Class anaesthesia for emergency cs

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Class anaesthesia for emergency cs

  1. 1. Anaesthesia for Emergency Caesarean SectionGUIDE: Dr. Mukesh SomwanshiPRESENTER: Dr. Khushboo
  2. 2. Cesarean Section-Introduction C/S rate 30% at US (18% in India) Emergency CS makes up about 2% of births Guideline of ACOG &ASA- CS be started within 30min of recognition for its need. More likely to be met if patient in theatre within 10 minutes of decisionDavies and Collis 2007 20 patients had GA for Grade 1CS 4/20 actually needed GA 10/20 could have regional 6/20 did not need a caesarean section
  3. 3. Anaesthesiarelated mortality• 3-12% maternal death• Sixth leading cause of maternal mortality ◦ Majority during G/A: failed intubation, ventilation, oxygenation and pulmonary aspiration of gastric content ◦ Risk factors: age>34yrs, nonwhite group, obesity, multiple pregnancy, hypertensive disorder of pregnancy, previous PPH, emergently performed
  4. 4. Caesarean Section-Grading Grade 1:An immediate threat to the life of the mother or fetus-Emergency Grade 2:Maternal or fetal compromise that was not immediately life threatening- Urgent Grade 3:The mother needed early delivery but there was no maternal or fetal compromise-Scheduled Grade 4:Delivery was timed to suit the mother or staff-Elective
  5. 5. Davis guideline• Davis related urgency of CS with method of anaesthesia.• If time of decision to operate to time of delivery desirable is-A. <30min:GAB. 30-45min:SABC. 45-60min:extension of existing epiduralD. 60-90min:new epidural block
  6. 6. Caesarean section- elective(grade-4)Indication: A. Labour unsafe for mother and fetus: Risk of uterine rupture-previous CS Risk of maternal h’age B. Dystocia Abnormal presentation Fetopelvic disproportion Dysfunctional uterine activityAnaesthesia:• Epidural-If epidural catheter already introduced• Spinal-either single shot or CSE
  7. 7. caesarean section-Scheduled(Grade-3)Indication: Chronic uteroplacental insufficiency Abnormal fetal presentation with ruptured membrane (not in labor)Anaesthesia:• Epidural-if already established top up• Spinal-if epidural not established• General-if regional contraindicated
  8. 8. Cesarean Section-Urgent(grade-2)Indication: Dystocia Failed trial of forceps Active genital herpes infection with ROM Previous classical C/S and active labor Cord prolapse without fetal distress Variable deceleration with prompt recovery and normal FHR variabilityAnaesthesia:• Extension of preexisting epidural• Spinal-if time permits but no repeated attempts• general-if regional contraindicated
  9. 9. cesarean section-emergency(grade-1) Indications: Massive maternal hemorrhage Ruptured uterus Cord prolapse with fetal bradycardia Agonal fetal distress (e.q., prolonged bradycardia or late deceleration with no FHR variability)Anaesthesia: General anaesthesia unless preexisting epidural anesthesia can be extend satisfactorily
  10. 10. Proactive AnaestheticManagement Identify those at risk of anaesthetic complications Preconception During Pregnancy During labour (ward rounds) Particular Concerns Obesity Recent migrants Language, Social Issues, Undiagnosed/Untreated Illness Sepsis Preeclampsia
  11. 11. In Utero Fetal Resuscitation Syntocin off Position full left lateral Oxygen I.v. infusion of 1 litre RL Low blood pressure: i.v. vasopressor Tocolysis: -Terbutaline 250 μg (s.c), Glyceryl trinitrate 400 μg (metered aerosol doses) Monitor Fetus-It may get better
  12. 12. Anesthetic technique Spinal anesthesia Epidural anesthesia Combined Spinal-Epidural anesthesia General anesthesia
  13. 13. What Anaesthetic Technique?• Choice depends on Indication for the surgery The degree of urgency Maternal status Desire of the patient Overwhelming preference of RA for maternal safety GA -associated with significantly shorter DDI -associated with 16.7X greater risk of death -should be used only when absolutely necessary Risk for fetus?Is there time for Regional
  14. 14. Pre-Existing Epidural Is there an epidural in place? -Is it working? -Should I remove the epidural and put in a spinal/CSE• Do I have time for a spinal/CSE de novo - Anaesthetic factors -Patient factors Has it had a test dose? -Could it be intrathecal? -Could it be intravenous? When was this last topped up? Has it ever worked? Topping up an epidural -How Much?-20mls, Divided doses?
