Obstetric Anesthesia Considerations

• Two patients i.e. mother and fetus

• Maternal physiologic changes:

  1. Cardiac output increases by 50% by 2nd trimester w/ increased HR & SV

  2. Blood volume increases by 45% --> dilutional anemia

  3. Hypercoagulable state --> increases risks of periop thromboembolic events

  4. Aorto-caval compression w/ supine position --> oblique position for left uterine displacement --> prevents decrease in uterine blood flow and maternal hypotension

  5. O2 consumption increases by 60%

  6. Minute ventilation increases by 45% by increasing TV

  7. FRC decreases by 20% (30% in supine) --> decreased safe duration of apnea

  8. Delayed gastric emptying & increased intraabdominal pressure --> GERD --> aspiration prophylaxis e.g. 30ml NaCitrate, 10mg metoclopramide IV, 50mg ranitidine IV; RSI w/ cricoid pressure in case of GA

  9. Reduced MAC by 30%

  10. Reduced LA requirement by 25%

  11. Renal blood flow increased by 75% --> GFR increased by 50%

  12. Sizeable breasts, airway edema --> potential difficult airway

• Semi-urgent to urgent

• Risk factors:

  1. Family hx of PIH

  2. Chronic HTN?

  3. Previous hx of preeclampsia?

  4. Co-existing vascular / endothelial disease (e.g. chronic renal diseases, lupus, protein S deficiency etc.)

  5. Nulliparity, > 40yo, multiple gestations, DM, obesity?

• Multisystem involvement:

  1. Airway w/ internal and external edema --> potential difficult airway

  2. Pulmonary edema - uncommon; reduced colloid oncotic pressure, endothelial dysfunction and diastolic dysfunction predisposed to development of pulmonary edema

  3. CNS involvements e.g. cerebral edema, ICH, increased ICP, HA, visual disturbance, altered mentation, seizure

  4. Hypertension, labile BP --> Art line prior to GA induction; NTG, phenylephrine readily available during induction; hypertensive crisis, LV dysfunction / cardiomyopathy / CHF

  5. Reduced intravascular volume --> cautious with neuraxial blockade; volume expansion prior to spinal/epidural; phenylephrine readily available

  6. Coagulopathy --> early insertion of epidural catheter before any coagulopathy, epidural is also partially therapeutic

  7. Hemolysis, Elevated Liver enzymes, Low Platelets

     Platelets < 50 neuraxial technique contraindicated

     50-70: risk vs benefit judgement (consider trend, other competing factors e.g. airway, cardiac / neuro status)

     >70: likely safe

  8. Renal impairment due to glomerular endotheliosis

• Uteroplacental unit; increased chance of abruptio placenta

• Risks to baby: IUGR, increased risk of fetal asphyxia, IUD, prematurity

• Goals:

  1. BP control (sBP <160 mmHg, dBP <110 mmHg)

  2. Optimize volume status

  3. Maintain adequate uteroplacental perfusion

  4. Minimize end-organ issues e.g. seizures, ICH, cardiac ischemia

  5. Optimize labour analgesia to minimize exacerbation of BP due to pain

• Pharmacological intervention:

  1. MgSO4 4g IV over 10-15min, then 1-3g per hour for maintenance; constant monitoring of cardiopulmonary status, knees DTR, urine output; Ca gluconate 1g IV over 3-5min in case of overdose

  2. MgSO4 also for neuroprotection in premature babies

  3. Hyralazine 5-10mg IV bolus, then 5mg per hour

  4. Labetolol 20mg IV repeated q15min prn, 20mg/hr maintenance

• Placenta Previa

  • Access severity i.e. Total, partial or marginal; Anterior vs posterior

  • 1 in 200 pregnancies; risk factors - multiparity, advanced maternal age, previous C-section & previous previa, 10% associated with abruption & preterm labor

  • Dx – painless vaginal bleeding, confirm with u/s, no vaginal exam

  • Anesthetic management

    • Elective vs urgent / embergent C-sectioin

    • AMPLE hx / px / labs

    • Cross & Type

    • Large bore IV access x 2

    • Risk of bleeding due to cutting into placenta, poor contraction of the lower uterine segment & increased risk of accreta

      • Regional – if hemodynamically stable & not actively bleeding; fetus stable to allow time for neuraxial technique

• Vasa Previa

  • Rare cause of APH

  • Abnormal insertion of umbilical cord into the chorioamnion such that vessels run some distance within the amniotic membranes – primary risk is fetal hemorrhage / exanguination

  • Presents as vaginal bleeding with FHR changes (tachy followed by brady)

  • Fetal distress is disproportionate to the amount of bleeding

  • Emergent C-section

  • Elective C-section if diagnosis made antenatally

• Placental Abruption

  • Access severity, amount of blood loss, fetal / maternal status

  • Risk factors – HTN / preeclampsia, abdominal trauma, advanced age & parity, premature rupture of membranes, tobacco & cocaine use, prior abruption

  • Major risk for fetal hypoxia & maternal / fetal blood loss; 10% complicated by DIC

  • Presents as vaginal bleeding, uterine tenderness & increased uterine activity

  • OB management:

