PONV 30 Mar 2010 Amit
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Transcript of PONV 30 Mar 2010 Amit
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Postoperative Nausea and
Vomiting
Dr Amit Kocheta
DNB Trainee
Anesthesiology
BMHRC
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Introduction
The most common and distressing symptoms,which follow anesthesia and surgery, are pain andemesis.
During ether era, reported incidence of PONV was
as high as 7580%. Eighty years ago, Flagg suggested that PONV may
result from causes other than anesthetics : thereare at least three kinds of vomiting,
the first of which has been attributed to anesthetics
such as ether, the second to reflex responses,
the last to opioids.
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The incidence of postoperative emesis in somelarge studies has been reported to be in therange of 2030 %.
Intractable PONV is the most frequent
anesthetic related cause for unexpectedhospital admission of surgical out patients.
PONV causes increase in IOP & ICP, suturedehiscence, esophageal rupture, hematoma
formation & aspiration pneumonitis.
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Definitions
Nausea : It is an unpleasant sensation referredto a desire to vomit, not associated withexpulsive muscular movement.
Retching : When no stomach contents areexpelled even with expulsive muscular efforts.
Vomiting : It is the forceful expulsion of even asmall amount of upper gastrointestinal contents
through mouth.
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Overview
Physiology
Aetiology
Associated factors
Management Prevention
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Physiology
Vomiting reflex
Afferent inputs
Processing centre
Motor efferents
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Vomiting Centre
Located in the medulla
Represents multiple nuclei involved inthe integration of the vomiting reflex
The motor component of the vomiting
reflex is mediated by both autonomicand somatic systems, whose activity iscoordinated in the vomiting centre
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Afferent pathways
Gastrointestinal tract (5HT3, D2)
Mechanoreceptors located in the wall of thegut are activated by abnormal distension,
contraction, physical damage or manipulationduring surgery
Chemo receptors located in the mucosa aretriggered by noxious chemical stimuli
Information relayed via the vagus nerve to thenucleus tractus solarius in the vomiting centre
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Afferent pathways
Chemoreceptor Trigger Zone Area Postrema Located in the floor of the 4th ventricleDefective BBB for detecting circulating toxins in the
blood and CSFWorks through the 5-HT3 receptors as well as
dopamine type 2 receptors
Others Vestibular system: responsible for motion sickness
Cardiovascular system: afferents from cardiacventricles and blood vesselsHigher centers: limbic system, olfactory and visual
cortex Pharyngeal afferents (?gag reflex)
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Chemoreceptor Trigger Zoneand Emetic Center
AntagonistAntagonist
AgonistAgonist
Receptor SiteReceptor Site
Area
Area
Pos
trem
a
Pos
trem
a ChemoreceptorChemoreceptorTriggerTriggerZoneZone(CTZ)(CTZ)
EmeticCenter
5-HT5-HT33 RAsRAs
5-HT5-HT33
PromethazinePromethazine
HistamineHistamine
AtropineAtropine
MuscarinicMuscarinic
DroperidolDroperidol
Dopamine (DDopamine (D22))
Nitrogen mustardNitrogen mustard
CisplatinCisplatin
Digoxin glycosideDigoxin glycoside
Opioid, analgesicsOpioid, analgesics
Vestibular portionVestibular portionof 8th nerveof 8th nerve
NN22OO
GI tract distensionGI tract distension
Higher centers (vision, taste)Higher centers (vision, taste)
PharynxPharynx
ParvicellularParvicellular
ReticularReticularFormationFormation
MediastinumMediastinum
??
VagusVagus
NK-1 RANK-1 RA
Substance PSubstance P
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Efferent pathways
Vomiting reflex is divided into 2 phases
Pre-ejection or Prodromal phase: relaxation ofthe gastric muscles followed by small intestinalretrograde peristalsis
Ejection phase : comprises of retching and vomitingwith expulsion of gastric contents.