  15. 15. General points Assess all patient for GA Consent form signed Explain the procedure to patient LUD maternal position Secure a large bore IV cannula Give IV fluid RL 15-20ml/kg in 30min In urgent situation don’t wait Give antacid therapy Effect of Block form T4 to S5 Agree the start of op with surgeon Avoid medication before the delivery of baby Oxytocin 5IU slow IV after delivery of baby and Infusion of oxytocin 20IU in 500ml RL for 4hrs Monitoring : ECG, NIBP, pulse oximeter, fetal monitoring Additional monitors for GA: ETCO2, nerve stimulator, temp probe
  16. 16. Spinal Anaesthesia• Position-sitting/lateral• Insert spinal needle with aseptic precaution in L3-4 or L4-5 interspace• Inject 2-3ml bupivacaine 0.5% heavy alone or with adjuvant• Lie the mother in left lateral tilt• Monitor BP in every 2min• Avoid fall in BP• vasopressor if reqired Phenylephrine or epheridine• Check the effect and Allow to start
  17. 17. DRUGS USED FOR SPINAL ANAESTHESIAChoice of drug: 2-3ml of 0.5% heavy bupivacaine +/-additive: 200-300mcg morphine :5-10 mcg sufentanil : 10-25mcg fentanyl Drug DOSAGE(mg) Duration(min)Lignocaine 50-60 45-75Bupivacaine 10-15 60-120Tetracaine 7-10 120-180Procaine 100-150 30-60Adjuvant drugsMorphine 0.200-0.300 360-1080Fentanyl 0.010-0.025 180-240Sufentanil 0.005-0.010 180-240
  18. 18. Spinal anaesthesiaAdv:  Simple  Rapid onset  Dense blockade  Awake patient  Negligible maternal risk of systemic local toxicity  Minimal transfer of drug to infant  Negligible risk of local anesthetic depression of infant  No risk of failed intubation/aspiration
  19. 19. Disadv:  Rapid onset of sympathetic blockade – abrupt, severe hypotension  Recovery time may be prolonged (if procedure shorter than anticipated)  Could not prolong the anaesthesia  Airway not secured for emergency  Not possible for emergency
  20. 20. Epidural Anaesthesia• Not the first choice for CS;only used if epidural in situ for labour• Check the epidural position and patency• Top up with local anaesthetic agent with or without adjuvant as 20-30ml solution slow bolus• Monitor the BP(hypotension less likely but if occur treat with ephedrine or phenylephrine)• If time allow use gold standard method(5ml increment in 5min)
  21. 21. DRUGS USED FOR EPIDURAL ANAESTHESIAChoice of drugs:1. 20 ml lignocaine 2% + 1:200,000 adrenaline (slightly fasteronset)2. 20 ml (levo-)bupivacaine 0.5% (slightly better quality block?)3. 10 ml lignocaine 2% + 1:200,000 adrenaline + 10 mlbupivacaine 0.5% (the best of both worlds?) Drug Dosage (mg) Duration (min) 2% lido with epineph 300-500 75-100 2-chloroprocaine 450-750 40-50 0.5% Bupivacaine 75-125 120-180 0.5% Ropivacaine 75-125 120-180 Adjuvant Drugs Morphine 3-4 720-1440 Fentanyl 0.050-0.100 120-240 Meperidine 50-75 240-720 sufentanil 0.010-0.020 240-720
  22. 22. Epidural anesthesiaAdv:  Titrated dosing and slower onset (volume dependent, not gravity dependent) risk of severe hypotension and reduced uteroplacental perfusion  Incremental dose (for longer operation) Duration of surgery not an issue  Less intense motor blockade good for pts with multiple gestation or pulmonary disease  Lower extremity “muscle pump” may remain intact may incidence of thromboembolic disease
  23. 23. Disadv: • Dural puncture :1/200-1/500 in experienced hands, higher in training institution • If unintentional dural puncture, PDPH • Slower onset • Cant use for emergency situation if epidural catheter is not introduced previously • Risk of systemic local toxicity
  24. 24. Combined spinal epidural Not used commonly Either needle through needle or seperate space technique Two different technique used: -normal spinal dose and epidural for back up or; -small intrathecal dose with extension through epidural Monitor the BP
