From the Editor

Tackle the challenging shoulder dystocia emergency by practicing delivery of the posterior arm

OBG Manag. 2014 October;26(10):10,12,14

References

1. Allen RH, Rosenbaum TC, Ghidini A, Poggi SH, Spong CY. Correlating head-to-body delivery intervals with neonatal depression in vaginal births that result in permanent brachial plexus injury. Am J Obstet Gynecol. 2002;187(4):839–842.
2. Leung TY, Stuart O, Sahota DS, Suen SS, Lau TK, Lao TT. Head-to-body delivery interval and risk of fetal acidosis and hypoxic ischaemic encephalopathy in shoulder dystocia: a retrospective review. BJOG. 2011;118(4):474–479.
3. Lerner H, Durlacher K, Smith S, Hamilton E. Relationship between head-to-body delivery interval in shoulder dystocia and neonatal depression. Obstet Gynecol. 2011;118(2 pt 1):318–322.
4. Leung TY, Stuart O, Suen SS, Sahota DS, Lau TK, Lao TT. Comparison of perinatal outcomes of shoulder dystocia alleviated by different type and sequence of manoeuvres: a retrospective review. BJOG. 2011;118(8):985–990.
5. Hoffman MK, Bailit KL, Branch DW, et al. A comparison of obstetric maneuvers for the acute management of should dystocia. Obstet Gynecol. 2011;117(6):1272–1278.
6. Barbieri RL. You are the second responder to a shoulder dystocia emergency. What do you do first? OBG Manag. 2013;25(????):10, 12, 15.
7. Beer E. History of extraction of the posterior arm to resolve shoulder dystocia. Obstet Gynecol Surv. 2006;61(3):149–151.
8. Kung J, Swan AV, Arulkumaran S. Delivery of the posterior arm reduces shoulder dimensions in shoulder dystocia. Int J Gynaecol Obstet. 2006;93(3):233–237.
9. Poggi SH, Spong CY, Allen RH. Prioritizing posterior arm delivery during severe shoulder dystocia. Obstet Gynecol. 2003;101(5 pt 2):1068–1072.
10. Rodis JF. Shoulder dystocia, intrapartum diagnosis, management and outcome. UpToDate, Waltham MA.
11. Mazzanti GA. Delivery of the anterior shoulder; a neglected art. Obstet Gynecol. 1959;13(5):603–607.
12. Wetzel CM, Kneebone RL, Woloshynowych M, et al. The effects of stress on surgical performance. Am J Surg. 2006;191(1):5–10.
13. Grobman WA, Miller D, Burke C, Hornbogen A, Tam K, Costello R. Outcomes associated with introduction of a shoulder dystocia protocol. Am J Obstet Gynecol. 2011;205(6):513–517.

Newborn injuries associated with shoulder dystocia
In a large retrospective study of 132,098 vaginal cephalic singleton births there were 2,018 cases of shoulder dystocia, representing a 1.5% rate of shoulder dystocia during vaginal birth.⁵A total of 101 neonatal injuries were reported in association with a shoulder dystocia, the most common being Erb’s palsy, clavicular fracture, and hypoxic ischemic encephalopathy. Some newborns incurred multiple injuries.
Type of injury	No. of newborns with injury	Rate of injury per 100 shoulder dystocias
Erb’s palsy	60	3
Clavicular fracture	39	1.9
Hypoxic ischemic encephalopathy	6	0.3
Klumpke’s palsy	4	0.2
Humerus fracture	2	0.1
Neonatal death	0	0
^{Source: Hoffman, et al. Obstet Gynecol. 2011;117(6):1272–1278.}

Approaches to grasping the posterior arm
The posterior arm may be in one of three positions, and your approach to each position will be different.

Fetal hand near the chin. Delivery of the posterior arm is relatively easy when the fetal hand is in this position. Grasp the wrist gently and guide it out of the vagina. The fetal wrist should be pulled toward the fetal ear closest to the maternal symphysis.

Fetal hand on the abdomen. In this position, the operator can exert pressure on the antecubital fossa with the index and middle fingers, resulting in flexion of the forearm at the elbow. This will bring the fetal hand and wrist to the upper chest. The wrist then can be grasped and pronated over the fetal chest. The wrist and forearm are then pulled upward along the chest toward the fetal ear closest to the maternal symphysis.

Fetal upper extremity is extended with the hand next to the thigh. The most challenging situation is when the upper extremity of the fetus is extended along the trunk or behind the buttocks. In this situation the hand and wrist may be near the fetal thigh and very difficult to reach. In addition, the upper extremity may be tightly pinned between fetal trunk and maternal tissues, making it impossible to flex the forearm by gentle pressure on the antecubital fossa.

In this situation the operator’s hand must reach the fetal wrist and distal forearm, grasp these structures, and pull hard across the trunk to free the pinned upper extremity. The fetal wrist and distal forearm can be securely grasped using techniques pictured in the Figure. It can take 30 to 90 seconds for the operator to place a hand in the vagina, identify the posterior shoulder, follow the extended arm to the hand, and secure the wrist. Given the amount of time that it may take to accomplish the first steps of the maneuver, the nurse in the room should call out the time elapsed since the birth of the head at regular intervals to assist the obstetrician in pacing the speed of the intervention.

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		Figure. When the fetal upper extremity is extended and the hand is near the fetal thigh the fetal upper extremity may be tightly pinned between maternal and fetal tissues. Gentle pressure in the antecubital fossa may not cause the forearm to flex toward the vaginal introitus. In this situation it may be very difficult to grasp the fetal wrist or forearm. The operator should be prepared to place their entire hand and forearm into the vagina to reach the fetal wrist (Top left). Two options for grasping the fetal wrist are with the index finger and middle finger (Top right), or by encircling the wrist with the thumb and index finger (Bottom left). For many obstetricians, the index and middle fingers extend much further from their wrist than the thumb. Consequently, when the fetal wrist and hand are against the fetal thigh it may be easier to reach the fetal wrist with the operator’s index and middle finger. However, many obstetricians find that the thumb and index finger provide a more secure grip of the fetal wrist.

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When the posterior arm is fully extended and pinned between fetal trunk and maternal tissues it can be very difficult to reach the fetal wrist. To help successfully complete the maneuver, the obstetrician should visualize placing his or her hand and entire forearm up to the elbow in the vagina to reach the fetal wrist. It may not be necessary to insert the entire forearm in the vagina, but the operator should visualize this step so he or she is prepared for the possibility.Surprisingly, the hollow of the sacrum often provides sufficient space for inserting the hand and entire forearm of the operator. In this process the operator’s hand and forearm may be strongly compressed by maternal and fetal tissues, cutting off circulation to the upper extremity. The operator’s upper extremity may quickly become numb, resulting in a reduction in tactile sensation and strength.

Tackle the challenging shoulder dystocia emergency by practicing delivery of the posterior arm

References

Newborn injuries associated with shoulder dystocia

Source: Hoffman, et al. Obstet Gynecol. 2011;117(6):1272–1278.

Pages

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^{Source: Hoffman, et al. Obstet Gynecol. 2011;117(6):1272–1278.}