    • Ongoing FHR & maternal monitoring, O2, left lateral, IV access, G&S

    • Definitive tx is delivery by c-section as soon as possible after dx

    • Consider expectant management if preterm, minimal abruption and no fetal distress to allow for fetal lung maturation

  • Anesthetic management:

    • Depends on severity and urgency

    • Neuraxial in less severe cases i.e. mother hemodynamically stable, no fetal distress

    • In more severe cases: volume resuscitation, large bore IV access, invasive monitoring, GA

    • Massive transfusion protocol prn

• Uterine Rupture

  • Dehiscence – wall defect not resulting in fetal distress or hemorrhage

  • Rupture – results in distress / hemorrhage

  • Risk factors - previous uterine surgery e.g. C-section, trauma, grand multip, augemtation of labor

  • Dx – bleeding, hypotension, fetal distress, cessation of labor, persistent abdominal pain

  • OB management - emergency C-section – uterine repair, arterial ligation or hysterectomy

  • Anesthetic management

    • Large bore IVs, volume resuscitation, transfusion, invasive monitoring

    • GA in most cases

    • Massive transfusion protocol prn

• Emergent, liaise with Ob team, consider activating OB massive transfusion code and consult transfusion medicine, notify ICU for post op care

• DDx:

  1. Atonia

  2. Vaginal laceration

  3. Coagulopathy

  4. Retained placenta

  5. First trimester hemorrhage DDx - miscarriage

  6. Second/third trimester hemorrhage DDx - abruptio placenta, placenta previa

• Airway - ensure patent airway; prepare for emergency intubation

• Breathing - ensure adequate ventilation, oxygenation

• Circulation – BP, organ perfusion e.g. brain (mentation), heart (ischemia), kidneys (AKI)

• Full set of vitals including temp and O2 saturation

• 2 large bore IVs, level I fluid warmer, ensure blood products readily available

• Replace blood loss w/ crystalloid, colloid, blood --> hemodynamic goals directed e.g. HR, PPV

• Apply 100% O2 to maximize maternal oxygenation

• Blood work: CBC, INR, PTT, D-dimer, FDP, fibrinogen

• Pharmacological intervention:

  1. Oxytocin 5U slow bolus, then maximum 40U/L IV infusion; watch out for anaphylactoid reactions (hypotension, pruitus, urticaria, facial flusing, N/V)

  2. Ergot 0.125-0.25 mg IV/IM w/ maximum dose 1.25mg; watch out for hypertension, increased CVP, coronary spasm, MI, arrythymia, bronchospasm, N/V; patients w/ CAD are contraindicated

  3. Hemabate 0.25mg IM/IMM q15min; maximum 8 doses; watch out for N/V, bronchospasm, diarrhea, HTN, HA, flushing, diaphoresis, restlessness, pulmonary vasoconstriction

  4. Misoprostol 1mg PR; systemic/pulmonary dilator

  5. TXA

• Transfusion: massive transfusion protocol, fibrinogen concentrate, maintain fibrinogen > 2

• Consider surgical control: uterine massage, B lynch suture, packing, uterine artery ligation, IR embolization, hysterectomy

• 2024 CAS Guideline

1. 1. In a pregnant patient with a clinical history, physical exam, or laboratory results indicating thrombocytopenia (platelet count < 100x10⁹/L), the anesthesiologist should determine if the patient has a qualitative defect (i.e., a problem with platelet structure or function) or an active coagulopathy that would contraindicate a neuraxial technique. [in the guideline, there is no elaboration on what tests / history / physical one would employ to determine such qualitative defect]

   2. In a pregnant patient with suspected qualitative defects or active coagulopathy, it may be reasonable to avoid a neuraxial technique or to seek expert hematologic consultation before proceeding with the neuraxial technique.

   3. Pregnant patient with isolated thrombocytopenia with no other associated signs of a qualitative defect or an active coagulopathy

• • • • platelet counts greater or equal to 70x10⁹/L, there may be a low risk fo spinal epidural hematoma and it is reasonable to proceed with a neuraxial technique

      • platelet counts between 50 and 70x10⁹/L, the anesthesiologist should consider the risks and benefits of proceeding or avoiding a neuraxial technique and share the decision-making with the patient. Factors to consider: etiology of thrombocytopenia, trend of platelet count over time, patient comorbidities, Ob risk factors, airway and back examination, the risk of GA and patient preference.

      • platelet counts of < 50x10⁹/L, there may be an increased risk of subdural or epidural hematoma and it is reasonable to avoid a neuraxial technique.
        

         
        

• SOAP Interdisciplinary Consensus Statement on Neuraxial Procedures in Obstetric Patients With Thrombocytopenia; Anesthesia Analgesia 2021

• Etiologies:

  1. Gestational thromobocytopenia; incidence during pregnancy 5-11%, onset late 2nd or 3rd tremester, platelet count >75000, generally asymptomatic

  2. Preeclampsia; incidence 5-8%, onset late 2nd or 3rd trimester

  3. HELLP syndrome; incidence <1%, 70% onset later 2nd or 3rd trimester, 30% onset postpartum, 15%–20% of cases no hypertension or proteinuria, platelet count nadir occurs 24–48 h after delivery

  4. ITP; incidence <1%, onset at any trimester, thrombocytopenia outside of pregnancy possible, platelet count <100,000 ± large platelets on blood smear, rarely may have signs of bleeding, bruising, and petechiae

