ASSESSMENT OF THE FETUS AT BIRTH
The Apgar score, if done properly, is a simple, useful guide to
neonatal well-being and resuscitation ( Table
59-1
).[44]
[45]
It is only a guide. The 1-minute score correlates
well with acidosis and survival.[46]
The 5-minute
score may be predictive of neurologic outcome.[47]
[48]
To be of value, each variable encompassed
by
the score must be evaluated at 1 and 5 minutes. Clinicians must recognize that some
neonates have relatively normal Apgar scores at 1 and 5 minutes but are very acidotic.
When this occurs, these neonates often have peripheral vasoconstriction and pallor
despite relatively normal heart rates and arterial blood pressures.
Heart Rate
The heart rate of normal neonates is 120 to 160 beats/min. Although
most neonates tolerate heart rates up to 220 beats/min with little detrimental effect,
heart rates below 100 beats/min are often poorly tolerated because rates this low
reduce cardiac output and tissue perfusion. Unfortunately, bradycardia is common
in asphyxiated neonates. Occasionally, bradycardia is associated with congenital
heart disease, congenital heart block, and congestive heart failure. A prenatal
electrocardiogram and echocardiogram allow diagnosis of these problems before birth.
If one of these problems exists, the physician must be prepared to treat the bradycardia
if the arterial blood
TABLE 59-1 -- The Apgar scoring system
|
Score
*
|
|
Sign |
0 |
1 |
2 |
|
Heart rate |
Absent |
Less than 100/min |
More than 100/min |
|
Respiratory effort |
Absent |
Slow, irregular |
Good, crying |
|
Color |
Blue, pale |
Body pink, extremities blue (acrocyanosis) |
Completely pink |
|
Reflex irritability (response to insertion of a nasal catheter) |
Absent |
Grimace |
Cough, sneeze |
|
Muscle tone |
Limp |
Some flexion of extremities |
Active motion |
*Each
variable is evaluated individually and scored from 0 to 2 in an infant at 1 and 5
minutes of age. The total score at each time is the sum of the scores of the individual
variables. A total score of 10 is perfect.
pressure and tissue perfusion are compromised (e.g., lactic acidosis).
