Ether Resources for Anesthesia Research and Education

OB Anesthesia Resources

  • Files
  • Phones
  • Labor
  • C-Sec/OR
  • Cog. Aids
  • Newsletter
  • Credits

Educational resources for the obstetric anesthesia rotation can be downloaded here.

ZIP File Click on the links below to download files.

The archive also contains the following files:

  1. OB Anesthesia Resident Manual 2008-2009 (MS Word) (PDF)
  2. OB Anesthesia Rotation Guide (MS Word) (PDF)
  3. LPCH Training Guide - SurgiNet Anesthesia (MS Word) (PDF)
  4. Placement of an Epidural for Labor Analgesia (View Online)

Obstetric Anesthesia at Stanford

L&D main desk

723-5403

OR A

725-7550

Attending phone

10865 (650. 7210865)

OR B

725-7551

Fellow phone

10866 (650. 7210866)

OR C

498-7101

Resident 1/on-call resident

10867 (650. 7210867)

 

 

Resident 2

10868 (650. 7210868)

 

 

Attending call room

725-7556

 

 

Resident call room

725-7538

 

 

Men’s bathroom code

7400

 

 

Women’s bathroom code

26262

 

 

Epidural cart code

1234

 

 

  • Labor Epidural
  • Labor CSE
  • Continuous Spinal

Epidural block

Overview

Epidural blocks may be performed at any stage of labor. The spontaneous delivery rate with these techniques is high, as patients can usually push well during the second stage of labor.  Dense surgical perineal analgesia is often not present for delivery with these techniques, but mild discomfort is usually well tolerated by patients who desire vaginal birth. 

Technique

  1. Place lumbar epidural catheter in the usual sterile fashion.  No routine lidocaine with epinephrine test dose is given unless there is suspicion of intravascular placement.  Dose incrementally, looking of signs of intravascular or intrathecal placement.  The risk of intravascular toxicity with incremental injection is very low, and analgesia will not result if the catheter is IV.  Observe for spinal block after 1st increment.
  2. 15 ml 1/8% (0.125%) bupivacaine + sufentanil 10 µg (or fentanyl 50-75 µg) given in two or three increments 2-3 min apart.  The first increment serves as a test dose: observe for spinal block prior to giving second increment.
    1. Most often, 15 ml of local is all that is needed at this point and you want to limit motor block early on.  However, some women require more. The key is to stay in the room and give more local until the patient is comfortable.
  3. Infusion and patient controlled epidural anesthesia (PCEA) settings    
    1. Continuous infusion: 8-15 ml/h (most use 12 ml/hr; higher infusion rates provide better sacral analgesia but more motor block)
    2. Bolus:  10-12 ml  (most use 12)
    3. Lockout: 12 min (it takes the pump almost 8 minutes to get the dose in)
    4. Air sensitivity: OFF
    5. 1 hour maximum: 3-4 boluses
    6. Instruct patient to request physician evaluation and bolus if no relief after 2 self-administered boluses within 40 min.

Troubleshooting

  1. If a wet tap occurs, thread the catheter to block further egress of CSF.  Inject 10 cc of sterile PF saline then pull catheter.  Epidural may be attempted again in different space.
  2. If pain relief is inadequate, bolus with bupivacaine (e.g. 7 to 10 ml of 0.125% bupivacaine, or 7 to 10 ml of 0.25% bupivacaine) and increase infusion rate and hourly maximum if necessary.  Consider a second bolus.  If the patient is still uncomfortable (not explained by rapid progression of labor), suspect intravascular placement and consider giving an epinephrine-containing test dose.  If negative, treat with a large dose of 0.25% bupivacaine or consider replacing the catheter. 
  3. For pain relief during the second stage:
    1. 10 ml of 0.25% bupivacaine if there is significant pain
    2. 10 ml of 0.125% bupivacaine if there is moderate pain.
    3. The key point here is to use enough volume to cover the sacral roots.