  5. Other rare causes: acute fatty liver of pregnancy, TTP, sepsis-induced thrombocytopenia; not covered by the consensus statement

• Incidence of spinal epidural hematoma in the general obstetric population 1:200,000 to 1:250,000; incidence in obstetric patients with thrombocytopenia (<100,000) is unknown; retrospective studies suggest incidence of 0.19% (plt count 70,000 - 100,000), 2.6% (plt 50,000 - 69,000) & 9% (plt < 50,000)

• Other than platelet count on CBC, no other lab test (including PFA-100, TEG or ROTEM) can reliably assess platelet function or bleeding risk

• First assess for any clinical history of abnormal bleeding, any signs of DIC (bleeding from IV sites, catheters, wounds, or new mucocutaneous bleeding)

• Decision Algorithm

• Platelets transfusion:

  1. Not recommended for the sole purpose of neuraxial technique

  2. ACOG recommends platelet transfusion in preeclampsia for active bleeding or to improve the platelet count to 50,000 before cesarean delivery

  3. IVIG & steroid are treatment of choice for ITP

  4. Platelet transfusions are recommended to temporize only in cases of life-threatening hemorrhage or to prepare for urgent surgery because the response to platelet transfusion is short-lived

• Insufficient evidence to make recommendation regarding neuraxial procedures in obstetric patients with thrombocytopenia who are also taking aspirin concurrently

Ultimately, the decision of whether or not to proceed with a neuraxial procedure in an obstetric patient with thrombocytopenia occurs in a clinical context with relevant factors that include maternal comorbidities and airway examination, obstetric risk factors, available airway equipment, type of neuraxial procedure, and patient preference

• Urgency depending on presentation; can range from elective to emergency

• Risk factors:

  1. Multiple previous C-sections

  2. Placenta previa

  3. Multiparity

  4. Advanced maternal age > 35

  5. History of uterine surgery e.g. myomectomy

• Significantly increases likelihood of PPH especially with percreta or increta with neighboring organ e.g. urinary bladder invasion

• Elective C-section

  1. Preop consultation for adequate optimization e.g. hemoglobin and discussion of anesthetic plans; consider blood conservation clinic

  2. Liaise with OB team to clarify severity of accreta, plan for uterus perservation or Cesarean hysterectomy

  3. Consult other specialty e.g. urology or general surgery in cases of percreta

  4. Consult NICU

  5. ICU or step down monitored bed for post op care

  6. Case generally done in main OR for easier access for additional equipments, personnels and surgeons

• Urgent

  1. Likely scenarios e.g. patient goes into labor, bleeding persistently or suddenly and/or needing more than 1 transfusion/day

  2. Obstetrics on call to notify Gyne as backup to perform Ceasarean. Urology to be called if needed

  3. NICU to bring warmer and appropriate personnel/equipment

  4. Call for help e.g. AA, another anesthesiologist

  5. Liasie with blood bank for potential massive transfusion

• Emergent

  1. Similar to Urgent

  2. Sudden hemorrhage occurs that renders the patient too unstable to transfer to main OR from L&D, the case should then be done on L&D, and appropriate services and surgical equipment will be transferred up to L&D OR

  3. Activate code Ob massive transfusion

  4. Notify ICU

• OR/Personnel Setup:

  1. Arrange cell saver - cell salvage should only be initiated AFTER baby is delivered, after amniotic fluid is suctioned with a separate system, and with the use of appropriate filtration system

  2. Level 1 rapid Infuser primed

• Induction of Anesthesia:

  1. Ensure patient is in left lateral tilt to prevent aorto-caval compression until baby is delivered

  2. Mode of anesthesia to be judged on a case by case basis depending on the urgency and other factors:

     • If high likelihood of massive hemorrhage, coagulopathy, fluid resuscitation leading to airway edema, suggest general anesthesia from the start

     • If patient is stable and there is no contraindications, then a CSE +/-conversion to general anesthesia after delivery of baby

     • If GA from the outset, concurrent surgical prep during pre-oxygenation to minimize exposure of volatile/meds to fetus. Minimal time between intubation and incision with goal to minimize exposure of baby to anesthetic.

  3. Arterial line, large bore IV or central venous line

  4. NICU must be in the room

  5. Short laryngoscope handle available, size 7.0 and 6.0 ETT with stylets with additional difficult airway equipment as needed

  6. TXA 1g prior prior to incision. Repeat 1g 30min after initial dose if bleeding is concerning

• Maintainence of Anesthesia:

  1. Before baby is delivered - maintain anesthesia with 50% 02, 50% nitrous oxide and ~Sevo 1.0

  2. After baby is delivered - maintain with 30% 02, 70% nitrous oxide and lower MAC volatile ~Sevo 0.5 to minimize uterine atony and further hemorrhage

  3. Supplement with IV anesthetics as needed

  4. Once uterus is removed, risk of atony and related hemorrhage is also gone and one can resume 'regular' anesthesia as tolerated

  5. Urotonic agents after delivery of baby

  6. It is common for these patients to go into rapid DIC, so perform regular blood work (q1hr at least) assessing CBC, coagulation, and fibrinogen to guide transfusion therapy

