Or, The head’s out; what next? Ahmad Alkathiri MD Shoulder Dystocia Or, The head’s out; what next? Ahmad Alkathiri MD

Objectives At the completion of this presentation, the participant should be able to: Define shoulder dystocia (MK) Name three risk factors for shoulder dystocia (MK, PC) List potential complications, both maternal and fetal, of shoulder dystocia (MK) Describe the maneuvers used to relieve a shoulder dystocia (MK, ICS)

Definition “…a delivery that requires additional obstetric maneuvers following failure of gentle downward traction on the fetal head to effect delivery of the shoulders.” ACOG, Practice Bulletin 40 (November 2002)

Definition “Prolonged head-to-body expulsion time” Objectively defined as 60 seconds Deliveries with head-to-body interval of > 60 seconds more commonly have higher birth weight, shoulder dystocia, and low 1 minute Apgar scores Beall et al 1998; Spong et al 1995

Functional Definition A delivery in which the shoulders do not follow the head as usual, but rather are delayed in delivering or require the use of ancillary obstetric maneuvers to effect delivery. The anterior shoulder may be impacted behind the symphysis pubis, or (less commonly) the posterior shoulder behind the sacral promontory

Incidence Reported to occur in 0.2-2% of births May recur with a higher frequency, but this is really unknown Many women and clinicians will opt for cesarean in the future, especially if there has been a fetal injury Recurrence rates reported 1-17%

Risk Factors Maternal diabetes mellitus Fetal macrosomia Multiparity Post-term pregnancy Previous macrosomic infant Previous shoulder dystocia

Macrosomia Birth weight in excess of a specific weight, usually defined as either 4500 grams (1.5% of births) or 4000 grams (10% of births) Birth weight > 4500 grams – rate of shoulder dystocia is 10-25% Birth weight > 4500 grams AND maternal diabetes – rate of shoulder dystocia is 20-50%

Large for gestational age Birth weight that exceeds the 90th centile of a standard growth curve, regardless of gestational age. A baby may be LGA without being macrosomic

Pathophysiology A “mismatch” between fetal size and maternal pelvic capacity Positional variations – vertical rather than oblique orientation of shoulders Increased diameter of shoulder girdle Subcutaneous fat deposition may be increased in infant of diabetic mother – especially with sub-optimal glucose control

Anatomy of the Brachial Plexus Nerve roots from C5-C8 and T1 Merge into three trunks Superior (C5, C6) Middle (C7) Inferior (C8, T1) Each splits into anterior and posterior divisions

Anatomy of the Brachial Plexus The six divisions regroup into three cords Posterior – all 3 posterior trunk divisions (C5-T1) Lateral – anterior divisions of upper and middle trunks (C5-C7) Medial – continuation of lower trunk (C8, T1)

Anatomy of the Brachial Plexus

Anatomy of the Brachial Plexus

Brachial Plexus Injuries Strain or stretch Partial disruption Complete avulsion

Brachial Plexus Injuries Injury primarily to lateral trunk (C5,6, 7) leads to Erb’s palsy – adducted shoulder, extended elbow, and flexed wrist (“waiter’s tip”) Injury primarily to the medial trunk (C8, T1) leads to Klumpke’s palsy – paralyzed hand with good shoulder and elbow function

Maternal Complications Post-partum hemorrhage occurs in 11% 4th degree laceration occurs in 3-4%

Into the Delivery Room…

Clinical Management Step One: Recognize the presence of a shoulder dystocia Step Two: Be sure enough help is present Nursing Obstetrics Pediatrics Anesthesiology

Clinical Management Step Three: Apply primary maneuvers Mc Roberts maneuver Oblique suprapubic pressure Step Four: Apply secondary maneuvers; no prescribed order Rubin; Woods screw; Posterior arm; All-fours; Clavicular fracture

Clinical Management Step Five (concurrent): Repeat steps three and four (different operator?) Consider if an episiotomy is needed (intentional 4th degree?) Step Six: Apply final (heroic) maneuvers Zavanelli; symphysiotomy

Steps One and Two The operator determines a shoulder dystocia is present Personnel needed: Nursing At least two to assist with maneuvers One to serve as “recorder”, as in a code 12 situation Pediatrics – full resuscitation readiness

Steps One and Two Personnel (continued) Anesthesiology Obstetrics Attending to supervise and step in as needed 2 residents at minimum Ideally 2 at perineum One to assist with maneuvers (suprapubic pressure) away from perineum

Step Three – Primary Maneuvers McRoberts maneuver Patient positioned with hips at edge of the broken-down birthing bed Both hips are sharply flexed with knees remaining flexed (“knees to shoulders”) Ideally performed by staff, not family, to assure it is adequately performed No benefit to “prophylactic” McRoberts

