Anaesthetic management of obstetric emergencies Dr M Booyens Mb,chb (ufs), da (sa) Medical officer – anaesthesia – RMS Hospital

Content Umbilical cord prolapse Antepartum Hemorrhage (APH) Postpartum Hemorrhage (PPH) Hypertensive disorders HELLP syndrome Amniotic fluid embolism Anaesthesia for obstetric patients Maternal resuscitation

Indications for emergency cesarian section True emergency vs urgent surgery Emergency (threat to mother, baby or both): Massive bleeding Umbilical cord prolapse Fetal distress Close communication with obstetricians Choice of anaesthetic technique Maternal safety Technical issues Personal experience

Signs of fetal distress Non-reassuring heart rate pattern Late decelerations Loss of variability Depth of decelerations and rate recovery Fetal Bradycardia (<80beats/min) Fetal scalp pH<7,2 IUGR Meconium stained amniotic fluid

Umbilical cord prolapse Cord is present in front of the presenting fetal part (cord presentation) Leads to cord compression and fetal asphyxia Risk factors Excessive cord length Malpresentations Low birth weight Grand parity (>5) Multiple pregnancies AROM

Management Immediate steep Trendelenburg position Pt can be placed in a knee position – not ideal for anaesthesia Manual elevation of presenting part by assistant Fetus is elevated to relieve pressure on the cord Palpate cord for pulsation to evaluate effectiveness Patient is prepared for a general anaesthetic If the fetus is not viable – vaginal delivery

Antepartum Hemorrhage Most common obstetric emergency High morbidity to mother and baby if not managed correctly Uterus receives 12% cardiac output Should be no delay in managing APH May be concealed Fetus at greater risk due to maternal haemorrhage Main problems Hypovolaemia Aneamia

Causes Abruptio Placentae Placentae previa Uterine rupture Bleeding associated with pain May be concealed retroplacental Small concealed bleeds may be treated conservatively, but monitored closely Placentae previa Painless bleeding Different degrees Uterine rupture Fetal distress Very painful Loss of contractions / uterine tone

Postpartum Hemorrhage Defined: Blood loss >500ml post delivery 4 T’s Trauma: Vaginal tract laceration Tumor: Retained products/placenta Tone: Uterine Atony or Inversion Thrombin: Clotting abnormalities

Management of Haemorrhage Have a protocol set-up prior Call for help Give supplemental oxygen via facemask If airway reflexes are lost or LOC = intubate Remember your pelvic tilt – aortocaval compression Two 14 G peripheral lines and blood for cross matching Fluid resuscitation with crystalloids and colloids Don’t fall behind Consider vasopressors if haemodynamically unstable Start appropriate monitoring of mother and fetus Keep the patient informed – if awake

Cont… Treat the cause – surgery General anaesthesia Blood transfusion as per situation Rule of thumb: aim for an Hb of 7 Individualize Try and wait until bleeding is controlled Hospital protocol for massive transfusion: 1:1:1 vs 3:1:1 Consider auto transfusion devices Correct coagulopathies with FFP, cryo and Plt Keep your patient warm! Continuous communication with obstetrician Early communication with ICU

Uterotonic drugs Oxytocin Ergometrine Synthetic Causes uterine contraction and peripheral vasodilation Mild antidiuretic effect Can be given IM or IV Rule of 3’s: 3U, every 3 min, times 3 Infusion: 30U in 1L R/L – titrate to effect an BP Ergometrine Ergot alkaloid derivative Nausea and vomiting common side effect Potent vasoconstriction – CI in hypertensive pt’s 0,5mg IM or 0,125mg IV (slowly)

cont Carboprost (Prostaglandin F2a) Misoprostol Effective uterine contractions Also causes nausea, vomiting and diarrhoea May produce bronchospasm 0,25mg intramyometrial or IM every 15 min Max dose of 2mg Misoprostol Very similar effect as carboprost Less potent bronchospasm Can be given sublingual or PR

Surgical interventions Rubbing of the uterus Bimanual compression of uterus Balloon cath of uterus (temporary) B-Lynch suture Ligation of uterine arteries Ligation of internal iliac arteries Hysterectomy Reserved as last line

Amniotic fluid embolism Incidence: 1:20000 deliveries Effects due to anaphalctic reaction to fetal tissue 86% mortality rate 50% in the first hour Amniotic fluid can enter through any break in the uteroplacental membrane Fetal debris, prostaglandins and leukotrienes are involved

Risk factors Age>25 Multiparous women Obstructed labour Multiple pregnancy Abruptio placentae Uterine rupture Placenta praevia

