Download Premedication mgmc

Dr. S. Parthasarathy
MD., DA., DNB, MD (Acu),
Dip. Diab. DCA, Dip. Software statistics
PhD (physio)
Mahatma Gandhi medical college and research institute –
Puducherry – India
PREMEDICATION
WHY WE NEED ??
Sedation and anxiolysis
 Analgesia and amnesia
 Antisialagogue effect
To maintain hemodynamic stability, including
decrease in autonomic response
 To prevent and/or minimize the impact of
aspiration
 To decrease postoperative nausea and vomiting
 Prophylaxis against allergic reaction
 VAAAAAS-- pneumonic

BEFORE WE WRITE !!
Patient age and weight
 Physical status
Levels of anxiety and pain
 Previous history of drug use or abuse
 History of postoperative nausea, vomiting or
motion sickness
 Drug allergies
Elective or emergency surgery
 Inpatient or outpatient status
 Familiarity with drugs

PSYCHOLOGY
Anxiety
 40 -80 %

55 % in one study
 Counselling
 Drugs

WHEN TO ADMINISTER

Drug , route

Choose so that the peak action time is at their
entry into the operating room
BENZODIAZEPINES
Sedation
 Anxiolysis
 No nausea
 but
 No analgesia
 Excess sedation, paradoxical agitation
especially in Old age ??
 oral, IV, spray midaz,
 oral diazepam .Lorazepam
 Sublingual – midaz can be used

OTHER DRUGS
Oxazepam
 Temazepam
 Triazolam
 Alprazolam

ANTIHISTAMINICS (H1)
Sedation
 Anticholinergic
 Antiemetic


Diphenhydramine – oral dose of 50 mg
OPIOIDS
Previous
 Morphine and pethidine IM


Now fentanyl IV
OPIOIDS
++ AND ---
Where we need analgesia
 Ortho
 IV and arterial lines
 Decrease anaesthetic requirements


But respiratory depression, Sphincter of Oddi,
PONV – problems
ANTISIALOGOGUES

Popular in ether days
Now only in
 Ketamine
 Fibreoptic intubation

REDUCTION IN VAGAL RELEXES (CLINICAL SCENARIO)
Traction of ocular muscles
 Second dose of scoline
 Propofol, fentanyl, halothane
 Atropine and glyco pyrollate
 But – problems
 central anticholinergic syndrome, tachycardia,
blocking sweat glands ??

ADRENERGIC AGONISTS
Clonidine
 in doses of 2.5 to 5 µg/kg – oral
 sedation,
 prevent hypertension and tachycardia from
endotracheal intubation and surgical
stimulation
 Hypotensive anaesthesia
 IM,IV – OK

ASPIRATION

pH of 2.5 and a volume of 25 ml

Danger zone

Ranitidine , famotidine, nizatidine are H2
blockers
ANTACIDS

Nonparticulate antacid 0.3 M sodium citrate

Colloid antacid suspension
Immediate , no lag time
 Increase volume,
 with food ??

OMEPRAZOLE
Intravenous doses of 40 mg 30 minutes before
induction have been used.
 Oral doses of 40 to 80 mg must be given 2 to 4
hours before surgery to be effective


Other PPIs – used
GASTROKINETIC AGENTS
Gastrokinetic agents are useful because of
their effectiveness in reducing gastric fluid
volume.
 Metoclopramide
 Increased gastric emptying – but no
guaranteed emptiness of stomach
 Antiemetic
 No change in pH

AT THE END ?? ANTIEMESIS

Many anesthesiologists prefer not to administer
antiemetics as part of a preoperative regimen,
but believe that antiemetics should be
administered intravenously just before they are
needed at the conclusion of surgery.

Droperidol, metoclopramide, ondansetron, and
dexamethasone
PROMETHAZINE
Sedation
 Anxiolysis
 Antiemesis
 Alpha blocker
 Anticholinergic

THEY ARE NOT PREMEDICANTS IN STRICT
SENSE BUT WE USE
Steroids
 Antibiotics
 Insulin
 Methadone

ANTIBIOTICS
Infective endocarditis prophylaxis
 Probable contamination
 Immunosupressed
 Diabetic
 On steroids
 Cephalosporin –ok around one hour prior
 Vancomycin 2 hours prior
 Tourniquet !! Give antibiotics before inflation

STEROIDS
consider treatment in any patient who has
received corticosteroid therapy for at least 1
month in the past 6 to 12 months.
 80 mg 6 hourly
 Why ??
 300 mg / day – maximal daily production to
stress

OTHER PREMEDICANTS TO CONTINUE
Beta blockers
 Thyroxine
 Statins


And the other dugs he /she is taking for
systemic illness
DEEP VEIN THROMBOSIS

Heparin

Warfarin

Clopidogrel

When to use and stop – guidelines are there
IN A CHILD ??

parental presence on induction of anesthesia
an increase in heart rate and skin conductance
levels in mothers
Oral midaz better than parent and the combined is
not very superior
IV midaz – wait for 4.8 minutes
Intranasal – 10 minutes
BENZODIAZEPINES IN PAEDIATRICS
Lorazepam
 slow onset and offset of action, and therefore
is better used for inpatients

Diazepam
 immature liver function that would lead to a
prolonged half life

PEDIATRIC
VS. ADULT PATIENTS
Vagolysis
 Anticholinergic
 Anxiolysis
 Oral/ nasal/SL routes
 IM ??

PEDIATRICS

Upto 6 months – no problem in parental
separation

6 months to 5 years -- maximal psychological
problem and anxiety

5 years and above – easy to convince
DEXMED PREMED

Intranasal dexmedetomidine produces more
sedation than oral midazolam when children
were separated from their parents and at
induction of anesthesia
KETAMINE

Nasal transmucosal ketamine at a dose of 6
mg/kg is also effective in sedating children
within 20 to 40 minutes before induction of
anesthesia.

Oral ketamine, IM ketamine , IV ketamine
PATCHES FOR VENIPUNCTURE
EMLA cream
 (eutectic mixture of local anesthetic),
is a mixture of two local anesthetics (2.5%
lidocaine and 2.5% prilocaine).
ELA-Max (4% lidocaine) ,
Ametop (4% tetracaine )
The S-Caine Patch (eutectic mixture of lignocaine
and tetracaine – 70 mg of each drug/ patch )

SUMMARY
Goals
 Factors
 Route
 Drugs -- benzo, opioids, anticholinergics,
promethazine, clonidine, aspiration,antiemetics
others
 Paediatric

Thank you
all