from print to practice: recent ob anesthesia publications and impact on anesthesia care joy l....

From Print to Practice: Recent OB Anesthesia

Publications and Impact on Anesthesia Care

Joy L. Hawkins, M.D.

* I have no conflicts to disclose*

LEARNING OBJECTIVESUpon completion of this presentation, participants will be able to discuss how emerging research is changing clinical practice in obstetric anesthesia by challenging long-held beliefs in the areas of:

1.Policies and procedures on L&D

2.Providing analgesia for labor

3.Anesthesia for cesarean delivery

4.Management of complications

POLICIES&

PROCEDURES

What laboratory tests are needed in a

healthy parturient prior to epidural or spinal placement?

None.

ASA PRACTICE GUIDELINESIn the section on Perianesthetic Evaluation, the ASA Practice Guidelines for Obstetric Anesthesia state:

1. “Order or require a platelet count based on a patient’s history, physical examination, and clinical signs; a routine intrapartum platelet count is not necessary in the healthy parturient.”

ASA PRACTICE GUIDELINES

2. “Order or require an intrapartum blood type and screen or cross-match based on maternal history, anticipated hemorrhagic complications (e.g., placenta accreta in a patient with placenta previa and previous uterine surgery), and local institutional policies; a routine blood cross-match is not necessary for healthy and uncomplicated parturients.

Anesthesiology 2007; 106: 843

What is the appropriate skin prep solution to use

prior to placement of spinal or epidural

anesthesia?Chlorhexidine-alcohol

(not Betadine®)

ASRA CONSENSUS STATEMENT“Alcohol-based antiseptic solutions will provide the maximal degree of antimicrobial activity with extended duration when compared with nonalcoholic antimicrobial or non-antimicrobial preparations (Grade A). A distinct advantage of chlorhexidine is its ability to adhere to the stratum corneum, thus extending its duration of action several hours beyond its initial application.

Reg Anesth Pain Med 2006; 31: 311

CHLORHEXIDINE PREP?

A letter to the APSF Newsletter editor asks: “Since ASRA guidelines and APSF have both recommended chlorhexidine solutions as the antiseptic of choice for regional anesthesia procedures, why does the applicator package still say that it should not be used for lumbar puncture or in contact with meningeal structures?”

CHLORHEXIDINE PREP?The manufacturer of chlorhexidine responds:

“Interestingly, povidone iodine is also not approved for lumbar puncture…from the perspective of the FDA, there is no perceived need to suggest a label change [to approve chlorhexidine for neuraxial procedures] and no adequately powered prospective evaluations in the setting of regional anesthesia. From the perspective of a manufacturer, the expense of obtaining a label change is prohibitive.”

APSF Newsletter, Fall 2008

ASA PRACTICE ADVISORY

“Aseptic technique should always be used during…placement of neuraxial needles and

catheters, including: …use of individual packets of antiseptics for skin preparation…

use of chlorhexidine (preferably with alcohol) for skin preparation, allowing for

adequate drying…


When should antibiotics be given for cesarean

delivery?

Prior to skin incision (same as other OR cases).

ANTIBIOTIC PROPHYLAXISCurrent ACOG guidelines recommend antibiotics before skin incision in C/S.

•1052 ASA members responded to a survey

•Only 66% reported pre-incision antibiotics as standard of care vs. endorsing giving after cord clamp or at the discretion of OB

•Teaching > community hospitals

•West > Southwest or southeast

Anesth Analg 2013; 116: 644

ANALGESIAFOR

LABOR

Is informed consent of any value in the actively

laboring patient? Will it protect me?

Will she remember anything I tell her?

Yes, yes and yes!

INFORMED CONSENT• Laboring patients do remember your

discussion, so mention risks and document on your record or a consent form.

• Recall is not hindered by pain or opioids.• Written materials improve recall by 50%.• Include the common problems: falls in

blood pressure, temporary back soreness, patchiness or inadequate analgesia that require replacement, and headache.