  25. 25. combined spinal epiduralAdv:  Rapid onset and density of spinal anesthesia combined with versatility of epidural anesthesiaDisadv:  Potential for high spinal  Inability to test epidural catheter  Higher spinal failure rate  Only 1 published report of presumed unintentional insertion of epidural catheter through dural puncture site  Not useful for emergency condition
  26. 26. M/m of inadequate regional block If can not do spinal-> try epidural If can not do epidural-> try spinal If can not do regional->call for help or; give GA If pt c/o pain intraop -if epidural in place give topup of LA+/-opioid -small increment dose of iv opioid (if post delivery) -low dose ketamine 0.25mg/kg -if pt does not respond GA -iv midazolam if pt anxious post delivery but having good analgesia
  27. 27. Complication1.Hypotension: 20-30% decrease in BP or <100mm Hg d/t sympathectomy+a-c compression t/t-IV fluid bolus -LUD -Supplemental oxygen -iv bolus of ephedrine(5-15mg) or phenylephrine(25-50mcg)
  28. 28. 2.Unintentional IV injection:a)Lignocaine and chloroprocaine presents as frank seizuresm/m-thiopental50-100mg /propofol small dose -maintenance of airway and oxygenationb)Bupivacaine cause rapid and profound cardiovascular collapsem/m-amiodarone -cardiac resuscitation
  29. 29.  3.Unintentional intrathecal injection: (Total spinal) If recognised immediately try to aspirate Pt placed supine with LUD Treat hypotension with iv fluid and vasopressors If high spinal intubate and ventilate with 100%oxygen
  30. 30.  4.PDPH Mostly after unintentional dura puncture m/m-bed rest;hydration; oral analgesic -epidural saline injection(50ml) -caffiene sodium benzoate(500mg iv) -epidural blood patch(15-20ml)
  31. 31. General anaesthesia• More than 90%of CS are in regional because increased mortality and morbidity with GA• Indications for GA:1. technical failure of regional technique2. contraindication to regional technique - pt refusal - sepsis -hemodynamic instability -raised ICP -abnormal coagulation3. surgical indication (eg. anterior placenta previa with previous CS)4. obstetric indication (eg. severe fetal distress)
  32. 32. Pre operative Fast pre-op assessment Essential equipment to be carefully checked and laid out before induction of anaesthesia-Macintosh laryngoscopes: 1 standard blade, 1 long blade and 1 polio blade or short handle-McCoy levering laryngoscope-Endotracheal tubes (ETT) with a range of sizes 6 – 8-Oral and nasopharyngeal airways-Malleable introducer-Gum elastic bougie-Laryngeal mask airway (LMA) and ProSeal laryngeal mask-Cricothyroidotomy set-Wedge for prevention of a-v
  33. 33. Premedication Antacid regimen:Elective-rantidine150mg orally 2hrs preop-0.3 molar sodium citrate 30ml orally-10mg metoclopromide orallyEmergency-rantidine50mg diluted in 20ml saline slow iv-0.3 molar sodium citrate 30ml orally• Antisecretory: Glycopyrrolate 0.1mg iv• No opioids or BZDs before delivery of baby
  34. 34. Rapid sequence InductionPreoxygenate(O2 6 l/min for3 mins/4 vital capacity breaths)IV Thiopentone 250 - 350 mg (4-5mg/kg)In hypotensive crises Ketamine(1-1.5mg/kg)Start cricoid pressure as consciousness lost &maintain till intubateSuccinylcholine 50-100 mg(1-1.5mg/kg)Intubation with a smaller ETT size 6-7mm Cuff inflated and found to be leak free. CHECK POSITION OF ENDOTRACHEAL TUBE (ETT)
  35. 35. Maintenance• Before delivery of baby 50% nitrous oxide + 50% oxygen pre-delivery +volatile agent 0.5%halothane/iso/sevo NDMR atra/vec/roc(given once the suxamethonium has worn off check by peripheral nerve stimulator)• After delivery of baby 70% nitrous oxide + 30% oxygen +/-volatile agent 0.5%halothane/iso/sevo Once umbilical cord clamped–oxytocin 5IUstat;10-20 IU oxytocin in 500 mL crystalloid at40-80 mIU/min IV Opioid