• Emergent; requires prompt assessment, diagnosis & management

• Goal to avoid delay in diagnosis and to intitiate early treatment

• Organ dysfunction resulting from infection during pregnancy, childbirth, postabortion, or postpartum period (up to 42 days postpartum)

• Second leading cause of maternal death in the United States; ~ 12% of all pregnancy related deaths; 23% of in-hospital maternal deaths, 45% of which occurred during postpartum readmission (mean interval of 13 days after initial discharge)

• Patients and families should receive discharge information on the symptoms and signs of infection and sepsis (e.g. pyrexia, nonhealing incision, increasing pain, erythema or drainage from incision, foul-smelling discharge)

• Antepartum sepsis most commonly originates from nonpelvic source e.g. pneumonia, whereas intrapartum and postpartum cases are more commonly related to pelvic source e.g. GU; 30% of cases, source is not identified

• Maintain high level of suspicion: Does the parturient look sick or feel unwell? Is there a source of infection e.g. PPROM, pyelonephritis, pneumonia? Is the fetal heart rate ≥ 160 bpm

• Risk stratification using MOEWS chart

• Timely intiation of Sepsis Six care bundle: oxygen, cultures, antibiotics, fluids, lactate measurement and urine output monitoring

• Broad-spectrum IV antibiotics within 1 hour of presentation for patients diagnosed with sepsis, ideally after blood cultures have been obtained

• Multidisciplinary team approach and early critical care involvement

• True obstetrical emergency due to rapid blood loss

• Call for help, activate Ob massive transfusion code

• Management goals:

  1. Ongoing hemodynamic / volume resuscitation

  2. Uterine relaxation / tocolysis for successful manual re-position

  3. Adequate analgesia for manual re-position

• Quickly get full set of vitals BP, HR, SpO2, temperature

• Do a focused hx including previous anesthetics, co-morbidities, meds, allergy

• Do a focused cardiopulmonary exam and airway exam, GA is highly possible

• Diagnose and treat at the same time

• Clinical assessment of volume status / shock? level of consciousness, JVP, postural BP/ HR change, capillary refill, diminished urine output

• 100% O2, 2 large bore IVs, communicate with blood bank to have 4u of PRBC available, call for help

• CBC, INR, PTT, fibrinogen

• Quickly assess if any other causes of postpartum hemorrhage; tone, tissue, trauma, coagulopathy

• Transport patient to OR for further management while keeping ongoing O2 and fluid resuscitation en-route

• Tocolysis:

  1. Terbutaline 0.25mg IV (could cause hypotension, exacerbation of shock)

  2. Nitroglycerine 50ug IV boluses

  3. Magnesium sulphate 4g IV (at least 10 mins for onset), gives slowly to avoid cardiovascular depression, monitor toxicity

  4. Beta agonist e.g. ventolin

  5. Volatile agents, therefore GA. Might consider as first line option

• If there is epidural in-situ, could potentially use it for analgesia for manual reduction. But be very careful with hemodynamic collapse since these patients are volume depleted

• Prudent to avoid using neuraxial for analgesia (does NOT relax uterus), instead IV opioid (e.g. morpine 2-4mg) can be used

• If going for GA:

  1. Call for help

  2. RSI

  3. Styletted tube ready

  4. Ideally arterial line pre-induction but don’t spend too much time on getting one

  5. Preoxygenate

  6. Ketamine 1-1.5mg/kg

  7. Succinylcholine 1.5mg/kg

  8. Any volatile at MAC 0.8-1 balancing between uterine relaxation and cardiac depression

  9. O2/N2O

  10. Once reduced, should followed by uterotonics injection i.e. oxytocin 2-5u slow bolus & 20-40u oxytocin in 1000ml volume infusion, escalating to ergot, hemabate if necessary

• If ongoing bleeding despite full treatment of uterotonics and correction of clotting factors including platelets, FFP, fibrinogen concentrate; and avoid acidosis or hypothermia

• If utereus is appropriately contracted but still ongoing shock, consider retroperitoneal bleed which could be amenable to embolization by interventional radiology or surgical intervention

• Obstetrical emergency requires prompt assessment, diagnosis and management

• Overt prolapse (cord exits the cervix past the fetal presenting part & Occult prolapse (cords exits the cervix alongside the fetal presenting part)

• Clinical diagnosis by palpation of a pulsating cord or a visible cord in the vagina (overt prolapse). For occult prolapse, only fetal bradycardia or sever variable decelerations is present

•  Risk factors:

  • Premature rupture of membran

  • Preterm delivery

  • Low birth weight

  • Polyhydramnios

  • Breech presentation

  • Multiple gestation

  • External cepahlic version

• Management

  • Goal to avoid cord compression and umbilical vessels vasospasm that can lead to fetal hypoxia potentially causing fetal demise or permanent cerebral injury

  • Activate code obstetrics (code 33), call for help (Ob, Anesthesia, RT / AA, Neonatoloy, OR team)

  • Establish IV line, oxygen via face mask

  • Avoid aortocaval compression

  • Minimize handling of the cord to avoid vasospasm

  • Umbilical cord prolapse necessitates immediate delivery usually via emergent C-section, most likely under GA given the emergency

