine, sodium bicarbonate or dextrose. Even O neg blood
  14. E- environmental temperature by switching on radiant warmer and using warm blankets/ bunny rugs for premature baby

Apnoea- BMV and proper postioning. Ventilate for 30 seconds at a rate of 40-50 times/min

Bradycardia- less than 60bpm or Less than 6 beats in 6 seconds but chest is rising.-- 

chest compression with 100% oxygen CPAP
Firm support for baby back
Compression on lower 1/3rd sternum. 
Use fingertips of middle and index fingers or use distal portion of both thumbs
Compress sternum approx 1/3 AP diameter of chest to count cadence of  "one and two and three and breath and " 

Reassess baby after 30 seconds

Baby pink, HR>100- adequately resuscitated
Baby cyanosed on ventilation and chest compression, HR 60-100- ET and ventilation with chest compression
If cyanosed on ventilation and chest compression and HR <60 continue ventilation and chest compression along with epinephrine 1:10 000 for inotropic support, 0.01-0.03mg/kg if heart rate is less than 60




Ventilation breaths vs Inflation breaths
Much shorter
Mimic baby's pattern of breathing
35-40 per minute

Reassess after 30 seconds

Complications
Chest compressions

broken rib
laceration of liver
pneumothorax

Intubation
Pneumothorax
contusion of the airway


When to discontinue resuscitation

If neonate has demonstrate no signs of life after 10 minutes of resuscitation becomes outcome is associated with high early mortality and unacceptabl high morbidity among the rare survivors

Anaesthesia in OBG

Advantages of Regional Anaesthesia

Lower maternal mortality
Patient awareness
Post operative analgesia
Reduced incidence of DVT
Less neonatal depression
Reduced blood loss
Quicker return of GI function
Improved maternal bonding
Mother can participate in birth

Contraindications

Maternal refusal
Coagulopathy
Infection at injection site
uncorrected hypovolaemia
Raised ICP
Maternal haemorrhage and instability

0.5% Bupivacaie 2.2-2.5ml with Fentanyl 10-20mcg- post op analgesia plus reduce need for local anaesthesia
Co-load with 500ml of fluids or colloids to reduce hypotension after induction.
Treat hypo with phenylephrine


Advantages epidural over spinal anaesthesia

Ability to titrate the level of the block
Reduces the risk of profound and sudden hypotension
Unlimited duration of action if the catheter is used postoperatively for analgesia
Good for pre-eclamptic

Disadvantage of epidural

Inadvertent IV or subarachnoid injection
Increased time to surgical anaesthesia
Increased risk of post dural puncture headache if the dura breached and
Failed block/ inadequate block
Not all sensations will be blocked, especially during delivery of the baby. Can feel touch and movement but not pain


First test for light touch and then cold.
Sympathetic block is 2 segments higher than sensory block

Block from T4 (peritoneum) to T12
Advantages of combined spinal epidural

Rapid onset
All advantages of epidural



Regional Anaesthesia

Baseline maternal tachycardia indicates relative hypovolaemia and impending hypotenison
Give prophylactiv phenylephrine 100mcg per minute
Treat bradycardia with atropine
Dyspnoea and ineffective cough if extends to thoracic segments000 oxygenation with fae mask
Must check upper limb power to exclude possibility of an impending total spinal.
Itch- neuraxial opioid
Shivering- 20-25mg Pethidine or 25-50mcg Clonidine IV


Complications

Total spinal block
IV injection of LA
Headache
Obstetric palsy-- obturator nerve, femoral nerve and common peroneal nerve
Spinal or epidural abscess- permanent paralysis

Safest time for surgery
 Early to mid 2nd trimester
- lower risk of preterm
- uterus still small


24-34 weeks- corticosteroids

15 degrees left lateral tilt to prevent aortocaval compression

Induction of labour reduces variability
Vasoactive and chronotropic modifying agets cross the placenta and can produce changes in fetal heart rate in accordance with their vasoactive effect


Progesterone supplementation is recommeded when the corpus luteum is removed prior to 7-9 weeks of gestation
Progesterone 50-100mg vaginal suppositivery every 8-12 hours or a daily IM injection of 1mL (50mg) progesterone in oil


Problems with general anaesthesia


  • Failed intubation- significant upper airway edema and vascular engorgement in pregnancy 

  • Aspiration of gastric contents- difficult intubation, lower esophageal sphincter tone, labour pain and opiates delay gastric emptying. Prophylaxis: abstain from solid food for at least 6 hours prior to surgery, 8 hours for fried or fatty foods, clear liquids 2hours. Antacid, histamine receptor blocker and metoclopramide. Sodium citrate keeps pH >3.0 for 30 minutes. Cricoid pressure application at the time of rapid sequence induction of endotracheal intubation prevents aspiration of gastric contents until the airway has ben protected with a cuffed endotracheal tube
  • Hypoxia- vasodilation due to decreased sympathetic tone during endotracheal itubation and direct cardiodepressant effect of inhalational anaesthetic agents-- hypotension--- decreased uterine blood flow. Controlled hypotension is dangerous for the fetus and should be avoided.
  • Anaesthetic drug:
    • Propofol
    • THiopental- decrease dose
    • Halothane, Isoflurane and enflurane- tocolytic effect, decreases uterine tone and inhibit labour during the procedure
    • Inhaled NOx- no effect on uterine tone, maternal haemodynamic status nor fetal heart rate variability
  • mechanical ventilation effect
    • High progesterone in pregancy- respiratory alkalosis with an average pH of 7.44
    • PaCO2 of 32mmHg
    • HCO3 of 20mmHg
    • SInce fetal and maternal PaCO2 correlate, maternal respiratory acidosis may lead to myocardial depression, hypotension and clinically significant vasoconstriction which csn compromise fetal oxygenation