Anesth Analg 2011;112:912

INFORMED CONSENT

Legal cases addressing the adequacy of anesthetic consent given during labor have not even speculated that consent obtained during the stress of labor would be inadequate.

Three factors support “implied consent” in labor:

1. Information is given to the patient

2. Lack of objection by the patient to proceeding

3. Her cooperation given during the procedure

Anesthesiology 1990;72:211

Is CSE or epidural labor analgesia preferable?

Neither; there are pros and cons for both techniques.

Are complications more common after CSE than epidural analgesia? No.

CSE versus CLEIn a retrospective review of 12,590

neuraxial labor analgesia blocks:CLE CSE

Overall failure rate 14% 10%Inadequate analgesia 8.4% 4.2%Needed replacement 7.1% 3.2%Wet tap 1.4% 0.8%

Int J Obstet Anesth 2004;13:227

CSE versus CLEA Cochrane Review of 2658 women in 19 trials found

no differences in any major complication studied:• Maternal satisfaction (even though CSE had faster

onset and lower need for rescue analgesia)• Ability to mobilize during labor (motor block)• Modes of delivery and newborn outcome• PDPH or blood patch• HypotensionConclusion: No difference between the techniques.

Cochrane Database Syst Rev 2007;CD003401

CSE versus CLE

800 women received CSE or CLE with PCEA in a busy private practice hospital by experienced anesthesiologists (new model).

•No difference during 2nd stage and at delivery

•CSE → better pain scores in 1st stage of labor +

•Fewer CSE patients needed top-ups (16 vs 26%)

Anesth Analg 2013; 116: 636

Is there a difference in the quality of epidural analgesia if you use loss of resistance to air

versus saline to locate the epidural space?

No, as long as it’s the technique you are accustomed to.

AIR vs. SALINE

A meta analysis of 5 studies that included 4422 patients failed to find any statistical difference in adverse outcomes between air and saline for the obstetric patient.

• There was no difference in difficult catheter insertion, paresthesia, intravascular catheters, dural puncture, PDPH, or patchy block.


AIR vs. SALINELabor epidural records were reviewed to assess

outcomes after loss of resistance to air (53%) or saline (47%) during placement.

• There was no difference in block success, IV or intrathecal placement, or need for replacement.

• BUT, if the anesthesiologist was able to use their preferred technique (the one they used > 70% of the time), they made fewer attempts (1.3 vs. 1.6 attempts at placement), had fewer paresthesias (OR 0.42), and fewer wet taps (1.0 vs. 4.4%).


AIR vs. SALINE345 women were randomized to LOR to air or

saline during CSE for labor analgesia.• There was no difference in block success or

epidural drug consumption between groups.• BUT, if epidural catheters were inserted

without having seen spontaneous return of CSF in the spinal needle, those catheters had to be replaced more often (28.6% failure rate vs. 4.1% when CSF was seen).


Is there evidence that neuraxial analgesia for

labor increases cesarean delivery rate in

spontaneously laboring patients?

Not in modern practice.

PROGRESS OF LABOR

A systematic review of seven randomized controlled trials involving 2962 nulliparous women comparing low dose epidural infusions with parenteral opioids concluded:

1. Epidural infusions with low concentration local anesthetics are unlikely to ↑ the risk of cesarean section in nulliparous women.

PROGRESS OF LABOR2. Although epidural analgesia is associated with

an risk of instrumental vaginal delivery (i.e. forceps, vacuum), operator bias cannot be excluded.

3. Epidural analgesia is associated with a longer second stage of labor (mean 15 minutes) and oxytocin requirements, but the importance of these is unclear as maternal analgesia and neonatal outcome may be better with epidural analgesia.

