Hawkins, Joy Obstetric Emergencies

THE MANAGEMENT OFOBSTETRIC

EMERGENCIES

Joy L. Hawkins, M.D.University of Colorado SOM

Denver, CO(**I have nothing to disclose)

“If you can keep your head when all about you are losing theirs, it’s just possible you haven’t grasped the situation.”

Jean Kerr

CRASH 2007 HAWKINS, JOY, MD

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Vigilance is great, but you have to remember that studies show

the half-life of vigilance is about 15 minutes.

Author unknown


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PREVENTABILITY

A comprehensive review of maternal deaths in a single state found that 40% could have been prevented.

• Almost all deaths due to hemorrhage or chronic disease were preventable.

• None of the deaths due to AFE or CVA were considered preventable.

Obstet Gynecol 2005;106:1228


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HEMORRHAGE

Antepartum: Placenta previa/accreta/percretaPlacental abruptionUterine rupture

Postpartum: Uterine inversionUterine atonyBirth trauma or lacerations


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3Magnesium therapy6Multiple gestation

7Preeclampsia/eclampsia

7Chorioamnionitis

8Intrauterine fetal demise

16Placental abruption

34Placenta previa

∞Placenta accreta / placenta percretaOdds Ratio

Risk Factors in Obstetric Patients for Transfusion vs. No Transfusion


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“Lots of people confuse destiny with bad management.”

Kin Hubbard

To avoid “bad management”, we should know:• Risk factors• Diagnostic criteria• Obstetric management• Anesthetic management


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PLACENTA PREVIA, ACCRETA, and

PERCRETA


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PATIENT RISK FACTORS FOR ABNORMAL PLACENTATION

Uterine fibroidsPrior cesarean sectionHistory of postpartum hemorrhageMultiparity


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RISK FACTOR: PREVIOUS CESAREAN WITH PLACENTA PREVIA

Number of Prior C/S % With Accreta0 51 242 473 404 67



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DIAGNOSIS OF PLACENTAL ABNORMALITIES

Placenta Previa• Painless, bright red vaginal bleeding• Ultrasound for location of placenta

Accreta/Percreta• Antepartum: suspicious ultrasound → MRI

Obstet Gynecol 2006;108:573• At delivery: placenta does not separate


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OB MANAGEMENT

Placenta Previa• Cesarean delivery: elective (if stable) or

urgent (if hemorrhaging)

Accreta/Percreta• Recognition and (probably) hysterectomy• May need surgeons with experience in

bowel or urological surgery for percreta


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OB MANAGEMENT

• At the time of delivery when placenta accreta is documented, the obstetrician can choose to remove the placenta or leave it in place.

• Conservative therapy reduces hysterectomyfrom 85→15%, DIC from 39→5% and transfusion by half, but requires close follow-up for increased risk of infection.



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ANESTHETIC MANAGEMENT FOR PREVIA

• Examine the airway in case emergent GETA is required and provide aspiration prophylaxis.

• Ask OB about involvement with any previous cesarean scar on ultrasound (risk of accreta).

• Place two large-bore IV lines and have warmers (Level I) available.

• Assure that blood is type and cross-matched.• What type of anesthetic?


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A review of 514 women with placenta previa found:• No difference between general or regional anesthesia

in anesthetic or operative complications.• General anesthesia was associated with ↑ EBL and

transfusions and ↓ postop Hgb.• Greatest risk factor for hysterectomy was prior C/S.

Am J Obstet Gynecol 1999;180:1432


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A retrospective review of 350 consecutive cases of placenta previa (60% using regional anesthesia, 40% using GETA) found:• ↓ EBL with regional vs. GETA• ↓ transfusion with regional• No difference in incidence of hypotension• Two spinals were converted to GETA 2o C-hyst• Two GETA patients had thrombotic cx

Br J Anaesth 2000;84:725


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ANESTHETIC MANAGEMENT FOR ACCRETA, PERCRETA

• Look for risk factors preop (hx C/S, previa).• Type of anesthetic? Consider duration, blood

loss, availability of help.• When recognized, get additional IV access,

pressure/warming systems, and blood available.

• Have pressors and invasive monitoring capability available.


