Professor of anesthesia
King Khalid University Hospital, Riyadh. 11461. P.O.Box 2925. Saudi Arabia
Fax 00966 1 467 9364
12th world Congress on Anesthesiologists
June 4-9th 2000
The newborn after delivery may need resuscitation if he is diagnosed as being asphyxiated. The asphyxiated infant passes through a series of events:
Rapid breathing and decrease in heart rate (primary apnoea).
irregular gasping further decrease in heart rate and drop in blood pressure (secondary apnoea) Most infants in primary apnoea will resume breathing when stimulated. Once in a secondary apnoea, infants are unresponsive to stimulation.
Should be kept relatively warm and the radiant heater should be preheated when possible. Prewarming of towels and blankets can also be helpful in preventing excessive heat loss from the neonate.
Prevent heat loss
Open the airway
Evaluate the infant
Method of resuscitation
Ventilation - bags and mask
Equipment and technique
When ventilatory support is required, the lungs of most neonates can be adequately ventilated with a bag and mask. Positive-pressure ventilation (PPV) is indicated when:
Apnoea or gasping respiration is present
The heart rate is less than 100 beats /min -1
Central cyanosis persists despite 100 O 2 Ventilation should be adequate with 40 to 60 assisted breaths per minute. Initial lung inflation may require a pressure as high as 30-40 cm H 2 O but subsequent breaths should be in the 15 -20 cm H 2 O range.
Observing chest wall motion and hearing breath sounds bilaterally assesses adequate ventilation. If chest expansionis inadequate, the following steps should be followed in sequence:
Reapply the facemask to rule out a poor seal
Reposition the head - extend the head a bit further - reposition the shoulder towel
Check for secretions - suction if necessary
Try ventilating with the infant's mouth slightly open - perhaps with an oral airway
Increase pressure to 20-40 cm H 2 O - abandon bag and mask - intubate trachea After 15-30 sec of effective ventilation, the heart rate of the neonate should be evaluated. To save valuable time, the heart rate over a six-second period is counted and multiplied by ten to given an approximation of the one-minute heart rate (e.g., eight beats in six seconds = 80 bpm). The next step in the resuscitation depends on the heart rate, which is determined:
HR>100 if spontaneous breathing efforts are present, gradually reduce PPV and provide gentle tactile stimulation plus free-flow O2
HR<60 Immediately begin chest compressions.
And ensure that ventilation is adequate and that 100% O2 is being delivered.
60<HR<80 continue ventilation and begin chest
Continue ventilation (increasing)
Chest compressions must always be accompanied by ventilation with 100% oxygen. Pressing on the sternum compresses the heart and increases the intrathoracic pressure, causing blood to be pumped into the arterial circulation. Release of the sternal pressure will increase venous blood to return to the heart.
1. When to begin chest compressions: After 15-30 sec of PPV with 100% O 2
- The heart rate is <60 bpm - the heart rate is between 60 and 80 and not increasing
2. When to stop chest compressions: - the heart rate is 80 bpm or greater
1 Location: Pressure should be applied to the middle third of sternum, just below an imaginary line drawn between the nipples. Take care not to apply pressure to the xiphoid.
Thumb method: Encircle the torso with both hands and compress the sternum with both thumbs side-by-side while the fingers support the back. In very small neonates the thumbs may have to be superimposed. Use just the tips of the thumbs to compress to avoid squeezing the whole chest wall and fracturing ribs.
Two-finger method: This method is used if the resuscitator's hands are too small to encircle the chest properly or if access to the umbilicus is necessary for medications. The middle and ring fingers of one hand are held perpendicular to the chest and the tips apply pressure to the sternum while the other hand is used to support the back from below. Pressure: Use just enough pressure to depress the sternum 1.5 cm, then release the pressure to allow the heart to fill. One compression consists of the downward stroke plus the release. Rate: To match the heart rate of the normal neonate, the compress/release action should be repeated 120 times per minute (two per second).
Cautions: Do not remove the tips of your fingers from the chest. You may waste time relocating the compression site or end up compressing the wrong area, producing broken ribs with the possibility of pneumothorax or a lacerated liver. To make sure the circulation produced by the chest compressions is adequate, the rate and the depth of the compressions must be consistent.
Ventilation during chest compressions
Positive-pressure ventilation must always accompany chest compressions. The most recent guidelines recommend interposing chest compressions with ventilation, suggesting that simultaneous PPV and chest compressions may affect the efficiency of ventilation, particularly when using a bag and mask, by forcing air into the stomach. A 3:1 ratio of chest compressions to ventilation is recommended. The three compressions are followed by a pause to interpose an effective breath. The combined rate of compressions with ventilation should be 120 per minute - resulting in 90 compressions and 30 ventilations each minute. Although bag and mask ventilation can be performed effectively over a prolonged period of time, ventilation is much easier if the infant's trachea is intubated. However, it is vital that one remembers that the priority is ventilation and not intubation, particularly if the intubation proves difficult. Should prolonged PPV by bag and mask be necessary, an orogastric tube should be passed to prevent distension of the stomach.
In the neonate whose trachea is intubated, particularly with mechanical ventilation, one may wish to perform the chest compressions (120 per minute) and ventilation (40-60 per minute) independently of each other.
Evaluating the heart rate
After the first 30 sec of chest compressions, the heart rate should be checked.
During the heart rate check, the chest compressions are interrupted for no more than the six seconds it takes to count the heartbeats and make the calculation.
If the infant is showing a positive response to the resuscitative efforts then one should check the heart rate every 30 sec in order to stop chest compressions when the infant's own heart rate increases to 80 or above. Ventilation should be continued until the heart rate is >100 bpm.
Should the infant's heart rate remain <80 bpm despite at least 30 sec of adequate chest compressions and ventilation, resuscitation should progress rapidly to the next step of giving medications.
-Pressure ventilation is required,
- Prolonged PPV required (avoiding gastric distension
Bag and mask ineffective (poor chest expansion, continuing low HR)
Tracheal suctioning required (thick or particulate meconium)
- Diaphragmatic hernia suspected (prevent bowel distension in the chest)
Vocal cord guide
Resuscitation bag and mask connected to 100% O2:
Positioning the infant
Inserting the laryngoscope blade
Confirmation of ET tube placement
Complications of intubation
Tracheal suction for meconium aspiration
Routes of administration
Drugs and fluids
For the majority of infants who require resuscitation, the only medication needed will be 100% oxygen delivered with effective ventilation. Some will require chest compressions. In only a very few infants will this next step be necessary.
INDICATIONS: - the heart rate stays below 80 despite effective ventilation with 100% oxygen and chest compressions for at least 30 sec - the heart rate is zero
Epinephrine has both Alpha and Beta-adrenergic stimulating properties. The alpha effect causes vasoconstriction, which raises the perfusion pressure during chest compressions, augmenting oxygen delivery to both heart and brain. The beta effect enhances cardiac contractility, stimulates spontaneous contractions and increases heart rate. This drug can be given either iv or via an ET tube and can be repeated every three minutes.