  • Keep the cord warm and moist if imminent delivery is not feasible

  • Tocolysis if delivery is expected to be delayed

  • Elevate fetal presenting part to help with cord (funic) decompression

    1. manual elevation of fetal presenting part with fingers / hand

    2. steep trendelenburg or knee-chest position

    3. filling urinary bladder (500ml NS) with foley catheter

• An obstetric emergency requires timely management / delivery to minimize risk of fetal asphyxia

• Descent of the fetal anterior shoulder is obstructed by the maternal pubic symphysis, or less commonly the fetal posterior shoulder is impacted on the maternal sacral promontory

• Retraction of the delivered fetal head against the maternal perineum between pushes, i.e. “turtle sign.” This subtle sign can be an indication of shoulder dystocia

• Risk factors

  • History of shoulder dystocia with previous deliveries

  • maternal diabetes, obesity

  • fetal macrosomia

  • prolonged second stage of labor

  • multiparity

  • BUT most cases of shoulder dystocia happen with normal sized babies and most vaginal deliveries with high birth weight do not result in shoulder dystocia i.e. shoulder dystocia occurs unpredictably

• Management

  • Call for help, activate code obstetrics (code 33) - mobilize Anesthesia, AA / RT, Obstetrics, Nursing and Neonatology

  • Supplemental oxygen via face mask

  • If available, top up epidural to provide analgesia for management maneuvers 

  • Goal of treatment is to perform maneuvers that increase the functional diameter of the pelvic ring, decrease the breadth of the fetal shoulders, or change the relationship of the breadth of the fetal shoulders within the pelvis

  • The pregnant woman should be instructed to stop pushing, move buttocks to end of the bed to aid management maneuvers e.g. McRoberts, suprapubic pressure

• Emergent; call for help, activate code OB, notify ICU

• Assess, diagnose and management simultaneously

• Multisystem involvement:

  1. Cardiovascular collapse, biventricular failure

  2. Pulmonary edema, hypoxia

  3. Altered mentation, LOC, seizure

  4. DIC , coagulopathy

• DDx:

  1. Obstetrical:

     • Eclampsia

     • Abruptio placenta

     • Uterine rupture

     • Peripartum cardiomyopathy

  2. Non-obstetrical:

     • PE

     • Myocardial infarction

     • Sepsis

     • Anaphylaxis

     • Venous air embolism

  3. Iatrogenic:

     • High spinal

     • Local anesthetic systemic toxicity

     • Medication error

• Establish definitive airway for adequate ventilaion & oxygenation, 100% oxygen

• Central venous access for fluid resuscitation and/or intropes and pressors

• Arterial line for hemodynamic montoring and frequent blood sampling

• ACLS protocol with OB modification e.g. manual uterine displacement; on-scene peri-mortem cesarean section if no ROSC within 4 minutes of resuscitation

• Consider A-OK therapy (i.e. IV Atropine 1mg, Ondansetron 8mg & Ketorolac 30mg)

• Treatments focus on increasing cardiac output and pulmonary vasodilation, decreasing right heart strain, and providing massive transfusion of blood  products in case of DIC. Dobutamine, inhaled nitric oxide and inhaled prostacyclin are to be considered to assist with pulmonary vasodilation.

• Contact blood bank for C1 esterase inhibitor (C1INH).

• Increases maternal issues:

  1. Exaggerated aorto-caval compression, propensity to desaturation

  2. PPROM

  3. Preterm labor

  4. Prolonged labor

  5. Pre-eclampsia/eclampsia

  6. Placental abruption

  7. Operative delivery

  8. Uterine atony

  9. Antepartum & PPH

• Fetal issues:

  1. Premature delivery

  2. IUGR

  3. Twin-twin transfusion

  4. Polyhydramnios

  5. Cord entanglement

  6. Umbilical cord prolapse

  7. Malpresentation

• Trial of labor & vaginal delivery

  1. To be performed in OR with double setup in preparation for possible C-section

  2. Adequate epidural analgesia

  3. 2 large bore IV's

  4. Prepared for STAT C-section with GA

  5. Diluted nitroglycerine available for uterine relaxation to facilitate internal version & breech extraction

  6. NICU personnel present

• Cesarean section

  1. 2 large bore IV's & cross matched

  2. Modes of anesthesia - epidural, spinal, & GA depending on risks vs benefits

  3. Be prepared for exaggerated aortocaval compression & rapid desaturation

  4. Nitroglycerine ready for uterine relaxation

  5. Be prepared for post partum hemorrhage, need for resuscitation & uterotonics

  6. NICU personnel present

• Leading cause of non-obstetrical maternal mortality; non-lethal injuries 1 in 12 pregnant women

• MVC, fall, domestic violence and other non-accidental causes etc. GSW, stabbing

• Every female of reproductive age with significant injuries should be considered pregnant until proven otherwise

• Emergent; assess, diagnose and manage simultaneously

• Urgent Ob / neonatology consult especially at a viable age i.e. 23 weeks or older

• Pregnancy considerations: two patients, aortocaval compression, full stomach, difficult airway, baseline compensated respiratory alkalosis etc.

• Trauma considerations: multi-system involvement, hemodynamic instabilities, potential C-spine injury, potential facial / neck injuries impacting on airway management, chest injuries causing respiratory / hemodynamic compromise, full stomach, substance intoxication, possible TBI, hypothermia etc.

