Page 879 - TNFlipTest

Toronto Notes 2019 Abnormalities and Complications of Labour and Delivery Shoulder Dystocia
Definition
• fetalanteriorshoulderimpactedabovesymphysispubisafterfetalheadhasbeendelivered • lifethreateningemergency
Etiology/Epidemiology
• incidence0.15-1.4%ofdeliveries
• occurswhenbreadthofshouldersisgreaterthanbiparietaldiameterofthehead
Risk Factors
• maternal:obesity,DM,multiparity,previousshoulderdystocia
• fetal:prolongedgestation,macrosomia(especiallyifassociatedwithGDM) • labour
■ prolonged 2nd stage
■ instrumental midpelvic delivery
Presentation
• “turtlesign”:headdeliveredbutretractsagainstinferiorportionofpubicsymphysis • complications
■ fetal
◆ hypoxic ischemic encephalopathy (chest compression by vagina or cord compression by pelvis
can lead to hypoxia)
◆ brachial plexus injury (Erb’s palsy: C5-C7; Klumpke’s palsy: C8-T1), 90% resolve within 6 mo
◆ fracture (clavicle, humerus, cervical spine) ◆ death
■ maternal
◆ perineal injury
◆ PPH (uterine atony, lacerations) ◆ uterine rupture
Treatment
• goal:todisplaceanteriorshoulderfrombehindsymphysispubis;followastepwiseapproachof maneuvers until goal achieved (see sidebar)
• otheroptions
■ cleidotomy (deliberate fracture of neonatal clavicle)
■ Zavanelli maneuver: replacement of fetus into uterine cavity and emergent C/S ■ symphysiotomy
Prognosis
• 1%riskoflong-termdisabilityforinfant
Umbilical Cord Prolapse
Definition
• descentofthecordtoaleveladjacenttoorbelowthepresentingpart,causingcordcompression between presenting part and pelvis
Etiology/Epidemiology
• increasedincidencewithprematurity/PROM,fetalmalpresentation(~50%ofcases),low-lyingplacenta, polyhydramnios, multiple gestation, CPD
• incidence:1/200-1/400deliveries
Presentation
• visibleorpalpablecord
• FHRchanges(variabledecelerations,bradycardia,orboth)
Treatment
• emergencyC/Sifnotfullydilatedandvaginaldeliverynotimminent
• O2 to mother, monitor fetal heart
• alleviatepressureofthepresentingpartonthecordbyelevatingfetalheadwithapelvicexam(maintain
this position until C/S)
• keepcordwarmandmoistbyreplacingitintothevagina±applyingwarmsalinesoaks • rollmomontoallfours
• position mother in Trendelenburg or knee-to-chest position
• iffetaldemiseortoopremature(<22wk),allowlabouranddelivery
Obstetrics OB39
Approach to the Management of Shoulder Dystocia
ALARMER
Apply suprapubic pressure and ask for help Legs in full flexion (McRobert’s maneuver) Anterior shoulder disimpaction (suprapubic pressure)
Release posterior shoulder by rotating it anteriorly with hand in the vagina under adequate anesthesia
Manual corkscrew i.e. rotate the fetus by the posterior shoulder until the anterior shoulder emerges from behind the maternal symphysis Episiotomy
Rollover (on hands and knees)
*Note that suprapubic pressure and McRobert’s maneuver together will resolve 90% of cases
Umbilical Cord Accident Causes
• Nuchal cord •TypeA(looped) •TypeB(hitched)
• Body loop
• Single artery
• True knot
• Torsion
• Velamentous
• Short cord <35 cm • Long cord >80 cm
• 1/3 of protraction disorders develop into 2o arrest of dilatation due to CPD
• 2/3 of protraction disorders progress through labour to vaginal delivery