1. Latest & Greatest Trends in OB Anesthesia
Holly Ende, M.D.
Assistant Professor
Division of Obstetric Anesthesiology
Vanderbilt University Medical Center

2. I have no disclosures

3. October 2017
December 2017
And as I was preparing
Over past months

4. LABOR
ANALGESIA
CESAREAN ANESTHESIA
HEMORRHAGE
OPIOID USE

5. LABOR
ANALGESIA

6. LABOR ANALGESIA
Neuraxial Anesthesia
Nitrous Oxide

7. Maternal satisfaction Need for manual anesthetic interventions
Labor progression
Mode of delivery
For a good review of the current data
9 RCT
George RB, et al. Anesth Analg 2013; 116(1):

8. Maternal Satisfaction
PIEB --- CEI
4/5
George RB, et al. Anesth Analg 2013; 116(1):

9. Need for Manual Anesthetic Interventions
Cumulative data favorable
not statistical significance
George RB, et al. Anesth Analg 2013; 116(1):

10. Labor Progression
George RB, et al. Anesth Analg 2013; 116(1):

11. Mode of Delivery: Instrumented VD
And finally
1/9
designed and powered
Pooled results approached
George RB, et al. Anesth Analg 2013; 116(1):

12. Mode of Delivery: CD
George RB, et al. Anesth Analg 2013; 116(1):

13.  Maternal satisfaction  Instrumented vaginal delivery rate (?)
 Need for anesthesia intervention (?)
George RB, et al. Anesth Analg 2013; 116(1):

14. TREND: PIEB likely has benefits over CEI and is gaining popularity in obstetric units throughout the country
ideal regimen
dose, interval, drug concentration

15. LABOR ANALGESIA
Neuraxial Anesthesia
Nitrous Oxide

16. Is it effective? Are patients satisfied?
Blender devise (Nitronox) or premixed (Entonox)
Likis FE et al. Anesth Analg 2014; 118(1):153-67

17. Proportion of “very effective” responses
Effectiveness
Retrospective questionnaire study (n=2482)
2 months postpartum
Proportion of “very effective” responses
Primiparas
Multiparas
Epidural
84%
72%
Nitrous
38%
49%
Waldenstom U et al. J Psychosom Obstet Gynaecol 2006; 27(3):147-56

18. Satisfaction Retrospective survey study (1999, Sweden)
Nitrous oxide associated with dissatisfaction with birth experience (independent of pain scores)
Prospective RCT (2000, Kuala Lumpur)
Nitrous oxide group less satisfied with pain relief compared to epidural group (p<0.01)
Waldenstrom U, et al. J Psychosom Res 1999; 47:471-82
Leong EW, et al. J Obstet Gynaecol Res 2000; 26:271-5

19. Vaginal deliveries with anesthetic care N=6242 Nitrous oxide
Delivered with nitrous
N=753 (60%)
Converted to neuraxial
N=493 (40%)
Neuraxial anesthesia
N=5261 (81%)
Richardson MG. Anesth Analg 2017; 124(2):548-53

20. Effectiveness Satisfaction
Richardson MG. Anesth Analg 2017; 124(2):548-53

21. TREND: Nitrous oxide is gaining popularity in the U. S
TREND: Nitrous oxide is gaining popularity in the U.S. as a labor analgesic and appears safe and reasonably effective in certain populations

22. CESAREAN ANESTHESIA

23. CESAREAN ANESTHESIA
Norepinephrine

24. Norepinephrine during Cesarean Delivery
Phenylephrine Reflex bradycardia
( agonist)  Cardiac output
Norepinephrine  Negative effects on (+ agonist) HR and CO
While norepinephrine is certainly not a common choice

25. Computer-controlled infusion
Starting dose: Norepinephrine µg/min Phenylephrine µg/min
CO 5min after induction greater in NE group
One investigator in particular
104
computer-controlled closed-loop
primary outcome
greater HR (decreased incidence bradycardia), lower SVR, similar neonatal outcomes
suprasternal Doppler (USCOM 1A Cardiac Output Monitor)
Ngan Kee WD, et al. Anesthesiology 2015; 122(4):736-45

26. Intermittent NE bolus (3, 4, 5, 6, 7, or 8 µg) when SBP<100% baseline
Primary outcome: success to maintain SBP≥80% from induction to delivery
ED90 ~ 6 µg
Onwochei DN, et al. Anesth Analg 2017; 125(1):212-18

27. Norepinephrine Protocol
Group 1 (infusion)
Started 2.5 ug/min
Titrated 0-5 ug/min
Group 2
(bolus)
No ppx vasopressor
5 ug bolus when SBP<80% baseline
110
primary outcome was the incidence of hypotension from IT injection through delivery,
incidence and timing – using survival analysis
systolic blood pressure was maintained closer to baseline in the infusion group
Ngan Kee WD, et al. Anesth Analg 2017; Epub ahead of print

28. Norepinephrine Protocol ≥ 1 Hypotensive Episode(%)
Total norepinephrine (median [IQR])
Group 1 (infusion)
Started 2.5 ug/min
Titrated 0-5 ug/min
17%
61.0 µg
[ ]
Group 2
(bolus)
No ppx vasopressor,
5 ug bolus when SBP<80% baseline
66%
5.0 µg
[0-18.1]
The infusion group also had significantly fewer episodes of hypotension overall as well as increased total dose of norepinephrine administered
Ngan Kee WD, et al. Anesth Analg 2017; Epub ahead of print

29. TREND: Dilute solutions of norepinephrine may be a reasonable alternative to phenylephrine for treatment of post-spinal hypotension

