WOMEN AND NEWBORN HEALTH SERVICE
King Edward Memorial Hospital
CLINICAL GUIDELINES
ANAESTHETICS
4. LABOUR ANALGESIA
Date Issued: August 2007
Date Revised: Feb 2014
Review Date: Feb 2017
Authorised by: Dept of Anaesthesia and Pain Medicine
Review Team: Dept of Anaesthesia and Pain Medicine
4.11 Intravenous Patient-Controlled Analgesia in Labour - Medical
Section E
Clinical Guidelines
King Edward Memorial Hospital
Perth Western Australia
4.11 INTRAVENOUS PATIENT-CONTROLLED ANALGESIA IN
LABOUR - MEDICAL
Intravenous and intramuscular opioids are at best of only very modest efficacy in reducing the intensity
1
2, 3
of pain during labour , but do result in clinically meaningful relief for about 30% of women .
Patient-controlled intravenous analgesia (PCIA) with opioid is a method that may also produce
satisfactory analgesia for a proportion of labouring women. PCIA with remifentanil is more effective and
4-6
reliable than intramuscular or intravenous morphine and pethidine or nitrous oxide inhalation . The
fetal and neonatal effects of repeated maternal opioid exposure must be considered and staff skilled in
neonatal resuscitation available.
MEDICAL CONTRAINDICATIONS INCLUDE
1.
Allergy to the proposed opioids (usually fentanyl or remifentanil).
2.
The presence of clinically significant maternal respiratory depression from previous exposure to
opioids and sedatives.
INTRAVENOUS PATIENT-CONTROLLED ANALGESIA MANAGEMENT
This patient-controlled intravenous analgesia (PCIA) approach is used infrequently during labour at
King Edward Memorial Hospital (KEMH) but is widely used postoperatively and patient-controlled
epidural analgesia (PCEA) is frequently used during labour.
PCIA is most commonly used for women who have poorly controlled pain and who have
contraindications to, are unsuitable for, or who refuse to have, epidural analgesia.
Opioids without active metabolites and with less adverse clinical effect on the neonate are preferable
7
for PCIA. Currently those of choice are fentanyl and remifentanil (which has had substantial recent
investigation in this setting, although this is not an approved indication).
GENERAL PRINCIPLES
PCA has some inherent advantages in allowing the woman to titrate analgesic against the fluctuating
pattern and changing intensity of labour pain. Nevertheless, as with nitrous oxide inhalation, it is not
possible to time self-administration such that peak analgesic effect coincides with peak pain intensity
during a contraction, even with an extremely rapidly and short acting drug such as remifentanil.
The potential exists for maternal respiratory depression, particularly between contractions,
8, 9
mandating continuous monitoring . In addition, the very high potency of remifentanil can cause an
overdose after inadvertent administration of a very small volume of remifentanil solution (1mL to 2mL).
Meticulous attention to intravenous cannula function and administration sets is necessary to
avoid back-flow of solution into intravenous tubing or flushing of dead-space solution.
Intravenous PCA should be administered via a dedicated small gauge ( eg 20G or 22G ) intravenous
cannula with the PCA administration set connected directly to this cannula. No other fluids or
medications are to be given through this administration set or cannula.
Blood pressure measurements should be taken in the opposite arm to the PCA to ensure unimpeded
flow of remifentanil/fentanyl into the systemic circulation.
Midwives should be familiar with the operation of the Gemstar patient controlled analgesia pump, which
is the only electronic PCA pump currently used at KEMH.
DPMS
Ref: 8689
All guidelines should be read in conjunction with the Disclaimer at the beginning of this manual
Page 1 of 4
INTRAVENOUS PATIENT-CONTROLLED ANALGESIA IS AVAILABLE WHEN THERE IS
SUFFICIENT ANAESTHETIC COVER TO MEET ALL HOSPITAL SERVICE REQUIREMENTS
The anaesthetist should be contacted by the obstetrician or midwife. An adequate history should be
provided to the anaesthetist.
ONLY AN ANAESTHETIST SHOULD PROGRAM THE PCA PUMP OR ADJUST VARIABLES
The choice of opioid, dosing and drug delivery method is the decision of the anaesthetist, in
consultation with the woman, obstetrician and midwife.
The anaesthetist should stay with the patient until at least 5 min after the first dose is administered.
Room lighting should be appropriate to allow early detection of sedation and respiratory depression.
MONITORING
Continuous maternal respiratory monitoring should be used. This includes

