Dr.K.VENKATESAN MD II YEAR

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SYNERGISTIC EFFECT OF MAGNESIUM SULPHATE AND
FENTANY ADDED TO INTRATHECAL BUPIVACAINE FOR
MILD PREECLAMSIA

• Dr.K.VENKATESAN MD II YEAR

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GUIDE

• PROFHOD.DR.P.S.SHANMUGAM MD,DA.
• DEPARTMENT OF ANESTHESIA
• KILPAUK MEDICAL COLLEGE HOSPITAL
• CHENNAI

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aim of the study

• To study and compare the effect of added fentanyl
  25(mic gm) Mgso4 0.1cc 50(50mg) to 0.5
  2cc(10mg)bupivacaine in spinal anesthesia
• Patients undergoing elective LSCS
• With mild gestational hypertension(PIH)

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background

• Adequate analgesia following caesarian section
  decreases morbidity , improves patient ambulation
  outcomes ,facilitate care of the new born.
• Intrathecal MgSO4 , NMDA antagonist has been
  shown to prolong analgesia without significant
  side effects in healthy parturients
• Correlation was found between serum CSF Mg
  concentration in patients with preeclampsia

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METHODS

• Ethical committee approval
• Informed patient consent
• Randomised double blind controlled study
• Statistical significance is p value less than
  0.05
• SAB performed
• With pt in right lateral position
• 25G quincke needle

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Patient selection

• 60 patient ASA risk I II undergoing elective
  caesarian section with mild PIH .
• IV line secured with 18G venflon, and preloaded
  with RL 10-12ml /kg
• All pts received 5L of O2 / min through face mask
  throughout procedure
• Pts treated with titrated doses of
• Inj.ephedrine 6mgI.V if BPlt90mmhg
• Inj.Atropine 0.6mg if HRlt60/min
• After delivery of baby Inj. Syntocin 10 IU in
  drip and 10 IU IM given

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METHODOLOGY

• Mild PIH is defined as SBP 140 160 and DBP 90
  110mm Hg with or without proteinuria after 20 wk.
  gestation
• 60 pts with average age of 18 35 undergoing
  elective LSCS under SA were randomized into three
  groups of 20 each
• Minimal fasting period is 8hrs
• All pts received premedication with Inj.
  Ranitidine 50mg IV and Inj. Metoclopramide 10 mg
  IV, 15 min before surgery

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criteria

• Age between 18-35 years
• Elective LSCS
• under spinal anesthesia
• Mild PIH (BPlt160/110mmhg)
• ASA I/II

• Contraindication to regional anesthesia
• Heart disease
• Fetal distress
• Seizure disorder
• Severe eclampsia
• Pts with coagulation defect
• Allergy to LA

• INCLUSION

• EXCLUSION

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groups

• Group C
• control group,(N20) patients 0.5
  2cc(10mg)bupivacaine 0.6cc normal saline .
• Group F
• Fentanyl(N 20) patients received 0.5 2cc
  bupivacaine 0.5cc( 25mic gm )fentanyl 0.1cc NS.
• Group M
• Mgso4 group (N20),0.5 2cc bupivacaine 0.5cc
  fentanyl 0.1cc 50(50mg) Mgso4 .

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STATISTICS

• Variables were analysed by ANOVA
• Variables analysed and interperted by post Hoc
  test
• Statistical significance is p lt0.05

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INTRA OP MONITORING

• NIBP
• PULSEOXIMETER
• ECG
• RESPIRATORY RATE
• URINE OUTPUT

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BROMAGE MOTOR SCALE
GRADE RESPONSE DEGREE OF BLOCK
0 NO MOTOR BLOCK NIL(0)
1 UNABLE TO STRAIGHT LEG RAISE PARTIAL(33)
2 UNABLE TO FLEX KNEE AGAINST RESISTANCE ALMOST COMPLETE(66)
3 UNABLE TO FLEX ANKLE COMPLETE
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Ramsey sedation score
SCORE RESPONSE
1 ANXIOUS OR RESTLESS OR BOTH
2 COPERATIVE, ORIENTED TRANQUIL
3 RESPONDS TO COMMANDS
4 BRISK RESPONSE TO STIMULUS
5 SLUGGISH RESPONSE TO STIMULUS
6 NO RESPONSE TO STIMULUS
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Sens0ry score
SCORE RESPONSE
0 NORMAL SENSATION
1 ANALGESIA (LOSS OF PIN PRICK SENSATION)
2 ANAESTHESIA (LOSS OF TOUCH SENSATION)
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Parameters observed

• Block onset time
• Duration of sensory blockade
• Higher level of sensory block
• Time to reach highest block
• Two segment regression time
• Duration of postop analgesia
• Hemodynamic parameters