BMJ 2004;328:1410

PROGRESS OF LABOR

ACOG Committee Opinion #339: Analgesia and Cesarean Delivery Rates

“Neuraxial analgesia techniques are the most effective and least depressant treatments for labor pain….more recent studies have shown that epidural analgesia does not increase the risks of cesarean delivery….the fear of unnecessary cesarean delivery should not influence the method of pain relief that women can choose during labor.”

Obstet Gynecol 2006;107:1487

When a woman has severe pain in early labor, will use

of neuraxial analgesia adversely impact the

progress of her labor? No.

EARLY ANALGESIA

750 nulliparous women in spontaneous labor, < 4cm were randomized to receive spinal fentanyl (ITF) or IV hydromorphone.

• Pain scores were lower after ITF (2 vs 6).• Rates of C/S were no different (18 vs 21%).• Time to complete dilation (duration of first stage of

labor) was 90 minutes shorter in the ITF group.• Newborn outcome (Apgar < 7) was worse after

parenteral narcotic.NEJM 2005; 352: 655

EARLY ANALGESIA

• Randomized controlled trial of 449 term, nulliparous women: early epidural < 3cm dilation versus late epidural when > 4cm.

• Mean dilation was 2.4 vs 4.6 cm at placement.• Rates of cesarean were no different (13 vs 11%).• Labor was 42 minutes shorter in the early group.• Women preferred early epidural analgesia.

Am J Obstet Gynecol 2006;194:600

EARLY ANALGESIA

806 nulliparous women undergoing induction of labor who requested analgesia < 4cm were randomized to CSE or IV/IM hydromorphone:

• No difference in cesarean rates (33 vs 32%).• No difference in non-reassuring FHR tracings or

newborn outcomes.• Pain scores were lower with CSE (1 vs 5)• Labor was shorter with CSE (41 min)

Obstet Gynecol 2009; 113: 1066

EARLY ANALGESIA

EDITORIAL: “No longer should a patient be made to feel guilty about her wish for pain relief early in labor, powerless in her choices or conflicted about the consequences of such a choice….What a concept – pain relief of real pain when requested. We all should now feel comfortable supporting this position for the patient in labor.”


Does the use of epidural analgesia for labor adversely affect

breast-feeding?

Probably not, but the verdict is still out.

BREAST-FEEDING

What is in the lactation literature?“…recommend a reduction in the use of epidural

analgesia to enhance breastfeeding.”J Human Lactation 1996;13:131

“Women who had epidurals were less likely to fully breastfeed their infant in the few days after birth and more likely to stop breastfeeding in the first 24 weeks.”

Int Breastfeeding Journal 2006;1:24

BREAST-FEEDING• Studies have correlated epidural fentanyl doses

> 150 µg during labor with rates of breast-feeding on PP day 1 and at 6 weeks.

• However, we know that epidural fentanyl improves analgesia and motor block.

• Recommendation: Avoid boluses of fentanyl if possible and provide more intervention and education by lactation consultants for high risk women.

BJOG 2005;112:927 Anesthesiology 2005;103:1211

BREAST-FEEDINGMultiparous women who had breast-fed

previously and planned to breast feed again received epidural analgesia with fentanyl.

• >95% were breast-feeding at 6 weeks.BUT

• Median maternity leave was 1 year (Canada).• 69% received postpartum lactation counseling

and support in the hospital.Int J Obstet Gynecol 2010;19:273

ANESTHESIAFOR

CESAREANDELIVERY

Which pressor produces the best outcome for

mother and baby when treating hypotension due to

spinal anesthesia?-agonists

Phenylephrine.

CHOICE OF PRESSOR

Women having an elective C/S under spinal anesthesia were randomized to ephedrine or an α-agonist to support their blood pressure.

• The -agonist provided closer control of maternal systolic pressure and less nausea and vomiting.

• Umbilical pH was higher and base deficit was less after the -agonist.

• Uterine artery pulsatility by Doppler was similar in both groups.