continuous pulse oximetry

continuous presence of a registered nurse/midwife or medical staff in the room

observation of conscious state and respiratory rate 30 minutely.
An oxygen source must be readily accessible and naloxone should be available within the labour and
birth room.
The following algorithm is suggested:
1. If maternal oxygen saturation is 85% - 94%,, respiratory rate is above 8, and patient is awake
then oxygen should be administered via Hudson mask at 6L/min and the woman should be
encouraged to take deep breaths. Oxygen delivery may be changed to nasal prongs at 2 to
3L/min to maintain saturation above 94%.
2. If saturations remain 85% - 94% or respiratory rate is 5 - 8/min or patient is drowsy ( sleepy but
responds to verbal stimulation) : stop the PCA pump and notify the duty anaesthetist ( direct dial
6225 ) The anaesthetist may choose to modify or cease the PCA regimen or to administer higher
concentrations of oxygen or naloxone.
3. If the saturation is less than 85% or respiratory rate less than 5/min or patient does not respond to
verbal stimulation : give naloxone 400microgram intravenously, call a “code blue medical” and
support airway and ventilation as required.
NEONATAL CARE
A person skilled in neonatal resuscitation must be present at the time of birth. In cases in which large
doses of opioid have been administered, it may be appropriate to ensure that a neonatology staff
member is present.
Opioids may cause neonatal respiratory depression (sedation, apnoea, slow establishment of
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respiration and hypoventilation). Remifentanil may rarely cause neonatal chest wall rigidity making
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positive pressure ventilation difficult . Naloxone may be required.
PCIA REGIMENS
FENTANYL
5microgram/mL solution (500microgram in 100mL Sodium chloride 0.9% via Gemstar PCA
pump)

Commence with a demand only approach (20 to 25microgram in 4 to 5mL depending on the
intensity of pain) using a 5 minute lockout time.