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attributes

• SENSORY BLOCK ONSET TIME
• Time interval between end of anesthetic injection
  and appearance of cutaneous analgesia in
  dermatomes T-12,T-10,T-8,T-6
• DURATION OF MOTOR BLOCK
• Administration of anesthetic and attainment of
  grade 0 in Bromage motor scale
• DURATION OF ANALGESIA
• Administration of anesthetic and disappearance of
  cutaneous level of sensation at each dermatomal
  level
• POST-OP ANALGESIA DURATION
• Administration of anesthetic and time of
  analgesic requirement in PACU

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results

• The onset of both sensory and motor block was
  delayed in the group M ,when compared to both
  CF group(plt0.001)
• Motor block and analgesic duration was prolonged
  in the Group M , level of significance (plt0.05)
• Two segment regression time increased in M group
  (Plt0.001)
• Group M is hemodynamicaly stable when compared to
  other groups (plt0.019)
• Attainment highest level sensory block varies
  from T1-T6 , delayed in group M with significance
  level (plt0.08)
• Intensity of motor block is more with group M,
  but with less significance (plt0.291)

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Contd

• Occurrence of other complications like
  Bradycardia , nausea ,shivering were comparable
  in all groups
• Two Patient in group F complained of itching
• Usage of vasopressors is more in group C when
  compared to other groups
• Fetal outcome assessed by first min and fifth min
  APGAR was similar between groups (pgt0.3)
• Height and weight are similar between
  groups(plt0.586)
• Investigations were similar between groups
  (plt0.32)

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Contd..

• Duration of post-op analgesia is prolonged in M
  group when compared to other groups (plt0.001)
• Use of vasopressors is reduced in group M(plt0.03)

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SENSORY BLOCK ONSET TIME
F
C
M
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F
M
C
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F
M
C
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ANALGESIC MOTOR BLOCK DURATION
F
M
C
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MOTOR BLOCK ONSET TIME
F
M
C
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POST-OP ANALGESIA DURATION
F
M
C
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MagNESIUM sulPHATE

• Magnesium is the second most abundant
  intracellular cation
• Involved in the regulation of many ion channels
  and enzymatic reaction
• Has application in anesthesia because of its
  action as a non competitive NMDA receptor
  antagonist with anti-nociceptive effect

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MagNESIUM sulPHATE

• Mgso4 has been shown to have anti-nociceptive
  effects , because of its antagonistic action on
  the NMDA receptor
• Passage of magnesium across BBB is limited
• It can potentiate opioid analgesia by both
  central and peripheral mechanism
• MgSO4 causes
• 1.vasodilation by ca2 block
• 2.analgesic effect
• 3.inhibition of catecholamine release

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Cont..

• Mg inhibit calcium entry into the cell via a
  non-competitive NMDA receptor blockade
• Mg is also a physiological calcium antagonist at
  different voltage gated calcium channel, it may
  be important for anti-nociception
• Mg decreases incidence of post operative
  shivering
• Response to NMDA receptor is greatly enhanced
  when ECF Mg concentration below physiological
  level.

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Cont

• Decrease in pain intensity is not due to direct
  analgesic effect of Mg
• But due to prevention of subsequent NMDA
  activation
• Baseline CSF Mg level in pt with preeclamsia
  differ from normal patients which suggest base
  line alteration in BBB
• Normal CSF Mg level was 2.2meq/- 0.9, plasma
  1.6Meq, CSFplasma ratio 1.39
• Mg is neuroprotective in ischemic as well as
  excitotoxic brain injury

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Cont

• Mg may dilate cerebral blood vessel and thus
  responsible for relieving vasospasm in pt with
  preeclampsia
• Clinical relevant dose of Mg has no significant
  effect on V MCA, autoregulation and cerebral
  reactivity CO2
• Mg produce central desensitisation
• Mg can potentiate NM junction
• Spinal NMDA receptor antagonist is the reason for
  potentiation of LA and prolongation of post
  operative analgesia

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FENTANYL

• It is a synthetic opioids
• Phenylpiperidine derivatives
• Directly inhibit the NMDA receptor
• Action of opioids in the bulbospinal pathways are
  critical for analgesic efficacy
• Distribution of opioids receptors in descending
  pain control circuits indicates substantial
  overlap between µ ? receptors
• µ receptors produce analgesia within descending
  pain control circuits.

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FACTOR influencing block height
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CONCLUSION

• In parturients with mild PIH undergoing LSCS the
  addition of Mgso4 50mg to the intrathecal
  combination of bupivacaine fentanyl
• prolongs the duration of analgesia
• Prolongs motor block duration
• Delayed onset of sensory block
• Prolongs post op analgesia
• Ref.pubmed,intl.journal of obstetric anesthesia
  ,SOAP.

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THANK U