[CLMD] Dysfunctional Lab [Moulton] Flashcards
How do Uterine Contractions work Physiologically?
Stimulation of Oxytocin recptors activates actin myosin element
(Gap Jxns help faciliatate entire uterine contractions simulataneously)
– So we get an INCREASE in Intracellular Ca stores
– promoting interaction of actin and myosin causing uterine contractions
What are the two distinct segments of the uterus that are formed during labor – and what do they do?
Upper Segment – actively contracts and retracts to expel the fetus
Lower Segment/Cervix – Becomes thinner and passive
How does the cervix change during labor?
It becomes soft, pliable, and dilatable
(from collagenolysis, increase in hyaluronic acid, decrease in dermatan sulfate, which favors water content)
What are the stages of Labor?
Stage 1 – Onset of contractions to full dilation of cervix
Stage 2 – full dilation of cervix to delivery of infant
Stage 3 – delivery of infant to delivery of placenta
Stage 4 – delivery of placenta to stabilization of mother
What are the normal limits for nulliparious/multiparous women during the latent phase?
Null – up to 20 hours
Multi – up to 14 hours
What are the normal limits of the active phase for cervical dilation of Nulliparous/Multiparous women?
Fetal descent in active phase?
Null – cervical dilation of 1.2 cm/hr
Multi – cervical dilation of 1.5 cm/hr
[fetal descent]
Null – descent of 1 cm/hr
Multi – descent of 2 cm/hr
What is the difference between protraction and arrest?
Protraction – slower than normal rate
Arrest – complete cessation of progress (no further dilation or descent)
What are some of the causes of a prolonged latent phase of labor?
Entered labor w/o substantial cervical change
Excessive use of sedatives/analgesics
Fetal Malposition
What are some of the causes of active phase problems?
Inadequate Uterine Activity (contractions arent strong enough)
Cephalopevlic Disproportion (pelvis shape inadequate for birth)
Fetal Malposition
Anesthesia (mom aint pushing – she sleeping)
(POWER, PASSENGER, PASSAGE) – Dystocia (difficult labor)
How do you manage a patient who is having trouble with the active phase of labor?
Augmentation – stimulation of uterine contractions, when spontaneous contractions have failed
(use if contractions are less than 3 in 10 mins)
Oxytocin – after assessing, Maternal Pelvis, Fetal Position, Station, Maternal and Fetal status
How do you assess the Power component of a patients dystocia?
IUPC (Intrauterine Pressure Catheter) – to assess the Power component (of their Dystocia
**The patient must have already had their MEMBRANES RUPTURED**
Calculate their Montevideo Units (MVU); >200 MVU for at least 2 hours
Start Pitocin – to stimulate labor
How do you assess the Passage component of active labor?
CPD (Cephalopelvic Disproportion) – the size of the pelvis to the fetal head
Measure
Pubic Arch
Ischial Tuberosities
Diagonal Conjugate,
Prominence of Ischial Spines
(This tells you the type of Pelvis they have: Arthropoid, Gynecoid etc)
How do you assess the Passenger component of the active phase?
Determine Fetal Position:
- Occiput Status (OA, LOP, LOA etc.)
Note possibility of
Macrosoma/LGA
Dystocia
Hydrocephalus
Fetal Ascites
Immune Hydrops – Rh Isoimmunization
Non-Immune Hydrops
Conjoined/Locked twins
What is the usual way the fetal head engages the pelvis?
OT position, then rotates to OA
(sometimes rotates to OP)
If the fetal head doesnt rotate and flex into the OA position, what are the likely causes?
CPD
Android/Platypelloid pelvis
Relaxed Pelvic Floor (Epidural)
If the fetal head is stuck in the OT or OP position, what line of the fetal skull is traversing through the maternal pelvis?
Occipitofrontal (11cm)
(Suboccipitobregmatic – is most favorable)
What is Transverse Arrest of Descent?
a Persistent OT position with arrest of descent for a period of 1 hour or more
If you have a patient with a persistent OT position, and the pelvis is adequate, infant isnt macrosomic, and contractions are inadequate – what happens next?
What if the pelvis is inadequate, or infant is macrosomic etc?
Start Oxytocin
Manually Rotate (or use Keilland Forceps (only for OT))
Proceed with C-Section
If you have a persistent OP position, how do you manage this?
Observation of a prolonged second stage of labor
(may need vacuum or forceps)
What is Macrosomia vs LGA?
Macrosomia – fetus weighing 4500 grams
LGA – birth weight equal to or greater than 90% for a given gestational age
What are the Risk Factors for developing Macrosomia?
Maternal Diabetes
Previous History of Macrosomia
Obesity
Multipartity
Male Fetus
>40 weeks
Hispanic
<17 years old mother
+50 g glucose screen with a neg result on 3 hour
What are some risk factors from macrosomia?
Maternal Morbidity
Hemorrhage
C-Section
Fetal Morbidity:
Shoulder Dystocia
Fracture of Clavicle
Brachial Plexus damage
What are the 3 Brachial Plexus Injuries?
Erb-Duschenne – upper arm palsy [C5/C6]
Klumpke – lower arm palsy [C8/T1]
Paralysis of Entire Arm – [all 4 nerve roots]
What are the Risk Factors for Shoulder Dystocia?
Antepartum
Fetal Macrosomia
Maternal Diabetes
Obesity
Short Stature
Previous History of Macrosomic Birth/Shoulder Dystocia
During Labor
Labor Induction
Epidural Analgesia
Prolonged Labor
Operative Vaginal Deliveries
If you have a neonate who has shoulder dystocia, what are you likely to find in this patient?
Branchia Plexus Injuries
Fractured Clavicle or Humerus
Hypoxic
Death
How do we manage a neonate who presents with shoulder dystocia (turtle sign is present during labor)?
McRoberts Maneuver – hyperflexion and abduction of maternal hips
Suprapubic Pressure (dont apply fundal pressure)
Rotational Maneuvers
- Rubin Maneuver (decreasing the Bisacrominal diameter and free impacted shoulder)
- Woods Corkscrew Maneuver (apply pressure behind the posterior to rotate the infant and dislodge anterior shoulder)
Proctoepisiotomy (4th degree cut)
Zavanelli Maneuver (all cardinal movements in reverse) LAST RESORT
What are the intial maneuvers for shoulder dystocia?
What is the last resort maneuver?
McRoberts and Suprapubic Pressure
Zavanelli (followed by C-Section)