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USE OF CELL SALVAGE

A multicenter review of 139 patients who were auto-transfused during cesarean delivery compared them to a control group receiving banked blood. There was no difference in:

• Length of hospitalization• Need for ventilatory support / A.R.D.S.• Coagulopathy or amniotic fluid embolism• Infectious morbidity

Am J Obstet Gyn 1998;179:715


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USE OF CELL SALVAGE

Cell salvage combined with blood filtration produced blood samples equivalent to maternal central venous blood.

Editorial: Until a large prospective randomized study is done, cell salvage during C/S should only be used when necessary to preserve life – e.g., Jehovah’s Witness, difficult crossmatch.

Anesthesiology 2000;92:1519 and 1531


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INTERVENTIONAL RADIOLOGY• Prenatal diagnosis of placenta accreta /

percreta is now becoming more common (vs diagnosis at delivery) → develop a plan for potential major hemorrhage.

• Have a care conference in advance with Anesthesiology, OB, nursing and Interventional Radiology present.

Am J Obstet Gynecol 2005;193:1756Anaesthesia 2006;61:248


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INTERVENTIONAL RADIOLOGY

• Case report: A Jehovah’s Witness patient presented with placenta percreta invading the bladder. After uterine and iliac catheters were placed in IR, cesarean was performed. Placenta was extensively adherent to uterus and penetrating bladder wall. Uterine artery embolization was performed and the placenta left in place. At 3 months the uterus was empty by ultrasound. Methotrexate was considered, but was unnecessary.



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INTERVENTIONAL RADIOLOGYIn a series of 12 patients treated for massive

postpartum hemorrhage using selective uterine artery embolization, the success rate was 92%.

• One patient required hysterectomy.• There were no maternal deaths.• One patient has since had a normal

pregnancy and delivery.Eur J Obstet Gynecol Reprod Biol 2003;10:29


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PLACENTAL ABRUPTION


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RISK FACTORS FOR ABRUPTION

Hypertension, chronic or pregnancy-inducedAge > 35 yearsMultiparitySmokingCocaine useAbdominal traumaPremature rupture of membranesHx of previous abruption


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DIAGNOSIS OF ABRUPTION

• Vaginal bleeding with abdominal pain• Uterine hypertonicity• Fetal distress• Retroplacental clot on ultrasound

The presentation can be quite variable and difficult to diagnosis.


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OB MANAGEMENT OF ABRUPTION

• Evaluate maternal stability (vital signs, coagulation studies)

• Evaluate fetal well-being and maturityTHEN. . .

• If severe fetal distress and/or maternal instability urgent cesarean section

• If stable mother and fetus induction of labor and vaginal delivery


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ANESTHETIC MANAGEMENT OF ABRUPTION

• Assure good IV access and blood availability.

• Regional techniques are appropriate if maternal volume status and coags normal.

• If GETA is indicated, consider induction with etomidate or ketamine.

• Have several oxytocics available for treatment of uterine atony.


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UTERINE RUPTURE


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RISK FACTORS FOR UTERINE RUPTURE

Previous uterine surgeryAbdominal trauma – seat belt, fallUterine trauma - forceps, curettageGrand multiparityFetal macrosomiaFetal malposition


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DIAGNOSIS OF UTERINE RUPTURE

Fetal distress (#1)Cessation of uterine contractions (in labor)Vaginal bleedingAbdominal pain


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OB MANAGEMENT OF UTERINE RUPTURE

Uterine repair vs. Hysterectomy

• Uterine rupture occurs in 1% of LCT uterine incisions and 4-9% of classical incisions.

• ACOG has practice guidelines for management of VBAC.



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ANESTHETIC MANAGEMENT OF UTERINE RUPTURE

• Depends on ease of repair, but be prepared for GETA and volume replacement.


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UTERINE INVERSION


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UTERINE INVERSION

Risk Factors: Inappropriate fundal pressureExcessive traction on the cord

Diagnosis: Perineal or vaginal massMassive hemorrhageShock and hypotension


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OB MANAGEMENT OF UTERINE INVERSION

Replace the uterus as quickly as possible, then begin oxytocic drugs to induce contraction.