If ineffective, the anaesthetist may choose to increase the bolus dose, shorten the lockout time or
add a continuous infusion (e.g. 25microgram/hour).
Date Issued: August 2007
Date Revised: February 2014
Review Date: February 2017
Written by:/Authorised by: Department of Anaesthesia and Pain Medicine
Review Team: Department of Anaesthesia and Pain Medicine
DPMS Ref: 8689
4.11 Intravenous Patient-Controlled Analgesia in Labour - Medical
Section E
Clinical Guidelines
King Edward Memorial Hospital
Perth Western Australia
All guidelines should be read in conjunction with the Disclaimer at the beginning of this manual
Page 2 of 4
REMIFENTANIL
20microgram/mL solution (2mg in 100mL Sodium chloride 0.9%)
 May be more effective than fentanyl.
 More rapid onset and offset.
 Minimal accumulation of maternal plasma remifentanil and thus possibly lower incidence of
12, 13
neonatal respiratory depression.
 Remifentanil 2mg is in the Labour and Birth Suite Schedule 8 cupboard.
 If the maternal weight is > 100kg, calculate dosing at 100kg
 Use a demand bolus of 30microgram (1.5 mL) with a lockout of 2 minutes (Two Blue Gemstar with
a 2 minutes lock out are stored in Theatre recovery. Ask the theatre co-ordinator or recovery staff
for the pump and sign the log book so that the pump can be tracked and returned. Do not use a
Gemstar with a 5 minute lock out).
 The bolus dose must be delivered over 60 seconds.
If analgesia is unsatisfactory, consider adding a background infusion of 0.05microgram/kg/min
15ml/hr for 100kg woman ), then increasing the bolus dose to a maximum of
14, 15
80microgram (4 mL)
. The background infusion can be increased to a maximum of
0.1microgram/kg/min (30ml/hr for 100kg woman ).
(
KETAMINE
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Rarely, a ketamine infusion may be used in conjunction with PCIA . Indications include severe
uncontrolled pain and PCIA in an opioid-tolerant patient.
An appropriate regimen is ketamine 100mg in 100mL Sodium chloride 0.9% via an intravenous
17
infusion pump, at 0.1mg/kg/hour (for a 100kg woman, 10mL/hour) .
REFERENCES
1.
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4.
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6.
7.
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9.
Olofsson CH, Ekblom A, Ekman-Ordeberg G, Hjelm A, Irestedt L. Lack of analgesic effect of
systemicallly administered morphine or pethidine on labour pain. British Journal of
Obstetrics and Gynaecology. 1996;103:968-72.
Tsui MHY, Ngan Kee WD, Ng FF, Lau TK. A double-blind randomised placebo-controlled
study of intramuscular pethidine for pain relief in the first stage of labour. BJOG.
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Nelson KE, Eisenach JC. Intravenous butorphanol, meperidine and their combination relieve
pain and distress in women in labor. Anesthesiology. 2005;102:1008-13.
Thurlow JA, Laxton CH, Dick A, et al. Remifentanil by patient-controlled analgesia compared
with intramuscular meperidine for pain relief in labour. British Journal of Anaesthesia.
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Evron s, Glezerman M, Sadan O, Boaz M, Ezri T. Remifentanil: a novel systemic analgesic for
labor pain. Anesthesia and Analgesia. 2005;100:233-8.
Volmanen P, Akural E, Raudaskoski T, Ohtonen P, Alahuhta S. Comparison of remifentanil
and nitrous oxide in labour analgesia. Acta Anaesthesiol Scandinavia. 2005;49:453-8.
Morley-Forster PK, Reid D, Vanderberghe H. A comparison of patient-controlled analgesia:
fentanyl and alfentanil for labour analgesia. Canadian Journal of Anesthesia. 2000;47:113-9.
Egan TD, Kern SE, Muir KT, White J. Remifentanil by bolus injection: a safety,
pharmacokinetic, pharmacodynamic and age effect investigation in human volunteers. British
Journal of Anaethesia. 2004;92:335-43.
Richardson SP, Egan TD. The safety of remifentanil by bolus injection. Expert Opinion on
Drug Safety. 2005;4:643-51.
Date Issued: August 2007
Date Revised: February 2014
Review Date: February 2017
Written by:/Authorised by: Department of Anaesthesia and Pain Medicine
Review Team: Department of Anaesthesia and Pain Medicine
DPMS Ref: 8689
4.11 Intravenous Patient-Controlled Analgesia in Labour - Medical
Section E
Clinical Guidelines
King Edward Memorial Hospital
Perth Western Australia
All guidelines should be read in conjunction with the Disclaimer at the beginning of this manual
Page 3 of 4
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Morley-Forster PK, Weberpals J. Neonatal effects of patient-controlled analgesia using
fentanyl in labor. International Journal of Obstetrics and Anesthetics. 1998;7:103-7.
Carvalho B, Mirikitani EJ, Lyell D, Evans DA, et al. Neonatal chest wall rigidity following the use
of remifentanil for caesarean delivery in a patient with autoimmune hepatitis and
thrombocytopenia. International Journal of Obstetrics and Anesthetics. 2004;13:53-6.
Kan RE, Hughes SC, Rosen MA, et al. Intravenous remifentanil. Placental transfer, maternal
and neonatal effects. Anesthesiology. 1998;88:1467-74.
Volidas I, D M. Acomparison of pethidine and remifentanil patient-controlled analgesia in
labour. International Journal of Obstetrics and Anesthetics. 2001;10:86-90.
Balki M, Kasodedar S, Dhumne S, Bernstein P, Carvalho J. Patient-controlled analgesia with
background remifentanil infusion for labor pain. Anesthesiology. 2006;104(Supp 1):A-13.
Volmanen P, Akural E, Raudaskoski T, et al. Remifentanil in obstetric analgesia: a dosefinding study. Anaesthesia Analgesia. 2002;94:913-7.
Maroof M, Hakeem S, Khan RM. Ketamin 0.25mg/kg/hr infusion is effective in relieving labor
pain without incoherence. Anesthesiology. 1999;ASA abstracts: A1073.
Schmid RL, Sandler AN, Katz J. Use and efficacy of low dose ketamine in the management of
acute post operative pain. Pain. 1999;82:111-25.
Date Issued: August 2007
Date Revised: February 2014
Review Date: February 2017
Written by:/Authorised by: Department of Anaesthesia and Pain Medicine
Review Team: Department of Anaesthesia and Pain Medicine
DPMS Ref: 8689
4.11 Intravenous Patient-Controlled Analgesia in Labour - Medical
Section E
Clinical Guidelines
King Edward Memorial Hospital
Perth Western Australia
All guidelines should be read in conjunction with the Disclaimer at the beginning of this manual
Page 4 of 4