  36. 36. Recovery Residual NM blockade reversal (2.5mg neostigmine + 0.5mg glycopyrrolate) If mother full stomach-empty by nasogastric tube prior to extubation and remove nasogastric tube before extubation Extubate only once mother awake Morphine via a patient controlled analgesia for postop analgesia
  37. 37. Atonic uterus If atony does not respond to oxytocin: ◦ Methylergonovine 0.2 mg IM ◦ 15-methylprostaglandin F2-alpha 250 ug IM or IMM ◦ Discontinue volatile agentErgots: ◦ Severe hypertension ◦ Avoid in hypertensivePGF2α: ◦ N+V, diarrhea, fever, tachypnea, tachycardia, hypertension, bronchoconstriction
  38. 38. DIFFICULT INTUBATION•If2 or more adverse findings->consider regional•IF GA essential FOI/retrograde intubation•Limit succinylcholine to one dose unless the larynx can beseen and an adequate airway maintained with a facemask•There should normally be a maximum of 3 attempts beforeproceeding to a failed intubation drillTEST ADVERSE FINDINGSMouth opening < 4 cm (< two fingers)Extension at the atlanto-occipital joint- in the standard intubating position Little detectable movement at thegentle manipulation may reveal up to atlanto-occipital joint30 degrees of movementMallampati view of the pharynx withmouth open and tongue maximally grade III or more (uvula not seen)protrudedThyromental distance measured with < 6 cm (<three fingers)the head fully extended and mouthclosed
  39. 39. Failed intubation drill
  40. 40. Pulmonary aspiration syndrome/ mendelson’s syndrome Presentation: Bronchospasm, tachypnea, cyanosis, tachycardia, resp.distress Dx: CXR-patchy pulm infiltrate to pulm edema oxymetry-decreased oxygen saturation Prev:-avoid GA -avoid excessive sedation -antacid regimen -preoxygenation -correct cricoid pressure -skilled and rapid intubation -gastric emptying before extubation -awake extubation;lateral tilt after
  41. 41. >25 ml of gastric contents with a pH of <2.5 are considered to be critical factors M/m:-vigorous and immediate -suction of airway -increase inspired oxygen conc. -treat bronchospasm with salbutamol 250mcg iv or aminophylline 250mg iv -support circulation with ionotropes e.g;dopamine -manage in ICU with oxygen administration; chest physiotherapy;and if necessary IPPV
  42. 42. General anaesthesiaAdv: Fast; Reliable (if you get the tube in) Almost never fails Duration is flexible Controlled airway and ventilation Doesn’t cause sympathectomy Patient is not awake (to experience problems) Minimal cooperation needed from the
  43. 43. General anesthesiaDisadv: Risk of failed intubation and“can’t intubate, can’t ventilate” scenario. Risk of maternal aspiration and neonatal depression Patient not awake for birth. Nausea, post-op pain, sore throat Avoid GA in difficult intubation, hx of malignant hyperthermia, severe asthma Contribute to uterine relaxation or atony
  44. 44. General Anesthesia –Unconscious mother and awakeneonate? uptake by fetal liver (1st1) Preferential organ perfused by blood from umbilical vein)2) Higher relative water content of fetal brain3) Rapid redistribution of drug into maternal tissues rapid reduction in maternal – fetal conc gradient4) Non-homogeneity of blood flow to intervillous space5) Progressive dilution in fetal circulation
  45. 45. Effects of Anesthesia on Fetus andNeonate No significant difference in umbilical cord blood gas between general or regional anesthesia for elective or emergency cs Crawford – found uterine incision to delivery (U-D) interval is more important than I-D interval A U-D interval >3 mins associated with incidence of low umbilical cord blood pH and Apgar scores, regardless of anaesthetic technique
  46. 46. Conclusion High risk patients should be seen antenatally Anaesthetists should not feel bullied to achieve unsafe decision to delivery times Stay calm. Don’t endanger the mother to “save” the baby. DDI in grade 1 CS should be less than 75minutes and NOT less than
  47. 47. Thanks for yourattention!
