Obstetric anesthesia for the obese and morbidly obese patient: an ounce of prevention is worth more than a pound of treatment - PowerPoint PPT Presentation

Loading...

PPT – Obstetric anesthesia for the obese and morbidly obese patient: an ounce of prevention is worth more than a pound of treatment PowerPoint presentation | free to download - id: 4329ec-ZDBhY



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

Obstetric anesthesia for the obese and morbidly obese patient: an ounce of prevention is worth more than a pound of treatment

Description:

Obstetric anesthesia for the obese and morbidly obese patient: an ounce of prevention is worth more than a pound of treatment Soens MA, Birnbach DJ, Ranasinghe JS ... – PowerPoint PPT presentation

Number of Views:1123
Avg rating:3.0/5.0
Slides: 27
Provided by: Revi180
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Obstetric anesthesia for the obese and morbidly obese patient: an ounce of prevention is worth more than a pound of treatment


1
Obstetric anesthesia for the obese and morbidly
obese patient an ounce of prevention is
worth more than a pound of treatment
  • Soens MA, Birnbach DJ, Ranasinghe JS, van Zundert
    A.
  • Acta Anaesthesiol Scand. 2008 Jan 52(1) 6-19.

2
  • Maternal and fetal morbidity
  • Pregnancy, obesity and physiology
  • Anesthetic management of the obese parturient
  • Analgesia for labor
  • Continuous lumbar epidural analgesia
  • Combined spinal epidural (CSE) anesthesia
  • Continuous spinal analgesia
  • Anesthesia for cesarean delivery in the obese and
  • morbidly obese patient
  • Regional anesthesia
  • General anesthesia
  • Post-partum morbidity

3
Maternal and fetal morbidity
  • Obesity? ?? complications
  • Diabetes mellitus, hypertension, coronary
    artery disease, cerebrovascular disease, and
    gallbladder and liver disease.
  • pre-pregnancy maternal obesity? ??
  • pregnancy-induced risk
  • hypertension, venous thromboembolism, labor
    induction, cesarean delivery, gestational
    diabetes , large-for-gestational age fetuses,
    fetal macrosomia, neural tube defect(such as
    spina bifida), difficult ultrasono-exam. and
    wound infection.

4
Pregnancy, obesity and physiology
  • ???? sensation of dyspepsia
  • Uterus? respiratory function? ??? ??? ??? ??
  • ?? 5?? ??
  • Progressive decrease in expiratory reserve
    volume, residual volume,
  • fuctional RV ? Increased risk for
    obstructive sleep apnea
  • associated
    with systemic HTN, pulmonary HTN
  • importance of pre-oxygenation
  • Increased risk for coronary artery disease,
    stroke, cardiac arrhythmia
  • Increased risk for aspiration(Mendelsons
    syndrome) lower gastric pH
  • Increased risk for difficult or failed intubation

5
Anesthetic management of the obese parturient
  • Analgesia for labor
  • Continuous lumbar epidural analgesia
  • Combined spinal epidural (CSE) anesthesia
  • Continuous spinal analgesia

6
Analgesia for labor
  • Fetal macrosomia? incidence? ???? painful
    contraction? complicated labor? ???? ??.
  • BMI vs Severity of labor pain A positive
    correlation (Melzack et al.)
  • Regional analgesia many advantages in the
    obstetric patient,
  • BUT difficult anesthetic
    technique in the obese parturient.
  • General anesthesia for c/sec much higher risk of
    maternal mortality
  • as compared with regional
    anesthesia. (Hawkins and colleagues)
  • ?? ??? Maternal death claims? ?? ??? ?? ?? ??? ??
  • ? ???? ??. (The 1991 ASA Closed Claim Study)
  • The incidence of failed intubation in the
    morbidly obese parturient

  • High as 33
  • The American College of Obstetricians and
    Gynecologists (ACOG)
  • ??? ??? ??? ???? ?? ???? functioning epidural
    or spinal catheter? ???? ?? ?? ?? ??.

7
Continuous lumbar epidural analgesia
  • Anatomical landmarks? ??? ?? epidural placement?
  • morbidly obese patients? ??? often difficult.
  • Jordan et al.? ??? 1? ??? ??? ??? ??? 74.4??
  • 3? ?? ? ??? 14?
    ???.
  • ?? accidental dural puncture? incidence? 4(in
    morbidly
  • obese parturients)? ???? ??(0.52.5 in
    non-obese patients)
  • ?? ??.
  • 1) The patient position? Catheter insertion
  • (1) lateral recumbent head-down position
  • decrease the incidence of
    intravascular placement
  • by reducing venous congestion in
    the epidural veins
  • (2) sitting position
  • the line joining the occiput or
    prominence of C7 and the
  • gluteal cleft can be used to
    approximate the position of
  • the midline.