Symptoms Sudden onset of tachypnoea, cyanosis, shock and generalized bleeding. Three major pathophysiological manifestations Acute pulmonary embolism DIC Uterine atony Pulmonary oedema and right heart failure within the first 30min Often a diagnosis of exclusion, but should not be last on the differential

Management Mainly supportive ABC’s Deliver the fetus as soon as possible Mechanical positive pressure ventilation Inotropic support Invasive monitoring Coagulation monitoring and management Uterotonic drugs ICU admission

Hypertensive disorders Pregnancy induced Hypertension Chronic Hypertension Preeclampsia SBP>140mmHg or DBP>90mmHg after 20weeks gestation with proteinuria (>300mg/d) that resolves within 48h after delivery Superimposed preeclampsia Eclampsia Seizures HELLP syndrome

Pathophysiology Vascular dysfunction of placenta Leads to abnormal prostaglandin metabolism Elevated TXA2 and decrease in Prostacyclin TXA2 potent vasoconstrictor and promotor of plt aggregation Decrease production of nitric oxide and increase endothelin-1 Severe pre-eclampsia: BP>160/110 Proteinurea>5g/day Increased creatinine IUGR Pulmonary oedema CNS manifestations

Complications Neurological Hepatic Renal Pulmonary Cardiovascular Headache Impaired function Visual disturbances Elevated enzymes Hyperexcitability Hematoma Seizures Rupture Intracranial haemorrhage Renal Cerebral oedema Proteinuria Pulmonary Sodium retention Upper airway oedema Decreased GFR Pulmonary oedema Failure Cardiovascular Heamatological Decreased intravascular volume Coagulopathy Increased SVR Thrombocytopenia Hypertension Plt dysfunction Heart failure Microangiopathic hemolysis

Management Bed rest Sedation Antihypertensives MgSO4 Delivery!!!! B-blokkers: Labetalol 5-10mg IV every 10min Hydralazine 5mg Iv (max of 20mg) Ca-channel blokkers: Nifedipine 10mg oral MgSO4 Delivery!!!!

Anaesthesia Mild preeclampsia only requires caution and vigilance Normal anaesthetic practices Severe disease Hypertension controlled and hypovolaemia should be corrected prior to surgery Epidural is the golden standard – requires skill Plt count> 70 for regional techniques Invasive monitoring Hypotension should be treated with small doses of vasopressors Goal directed fluid therapy Nitrocine, labetalol or MgSO4 can be used to treat hypertension Magnesium potentiates muscle relaxants Calcium gluconate antidote

Eclampsia ABC’s Left lateral position – bag mask ventilation Obtain IV access Control seizures with 4g Magnesium IV over 5-10min Magnesium infusion @ 1g/hr Monitor levels Delivery with GA as soon as possible Consult ICU for post-op

HELLP syndrome Evidence of haemolysis Elevated liver enzymes Falling Hb without bleeding Haemoglobinuria Elevated bilirubin Elevated LDH Fragmentation on smear Elevated liver enzymes AST, ALT, GGT, ALP RUQ pain Falling or low plt count <100

Suggested technique for GA Supine position with wedge under right hip and ramped Preoxygenate with 100% oxygen for 3-5min Patient is cleaned and draped RSI Cricoid pressure Propofol 2mg/kg or Ketamine 1-2mg/kg iv SUX 1,5mg/kg Surgery is started once ETT is secured Avoid hyperventilation (keep ETCO2>25) Volatile agents: MAC 0,8 – avoid atomy Consider TIVA in cases were pt is at risk of atony Once neonate is born: give bolus of 3U oxytocin IV Opioids may no be given Consider post-op Abd wall blocks Patient is extubated fully awake and reversed in the head-up position

Maternal resuscitation – Key points After 20w gestation: wedge under right hip to minimize aortocaval compression Chest compressions done over sternum Fetus should be delivered as soon as possible Front room c/s Decreases aortocaval compression Improves survival of mom and baby Aspiration risk: intubate as soon as possible Consider obstetric causes of arrest with H’s and T’s Normal dosages of drugs should be used Adrenaline

Toxins (anaphylaxis/anaesthetic) Tension pneumothorax Thrombi H’s T’s Toxins (anaphylaxis/anaesthetic) Tension pneumothorax Thrombi Cardiac Pulmonary Bone cement Air Tamponade Trauma qT prolongation pulmonary hyperTension Hypoxia Hypovolaemia Hyper/HypoKalemia Hydrogen ion (acidosis) Hypothermia Hypoglycaemia malignant Hyperthermia Hypervagal

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