CSE: Combined Spinal/Epidural

Overview

Consider CSE …

  1. when rapid onset of intense analgesia is required, (e.g., in the multiparous or primiparous woman in rapidly progressing labor, complete dilation).  One rule of thumb is that any patient dilated beyond 6 cm with a pain score greater than 5 out of 10 should probably get a CSE.
  2. when no motor block is desired (i.e., in very early labor, when the patient wishes to ambulate, or when effective expulsive efforts are important)
  3. when loss-of-resistance is uncertain; spinal needle confirms correct placement
  4. in the technically difficult or uncooperative patient in whom a single shot spinal dose can be followed by placement of an epidural catheter when the patient is comfortable. 
  5. when replacing a failed epidural

Technique

  1. An initial dose of opioid + bupivacaine is administered via a long 26 gauge pencil-point needle introduced through the epidural needle. Rapid (within 6 min), profound analgesia results, lasting 90-120 minutes.
  2. Because these solutions are slightly hypobaric, THE PATIENT SHOULD BE PLACED HORIZONTAL, not in the usual head-up position, for about 30 minutes.
  3. Initial Labor Dose:  Intrathecal sufentanil 5 µg + bupivacaine 2 mg (0.8 ml of 0.25% plain) [dose range: IT sufentanil 2.5-7.5 µg and bupivacaine 1.25 - 2.5 mg.  Use smaller doses in very early labor and larger doses close to delivery.]
  4. Infusion/PCEA:  Do not bolus epidural initially.  Start epidural infusion as for labor epidural (see above).   Note that a test dose is not routinely given, as there is concern this may move the block up and result in an excessively high level. However, remember that the catheter has not been tested. If there is concern that the catheter might be intrathecal or intravascular, use a lidocaine with epi test dose right away to help rule out an intravascular catheter.  When a laboring woman is comfortable from the spinal injection, the sensitivity and specificity of the test dose is markedly increased.
  5. Monitoring:  FHR, BP as for epidural, SaO2 for the first 30 min.

Fetal bradycardia after CSE

  1. May occur somewhat more frequently than after epidural, most often in patients with preexisting fetal stress and those in tumultuous labor. This technique is therefore best avoided when there are preexisting FHR abnormalities or a non-reassuring FHR. Alternatively, one should expect fetal bradycardia any time after adequate analgesia is delivered to the patient, no matter which technique is used.
  2. The bradycardia may be due, in part, to uterine hypertonus resulting from diminution of beta-sympathetic tocolytic effect as epinephrine concentrations rapidly decline with the onset of analgesia.  Immediately discontinue oxytocin, administer oxygen and additional IV fluids, give nitroglycerin (located in the block cart) either as the sublingual spray (2 puffs, repeated as necessary) or IV as intermittent 100 µg boluses until uterine tone diminishes or blood pressure decreases. If uterine hypertonus persists, terbutaline 0.25 mg SC may be necessary. Administer phenylephrine if hypotension is present.

Continuous Spinal Anesthesia

  1. In case a catheter is inadvertently threaded into the intrathecal space during epidural placement or an intrathecal catheter is intentionally placed after an inadvertent wet tap, consider …
    1. intermittent doses of sufentanil (2.5 mcg) and bupivacaine (1.25 mg) or
    2. bolus as for labor CSE (sufentanil 5 µg + bupivacaine 2 mg (0.8 ml of 0.25% plain) and run a continuous infusion of our regular 0.0625% bupivacaine plus sufentanil 0.4 mcg/ml at 1 to 3 ml/hour
  2. Make sure to label the pump and catheter with conspicuous signs indicating that it is an intrathecal catheter.
  3. Disable patient controlled boluses.
  4. Immediately prior to pulling the catheter, consider bolus of 10cc of preservative-free saline.  This may reduce the incidence of headache.
  • Overview
  • Spinal for C-Sec
  • Epidural Top-up for C-Sec
  • CSE
  • Continuous Spinal for C-Sec
  • GA for C-Sec
  • Cerclage/PPTL