  48. 48. Special cases- Fetal distress Signs: nonreassuring FHR pattern :fetal scalp Ph<7.20 :MSL :Oligohydroamnios :IUGR Anaesth m/m:100% oxygen by face mask :LUD :Epidural in situ-top up :GA
  49. 49. Cord prolapse Sign: sudden fetal bradycardia or profound deceleration m/m:Elevate presenting part :100% oxygen :LUD :GA with rapid sequence induction
  50. 50. Hypovolemic shock m/m of shock Induction with etomidate(100mcg/kg) or ketamine(1.5mg/kg) 100% oxygen
  51. 51. Antepartum Haemorrhage Prevent active uterine contraction GA If - Active bleeding/coagulopathy -previous cs -risk of placenta accreta -haemodynamically unstable• RA if-placenta not encroaching ant wall -haemodynamically stable• Secure two large bore iv cannula• Iv fluid deficit vigorously corrected• Blood must be available• CVP Monitoring
  52. 52. Pregnancy induced HypertensionI. Pre-eclampsiaII. EclampsiaIII. HELLP (Hemolysis, Elevated Liver Enzyme, and Low Platelets)Anaesthesia:• Mild-standard anaesthetic practice• Severe-GA but Continuous epidural anaesthesia first choice• Seizures m/m-MgSO4
  53. 53. Important points in PIHRA-avoid if platelet<1lac/dl -Colloid fluid bolus before epidural activation -Avoid Epinephrine containing test dose -Hypotension treated with small dose of vasopressors (ephedrine5mg)GA-Difficult intubation -IV nitroprusside, trimethaphan or nitroglycerin to control BP during GA -IV Labetalol 5-10mg at the time of intubation
  54. 54. Maternal heart disease Aim:minimise wide fluctuation in HR and CO :Intensive monitoring• Anaesthesia: epidural anaesthesia is method of choice Judicious IV administration of crystslloid Small bolus dose of phenylephrine If GA-beta blocker and iv opioid before induction -rapid sequence induction with etomidate -maintenance with
  55. 55. Others Instumental delivery:-if epidural established : top up-spinal-GA: If regional not possible• Manual removal of placenta:-if haemodynamically stable : Regional-if not stable : GA(avoid excess conc of volatile agent)• Evacuation of retained product-spinal-If GA no need of intubation(mask
  56. 56. General Anesthesia –InductionAgentsThiopental • Extensive published data • Safe in obstetric pts • 4 mg/kg • Rapidly crosses placenta • Detected in umbilical venous blood within 30 secs • Equilibration in fetus rapid and occurs by time of delivery • With doses 4 mg/kg – peak conc in fetal brain rarely exceed threshold for
  57. 57. Induction agentPropofol Rapid, smooth induction of anesthesia Attenuates cardiovascular response to laryngoscopy and intubation more effectively than pentothal Does not adversely affect umbilical cord blood gas measurements at delivery Rapidly crosses placenta Rapidly cleared from neonatal circulation Detected low concs in breast milk Propofol and pentothol similar Apgar and neurobehavioural scores
  58. 58. Induction agentKetamine 1 mg/kg Rapid onset Analgesia, hypnosis, and reliably provides amnesia Good in asthma or modest hypovolemia 1 mg/kg does NOT uterine tone (larger doses do) Rapidly crosses placenta Similar umbilical cord blood gas and Apgar scores with ketamine or pentothal
  59. 59. General Anesthesia- muscle relaxantSuccinylcholine 1-1.5 mg/kg Muscle relaxant of choice for most patients Highly ionized and water soluble, only small amounts cross placenta so rarely affects neonatal NM function Pseudocholinesterase activity 30% in pregnancy, BUT recovery is not prolonged Vd offsets the effect of activity intragastric pressure by fasciculation
  60. 60. General AnesthesiaRocuronium 1 mg/kg Only very small amounts cross placenta Apgar and neurobehavioural scores not affected

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