Obstetrics 14: Shoulder Dystocia Portal
Incidence/Epidimiology
- For neonates weighing 2500 to 4000 g, the incidence is 0.3% to 1%.
- For neonates weighing 4000 to 5000 g, the incidence is 8% to 10%.
- Over 50% of shoulder dystocia occurs in normal birth weight neonates and are unanticipated.
Prediction and Prevention
-
Identify risk factors. These include:
|
Maternal
|
Fetal
|
Intrapartum Events/Risks
|
Treatment
Have a protocol established that may be activated quickly.
Shoulder dystocia may not have been anticipated and usually does not
become obvious until the head emerges.
Anticipate and prepare as much as possible. Alert nursing staff and other key personnel to a potentially difficult delivery: they may be needed quickly. These personnel vary with each facility but may include ED physicians, obstetricians, nurses, nurse anesthetists, anesthesiologists, and respiratory therapists. Prepare the patient and family for the possibility of a difficult delivery. Have the patient empty her bladder. Prepare the bed and remove unnecessary items from the room to allow for additional equipment and personnel.
The primary clinician managing the delivery directs personnel activities much like running a cardio-respiratory arrest code. Keep time. This is essential in that more definitive procedures may ensue as the duration becomes more critical.
Keep in mind that the pH of the neonate drops 0.04/min and thus will decrease by 0.28 in 7 minutes, making the infant extremely difficult to resuscitate. For the clinician managing the delivery, knowing what not to do is as important as what to do. Initial fundal pressure, excessive traction, pushing, and pivoting are all maneuvers that waste time and may contribute to morbidity. Therefore, the delivering clinician needs a clear understanding of the procedures that follow as well as the order in which to attempt them. The suggested length of time spent on any one procedure to reduce shoulder dystocia is outlined here but is meant to serve only as a guide. Use clinical judgment as your guide in the progression of procedures used.
Use the mnemonic HELPERR as a guide.
H — |
Call for HELP. You will need additional equipment and personnel. |
E — |
Cut a generous Episiotomy
(30 seconds). Some have recommended a fourth degree be intentionally cut. Many maneuvers require getting one's hand into the vagina alongside the baby. |
L — |
Legs: Use the McRobert’s
maneuver (60 seconds). Flex the mother's thighs onto the abdomen. This position simulates the advantages of a squatting position, increasing the inlet diameter. It also straightens the lumbosacral lordosis, removing the sacral promontory as an obstruction. Simultaneously, this procedure lifts the fetus and flexes the fetal spine, pushing the posterior shoulder over the sacrum. Finally, the direction of maternal force in this position is perpendicular to the plane of the inlet. When successful, this procedure will allow the posterior shoulder across the inlet and cause the release of the inward pressure on the fetal head. If the McRobert’s maneuver fails, go quickly to the next procedure. |
P — |
Pressure: Apply external-manual
or Rubin’s maneuver (30 seconds). Apply pressure over the suprapubic area with a CPR hand over the anterior shoulder, forcing it slightly anterior to the fetal trunk. This may be done in a rocking motion. Simultaneously, the delivering clinician should continue traction. If this fails, move quickly to the next procedure. |
E — |
Enter: Perform internal-manual
(30 seconds). This involves adduction of the most accessible shoulder while continuing traction. This is done using an internal hand, usually beneath the maternal symphysis pushing on the posterior aspect of the anterior shoulder to adduct the shoulder. If this fails, move to the next procedure. The Wood’s screw maneuver may be necessary. Wood’s screw is accomplished by applying pressure to the posterior aspect of the posterior shoulder and initially attempting to place the shoulders in an oblique diameter, thereby reducing the impacted anterior shoulder. If this fails, complete the procedure by continuing the rotation a full 180 degrees, making the anterior shoulder now posterior, allowing delivery to be accomplished. |
R — |
Remove the arm. Insert a hand into the vagina in front of the fetus (identifying the posterior arm and elbow and being sure the elbow is flexed across the front of the body). Grasp and deliver the forearm. Once the posterior arm and shoulder are delivered, the anterior shoulder may be delivered in the usual manner. (This procedure is at times associated with humeral fractures.) If all else fails, any one of these maneuvers may be tried a second time. Finally the Zavenelli Maneuver (cephalic replacement and cesarean section) has been successful in most cases. |
R — |
Rotate the patient to her hands and knees. In this position, the posterior shoulder is delivered first and then the anterior shoulder. |
The mnemonic to remember in shoulder dystocia is HELPERR.
H—HELP
E— Generous Episiotomy
Legs—(McRobert’s maneuver)
Pressure—(Suprapubic pressure externally)
Enter—(Enter the vagina using internal pressure to reduce impacted shoulder, finally using a Wood’s screw maneuver to bring the shoulders into oblique diameter and 180 degrees rotation, if necessary.)
Remove—the posterior arm. Finally, if all other maneuvers fail, cephalic replacement may be used in certain circumstances.
R—Rotate the patient to her hands and knees.