Anesthesia for C-Section

Overview

  1. Approximately 90-95% of cesarean sections at Stanford are performed with regional anesthesia. General anesthesia is usually reserved for emergency cesareans where there is acute fetal distress or maternal hemorrhage, or when regional block is contraindicated.  Spinal anesthesia is used for elective cesareans, and emergent or non-elective cesareans where a rapid onset of block is desirable or acceptable.  Epidural anesthesia is used for elective cesareans when a slower onset of block is preferred and for patients in whom a functioning catheter is already in situ. CSE should be considered if the duration of surgery is expected to last beyond that provided by spinal anesthesia.
  2. Avoidance of aortocaval compression: All patients must be tilted to the left as soon as they are placed on the OR table to minimize the adverse effects of the supine position, i.e., a decrease in cardiac output of 30-50%.  This is usually accomplished by placing a rolled blanket under the right hip, tilting the table, or a combination of the two methods.  Check that the uterus is actually displaced by whatever method you are using. Left uterine displacement is essential regardless of whether the patient is having a regional or a general anesthetic. If intraoperative hypotension occurs, check the adequacy of left uterine tilt.
  3. Prophylaxis against aspiration pneumonitis: All patients receive iv ranitidine 50 mg and metoclopramide 10 mg prior to their surgery.  The metoclopramide increases  lower esophageal sphincter tone and in the case of spinal anesthesia, decreases nausea. The ranitidine will lower gastric pH in about 60 minutes time.   This will help should the woman need intubation or extubation later and ranitidine will also decrease any reflux symptoms. Patients receiving general anesthesia should be given sodium citrate 30 ml p.o. 2 to 5 min before anesthesia. This drug has a short duration of action (20 minutes), so don’t give it too early.  In the elective situation, patients at increased risk should receive ranitidine 150 mg p.o. the night before and the morning of surgery.

Spinal Anesthesia for C/Section

Technique

  1. Hetastarch 500 ml + 1000 ml crystalloid in the 30 minutes or so before the block, or 1000 ml of crystalloid infused rapidly (with pressure bag) concurrent with and immediately after the block.  With severe preeclamptics, fluid restriction is generally advised to reduce the risk of pulmonary edema.  In these cases, give enough fluid to maintain urine output, but avoid preloading.
  2. 12 mg bupivacaine (1.6 ml of 0.75% hyperbaric bupivacaine) + 0.1 mg preservative-free morphine (0.2 ml) + 10 µg fentanyl (0.2 ml).  In urgent situations when time is precious, omit the opioid and use up to 15 mg bupivacaine (2.0 ml).  The dose of local anesthetic is not adjusted for patients in the normal range (5 - 6').   Remember that intubation because of failed blocks is much more common than intubation for high blocks!

Complications

  1. Hypotension: Phenylephrine 50-100 µg boluses at the first sign of hypotension, repeated p.r.n.  If there is bradycardia and consider glycopyrollate 0.2 mg, or atropine 0.4 mg. For hypotension with bradycardia after the baby is out, consider ephedrine.
  2.  Consider epinephrine in the event of severe hypotension or if the hypotension and bradycardia persist despite above measures. 
  3. Be vigilant for possible symptoms of a high-block or emergent total spinal anesthetic (following an epidural top-up if the catheter is in the subarachnoid space) as a cause for the bradycardia.

Epidural top-up for C/Section

Overview

  1. Surgical anesthesia may be obtained in 5-10 minutes with a functioning epidural in situ
  2. It may be necessary to start injecting the drug as soon as it is clear that surgery is needed, doing so en route to the OR if necessary.

Technique

  1. 15-20 cc of 2% lidocaine with 1:200,000 epinephrine + sodium bicarbonate 1 mEq/10ml given in 5 cc increments.   Check for loss of sensation to pinprick and cold to T4 bilaterally.  The density of the the block is best assessed with a nerve stimulator or light touch.  Usually if there is a good block to the nerve stimulator turned up to 10 to the T6 or T8 level, the block is adequate.
  2. In emergency situations, 20 cc of 3% 2-chloroprocaine (± bicarb 1ml per 10 ml of chloroprocaine) may be used instead of 2% lidocaine for more rapid block onset.