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ANESTHETIC MANAGEMENT OF INVERSION

• Uterine relaxation:NTG (50-500 µg), terbutaline, GETA

• Analgesia:Pre-existing epidural, ketamine, GETA

• Volume resuscitation• Uterine contraction with oxytocics once the

uterus is replaced


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NITROGLYCERIN

Pros: Rapid onset, short durationMinimal side effects (HA, ↓ BP)Clinically effective

Cons: Mechanism?Dose? Reported 50-1500μgRequires dilution


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UTERINE ATONY


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RISK FACTORS FORUTERINE ATONY

Multiple gestation Precipitous laborMacrosomia Prolonged laborPolyhydramnios Augmented laborGrand multiparity (>5) ChorioamnionitisMaternal age > 40 Tocolytic agents

Halogenated anesthetics


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OB MANAGEMENT OF UTERINE ATONY

• Bimanual uterine compression and massage

• Infusion of oxytocin• Evaluation for retained placenta• Use of other oxytocics


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OXYTOCIC DRUGSDrug/Dose Side Effects Oxytocin 20-80 U/L

Vasodilation with IV bolus, hyponatremia

Methergine® (methylergonovine) 0.2 mg IM

Diffuse vasoconstriction, pulmonary and systemic hypertension, coronary vasospasm, nausea

Hemabate® (prostaglandin F2α) 250 μg IM

Bronchospasm, pulmonary hypertension, hypoxia, nausea, diarrhea


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OXYTOCIN• The ED95 of IV bolus oxytocin during

elective cesarean is 0.35U.• The ED95 during cesarean delivery after

labor arrest (mean 9.8 hours of prior oxytocin infusion) is 3U – 9 times higher!

• Oxytocin receptor desensitization from exogenous oxytocin administration during labor → alternative uterotonics may be necessary and more effective.



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OXYTOCIN REGIMENS

The “Confidential Enquiries into Maternal Deaths, 1997-1999” describes two deaths in which the anesthesiologist gave an IV bolus of oxytocin after delivery with subsequent maternal cardiac arrest and death. The associated maternal conditions were:

• Postpartum hemorrhage with hypotension• Pulmonary hypertension


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OXYTOCINTwo abstracts evaluated hemodynamics after 5 units

IV bolus oxytocin in healthy women with spinal anesthesia for cesarean.

• MAP ↓ 27%, HR ↑ 17 beats per minute• Cardiac index ↑ 61% above baseline• Systemic vascular index ↓ 39% • No ↑ blood loss when given over 5 minutes

IJOA 2006;15:A-P01 and Anesthesiology 2006;105:A11


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COMPRESSIVE UTERINE SUTURES

Obstet Gynecol 2005; 106:569


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ANESTHETIC MANAGEMENT OF ATONY

• Volume ResuscitationLarge bore IVs, T&C, warmers, monitors

• AnalgesiaPre-existing epidural, ketamine, GETA

• OxytocicsKnow side effects!

• Move to O.R. sooner rather than later.• Consider notifying Interventional Radiology.


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ANESTHETIC MANAGEMENT

The authors present a series of 12 cases using recombinant factor VIIa for life-threatening postpartum hemorrhage. They recommend its use before resorting to hysterectomy in cases of intractable PPH.

• At their hospital, the cost of one dose of rFVIIa = 50 units PRBC = an embolization procedure = 2 days of ICU treatment. Cost effective??

Br J Anaesth 2005;94:592


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FETAL DISTRESSCRASH 2007 HAWKINS, JOY, MD

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CAUSES OF FETAL DISTRESS

During labor: Umbilical cord prolapseUmbilical cord compression→variable decelerations

Uteroplacental insufficiency→late decelerations

At delivery: Shoulder dystocia


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WHAT IS FETAL DISTRESS?

Obstetricians now use the term non-reassuring fetal status (NRFHT) followed by a further description of the findings (eg, deep variable decelerations) because “fetal distress” is imprecise, and fetal monitoring has a low predictive value of neonatal outcome (99% false positive!). “Birth asphyxia” is nonspecific and should not be used.