• Standard trauma algorithm, assessment and resuscitation priorities regardless of pregnancy; maternal well-being takes precedence ⇒ maintain uteroplacental perfusion and avoid fetal hypoxia and acidosis

• Early aggressive intravascular repletion and volume resuscitation in case of hypovolemic shock; vasopressor use could compromis placental perfusion

• History:

  1. AMPLE

  2. Mechanism of injury

  3. Past obstetrical history and course of the current pregnancy

  4. Vaginal discharge / bleeding, abdominal pain, intensity / frequency of contraction, maternal perception of fetal movement

• Physical Exam:

  1. Follow standard ATLS primary, secondary and tertiary servey

  2. Avoid aortocaval compression by left lateral tilt, manual displacement while supine or lateral tilt with backboard for spine precaution

  3. Paying particular attention to physiologic change in pregnancy: reduction in FRC and increased minute ventilation ⇒ prone to desaturation, increased plasma volume by 50% leads to delayed recognition of hemorrhagic shock, baseline tachycardia 15-20 bpm elevation by 3rd trimester

  4. Palpate uterus for fundal height, shape, hypertonus and tenderness

  5. With viable fetus (23 weeks or older), cardiotocography or electronic fetal monitor for at least 4 hours

  6. Ob to perform vaginal exam for cervical dilatation, effacement, fetal presentation / station; in case of vaginal bleeding, speculum or digital vaginal examination should be deferred until placenta previa is ruled out by U/S

• Lab & Investigations:

  1. Standard trauma panel; note normal pregnancy changes e.g. elevated WBC up to 20, dilutional anemia down to 100, reduction in creatinine, elevated ALP up to 140

  2. Coagulation profile including fibrinogen; note normal increase in fibrinogen during pregnancy up to 4+

  3. X-ray or CT studies as indicated for maternal evaluation and should not be deferred due to concerns regarding fetal exposure

  4. FAST is equally sensitive and specific

• Pregnancy specific concerns:

  1. Placental abruption

     • Could happen in even minor trauma ⇒ maintain high index of suspicion

     • Abdominal pain, uterine tendernes, uterine contraction, vaginal bleeding, preterm labour, abnormal EFM tracing

     • Bleeding could be concealed witout uterine tnederness or vaginal bleeding

     • Treatment shoud never be delayed for ultrasound confirmation since ultrasound is not sensitive for diagnosing placental abruption

     • Mostly managed with prompt C-section unless both monther and baby are stable

  2. Uterin rupture

     • Rare; 0.6% of all maternal injuries

     • Most ruptures involve the fundal area

     • Maternal shock, abdominal distension, irregular uterine contour, palpable featal parts, sudden abnormal fetal heart rate pattern, peritoneal irritation (abdominal rigidity, guarding and tenderness)

     • Highly morbid for mother and baby

     • Urgent laparotomy

  3. Preterm labour

     • Can be triggered by placental abruption, PPROM etc.

     • Nitrazine paper or ferning test ?ROM

     • Fetal fibronectin test ?preterm labour

     • Systemic steroid for fetal lungs maturation and MgSO4 for neuro protection

     • Neonatology consultation

  4. Amniotic fluid embolism

     • Rare

     • Catastrophic hemodynamic and respiratory collapse

     • Supportive maternal care

     • Expedited C-section delivery depending on gestational age

  5. Prevention of Rh alloimmunization

     • Rh antigen is well developed by 6 weeks gestation

     • 0.001ml of fetal blood can casue sensitization in Rh- mother

     • Anti-D IgG 300ug should be administered to all Rh- pregnant trauma patients within 72 hours on injury

     • KB test might be warranted to quantify amount of transplacental hemorrhage, if more than 30ml of fetal blood in maternal circulation, additional dose of anti-D IgG

  6. Perimortem C-section

     • Within 4 min following maternal cardiac arrest while maintaining CPR / maternal resuscitation

     • Recommended for viable fetus at or older than 23 weeks or fundal height 2 or more fingerbreadths above umbilicus

     • Should be performed at the scene of cardiac arrest instead of transferring to OR

• Chest tube placement - due to elevation of disphragm by gravid uterus, insertion sites should be 1-2 intercostal spaces higher to avoid intra-abdominal placement

• Tetanus shot prn; safe during pregnancy

• 1-2% of all pregnancy e.g. laparoscopic cholecystecomy, appendectomy

• Pregnancy considerations

• Latest 2019 April ACOG Committee Opinion

  No currently used anesthetic agents have been shown to have any teratogenic effects in humans when using standard concentrations at any gestational age

  A pregnant woman should never be denied medically necessary surgery or have that surgery delayed regardless of trimester

  Pregnant women undergoing nonobstetric surgery should be screened for venous thromboembolism risk and should have the appropriate perioperative prophylaxis administered

• Elective surgery should be delayed after delivery

• Ob +/- neonatology consult

• Goal to maintain uteroplacental perfusion; avoid hypotension, hypoxemia, acidosis

• Avoid NSAIDs (aspirin, ibuprofen, naproxen, diclofenac, and celecoxib) at 20 weeks or later gestation; potential risk of causing fetal renal issue leading to oligohyraminos. NSAIDs at 30 weeks and later is also not recommended because of the additional risk of premature closure of the fetal ductus arteriosus. These recommendations do not apply to low dose (81 mg) aspirin for specific pregnancy-related conditions under the direction of a healthcare professional, or to NSAIDs administered directly to the eye.