Failed Epidural Top-up for Cesarean Delivery

Prevention

  1. Most failed top-ups can be predicted.  Make sure the epidural is functioning adequately during labor. More than one request for an additional physician bolus may indicate a poorly functioning epidural that should be replaced.

Tricks to improve the block

  1. Titrate the local anesthetic in early (e.g. start on route to the OR).
  2. Check that the epidural catheter is still in-situ and not displaced.
  3. If the clinical situation allows, wait an adequate time for the onset (20 minutes) of anesthesia
  4. Turn the patient into the lateral position to improve cranial spread.
  5. If the block is not “coming up” do not keep administering more local anesthetic (beyond 20 to 25 ml) as this may limit the amount available if the block is replaced.

Failed block prior to cesarean section

  1. No urgency or urgent cesarean and non-reassuring airway:  Perform a CSE.  Use a reduced dose of bupivacaine (2.5 to up to 7.5 mg) depending on the block height and clinical situation.
  2. Urgent cesarean and reassuring airway:  GA
  3. BEWARE: A full dose single-shot spinal in a patient who has received significant amounts of epidural local anesthetic has a high risk of a high/total spinal!

Inadequate block during the cesarean section

  1. Inform surgeon and request avoidance of uterine externalization if possible.
  2. Request local anesthetic instillation into the wound (advise re the maximum allowable dose considering all local anesthetic already administered).
  3. Utilize the epidural catheter: Administer more local anesthetic (up to 30 ml), fentanyl up to 100 mcg.
  4. Analgesia: Consider IV fentanyl 50 mcg IV PRN, 50% nitrous oxide with oxygen.
  5. Sedation: Useful especially if highly anxious, but remember pregnant patients are more sensitive to anesthesia and have an unprotected airway. Midazolam 1 mg IV PRN, ketamine 10 mg IV PRN, propofol 10 mg PRN, sevoflurane 0.2-4%
  6. Convert to GA. If the airway is not reassuring, consider an awake FOI. (Note: The maximum allowable local anesthetic may be limited due to prior local anesthetic administration)
  7. DOCUMENT:  An inadequately managed failed block for cesarean is a cause for medico-legal action.

CSE for C/Section

Overview

  1. CSE is usually done if there is uncertainty about appropriate dosage or duration of the case.

Technique

  1. Placement of block is same as for labor CSE.  Spinal dosing is the same as for spinal for C/Section: 12 mg bupivacaine (1.6 ml of 0.75% hyperbaric bupivacaine) + 0.1 mg preservative-free morphine (0.2 ml) + 10 µg fentanyl (0.2 ml).
  2. Trendelenberg position, passive flexion of hips, and epidural space extension with 5 to 10 cc of preservative-free saline (or 2% lidocaine) via the epidural catheter may be used to increase the height of the block if necessary.

Continuous spinal anesthesia (CSA) for C/Section

Overview

  1. CSA is not commonly used for C/Sections,  but it may be considered when …
    1. Regional anesthetic failure cannot be tolerated, e.g. previously confirmed difficult airway combined with prolonged surgery (PPTL to follow, multple previous uterine surgeries, morbid obesity) or short stature patients for whom the appropriate intrathecal dose for single shot spinal is indeterminate.
    2. CSE is attempted but a wet tap is inadvertently obtained with the Tuohy needle
  2. Technique
  3. Normally, the same doses of IT bupivacaine and opioids as for the single shot spinal technique are used for the first dose and half those amounts are used for re-doses.
  4. Immediately prior to pulling the catheter at the termination of the case, consider bolus of 10cc of preservative-free saline.  This may reduce the incidence of headache.

