Improving Preterm Labor Management

1
Improving Preterm Labor Management

• Eric M. Buenviaje
• LCDR MC USN
• Naval Hospital Bremerton

2
The Case

• BR is a 23 year-old G1P0 at 313 weeks EGA who
  presented to the APTU
• Reported contractions of worsening severity and
  increasing frequency over 12 hours since
  intercourse
• No LOF or bleeding, Positive fetal movements
• No foul-smelling discharge or abdominal pain

3
The Case

• Uncomplicated prenatal course
• No tobacco, EtOH
• Meds PNV
• PMH, PSurgH, OBHx, GynHx, Soc Hx Unremarkable

4
The Case

• Exam
• Vitals Within Normal Limits
• Cervical 8cm/Complete/? Station (bulging bag)
• FHT pattern overall reassuring
• Labs
• GBS unknown O positive otherwise unremarkable

5
Initial Treatment

• Trendelenburg
• Terbutaline 0.25mg SQ x1
• Dexamethasone 6mg IM x 1 administered
• Magnesium Sulfate 4g load and 2g/hour IV infusion
  started
• Admitted secondary to advanced cervical
  dilatation

6
Initial Evaluation and Treatment

• Patient was counseled regarding the risks of
  preterm labor and the risks and benefits of
  Tocolysis for fetal considerations
• Unasyn 3g IV q6h started for exposed membranes
  and unknown GBS status
• Biometry Vertex Male, estimated FW 2113 grams,
  posterior placenta, GFM
• Initial contact made with Peds, MAMC MFM and NICU

7
Hospital Course

• Dexamethasone administered at q12 hour dosing
  schedule.
• Clinically, stable with no signs of magnesium
  toxicity
• Magnesium increased progressively to 4g/hour when
  contractions continued.

8
Hospital Course (contd)

• Magnesium infusion
• Later that day Nausea treated with IV
  antiemetics. Contractions essentially resolved.
• 12 hours into admission extreme nausea, fatigue,
  diplopia, hyporeflexia (Mag level 10.8)
• Decreased magnesium to 1g/hour with improved sx,
  but return of contractions.
• Magnesium d/cd, Nifedipine started.

9
Hospital Course (contd)

• After 24 hours, decision was made to AROM and
  deliver the child vaginally
• By early afternoon of that day, an infant male
  with apgars of 8/9 weighing 1927 grams was
  delivered and transferred to MAMC.

10
Process Improvement

• NHB 2nd Year Resident Process Improvement
  Projects
• Based on Standard Process Improvement Model --
  FOCUS-PDCA
• Exercise in process analysis, implementation of
  improvements, and the appropriate application of
  leadership in the military hospital setting

11
The Project

• Process Improvement
• Method of examining processes and making them
  more effective
• Benefits patients by providing better, more
  efficient care
• Benefits the command by reducing waste, cost,
  errors, and variability and increasing efficiency

12
FOCUS - PDCA

• Find a process to improve
• Organize a team and its resources
• Clarify current knowledge about the process
• Understand sources of variation and clarify steps
  in the process
• Select an improvement or intervention

13
FOCUS - PDCA

• Plan analyze the process, determine changes
  that would improve the process
• Do Put your change into motion on a small
  scale/trial basis
• Check/Study check to see if the change is
  working
• Act if the change works, implement on a larger
  scale if not, refine/reject, and try again

14
Preterm Labor

• The presence of contractions with progressive
  cervical effacement and dilation between 20-37
  weeks gestation
• 11-12 of all births in the U.S. are preterm
• Accounts for 70 of neonatal mortality
• Estimated cost 6 billion annually
• When Tertiery Care is not an option

15
Literature Search

• OVID Search
• Systematic Reviews
• OB Reviews
• OB Literature
• ACOG Practice Guidelines/Technical Bulletins

16
Tocolytics for Preterm Labor

• Delay Delivery
• Administration of Corticosteroids
• Reduces risk of neonatal RDS and mortality
• Goal is 48 hours, although some benefit is seen
  at 18 hours

17
Tocolytics

• The Evidence
• Magnesium Sulfate
• Calcium Channel Blockers
• Betamimetics
• COX Inhibitors

18
Tocolytics

• Contraindications
• Non-reassuring fetal assessment
• Intra-uterine fetal demise
• Severe IUGR
• Chorioamnionitis
• Maternal hemorrhage with hemodynamic instability
• Severe preeclampsia or eclampsia
• Lethal fetal anomaly

19
Magnesium Sulfate

• Efficacy
• Failed to demonstrate benefit vs placebo for
  prolongation of pregnancy. Cochrane review of 23
  trials showed no evidence of clinically important
  effect and did not significantly reduce the
  proportion of deliveries within 48 hours.