Anesthesiology 2001; 95:307

CHOICE OF PRESSOR

• Should we avoid using high doses of -agonists?• What is the optimal BP we should target after

regional anesthesia? Should we routinely allow BP to fall 20% before treating?

Women (n=75) receiving spinal anesthesia for elective cesarean delivery were randomized to receive enough phenylephrine to keep their blood pressure at either 100%, 90% or 80% of baseline.

(continued)

CHOICE OF PRESSORWhen BP was kept at 100% of baseline,

mothers and infants had the best outcomes:

• the fewest episodes of “hypotension”

• the fewest episodes of maternal N&V

• the highest fetal umbilical pH values

This despite receiving the highest doses of phenylephrine (mean dose 1520 g).

Br J Anaesth 2004;92:469

CHOICE OF PRESSOR“Keep the pressure up and don’t spare the

vasoconstrictors” (editorial)• Ephedrine’s activity may adversely affect the

fetus by increasing its metabolic rate.• Using -agonists does not cause vasoconstriction,

it returns status to normal.• Maternal sensitivity to vasoconstrictors is

decreased in pregnancy, especially the uterine arteries; this may also protect the fetus.


CHOICE OF PRESSORSampling cord blood at delivery, does ephedrine cross

the placenta and stimulate metabolism in the fetus?• 104 women randomized to ephedrine (E) or

phenylephrine (P) during elective CD under spinal.• E crossed the placenta more readily than P• E babies had ↓ pH and more base deficit, ↑ lactate,

glucose, epinephrine, nor-epi → more metabolic effects caused by β-adrenergic receptor stimulation

• Effects on fetal oxygen supply and demand favor PAnesthesiology 2009;111:506

Will adequate IV fluid preload prevent maternal hypotension after spinal

or epidural anesthesia for cesarean delivery?

No.

COLLOID or CRYSTALLOID?

Randomized comparison of crystalloid (1.5L) and colloid (0.5 or 1L) preload:

• All increased cardiac output (supra-sternal Doppler flow measures)

• No difference in hypotension• No difference in pressor dose required• No difference in neonatal outcome


COLLOID or CRYSTALLOID?

After crystalloid or colloid 1L co-load, parturients were monitored with suprasternal Doppler flow:

•No difference in cardiac output

•No difference in phenylephrine dose to treat hypotension

•No difference in newborn outcomes.


PRELOAD OR CO-LOAD?

Two studies compared colloid preload vs. co-load with similar conclusions:

• No differences in the incidence of hypotension or pressor doses.

• No differences in neonatal outcomes (Apgar scores or gases).

• Cardiac output and stroke volume increased with preload - not co-load - but the increase was not sustained past 10 minutes.

Anesth Analg 2009;108:1592 and 109:1219

PRELOAD REGIMENS1. Crystalloid or nothing

2. Crystalloid or colloid preload

3. Crystalloid preload or co-load

4. Colloid preload or co-load

5. Crystalloid or colloid co-load• No regimen produced any differences in

pressors required or in neonatal outcome.• Since no regimen prevents hypotension, have

pressors available and use them.

Anesth Analg 2011;113:677 (editorial)

Is spinal anesthesia for cesarean delivery safe and appropriate for women with severe

preeclampsia?Yes.

SPINALS IN PREECLAMPSIA

• Women with severe preeclampsia (BP 160/110) were compared to healthy women having spinal anesthesia for C/S.

• Severely preeclamptic patients had less hypotension than healthy women (17% vs 53%), despite receiving less fluid preload and a larger dose of spinal bupivacaine.



Is the decrease in hypotension due to preeclamptic factors or a smaller uterus?

• During spinal anesthesia for cesarean, preeclamptic patients had less hypotension (RR 0.6) and required less ephedrine (10 mg vs 16 mg) than parturients with preterm pregnancies.



In a randomized trial, spinal and epidural anesthesia were compared in severely preeclamptic patients; there were no clinically significant differences.