30. HEMORRHAGE

31. HEMORRHAGE
TXA
Oxytocin

32. WOMAN TRIAL WOMAN Trial Collaborators. Lancet 2017; 389:2105-16
2010 and 2016
20,000
death due to bleeding (shown in this forest plot)
within 3 hours of birth
flaws in study design
primary outcomes were adjusted mid-trial
WOMAN Trial Collaborators. Lancet 2017; 389:

33. “Given the mortality reduction findings, tranexamic acid should be considered in the setting of obstetric hemorrhage when initial medical therapy fails.”
Obstet Gynecol 2017; 130(4):923-5

34. WOMAN TRIAL: Trial Sites
Nigeria
Pakistan
Uganda
Kenya
Cameroon
Sudan
Tanzania
Nepal
Zambia
Albania
Democratic Republic of Congo
Bangladesh
Ethiopia
Burkina Faso
Ghana
clinical practice very different (early hyst, no blood, higher mortality rate)
Overall mortality rate %
Mortality 2/2 bleeding 1.5% (TXA) vs. 1.9% placebo
WOMAN Trial Collaborators. Lancet 2017; 389:

35. WOMAN TRIAL: Complications
safe (no thrombotic side effects)
mechanism makes sense (fibrinolysis is major component of PPH)
No difference in thromboembolic events or other complications (renal failure, cardiac failure, resp failure, hepatic failure, sepsis, seizure)
WOMAN Trial Collaborators. Lancet 2017; 389:

36. TREND: There is now data to suggest that TXA may be beneficial in the setting of uncontrolled PPH

37. HEMORRHAGE
TXA
Oxytocin

38. Oxytocin: NONLABORING Women
Reference
Year
Study Design
Oxytocin Dosing
Outcome
Carvalho et al.
2004
Biased coin up-down method
0.5 IU starting dose
ED90 = 0.35 IU
George et al.
2010
0.4 IU/min starting dose
ED90 = 0.29 IU/min
Sarna et al.
1997
RCT
5, 10, 15, 20 IU bolus
No difference in uterine tone between groups
Butwick et al.
0, 0.5, 1, 3, 5 IU bolus
Balki M, et al. Anesthesiol Clin 2014; 52:48-66

39. Oxytocin: LABORING Women
Reference
Year
Study Design
Oxytocin Dosing
Outcome
Balki et al.
2006
Biased coin up-down method
0.5 IU starting dose
ED90 = 2.99 IU
Munn et al.
2001
RCT
10 IU/500 ml over 30 min
80 IU/500 ml over 30 min
39% additional uterotonics
19% additional uterotonics
Balki M, et al. Anesthesiol Clin 2014; 52:48-66

40. Level A Recommendations
All obstetric care facilities should have guidelines for the routine administration of uterotonics in the immediate postpartum period
Uterotonic agents should be the first-line treatment for postpartum hemorrhage caused by uterine atony
The specific agent selected is at the health care provider’s discretion
Level B Recommendations
When uterotonics fail to adequately control postpartum hemorrhage, prompt escalation to other interventions are indicated
Tranexamic acid should be considered when initial medical therapy fails
Recommend existence of a designated multidisciplinary response team, a staged postpartum hemorrhage protocol that includes guidelines for escalation of care, and a functioning massive transfusion protocol
No specific mention of oxytocin for prophylaxis or treatment of hemorrhage, nor any recommended dosing regimens
Obstet Gynecol 2017; 130(4):923-5

41. WHO Guidelines for the Management of PPH
Dose and route
IV: Infuse 20 units in 1L IV fluids at 60 drops/min
Continuing dose
IV: Infuse 20 units in 1L IV fluids at 40 drops/min
Maximum dose
Not more than 3L of IV fluids containing oxytocin
Precautions/ Contraindications
Do not give as an IV bolus
No differentiation between laboring/nonlaboring
WHO guidelines; 2009

42. Balki M, et al. Anesthesiol Clin 2014; 52:48-66

43. TREND: Oxytocin doses can be lowered to minimize side effects while still achieving adequate uterine tone

44. OPIOID USE

45. The Ideal Opioid Prescription
Meet patients’ analgesic requirements
Minimize leftover opioids
severity and duration of pain
Normative opioid utilization patterns

46. 2 week postpartum telephone interview
85% filled opioid prescription at discharge
84% with unused tablets
survey study across 6 academic institutions in the US
contacted by phone 2 weeks following cesarean delivery
pain control and opioid use
720 subjects were included in the analysis
Bateman BT, et al. Obstet Gynecol 2017; 130:29-35

47. Patterns of Opioid Prescription and Use After Cesarean Delivery
Tablets dispensed
predicts
Median # prescribed: 40
Median # consumed: 20
The largest predictor of the number of tablets consumed by subjects was the number of tablets they had been prescribed,
EVEN AFTER adjusting for confounders such as pain scores
Tablets consumed
Bateman BT, et al. Obstet Gynecol 2017; 130:29-35

48. Patterns of Opioid Prescription and Use After Cesarean Delivery
>opioid related side effects
> tablets consumed when more were dispensed
NO DIFF
pain scores at 1 or 2 weeks
satisfaction with pain control
need for refills
Bateman BT, et al. Obstet Gynecol 2017; 130:29-35

49. TREND: Tailored opioid prescriptions post-cesarean delivery may help to prevent overprescribing and potential for diversion
shared decision making
algorithm-based prescribing based on inpatient opioid consumption

50. Benefits of PIEB include improved maternal satisfaction and likely need for fewer “top ups” Nitrous oxide is associated with reasonable effectiveness and satisfaction in motivated patients Norepinephrine may be a reasonable alternative to phenylephrine for treatment of post-spinal hypotension

51. TXA should be considered in the setting of uncontrolled PPH
Oxytocin doses can be lowered to minimize side effects while still achieving adequate uterine tone
Tailored opioid prescriptions post-cesarean delivery may help to prevent overprescribing and potential for diversion