General Anesthesia for C/Section

  1. Make sure the anesthetic machine is set for monitoring a patient having a general anesthetic (ETCO2 – this MUST be turned on!!!, volatile agent, etc.)
  2. Build intubating ramp if necessary.  Ensure good head and neck position.  Left uterine displacement.  Suction ready.
  3. Bicitra 30 ml PO + ranitidine 50mg IV + metoclopramide 10mg IV.
  4. Preoxygenate with at least four maximal breaths.
  5. Make sure the surgeon is scrubbed and ready to start before you start, and double-check that the pediatrician is present or has been alerted.
  6. Be prepared to deal with difficult intubation (see algorithm for management of failed intubation). Ensure a gum-elastic bougie is available
  7. Rapid sequence induction
    1. Propofol 2 to 2.5 mg/kg  or thiopental 4 to 6 mg/kg or (or ketamine 2 mg/kg in severely hypotensive patients)
    2. Succinylcholine 1.5 mg/kg.
    3. Immediately after securing the airway, inform the surgeon that they may begin.
  8. Maintenance with 50:50 N2O/O2 + 0.75 to 1.0 MAC sevoflurane or isoflurane until delivery.
  9. After delivery: 
    1. Increase N2O to 70% and decrease the potent inhalational anesthetic (sevoflurane or isoflurane) to 0.5 MAC.
    2. Give midazolam 2 mg i.v. for amnesia.
    3. Usual narcotic dosage is fentanyl 200 to 300 mcg IV plus 10 to 15 mg IV morphine
    4. Small doses of vecuronium (1 to 2 mg), rocuronium (10 to 20 mg), or cis-atracurium (2 mg) provide muscle relaxation of appropriately short duration. Administer only after recovery from sux is evident by respiratory efforts, movement, or presence of twitch with nerve stimulator.  If the patient is on magnesium, they usually don’t need more muscle relaxation with non-depolarizing muscle relaxants.  However, if you do give muscle relaxants to someone on magnesium, use small doses and monitor NMB carefully with nerve stimulator.
  10. Ensure patient is fully awake and reversed before extubation.
  11. IV-PCA opioids for postop analgesia.

Anesthesia for PPTL/Cerclage

Technique

  1. Usually require smaller spinal doses. (1.2 ml 0.75% bupivacaine (9 mg) +10 mcg fent, no morphine).  You will need a T6 level for tubals + a T10 level for cerclage.  If there is a labor epidural still in place, then you can use that as well.
  • Hemorrhage
  • Eclamptic Seizure
  • LA Cardiac Arrest
  • Maternal Code

Obstetric Hemorrhage

  1. Key Points: Maintenance of intravascular volume, an adequate hematocrit, proper coagulation function,  maintenance of body temperature, and ventilation and oxygenation are the goals.
  2. CALL FOR HELP  early (even if it is to run the rest of the service while you are busy. Call the front desk of the main OR to get the 1rst OR attending or resident or anyone else in the OR’s
  3. Call Ed Riley  650-804-0514
  4. Call the on call OB anesthesia fellow (list in the call room).
  5. Start at least 2 large bore IV’s and use the Level One fluid transfusion system to deliver your blood products.  Call the main OR tech if you want a second.
  6. Start an arterial line sooner than later.
  7. Start a CVP if central monitoring needed, but use IJ approach.
  8. Use the Bair Hugger to maintain normothermia
  9. LABS   Clinical Lab at LPCH Phone:  497-8613
  10. TO ORDER BLOOD:  Phone Number for Transfusion Services:  723-6444
  11. STAT Type and Cross will take 1 hour
  12. Send a runner to pick it up if need is immediate.
  13. If no cross-matched blood available, you need blood now, and bleeding is ongoing activate the Massive Transfusion Protocol (MTP):
    1. 6 Units of PRBC
    2. 4 Units of FFP
    3. 1 apheresis unit of platelets.
  14. If blood is needed quickly, but you do not need the full complement of components, order the Trauma Pack (2 units of uncross-matched blood).
  15. If you begin to give FFP and/or Platelets call transfusion services and ask for consult by transfusion doctor on call.  They can be helpful.
  16. CELL SAVER Call the main OR anesthesia tech and ask them to bring it over and help our tech set it up. 
  17. If time is crucial, send the labs by runner.
  18. Transfuse based on vital signs, estimated blood loss, and pathological bleeding if labs are not fast enough.