8
Continuous lumbar epidural analgesia
  • 2) Distance from the skin to the epidural space
  • (1) significantly shorter in the sitting
    position
  • (compared with the lateral decubitus
    position. (Hamza et al.)
  • (2) Hamza et al. also epidural space??? ???
    weight? BMI
  • ?? positively
    correlation? ???.
  • (3) HOWEVER, Watts? BMI is a poor predictor of
    distance to
  • the epidural space compared with the
    non-obese group.
  • (4) Only a few patients have an epidural space
    deeper than
  • 8cm (Hamza J et al.)
  • Standard epidural needle for the first
    attempt,
  • instead of one of the longer epidural
    needles available.

9
Continuous lumbar epidural analgesia
  • 4) Identify the midline of the spine
  • (1) Morbidly obese patients? ???, identify
    the midline??
  • ?? ?? tool? ?? ?? ?? ??? ? ? ??.
  • whether she feels the needle more on the
    left or the right
  • side of the spine-gt most accurate, with
    90 of the
  • volunteers able to identify the midline
    to within 6.5 mm.

  • ( In a pilot study by
    Wills et al.)
  • (2) Ultrasound guided approach?
  • Grau et al.? paramedian longitudinal
    approach? ??? ???
  • ?, ???? ??? transverse approach? ? ??? ??.

10
Continuous lumbar epidural analgesia
  • 5) Correct epidural catheter placement
  • (1) 3 cm skin movement in some patients,
    epidural catheters
  • ? walk? ???? routinely place
    catheters 7 cm in the
  • epidural space (Iwama and Katayama)
  • (2) Epidural catheters? ????? ?? skin? ????
    ??
  • inward?? 12.5cm ?? ??? ? ??? BMIgt30?
    ??
  • ? ? ?? ????? ?????. (Hamilton et al.)

11
Combined spinal epidural (CSE) anesthesia
  • Compared with classical epidural,
  • CSE provides a faster onset of effective pain
    relief,
  • and increases patient
    satisfaction.
  • However, intrathecal opioids? ???? ?? incidence
    of uterine hyperactivity and fetal heart rate
    abnormalities? ???? ??. controversial.
  • Due to increased abdominal pressures,
  • lower epidural analgesic requirements in obese
    parturients
  • (compared with normal patients).

12
Continuous spinal analgesia
  • Relatively high failure rate of epidural
    catheters in the obese population (accidental
    dural puncture), ???? often prefer intentional
    continuous spinal analgesia/anesthesia? ????? ??.
  • ONE possible complication of the continuous
    spinal
  • technique post-dural puncture headache
    (PDPH),
  • occurring in 3070 of obstetric patients
    following accidental
  • dural puncture with a 17 gauge Tuohy needle.
  • Faure et al.? the risk of PDPH is significantly
    decreased in
  • morbidly obese parturients. (because of
    ?elevating intra-
  • abdominal pressures and ?reducing the degree
    of spinal fluid
  • leakage through the dural puncture site)
  • ????? CSA? incidence of spinal headache?
    1????.
  • Catheter insertion 24 cm in the subarachnoid
    space.

13
Anesthesia for cesarean delivery in the obese and
morbidly obese patient
  • Obesity significantly increases the incidence
    of cesarean delivery.
  • Nulliparous patients a cesarean delivery rate
    (Weiss et al.)
  • -20.7 in the control group
  • -33.8 in the obese
  • -47.4 in the morbidly obese group
  • Obesity in maternal mortality, morbidity and
    operative Cx.
  • - Excessive blood loss
  • - Increased operative time
  • - Increased incidence of post-operative
    wound infection and
  • endometritis.

14
Anesthesia for cesarean delivery in the obese and
morbidly obese patient
  • morbidly obese parturient? ?? ? ??
  • ?? ? ??? ??? ??? ??? ?? ??? ??? ????,
  • ????, panniculus retraction, thromboembolism
  • prophylaxis, type and cross match,
    post-operative care and
  • overnight monitoring in an intensive care
    unit and possible
  • comorbidities and their consequences?? ?? ???
    ??.
  • (2) ????
  • (a) two operating tables (side by side)
  • impossible to raise, lower or change
    the position of the
  • tables in a completely synchronous
    manner.
  • (b) use one set of armboards
  • (3) the morbidly obese parturient? ??
  • (a) regional anesthesia? ???? ??? ??
  • position?? ??? ??
  • (b) sleep apnea? ?? ?? ? ? CPAP? ????? ??.

15
(No Transcript)
16
(No Transcript)
17
Anesthesia for cesarean delivery in the obese and
morbidly obese patient
  • The pre-operative initiation of CPAP in
    patients with severe obstructive sleep apnea, as
    this may improve their preoperative condition
    (The ASA Practice Guidelines for the
    Perioperative Management of Patients with
    Obstructive Sleep Apnea recommend).
  • Risk factor for venous thromboembolism
  • ?
    prophylaxis should be considered.
  • Difficulty with non-invasive blood pressure
    monitoring
  • radial intra-arterial catheter may be
    preferable,
  • especially in patients with comorbidities such
    as chronic hypertension and preeclampsia.

