Surgery and Healing in the Developing World - Dartmouth-Hitchcock

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126 Surgery and Healing in the Developing World
3. Assessment of the midpelvis: The midpelvic diameters are not directly accessible
to clinical pelvimetry. However, be alerted to a possibly narrow
midpelvis if the ischial spines are prominent, the pelvic sidewalls are felt to
converge, the biischial diameter of the pelvic outlet is narrow, and the curve
of the sacrum and coccyx is shallow. The transverse diameter of the midpelvis
at the ischial spines should exceed 10 cm.
4. A pelvis with a narrow pubic arch, prominent spines and converging
sidewalls, and with the sacral tip angled forward (an extreme “android”
pelvis in the Caldwell-Moloy system) should lead you to anticipate a difficult
vaginal delivery.
Positioning
The position of the laboring patient will reflect local custom. Basically, any comfortable
position is acceptable except the supine.
The rationale for use of the dorsal lithotomy position is the purported mobility
of the sacroiliac joint, which is thought to shift in this position to increase the diameter
of the pelvic outlet by 1.5 to 2.0 cm. The same effect is achieved by the squatting
position favored by many societies. Squatting has the intuitively obvious
advantage of maximizing the force of gravity to assist with labor. The disadvantage is
difficulty controlling the delivery (e.g., flexion of the head). In one study, this resulted
in more labial lacerations, although significantly fewer perineal lacerations
were encountered.
Intrapartum Fetal Assessment
If external electronic monitoring is not available, fetal heart tones should be
auscultated. In low risk pregnancies, auscultate every fifteen minutes, following a
contraction. High risk pregnancies require closer scrutiny, with auscultation every
five minutes. These observations must be recorded. Be alert for decelerations, especially
in association with changes in baseline. Repeated decelerations may be tolerated
for the short term if return to baseline is rapid. Repeated decelerations, especially
those which begin after the peak force of contraction has been reached, should be
treated by altering the position of the patient and administration of oxygen. Persistent
and prolonged decelerations should lead to an evaluation for assisted or operative
delivery.
Normal Delivery
In vertex presentation, the head and neck must extend to deliver under the symphysis
pubis. Controlling this process will reduce labial and perineal trauma and
thus your burden of surgery. As the head is delivering, lightly oppose this extension
by using the fingers of your upper hand to gently flex the head away from anterior
structures (clitoris, urethra, labia). As the head delivers, grasp with this hand to
control the degree of extension and speed of delivery of the head. As the head clears
the ring of vulvar tissue, instruct the woman to stop pushing so that you do not have
a violent expulsion of the shoulders and trunk.
While controlling extension and delivery of the head with your upper hand, use
your other hand to support the perineum in an effort to minimize stretching and
tearing as the head and trunk are delivered. Further control may be obtained by
employing the modified Ritgen maneuver. In the modified Ritgen, as the head forces
open the introitus to a diameter of 5 cm or more, use your toweled hand to exert