Eclamptic seizure

During/After seizure:

  1. Call for help (OB, Anesth, nursing, techs)
  2. Prevent patient harm (head trauma, bite block)
  3. Left uterine displacement or lateral decubitus
  4. Open airway, Suction, Administer 100% O2
  5. Support ventilation (O2/Ambu bag)
  6. Apply monitors (Maternal & Fetal) & Check Vitals
  7. Start Magnesium 6 Grams Over 20 Minutes--NO FASTER!!!
  8. If seizure continues small dose of anticonvulsant (midazolam, propofol, thiopental)
  9. Prepare for intubation if inadequate ventilation

After seizure:

  1. TRY TO AVOID POLYPHARMACY – Magnesium is FIRST LINE, and the seizure is usually self limited. Benzodiazipines, thiopental, propofol are back-up for refractory seizures.  Magnesium is critically important for prophylaxis against further seizures.
  2. TRY TO AVOID Delivering fetus IMMEDIATELY – Let fetus resuscitate in utero provided FHR reassuring
  3. INTUBATE ONLY IF: patient remains unconscious after the seizure, has aspirated, or remains hypoxemic. [Sympathetic outflow associated with laryngoscopy and tracheal intubation could potentially cause hypertension and result in stroke. Consider Labetolol if patient hypertensive; remember Magnesium will temporarily decrease blood pressure.]

Local anesthetic-induced cardiac arrest

  1. Maintain CPR.  Outcomes after local anesthetic inducted cardiac arrest are often excellent.
  2. Call for the cardiopulmonary bypass machine right away and use it if the patient is unresponsive to intralipid therapy.
  3. In the event of local anesthetic-induced cardiac arrest that is unresponsive to standard therapy, in addition to standard cardio-pulmonary resuscitation, Intralipid 20% should be given as specified below.
  4. If you use Intralipid to treat a case of local anesthetic toxicity, please report it at www.lipidrescue.org.
  5. How To Give Intralipid—It is stored in a box next to the MH kit box in the back hall by the ORs
    1. Intralipid 20% 1.5 mL/kg over 1 minute (this is 100 ml in a 70 kg person)
    2. Follow immediately with an infusion at a rate of 0.25 mL/kg/min (For a 79 kg patient give the rest of the bag over 15 to 20 minutes)
    3. Continue chest compressions (lipid must circulate)
    4. Repeat bolus every 3-5 minutes up to 3 mL/kg total dose until circulation is restored
    5. Continue infusion until hemodynamic stability is restored. Consider increasing the rate to 0.5 mL/kg/min if response not adequate.
    6. A maximum total dose of 8 mL/kg is recommended

OB Maternal Code

  1. Call for HELP: OBs, Anesth, Nurses, Techs (Ob&Anesth), Peds
  2. Chest compressions – 100/min (push hard, push fast)
  3. Left Uterine Displacement (wedge/manual)
  4. Call for Crash Cart, Stat C/S pack and equipment
  5. Ventilate: Ambu/O2; Early Intubation/Cricoid; LMA if difficult
  6. Usual BLS/ACLS Algorithms and Defibrillation
  7. START STAT C/S in OR or patient’s room after 4 min if > 20 weeks gestation and no response.
    1. Don’t Relocate Prior to Delivery: unacceptable delay!
    2. *No hypnotics, paralytics, or analgesics needed!
  8. Delivery by 5 minutes improves maternal outcome if gestation > 20 weeks and both maternal AND neonatal outcome if  if gestation > 24 weeks
  9. Deliver compressions slightly higher on sternum
  10. Try to avoid use of femoral veins because of caval compression
  11. If mother resuscitated,can move to OR for completion of C/S

COMMONLY USED OB ANESTHESIA TECHNIQUES

Authored by the Stanford OB Anesthesia Faculty and Fellows

Edited by Vincent Hsieh, May 1, 2009

 

 

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