• Neuraxial technique generally preferred

• If GA & mechanical ventilation, remember ABG during pregnancy (pH increases 7.4-7.47, PaCO2 decreases 30mmHg, PaO2 increases 105mmHg, HCO3- decreases 20mmol/L)

• In previable fetus (< 24 weeks), FHR by doppler pre and post surgery is sufficient

• For fetus > 24 weeks, FHR monitor & toco monitor pre and post surgery to ascertain fetal well being & sign of preterm labour. Introperative FHR monitor is rarely needed.

• Risk of preterm labour - consider steroids (Celeston) for lung maturity & magnesium for brain protection

• Surgical considerations of a gravid uterus e.g. trocar insetion

• Timely multidisciplinary involvement i.e. neurosurgery, obstetrics, neonatology, anesthesiologists specialized in obsetrical / neuroanesthesia

• Maternal considerations / well-being should take precedence in cases of emergent surgeries, irrespective of trimester

• Immediate assessment (etiologies, severity, co-morbidities, gestational age, pregnancy related issues, AMPLE history, physical & airway exam, baseline GCS) and concurrent management

• Paramount to minimize exacerbatioin of ICP, maintain cerebral & uteroplacental perfusion pressures

• Keep in mind lower normal PaCO2 during pregnancy (≤ 32mmHg)

• Goals to prevent secondary brain injury i.e. avoid hypoxemia, hypercarbia, hypotension, hyper / hypoglycemia, hyperthermia

• Minimize contrast load and radiation during cerebral angiography e.g. single vessel angiogram, abdominal shield. Or consider MRA for initial evaluation

• No evidence of mutagenic or teratogenic effects of iodinated contrast (category B i.e. no harm to animals, no human studies)

• Previable fetus, doppler is sufficient for fetal HR monitoring; for viable fetus, cardiotocography should be performed (before and after the procedure or positioning e.g. prone)

• For viable fetus with fetal pulmonary maturity, multidisciplinary decision regarding timing of delivery (mostly C-section) and surgical intervention i.e. before, after or concurrent

• Delivery before surgical intervetion has the theoretical advantage of eliminating concern for adverse fetal outcome related to interventions during surgery e.g. hyperventilation, induced hypotension, mannitol use etc.

• Neuraxial anesthesia is contraindicated in confirmed or suspected raised ICP

• Also potential dural puncture with a large bore Tuohy needle with subsequent intracranial hypotension causing traction on the dura could result in rebleeding in certain cases

• ICH

  1. Aneurysm

     • More than 70% of ICH during pregnancy

     • Patients with known (intact) intracranial aneurysms, the risk of rupture during pregnancy and delivery is NOT increased; most (70%) patients will be delivered via elective C-section

     • However, ruptured aneurysm should be treated within 48 hrs of presentation; i.e. neurosurgical considerations should trump obstetrical consideration in ruptured aneurysms

     • Ruptured aneurysms more likely happen in 3rd trimester

     • Treatment modalities i.e. clipping vs coiling

     • Low dose mannitol (0.5 g/kg) has been used safely during pregnancy

     • During temporary clipping, induced hypertension (20% above baseline) and neuroprotective agents e.g. propofol boluses

  2. AVM

     • About 20% of peripartum ICH

     • Increased risk of hemorrhage from pre-existing AVM during pregnancy (2nd & 3rd trimesters). Most would still recommend conservative management of unruptured AVMs in pregnant women

     • In cases of ruptured AVM, neurosurgical emergeny if herniation, acute hydrocephalus. Otherwise, need to balance fetal risk vs re-bleeding risk to decide whether to operate or expectant management. Case series has shown increased fetal and maternal mortality with conservative management

     • Treatment modalities i.e. endovascular +/- surgical resection

• Tumors

  • Rare, no increased in frequency of brain tumors in pregnancy

  • Expenctant management in benign / asymptomatic growth

  • Malignant and / or symtomatic (mass effect) ⇒ surgical intervention

  • Anesthesia goals similar to non-pregnant patients while be mindful of maintaining uteroplacental perfusion & avoidance of aortocaval compression

• TBI

  • Similar goals to non-pregnant patient, maintain uteroplacental perfusion and left uterine tilt

  • Avoid exacerbation of ICP i.e. head up 15-30 degrees, TIVA, avoid nitrous oxide, blunt hemodynamic response to intubation / pinning, avoid neck venous obstruction

  • In case of herniation, transient hyperventilation

  • Mannitol: pregnancy category B (no harm to animals, no human studies); hypertonic saline: pregnancy category C (no studies in animals or humans)

• Potentially urgent / emergent depending on hemodynamic stability and symptomatology

• Even in stable patients, arrhythmias during pregnancy warrant timely assessment / diagnosis / management

• History - cardiac symptoms e.g. dyspnea, SOBOE, chest pain / angina, PND, orthopnea, palpitation, syncope, presyncope; PMHx - CHD, structural heart disease, medication, past symptom; Family history of cardiac disease, sudden cardiac death