18
Regional anesthesia
  • ?? ??? ?? ?? ?? ??????? ??? ?? ????? high
    spinal block? ???? ??.
  • 1) Lower average CSF volume with a high BMI
  • decreased local anesthetic dose
    requirements in obese
  • patients due to decreased anesthetic
    dilution
  • 2) External abdominal compression and abdominal
    pressure
  • 3) Compression of the dural sac due to
    engorgement of the
  • epidural venous plexus and increased
    epidural space pressure

19
Regional anesthesia
  • Spinal anesthesia? c/sec?? ?? ??? ????
  • ??? ?? ??? ?? ??? ?? risk? ??.
  • 1) Risk of a high spinal block.
  • 2) ??? ??? ? ??? ???? ??? ??? ? ??.
  • ??? ??? ??? ??? ??? ? ???
  • 25??? ?? ???? ??? ????? ?? ? ??.
  • CSE technique lower doses of local
    anesthetics??
  • (compared with a
    single-shot spinal technique)
  • CSA catheter allows incremental dosing and
    precise extension of
  • the block
  • ?? ? Inadequate block?? ?? ????? ?? ? ??? ????
  • ???? catastrophic sequelae? ??? ? ??.

20
General anesthesia
  • Prevention of acid aspiration
  • 1) ??? ?????, ?? ?? 30??? antacid??
  • 2) ??????????, ??? ????? ?? ??? ?? 60-90
  • ??? H2 antagonist(ex. ranitidine) or
  • a proton pump inhibitor(ex.
    Omeprazole) ??
  • 3) ???? ?? ??? ??? ?? ??? ??
  • prokinetic agent? metoclopramide? ?? ???
    ?? ??.
  • Difficult airway? ??? ?? ??.
  • 1) ??, a large neck circumference and/or
  • a high Mallampati score
  • 2) ??? mask ventilation??? ??? ? ??.

21
General anesthesia
  • Preoxygenation(denitrogenation) before
    induction of G/A
  • 1) (m/c method) 35min of 100 O2 breathing.
  • 2) 4 maximally deep inspirations of 100 O2
    within 30 s
  • 3) 8 deep breaths within 60 s at an oxygen flow
    of 10 L/min
  • (more suitable for obstetric emergencies)
  • Position
  • 1) Pre-oxygenation? sitting? more effective
  • 2) failed intubation? ???? ?? ??? rapid
    sequence
  • induction with cricoid pressure ??
  • 3) elective??? awake fiberoptic intubation? ??
  • 4) fail???? ???? LMA? ??
  • 5) the ramped position improves the
    laryngeal view

22
General anesthesia
23
General anesthesia
24
General anesthesia
25
General anesthesia
  • ????? ????? ??
  • Oebsity blood volume, cardiac output and muscle
    mass? ??
  • 1) Thiopental higher initial induction dose,
    but ?????
  • ????? failed Intubation?
    ??? ????
  • 2) Propofol ??? initial distribution volume?
    ??? ??.
  • 3) Succinylcholine choice for intubation in the
    obstetric patient.
  • 4) ?? ??? obese patient? ?? ???? O2? ??? ??.
  • ( ???? N2O??? ???.)
  • 5) Desflurane faster recovery time ? higher
    oxygen saturations on entry in the recovery room
    (compared with sevoflurane)
  • 6) ?? ? ??? ???? ??? ?? midazolam? ??? ???
  • ??? ? ??.
  • 7) In obesity, lipophilic???? Prolonged
    sedation? ? ????
  • fully awake? ???? ?? ??.
  • semi-upright position
  • abdominal contents? ?? diaphragm? compression?
    ??

26
Post-partum morbidity
  • Post-partum complications
  • hemorrhage, endometritis, wound infection,
    respiratory depression, deep venous thrombosis,
    pulmonary embolism, hypoxemia
  • 1) Increased risk of endometritis and wound
    infection
  • ? prophylactic antibiotics after clamping the
    umbilical cord.
  • 2) Increased risk of respiratory depression and
    hypoxemia
  • ? Semirecumbent position, early mobilization
    and adequate pain
  • control (early resolution of atelectasis
    and a faster recovery of
  • pulmonary function.)
  • 3) Increased risk for venous thromboembolism
  • ? low molecular-weight heparin (LMWH) therapy
  • (1) European guidelines single daily dosing
    of LMWH
  • - catheters remove 1012 h after the
    last dose of LMWH
  • and 4 h
    before the next dose
  • (2) United States guidelines twice-daily
    dosing of LMWH
  • - catheters remove 2 h before the
    first
  • and the first
    dose should be 24 h after surgery.
  • 4) opioids? risk for respiratory depression? ??
    ???? ??
About PowerShow.com