20
Magnesium Sulfate

• Side Effects
• Fewer maternal side effects vs beta-mimetics
• Diaphoresis
• Flushing
• Nausea, vomiting, headaches, visual disturbances
• Loss of DTRs
• Pulmonary edema
• Possible increased fetal/neonatal complications
• Slight decrease in baseline FHR and variability
• Increased risk of total perinatal deaths
• Recommendation Magnesium Sulfate should not be
  used for tocolysis

21
Magnesium Sulfate

• Contraindications
• Myasthenia gravis
• Known myocardial compromise or hx of conduction
  abnormalities
• Impaired renal function

22
Nifedipine

• Efficacy
• No placebo-controlled trials. Nifedipine has
  been compared vs other tocolytics.
• Reduced s giving birth within 7 days (RR 0.76
  95CI 0.60-0.97). More effective than
  beta-mimetics in delaying delivery for 48 hours.
  Also noted were apparent reduction trends in NN
  RDS, NEC, and IVH.

23
Nifedipine

• Side Effects
• Maternal Nausea, flushing, headaches,
  dizziness, palpitations, decreased MAP (often
  with associated reflex tach)
• Fetal Animal studies reveal decreased uterine
  blood flow, but human doppler studies have not
  demonstrated this.
• Contraindications
• Concurrent use of other tocolytics, esp MgSO4
  could be synergistic, resulting in respiratory
  paralysis and/or cardiovascular collapse

24
Nifedipine

• Bottom line
• May be used as a first-line tocolytic with less
  severe side-effect profile than Magnesium or
  beta-mimetics

25
ß-mimetics(terbutaline and ritodrine)

• Efficacy
• 2 meta-analyses (890 and 1000 patients)
  demonstrated decreased likelihood of delivery
  within 48 hours of therapy initiation without
  significant increase in infant death rates

26
ß-mimetics

• Side effects
• Maternal
• Cardiotropic effects (increase heart rate,
  decreased stroke vol).
• Chest discomfort, palpitations, SOB. Myocardial
  ischemia and pulmonary edema are rare.
• Hypokalemia, hyperglycemia
• Fetal
• Tachycardia
• Hypoglycemia

27
ß-mimetics

• Contraindications
• Cardiac disease
• Hyperthyroidism
• Diabetes Mellitus
• Special Considerations
• Check serum K and glucose periodically

28
COX inhibitors(Indomethacin)

• Efficacy
• Systematic review found that COX inhibitors were
  effective in reducing birth before 37 weeks of
  gestation (RR 0.53, 95CI 0.31-0.94)
• More effective than placebo in inhibiting PTL
  over a 24 hour course of therapy

29
COX inhibitors

• Side Effects
• Maternal Nausea, reflux, gastritis, and emesis
  (approx 4)
• Fetal
• Ductus arteriosus
• Premature narrowing or closure
• More severe PDA post-partum
• Oligohydramnios
• Decreased fetal urine output
• Other possible
• Bronchopulmonary dysplasia, NEC, IVH?

30
COX inhibitors

• Contraindications
• Platelet dysfunction
• Bleeding disorder
• Asthma
• GI ulcerative disease
• Renal dysfunction
• Sonography q week for oligohydramnios and ductus
  arteriosus constriction if therapy gt48 hours

31
Summary

• Select agent based on efficacy and safety
  particular to each patient
• Beta-mimetics and indomethacin are more effective
  than placebo in prolonging gestation. Nifedipine
  has not been compared vs placebo, but appears to
  be as efficacious as other tocolytics (with a
  more desirable side effect profile).
• Know risks and side effects of each agent
• Caution with concurrent use

32
Other Issues

• Pediatrics
• No NICU, limited nursery capabilities
• No in-house peds after hours
• Equipment requirements for preterm delivery
• Isolette
• Appropriate sizes for ETT, NGT, blades
• Surfactant availability
• Appropriate concentration/dose of meds

33
(No Transcript)
34
(No Transcript)
35
(No Transcript)
36
References

• American College of Obstetricians and
  Gynecologists. Management of Preterm Labor. ACOG
  Practice Bulletin 43. American College of
  Obstetricians and Gynecologist, Washington, DC
  2005.
• Anotayanonth, S. Betamimetics for inhibiting
  preterm labor, Cochrane Database of Syst Rev 2005
• Crowther, C et al. Magnesium sulphate for
  preventing preterm birth in threatened preterm
  labour. Cochrane Database of Syst Rev 2005.
• Gyetvai, K et al. Tocolytics for preterm labor
  a systematic review. Obstet Gynecol 1999
  94869.
• Hollier, L. Preventing Preterm Birth What
  Works, What Doesnt. Obstetrical and
  Gynecological Survey 2005 602.
• Hyagriv, S and Cartis, S. Inhibition of preterm
  labor. UpToDate version 13.3, 2005
• King, JF et al. Calcium channel blockers for
  inhibiting preterm labour. Cochrane Database
  Syst Rev 2005.
• King, J. Cyclo-oygenase inhibitors for treating
  preterm labor. Cochrane Database of Syst Rev
  2005.
• Rodts-Palenik, S. and Morrison, J. Tocolysis An
  Update for the Practitioner. Obstetrical and
  Gynecologic Survey 2002 575.

37
Project Status

• M M
• FOCUS
• PDCA
• PAB Review
• Add to LD protocol notebook

38
Questions?