• Physical exam - vitals, SpO2, pre-cordial exam, respiratory exam

• Establish IV access; defibrillator in the room, mobilize anesthesia, AA, nurses, rapid response

• Investigations - 12-leade ECG, extended electrolytes, CBC, TSH; echocardiogram

• Cardiology consult +/- telemetry

• 0.1% of all pregnancy-related admissions are associated with arrhythmia; but it is not uncommon for pregnant patients to experience palpitation or some form of arrhythmias during pregnancy, however, most do not require admission

• Most frequent diagnosis sinus arrhythmia (60%), followed by atrial or ventricular extrasystole (19%) and paroxysmal supraventricular tachycardia (PSVT) (14%). Atrial fibrillation (AF) and atrial flutter (AFL) (1%), ventricular fibrillation (VF) (1%), and high-degree atrioventricular (AV) block (1%)

• Pregnancy related hemodynamic, hormonal and autonomic changes promote arrhythmias during pregnancy especially in older patients and patients with congenital or structural heart diseases

  

• Approach to the treatment of arrhythmias in a pregnant patient is largely similar to the approach in a nonpregnant patient, but with modifications based on fetal safety e.g. drugs exposure, avoid radiation (PPM placement or cardiac ablation), left uterine tilt and shared decision-making among care team i.e. Ob, cardio-obstetrics, electrophysiology, neonatology, anesthesia

  

  

• In pregnant patients with unstable SVT or VT, direct current synchronized cardioversion or defibrillation is recommended with energy dosing as in the nonpregnant patient. Electrodes should be placed to avoid breast tissues to optimize current delivery to the heart.

• In pregnant patients with hemodynamically significant sustained cardiac arrhythmias refractory or with contraindications to pharmacological therapy who are candidates for catheter ablation, the benefit of controlling maternal tachycardia should be prioritized over the potential radiation risks to the fetus, especially if the procedure is done after the first trimester and radiation exposure is minimized to as low as reasonably achievable. In many cases, ablation can be performed without fluoroscopy.

• In pregnant patients with cardiac arrhythmias, the route of delivery (vaginal or caesarean) should be determined by the birth plan and obstetrical factors in accordance with best clinical practice, along with continuation of antiarrhythmic drug therapy.

• Adequate pain control during labor, ideally with the use of neuraxial / epidural anesthesia, to avoid pain-induced catecholamine surges that may exacerbate arrhythmias

• PSVT

  • In pregnant patients with acute onset of SVT, vagal maneuvers are recommended as first-line therapy for tachycardia termination.

  • In hemodynamically stable pregnant patients with acute onset of SVT, intravenous adenosine is recommended as the first-line pharmacological therapy.

  • In hemodynamically unstable pregnant patients with acute onset of SVT, synchronized direct current cardioversion is recommended, with energy dosing as in the nonpregnant patient.

  • In hemodynamically stable pregnant patients with acute onset of SVT refractory or with contraindications to adenosine, intravenous beta-blockers, such as metoprolol or propranolol, are reasonable for termination of acute SVT.

  • In hemodynamically stable pregnant patients with acute onset of SVT refractory or with contraindications to adenosine or beta-blockers, intravenous calcium channel blockers, such as verapamil or diltiazem, or intravenous procainamide may be considered.

    

• Atrial Fibrillation / Flutter

  • Unstable hemodynamics, direct current cardioversion is recommended, with energy dosing as in the nonpregnant patient.

  • Hemodynamically stable pregnant patients with AF or AFL with rapid ventricular rates, intravenous beta-blockers are recommended as the first-line option and digoxin or nondihydropyridine calcium channel blockers, alone or in combination, are recommended as second-line options for initial rate control

  • Persistent symptoms or rapid ventricular rate refractory or with contraindications to beta-blockers or calcium channel blockers, elective direct current cardioversion is recommended with anticoagulation with LMWH (Warfarin [>5mg] & DOAC are contraindicated during pregnancy) as in nonpregnant patients.

  • In pregnant patients with AFib or AFlutter and additional risk factors that place them at high risk for thromboembolism, anticoagulation is recommended as in the nonpregnant patient.

  • Recurrent hemodynamically unstable AFib or atypical AFlutter in whom pharmacological therapy is ineffective or contraindicated, catheter ablation may be considered with attention to and techniques for eliminating or minimizing radiation exposure to as low as reasonably achievable.

    

•  V Tach

  

• Bradycardia / Heart Block

  

• Summary

  

• Recommended ACLS chest compression technique and defibrillation protocol is no different from the non-pregnant guidelines

• Epinephrine is preferred over vasopressin. Otherwise, ACLS drugs, including amiodarone, should be administered without modification

• BLS and ACLS with following caveats / modifications:

  • Gestation age > 20 weeks or uterine fundal height above umbilicus ⇒ pulseless pregnant patient should be placed in supine position with manual left uterine displacement maneuver

• • NICU team should be involved without delay

  • Perimortem cesarean delivery should be initiated after four to five minutes from the onset of cardiac arrest at the location that the arrest occurred

  • Intravenous access should be obtained above the diaphragm if possible

  • If a fetal scalp electrode is present, this should be removed prior to defibrillation if possible