• Hypotension was more frequent with spinal (51 vs 23%), but duration was short ( 1 min).

• There was more ephedrine used with spinal (6 vs 0 mg), but hypotension was easily treated.

• Neonatal outcomes were similar in both groups.


Should general anesthesia for cesarean delivery

always be avoided in the obstetric patient?

No.

GENERAL ANESTHESIA• In obstetric anesthesia, liability claims for pain

during surgery or emotional distress are often related to inadequate regional blocks used for cesarean delivery because of reluctance to convert to general anesthesia.

• Liability claims for adverse neonatal outcomes have been related to excessive time taken to place a regional anesthetic, rather than inducing general anesthesia.


GENERAL ANESTHESIA

• Safety of GETA has improved remarkably due to technical advances (e.g., LMA, videolaryngoscopy) and attention to difficult airway management.

• There are emergent clinical situations on L&D when general anesthesia is preferable; evaluate on a case-by-case basis. Do not cause unnecessary delays.

• Adhere to basic safety principles whether providing general or regional anesthesia; maternal complications can occur with either technique.

Obstet Gynecol 2011; 117: 69

Will general anesthesia become a common choice for elective obstetric anesthetics?

No, because our patients and obstetricians prefer neuraxial

techniques, and regional anesthesia has many benefits for

the mother and for her baby.

MANAGEMENT OF

COMPLICATIONS

1. Are women who have labor epidural analgesia more likely to have an temperature? Yes.

2. Is it associated with increased rates of infection in the mother or neonate? No.

3. Can an elevated maternal temperature cause fetal/newborn complications? Possibly.

EPIDURALS AND FEVERS

A randomized comparison of CSE analgesia versus non-pharmacologic pain relief examined changes in maternal temperature.

•All women receiving CSE increased their temperature but only 14% developed fever.

•No cases occurred in the control group.

•No maternal or neonatal infections occurred.

Br J Anesth 2011;107:762

EPIDURALS AND FEVERSWhy is neuraxial analgesia associated with fever?

• Selection bias: epidurals are used more often in long labors with prolonged rupture of

membranes and more cervical exams• No sweating below the sympathectomy• No hyperventilation with contractions• Increased shivering

Epidural-associated fever is associated with maternal, fetal, and placental culture-negative inflammation. Does CLE inflammation?

EPIDURALS AND FEVERS

Why is this clinically relevant? The risk of neonatal encephalopathy ↑ with maternal fever (> 37.5), neonatal acidosis (pH < 7.2) or both.

• Maternal fever risk was 1.9%, OR 8.1

• Neonatal acidosis risk was 2.8%, OR 11.5

• Fever + acidosis risk 12.5%, OR 93.9


EPIDURALS AND FEVERSIn a group of low-risk nulliparous women with epidural analgesia (n=1538) or without (n=363):

•19% had fever in epidural group vs. 2%

•No fever = no difference in neonatal outcomes•As fever increased in the epidural group, adverse neonatal outcomes increased in a linear fashion: Apgar < 7, ↓ tone, assisted ventilation, and seizures.

Pediatrics 2012; 129: e447

Pediatrics 2012;

Do anesthesiologists use evidence-based, optimal

prevention and treatment for post-dural puncture

headache (PDPH)?No.

PDPHAnesthesiologists’ practices vary widely in

managing wet tap and PDPH.• Ineffective treatments: hydration, IV or oral

caffeine, NSAIDs, bedrest, abdominal binders, passive second stage (no pushing).

• Techniques with evidence of success: ACTH or cosyntropin, neuraxial morphine, intrathecal catheters + saline, blood patches.

J Clin Anesth 2011;23:347

Doctors can’t make you immortal………….

But with good luck they can prolong your

suffering indefinitely.