Mediated by autonomic and somatic systems,coordinated in the vomiting centre
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Schematic representation of thefactors influencing nausea and
vomiting
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Risk Factors
Patient factors
Preoperative factors
Intraoperative factorsAnesthetic factors
Surgical factors
Postoperative factors
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Patient Factors
Age Highest in 6-16 age group
Gender Women 2-4x more likely than men
Obesity Non-smoker Gastro paresis
Diabetes, hypothyroidism, pregnancy, h/o
swallowing blood, full stomach, intra-abdominalpathology
History of motion sickness, PONV Chemotherapy patients
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Preoperative Factors
FoodProlonged pre-op fasting
Not starved
Anxiety
Premedication
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Intraoperative factors:Anesthetic
Intubation Deeper plane of anaesthesia Gastric inflation during mask ventilation Intraoperative dehydration Drugs : Opioids, Ketamine compared with
Propofol and Thiopentone Inhalation Agents: N20 compared with
Sevoflurane, Isoflurane, Desflurane
General anaesthesia compared with spinaland regional anaesthesia
Neostigmine: in high doses
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Postoperative factors
Head movement of patient afterwaking
Postoperative pain
Early ambulation, dizziness
Early intake of food
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Surgery factors
Duration of surgery
Type of surgeryGynecological
ENT
Abdominal
Head &neck
Squint correction
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Risk Score for Predicting PONVby Apfel
RISK FACTORS:1 -Female sex
2 - Hx. of motion
sickness or PONV
3 - Nonsmoking status
4 - Use of Postoperative
Opioids
NONE 1 Factor 2 Factors 3 Factors 4 Factors
79 %61 %39 %21 %10 %
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Management:Pharmacological Prophylaxis
Multiple receptors involved in thevomiting reflex
5HT-3
D2
M1 ACh
H1Neurokinin-1
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Drugs
Antagonists 5HT-3 :-Dolasetron,
Granisetron,Tropisetron,Ondansetron
D2:- Droperidol,Metoclopramide,Prochlorperazine
Ach :-Cyclizine,Scopolamine
H1 :-Promethazine,Cyclizine
Neurokinin-1:-Aprepitant
Agonists Steroids Dexamethasone
Benzodiazepines Midazolam Cannabinoids
Th i it f ti fThe main sites of action of
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The main sites of action ofThe main sites of action of
drugs affecting nausea anddrugs affecting nausea and
vomitingvomiting
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for the Prophylaxis of PONV in
AdultsAgentAgent DosageDosage
DroperidolDroperidol 0.625 1.25 mg Iv 5 min before termination of0.625 1.25 mg Iv 5 min before termination ofanesthesiaanesthesia
OndansetronOndansetron 4 mg IV immediately before induction4 mg IV immediately before induction8 mg PO 1 h before induction8 mg PO 1 h before induction
Recent data: more effective- end of anesthesiaRecent data: more effective- end of anesthesia
DolasetronDolasetron 12.5 mg IV intraoperatively12.5 mg IV intraoperatively100 mg PO 1 h before induction100 mg PO 1 h before induction
MetoclopramideMetoclopramide 10 (20) mg IV near the end (not effective when10 (20) mg IV near the end (not effective whenused alone)used alone)
PromethazinePromethazine 25 mg PO 1 h before induction25 mg PO 1 h before induction12.5 25 mg IV immediately before ind.12.5 25 mg IV immediately before ind.
ProchlorperazineProchlorperazine 5 15 mg PO 1 h before induction5 15 mg PO 1 h before induction5 10 mg IM 1 2 h before ind.; repeat once in5 10 mg IM 1 2 h before ind.; repeat once in
30 min,30 min,
5 10 mg IV 15 30 min before ind; x15 10 mg IV 15 30 min before ind; x1
GranisetronGranisetron20 40 mcg/kg IV20 40 mcg/kg IV
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Standard Dosages of Antiemetics forthe Treatment of PONV in Adults
AgentAgent DosageDosage
OndansetronOndansetron 1 4 mg IV postoperatively1 4 mg IV postoperatively
MetoclopramideMetoclopramide 10 mg IV q 46 h prn post-operatively10 mg IV q 46 h prn post-operatively
PromethazinePromethazine 10 25 mg PO prn post-operatively10 25 mg PO prn post-operatively12.5 25 mg IM or IV q4h prn post-operatively12.5 25 mg IM or IV q4h prn post-operatively
ProchlorperazineProchlorperazine 5 15 mg PO post-op.5 15 mg PO post-op.
5 10 mg IM; repeat once in 30 min prn5 10 mg IM; repeat once in 30 min prn
5 10 mg IV; may repeat once prn5 10 mg IV; may repeat once prn
ChlorpromazineChlorpromazine 10 25 mg PO q4-6h prn10 25 mg PO q4-6h prn
12.5 25 mg IM if no hypotension; repeat in 1h12.5 25 mg IM if no hypotension; repeat in 1h
DroperidolDroperidol 0.625 1.25 mg IV prn0.625 1.25 mg IV prn
DolasetronDolasetron 12.5 mg IV post-operatively12.5 mg IV post-operatively
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Standard Dosages of Antiemetics forthe Management of POV in Pediatric
PatientsAgentAgent DosageDosage
ProphylaxisProphylaxis
DolasetronDolasetron Age >2y: 1.8 mg/kg IV immediately before ind.Age >2y: 1.8 mg/kg IV immediately before ind.
OndansetronOndansetron 0.05 mg/kg IV (range: 0.05 0.15 mg/kg)0.05 mg/kg IV (range: 0.05 0.15 mg/kg)
DroperidolDroperidol 0.015 0.075 mg/kg per dose IV0.015 0.075 mg/kg per dose IV
TreatmentTreatment
ChlorpromazineChlorpromazine 0.55 mg/kg PO or IM0.55 mg/kg PO or IM
DroperidolDroperidol 0.1 mg/kg per dose IV0.1 mg/kg per dose IV
OndansetronOndansetron 0.05 mg/kg per dose IV0.05 mg/kg per dose IV
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Ondansetron (Emeset)
Serotonin 5HT3 antagonist
Adult dose : 4-8 mg IV
Pediatric dose : 50 100 mcg/kgIV up to 4 mg
Greater efficacy in prevention ofvomiting than nausea
Most effective whenadministered at end of surgery
Headache, dizziness, flushing,
elevated liver enzymes,constipation
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Droperidol
Butyrophenone Blocks dopamine-2 receptors in the
CTZ and area postrema Usual adult dose: 0.625-1.25 mg IV Pediatric dose : 50 -75 mcg/kg up to
1.25mg Duration of action: up to 12-24 hours Adverse effects: sedation, dizziness,
anxiety, hypotension, extra pyramidalside effects
More effective for nausea thanvomiting
FDA BLACK BOX WARNING 2001 Increased risk of lengthening of the QT
intervals in some patients Risk for cardiac patients!!!
