Download Obstetrics Simulation Workshop - Student Handout and more Exams Obstetrics in PDF only on Docsity!
Intro to Obstetrics: Simulation Workshop - Student Handout
History of the Labouring Obstetrical Patient
o GTPAL o Gestational age o Degree of prenatal care (e.g., IPS, MSSS, ultrasounds, last medical appointment) o Infection status (e.g., GBS, HIV) o Medical conditions associated with pregnancy (e.g., gestational diabetes, pre-eclampsia) o Fetal well-being (e.g., fetal movement) o Current vaginal bleeding or leaking fluid from vagina o Onset and frequency of contractions (if present) o Past medical history o Current medications o Allergies o Distance from home to hospital
Physical Exam of the Labouring Obstetrical Patient
o Vitals o Speculum exam for presence of fluid o Cervical assessment: Dilation Effacement Fetal station Consistency Position o Assessment of fetal well-being Fetal tracing
Definition of Labour
Labour is defined as uterine contractions producing cervical changes and is divided into four stages:
o First stage Onset of true labour to complete dilation of the cervix Includes latent and active phase Latent: early cervical effacement and dilation (usually considered up to 3-4 cm) Active: more rapid cervical dilation (~1cm/hour) o Second stage Full dilation (10 cm) to delivery of the fetus o Third stage Delivery of fetus to delivery of the placenta Generally occurs 2-10 minutes after the birth of the baby o Fourth stage Variability in the definition (6 hours to 6 week postpartum)
Management of Labour
o First stage Maternal ambulation or if lying, lateral recumbent position CBC, Hgb, blood group, Rh type, HBV status, urinalysis Maternal vitals q1-2 hours Assess need for analgesia Fetal monitoring (active phase) q30 minutes (uncomplicated pregnancy) or q15 minutes (obstetric risk factors) Monitor uterine contraction q30 minutes (uncomplicated) or continuously (complicated) Vaginal exams q2 hours (active phase) o Second stage Avoidance of supine position Encourage mother to bear down with each contraction Fetal monitoring q15 minutes (uncomplicated pregnancy) or continuously or q5 minutes (obstetrical risk factors) Vaginal exam q30 minutes to monitor fetal descent Put on gloves and set up tray Modified Ritgen’s maneuver or manual perineal support After delivery of the head, clear airway and check for nuchal cord Delivery of anterior shoulder (administer oxytocin) Delivery of posterior shoulder Place baby on to mum’s belly (and then into infant warmer) Clamp and cut cord and take cord samples o Third stage Placental separation occurs within 5-30 minutes Avoid fundal massage Inspect for signs of placental separation (fresh blood from vagina, umbilical cord lengthening, fundal rising, uterus feels firm) before applying traction on cord Deliver placenta and inspect for abnormalities/ensure completeness Examine mum for lacerations (and repair if necessary) o Fourth stage Monitoring for BP, HR, and blood loss
Management of Shoulder Dystocia*
o McRobert’s maneuver (may be done in conjunction with suprapubic pressure) Flexion of maternal legs against abdomen o Suprapubic pressure o Wood’s/corkscrew maneuver Apply pressure to scapula of posterior shoulder to try to rotate it into the anterior position o Insert hand into vagina, grasp posterior arm and move it across the chest (results in delivery of posterior shoulder and displacement of anterior shoulder from behind pubic symphysis) May result in fractured humerus o Fracture of one or both clavicles o Zavanelli maneuver Push fetal head back into vagina and prepare for c/s (may require uterine relaxant)
*Note these are listed in the order that they should be attempted
Indications for Operative Vaginal Delivery and Caesarean Section
Pharmacologic Options
Fetal Surveillance
Baseline Assessment
o Rate Normal (120-160 bpm) o Variability Short-term (beat-to-beat) is normally 5-25 bpm Long-term variability is 3-10 cycles/minute
Advantages Disadvantages
Systemic analgesia
Parenteral agents
Patient controlled opioid (e.g., Remifentanil PCA)
Less variable plasma concentration Superior pain relief with dose maternal respiratory depression placental transfer of drug Higher patient satisfaction
Specialized equipment Opioid side effects Small doses are not always effective Risks to fetus/neonate are unclear
Opioid adjuncts (e.g., barbiturates, BZDs)
Rarely used due availability of safer alternatives
Intermittent bolus parenteral opioid (e.g., meperidine, morphine, tramadol, fentanyl)
Simple Quick onset No specialized equipment or personnel
Maternal side effects (e.g., Nx, dysphoria, respiratory depression, drowsiness, delayed gastric emptying) Fetal side effects (e.g., decreased FHR variability, respiratory depression)
Inhalational agents
Nitrous oxide Negligible neonatal effect No effect on uterine activity
Requires maternal cooperation
Volatile anesthetic agents (e.g., isoflurane, sevoflurane)
Not used clinically at present
Regional analgesics
Epidural analgesia
Most effective analgesia Higher patient satisfaction Allows conversion to c/s if necessary
Contraindicated if: Increased ICP Active neurological disorder Infection at site of injection/systemic infection Frank coagulopathy Complications: Hypotension Extensive motor block Slowed labour progress Fetal effects Post-dural puncture headache (PDPH) Spinal analgesia
Combined spinal-epidural analgesia
Rapid onset with good sacral analgesia Delayed verification of functioning epidural catheter Higher incidence of pruritus Possible higher risk of fetal bradycardia Risk of PDPH Limited analgesia duration (in single-shot spinal)
Paracervical block Rarely used due to risk of uteroplacental perfusion Lumbar sympathetic block Pudendal nerve block (S2-S4) Frequent failure with risk of direct fetal trauma Perineal infiltration Rapid onset Incomplete epidural analgesia
Fetal Heart Rate Patterns
Description Fetal distress? Potential Explanation Intervention Accelerations FHR in response to contraction
No Physiologic response None needed
Early deceleration
FHR with lowest point at peak of the contraction
No Seen when fetal head engaged (head compression)
None needed
Late deceleration
FHR with lowest point after peak of contraction
Yes Uteroplacental insufficiency Fetal hypoxia Fetal metabolic acidosis Low arterial pH
Change maternal position (supine lateral) Maternal oxygen Discontinue oxytocin IV tocolytic c/s Variable deceleration
FHR with variable onset
Yes Umbilical cord compression Change maternal position 100% oxygen to mother Trendelenberg position Discontinue oxytocin IV tocolytics Amnio-infusion with normal saline Assisted vaginal delivery or c/s Decreased beat- to-beat variability
<5 bpm Possibly Fetal acidosis Quiet sleep state Maternal sedation (drugs)
Acoustic stimulation to differentiate between sleep state and something more concerning
Augmentation of Labour
o Artificial stimulation of labour o Artificial rupture of membranes (ARM), which may be done in conjunction with IV oxytocin infusion o Complications of oxytocin augmentation include: Hyperstimulation causing fetal distress as a result of ischemia May lead to uterine rupture Antidiuretic effect of oxytocin may lead to severe water intoxication Uterine muscle fatigue and post-delivery uterine atony (more commonly seen with prolonged oxytocin use)
References
Chen, Y. A., & Tran, C. (Eds.). (2011). Toronto notes: Comprehensive medical reference & review for MCCQE I & USMLE II. Toronto, ON: McGraw Hill Professional
Hacker, N. F., Gambone, J. C., Hobel, C. J. (2010). Essentials of obstetrics and gynecology (5th^ ed.). Philadelphia, PA: Saundiers Elseviers.
Wong, C. (2009). Advances in labor analgesia. International Journal of Women’s Health, 1 , 139-154.