INTRATHECAL CATHETER115 parturients with a “wet tap” were randomized to 3 groups for management:

#1 Epidural catheter at another interspace:

PDPH = 92%, EBP = 81%

#2 Spinal catheter removed at delivery:

PDPH = 51%, EBP = 31%

#3 Spinal catheter for 24 hours postpartum: PDPH = 6%, EBP = 3%

Reg Anesth Pain Med 2003; 28: 512

COSYNTROPIN

ACTH has been used to treat PDPH, but not for prophylaxis. Cosyntropin = synthetic.

• 90 parturients with accidental dural puncture were randomized to 1 mg IV cosyntropin (Cortrosyn™) or saline.

• PDPH occurred in 69% of controls but in only 33% who received ACTH.

• Need for blood patch was 30% vs. 11%Anesthesiology 2010; 113: 413

Should recombinant Factor VIIa (NovoSeven®) be

considered in life-threatening postpartum

hemorrhage?

Yes, except perhaps after amniotic fluid embolism.

rFACTOR VIIa A registry identified 97 women who received

Factor VIIa to treat obstetric hemorrhage.

• Median blood loss before treatment was 6L

• 70% had clinical coagulopathy, 5 later died

• 80% improved after 1 dose, 6% after 2 doses, and 14% failed therapy

• Adverse events: 4 thromboembolism, 1 rash


rFACTOR VIIaA review of 105 cases of off-label use in obstetric patients having PPH found:•83% had already received >5units PRBC•74% were acidemic, 34% severely so•Positive response rate was 76%, with 64% responding to the first dose•91% had survived at 1 month•2 thromboembolic events were reported

Anesth Analg 2009; 109: 1908

rFACTOR VIIa COSTA series reported on 12 women who received

recombinant factor VIIa for life-threatening postpartum hemorrhage. The authors recommend its use before resorting to hysterectomy during intractable PPH.

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

• Cost effective??Br J Anaesth 2005;94:592

rFACTOR VIIa• During AFE, high circulating tissue factor

concentrations can combine with VIIa to form intravascular clots.

• A review of 44 cases of AFE compared those who received VIIa to those who did not.

• Death or permanent disability were more common when VIIa was given (RR 2.2) versus full recovery.


Should postpartum tubal ligation (PPTL) procedures be

considered elective cases?No, we should make every

effort to get them done during the current hospitalization

and in a timely fasion.

POSTPARTUM TUBAL LIGATION

What happens to a patient when she requests a postpartum tubal ligation but does not receive it before discharge?

• 3 cohorts: 1) received PPTL as requested, 2) requested PPTL but it was not performed, and 3) those who chose other birth control methods

• After 1 year: 1) no pregnancies, 2) 47% were pregnant, and 3) 22% were pregnant.


50% of pregnancies in the U.S. are unplanned!

POSTPARTUM STERILIZATIONACOG encourages improved access to PPTL for women requesting it; an “urgent” surgery.

•50% rate of repeat pregnancy in the following year in women who request but do not receive PPTL.

•Limited time to perform the procedure.

•Medicaid has cumbersome consent process compared to private insurance.


Does the use of spinal or epidural analgesia for labor increase the incidence of back pain

in parturients?No, but childbirth

does.

BACK PAINA survey of women during pregnancy found:• 69% had back pain.• 58% said pain disturbed their sleep and interfered

with daily activities.• 30% had stopped at least one activity.• Only 32% had told their caregiver, and only 25%

of caregivers prescribed treatment.Obstet Gynecol 2004;104:65

Document pre-existing back pain in your preop evaluation!

BACK PAIN

Over 600 nulliparous women were randomized to receive IV meperidine or epidural analgesia for labor. Six months later, 83% replied to a questionnaire:

• 50% reported backache in meperidine group

• 48% reported backache in epidural group


“If physicians would read two articles per day out of the six

million medical articles published annually, in one year, they would fall 82 centuries behind in their

reading.”

WF Miser, 1999

from print to practice: recent ob anesthesia publications and impact on anesthesia care joy l....

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