McRoberts Maneuver

McRoberts Maneuver This maneuver assists delivery by: Straightening maternal lumbar lordosis Rotates symphysis superiorly and anteriorly Improving angle between pelvic inlet and direction of maximal expulsive force Elevates anterior shoulder allowing posterior shoulder to descend

McRoberts Maneuver

Oblique suprapubic pressure Usually applied in concert with McRoberts maneuver Directed downward and laterally in order to effect rotation of the fetal anterior shoulder under the symphysis Should be applied from the fetal posterior

Oblique suprapubic pressure

Step Four – Secondary Maneuvers There is no conclusive evidence that one maneuver is superior to another In each patient, the operator must decide which maneuver will be most effective This is a good time to decide about an episiotomy – is there room to get your hand in? Time to initiate perinatal code (4-2012)

Woods screw maneuver Apply pressure on the clavicle to effect rotation of the shoulders out of the vertical orientation As fetus rotates, anterior shoulder should pass under symphysis May be a good choice for a right-handed operator when the fetal occiput is oriented to the maternal right

Woods screw maneuver

Woods screw maneuver Potential complication: Fetal clavicular fracture IN DIRECTION OF APEX OF LUNG

Rubin’s maneuver Apply pressure to the fetal scapula to effect rotation of the shoulders out of the vertical orientation As fetus rotates, anterior shoulder should pass under symphysis May be a good first choice for a right-handed operator when the fetal occiput is directed to the maternal left

Rubin’s maneuver May result in need for less traction and less brachial plexus strain than McRoberts maneuver Gurewitsch, 2005

Delivery of Posterior Arm The operator inserts a hand into the vagina and locates the posterior arm. The operator applies pressure in the antecubital fossa to flex the elbow across the chest The operator grasps the forearm or hand and pulls it out of the vagina

Delivery of Posterior Arm The anterior shoulder should pass under the symphysis Rotation maneuvers (Woods or Rubin’s) can be applied if needed This maneuver will tend to be more difficult with one’s non-dominant hand

Delivery of Posterior Arm

Delivery of Posterior Arm Potential complications Fracture of humerus Fracture of clavicle

Gaskin All Fours Maneuver Attributed to midwife Ina May Gaskin An option for a patient without anesthesia Traction is applied in the opposite direction (still toward the floor, but now directed towards delivery of the posterior shoulder first)

Intentional clavicular fracture Apply pressure over mid-clavicle in a vector AWAY from the lung May be difficult to perform If successful, may reduce the diameter of the shoulder girdle Potential complication: Lung injury

Still not out?! What now???

Step Five – Regroup and Repeat Considerations: Time passed so far? Episiotomy? Different operator? Make OR preparations!

Step Six – Final Steps Zavanelli maneuver (cephalic replacement) Relax uterus with terbutaline Rotate head back to OA (“reverse restitution”) Flex neck Upward pressure To OR

Step Six – Final Steps Symphysiotomy Not commonly done when cesarean is available Last ditch effort Insert Foley catheter Use vaginal hand to laterally displace urethra to avoid injury Incise symphysis through mons pubis

Do not: Panic Apply any more lateral traction than would be applied in an uncomplicated delivery Apply fundal pressure – may worsen the shoulder impaction or even rupture the uterus Cut a nuchal cord until after the shoulders are released

Do: Remain calm Communicate well Call for help Mark time of head delivery Consider calling out time in one minute increments Call for help Document clearly and legibly

Do: Be sure to “debrief” as a team after the delivery is completed Opportunity to analyze situation and critique team performance Opportunity to be sure documentation is consistent Who did what becomes very important Send cord gases

Do: Review with the family exactly what happened and answer questions – soon after delivery, but probably not immediately Follow the baby’s course in the nursery Notify Risk Management

References Shoulder Dystocia (Practice Bulletin 40). American College of Obstetricians and Gynecologists. November 2002. Rodis, JF. Management of fetal macrosomia and shoulder dystocia. Up to date, v 14.1; last updated October 12, 2005. Brachial Plexus. Wikipedia, the online encyclopedia. http://en.wikipedia.org/wiki/Brachial_plexus Accessed March 21, 2006. Beall, MH, et al. Objective definition of shoulder dystocia: a prospective evaluation. Am J Obstet Gynecol 1998;179:934. Spong CY, et al. An objective definition of shoulder dystocia: prolonged head-to-body interval and/or the use of ancillary obstetric maneuvers. Obstet Gynecol 1995;86:433 Gurewitsch ED et al. Comparing McRoberts’ and Rubin’s maneuvers for initial management of shoulder dystocia: an objective evaluation. Am J Obstet Gynecol 2005;192:153.