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NORMAL UMBILICAL CORD BLOOD GASES

VEIN ARTERY

pH 7.34 7.28PO2 30 15PCO2 35 45Base deficit 5 7


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INTERPRETATION OF UMBILICAL CORD GASES

NORMAL RESPIRATORY ACIDOSIS

METABOLIC ACIDOSIS

pH 7.25-7.40 Decreased Decreased

PO2 18-22 Usually stable Decreased

PCO2 40-50 Increased Usually stable

Base deficit 0-10 Usually stable Increased


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UMBILICAL CORD GASES

The threshold for pH and base deficit that predict adverse neonatal sequelae are:

pH < 7.0Base deficit ≥ 12 mmol/L

The metabolic component (base deficit) is the most important variable associated with subsequent neonatal morbidity.

Am J Obstet Gynecol 1999;181:867Am J Obstet Gynecol 1997;177:1391


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UMBILICAL CORD GASES

ACOG Committee Opinion, November 2006:“Moderate and severe newborn encephalopathy and

respiratory complications…increase with an umbilical arterial base deficit of 12-16 mmol/L. Moderate or severe newborn complications occur in 10% of neonates who have this level of acidemia and the rate increases to 40% in neonates who have an umbilical arterial base deficit greater than 16 mmol/L.”



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CLOSED CLAIMS ANALYSIS

An analysis of claims for newborn brain injury from the ASA Closed Claims Project database found that in claims where anesthesia might have contributed (<30%):

• 50% some delay by anesthesia was alleged.• 17% maternal condition was involved.• 8% poor communication contributed.

Anesthesiology 2006;105:A7


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OBSTETRIC MANAGEMENT OF FETAL DISTRESS

Initiate attempts at intrauterine resuscitation:• Change maternal position.• Administer supplemental oxygen.• Maintain / improve maternal circulation.• Give a tocolytic for hypertonicity.• Start an intrauterine infusion to relieve cord

compression.


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INTRAPARTUM ASSESSMENT

Using oximetry to assess fetal oxygen saturation, what maneuvers improve fetal oxygenation during intrauterine resuscitation?

• IV fluid bolus of 1000 ml: ↑ 5%• Lateral position (vs. supine): ↑ 10%• Maternal oxygen 10L by mask: ↑ 9%



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WHAT’S AN “EMERGENCY”CESAREAN DELIVERY?

STABLE: to O.R. when the teams are available; use any anesthetic options

Examples:• Chronic uteroplacental insufficiency

(chronic HTN)• Breech presentation with ruptured

membranes (no active labor)


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URGENT: to O.R. within 30 minutes; place spinalor extend existing epidural

Examples:• Dystocia• Failed forceps• Previous classical C/S in labor• Active herpes with ruptured membranes• Variable decels with prompt recovery


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STAT: to O.R. emergently – use generalanesthesia, regional is rarely practical

Examples:• Massive hemorrhage• Cord prolapse• Agonal fetal distress


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UMBILICAL CORD COMPRESSION

Variable decelerations vary in duration, depth and shape from contraction to contraction.

They are often associated with decreased amniotic fluid: oligohydramnios, ruptured membranes.


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OBSTETRIC MANAGEMENT OF CORD COMPRESSION

• Change maternal position.• Stop oxytocin if in use.• Begin amnioinfusion to increase fluid.• Use fetal scalp stimulation or sampling

to assess well-being.


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ANESTHETIC MANAGEMENT OF CORD COMPRESSION

Anticipate need for expedited delivery• Perform a preop evaluation.• Administer aspiration prophylaxis.• Place an epidural catheter or

“optimize” if epidural in place.• Treat hypotension if indicated.


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UTEROPLACENTAL INSUFFICIENCY

Late decelerations begin after the onset of the contraction and end after the contraction is over.

Uteroplacental insufficiency may be associated with:• Postdates gestation• Hypertension• Diabetes• Intrauterine growth retardation• Abruption


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OBSTETRIC MANAGEMENT

• Improve oxygen delivery to fetusMaternal O2 supplementationLateral positionStop oxytocin and consider a tocolytic

• Expedite delivery


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ANESTHETIC MANAGEMENT

• When risk factors for uteroplacental insufficiency are present, consider aspiration prophylaxis and early placement of an epidural catheter.

• General vs. regional anesthesia for cesarean section depends on urgency.


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CONCLUSIONS

• Anticipate problems!• Cultivate a good relationship and

communicate with your obstetricians.• Be available and prepared:

Emergency O.R. set-upTransfusion and monitoring capabilityDifficult airway box


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Documents

Hawkins, Joy Obstetric Emergencies