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Metoclopramide (Reglan)
Benzamide
Blocks dopamine-2 receptors inthe CTZ and vomiting center
Prokinetic properties that
quicken esophageal clearance,enhance gastric emptying, andshorten bowel-transit time
Less effective than Ondansetronor Droperidol
Most commonly administereddose of 10 mg IV is not effectivefor prevention of PONV
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Metoclopramide (Reglan)
Usual adult dose for PONV: 25-50 mg IV
10-20 mg IV for rescue N/V
Duration of action: up to 6hours
Adverse effects: sedation,hypotension, extra pyramidalsymptoms, restlessness
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Promethazine (Phenergan)
Phenothiazine
Blocks dopamine-2 receptors in theCTZ and other areas of the brain
Also blocks histamine-1 receptors
and msucarinic-1 receptors Usual adult dose: 6.25-12.5 mg IV
Duration of action: 4-6 hours
Adverse effects: sedation,hypotension, extra pyramidal
symptoms
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Diphenhydramine(Benadryl)
Antihistamine
Suppresses motor-enhanced
vestibular neuronal firing
Adverse reactions: sedation,
dry mouth, blurred vision,urinary retention
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Scopolamine
Anticholinegic Transdermal patch
Blocks the muscarinic-1 receptors inthe cerebral cortex and pons andhistamine-1 receptors in thehypothalamus and vomiting centerto exert its antiemetic effects
Suppresses the noradrenergicsystem (improved adaptation tovestibular stimulation)
4 hour onset of action Needs to be placed the night before for
patients with increased risk of PONV
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Dexamethasone
Corticosteroid
Antiemetic action not fullyunderstood
Thought to work by antagonizing
prostaglandins or releasingendorphins that elevate mood,improving ones sense of well-being and stimulating appetite
Most effective when administered
before induction of anesthesia
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NK1 Antagonists
Future development in anti-emesis is looking at theneurokinin 1 (NK-1) receptor, where substance Pis the natural ligand. This receptor is found in thenucleus tractus solitarius and the area postrema,as well as the peripheralnervous system. Early
studies of NK-1 antagonists have been promising,especially in combination with Ondansetron
Neurokinin (substance P, NK1) antagonists -impressive antiemetic in the animal model. However,early clinical data have been disappointing, except forAprepitant (Emend) - has demonstratedsuperiority over Ondansetron in chemotherapyinduced nausea and vomiting.
Complementary Therapies:
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Complementary Therapies:Acupuncture and Related
Techniques Traditional Chinese medicinetreated nausea and vomiting withacupuncture
Uses needles that are inserted into
traditional acupuncture points inthe body, initiating a series ofphysiological events that counterPONV
Certain nerve fibers are stimulatedthat result in nerve impulses beingsent to the spinal cord Endorphogenic cells are stimulated to
release endorphins
Complementary Therapies:
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Complementary Therapies:Acupuncture and Related
Techniques Nerve impulses produced byacupuncture also transmit to theperiaqueductal gray area of themidbrain where enkephalin isreleased Causes a release of the monoamine
neurotransmitters serotonin andnorepinephrine in the spinal cord
3rd effect is release of beta-endorphins andadrenocorticotropic hormone(ACTH) from the pituitary glandinto the bloodstream andcerebrospinal fluid
Calming of the GI tract
Complementary Therapies:
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Complementary Therapies:Acupuncture and Related
Techniques Acupressure
Uses physical andmechanical pressure
instead of needlesover the samemeridians of thebody
P6 point stimulation
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Complementary Therapies:Aromatherapy
Dates back as far as2800 BC
Herbal preparations and
plant extracts Use of oil of ginger as a
prophylactic therapy
Isopropyl alcohol Oil of peppermint
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Complementary Therapies:Peppermint
Remedy formorningsickness,
dyspepsia, andother GIcomplaints
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Inhalation of Isopropyl AlcoholVapors
Study of 100 healthywomen undergoingoutpatient gynecologiclaparoscopic procedures
Randomly received 4 mgOndansetron or 70%isopropyl alcohol forpostoperative nausea
Use of alcohol padsresulting in quicker reliefof nausea
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Complementary Therapies:Oral Ginger
Oral ginger has beenused in China fortreating GI symptomssuch as nausea andvomiting
Ginger root, gingerpowder, ginger candy,and ginger gum
Ginger oil in form ofaromatherapy
Role not clearlydefined by research
St t i t R d
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Strategies to ReduceBaseline Risk
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ThanksThanks