ketamine....................................................................................................................................................................................................................................

1. ROLE INTRAOPERATIVE KETAMINE ON
MANAGEMENT OF POSTOPERATIVE PAIN

2. OBJECTIVES
•Mechanism of pain
•Post operative pain
•Multimodal analgesia
•Ketamine Uses and adverse effects
•Systematic review
•Guidelines
•Conclusion

3. MECHANISM OF ACUTE PAIN
Tissue injury leads to release of inflammatory
mediators with subsequent nociceptor
stimulation.
Pain impulses are then transmitted to the dorsal
horn of the spinal cord.
where they make contact with second-order
neurons that cross to the opposite side of the
cord and ascend via the spinothalamic tract to the
RAS and thalamus.
The localization and meaning of pain occurs at
the level of the somatosensory cortex

4. POST OP
PAIN….

5. POSTOPERATIVE PAIN
PPP is one of the most undesirable
experiences for a patient
undergoing surgery
Recent studies show that PPP has
an incidence as high as 40% [1]
Furthermore, 18.3% of patients
report that this pain is moderate
to severe [1]
To date, the mainstay of treatment
has been the administration of
exogenous opioids

6. MULTIMODAL ANALGESIA
Acute pain is an integrated process that is mediated by activation of
numerous pathways,
Therefore, administration of analgesics acting on different targets is a
rational for postoperative analgesic strategy.

7. KETAMINE SYNTHESIZED 1960S
•Ketamine is a noncompetitive, reversible inhibitor of the (NMDA) receptor,
mu opioid receptors, monoaminergic receptors, gamma aminobutyric acid
receptors..
•Used At subanesthetic doses in the perioperative period, generally for
patients whose pain may be difficult to manage with opioids alone, either
due to a very painful surgical procedure, or due to opioid tolerance or
dependence.
•Ketamine may also be useful for patients who are at increased risk of
opioid-related respiratory depression (eg, patients with obstructive sleep
apnea [OSA]
•Ketamine is increasingly used as part of multimodal postoperative
analgesia regimens, particularly because of its potential to reduce opioid
consumption

8. Methods:
N = 80 patients open cholecystectomy
Allocated into two equal groups in a randomized double-blinded
way.
The general anesthetic technique was standardized in both groups.
Treatment groups
1. received bolus of ketamine 0.2 mg/kg intravenously followed by an infusion of 0.1
mg/kg/h before skin incision which was continued up to the end of surgery
2. Similar volume of saline was infused in Group C (n = 40).
The pain score at different intervals and cumulative morphine consumption over 24 h
was observed
Results & Conclusion:
 low doses of ketamine reduce rescue analgesia requirements, pain
scores, PCA morphine consumption.
 No major difference in side effects

9. ADVERSE EFFECTS
•The clinical use of ketamine is limited by its potential to cause hallucinations and a
dissociative mental state.
Katalinic review showed that most of the research conducted using
subanesthetic doses of ketamine has resulted in a transient
increases in the +/- symptoms of SCZ, dissociative symptoms, and
manic symptoms [2]
And are only present at times of administration and usually
disappear within 60 minutes of administration [2].
when ketamine is administered alone, the prophylactic use of a
sedative agent such as 3.75–7.5 mg oral midazolam has generally
decreased their incidence and severity
•urinary tract symptoms,
•hepatotoxicity
•Increase ICP

10. INTRAOPERATIVE KETAMINE
Ketamine therapy for perioperative pain management is
commonly initiated intraoperatively with a bolus dose of 0.3 to
0.5 mg/kg IV followed by an infusion of 0.1 to 0.5 mg/kg/hour
[2].
The infusion should be discontinued 60 minutes prior to the
end of surgery to prevent prolonged emergence from
anesthesia.

11. TEMATIC REVIEW…

12. Methods
published studies from 1966 to 2010 which were
randomized, double-blinded, and placebo controlled
using intravenous ketamine (bolus or infusion) to
decrease postoperative pain.
Studies using any form of regional anesthesia were
excluded. No limitation was placed on the ketamine
dose, patient age, or language of publication

13. in 47 studies involving 4,701 patients
met the inclusion criteria (2,652 in
ketamine groups and 2,049 in
placebo groups)

17. GUIDELINES…

18. In 2018, consensus guidelines on the use of intravenous
ketamine for acute pain were published from
American Society of Regional Anesthesia and Pain Medicine,
American Academy of Pain Medicine
American Society of Anesthesiologists .
These guidelines are based on consensus of experts and offer
reasonable guidance, with the proviso that this is an area of
great interest and emerging experience.

19. WHICH PATIENTS AND ACUTE PAIN CONDITIONS
SHOULD BE CONSIDERED FOR KETAMINE
TREATMENT?
• The first group of patients are those undergoing surgery in which the expected postoperative pain
will be severe.
• upper abdominal and thoracic surgery, where the greatest benefit in opioid reduction has been
reported, as well as lower abdominal, and orthopedic (limb and spine) procedures
• Patients undergoing procedures with expected mild levels of pain, such as tonsillectomy and head
and neck surgery, have not been shown to benefit from perioperative ketamine
• Another group of patients who may be considered for acute ketamine therapy are those who are
opioid tolerant or opioid dependent and presenting for surgery or those with an acute exacerbation
of a chronic condition.
• The last subset of patients for whom ketamine may be beneficial is those who are at increased risk
for opioid-related respiratory depression, such as those with obstructive sleep apnea (OSA)

20. WHAT ARE THE CONTRAINDICATIONS TO KETAMINE
INFUSIONS IN THE SETTING OF ACUTE PAIN
MANAGEMENT, AND DO THEY DIFFER FROM
CHRONIC PAIN SETTINGS?

21. DOES ANY EVIDENCE SUPPORT PATIENT-
CONTROLLED IV KETAMINE ANALGESIA FOR
ACUTE PAIN?
•Intravenous PCA is a common manner of medication delivery in
acute medical and postoperative pain settings.
•Opioid medications are the most common analgesic medication
administered using this method
•Ketamine as a sole IV-PCA analgesic was effective in treating central
pain in a single case report (average of 7 mg/h)
•concluded that evidence is limited for the benefit of IV-PCA–
delivered ketamine as the sole analgesic for acute or periprocedural
pain (grade C recommendation, low level of certainty)
•concluded that moderate evidence supports the benefit of the addition
of ketamine to an opioid-based IV-PCA for acute and perioperative
pain management (grade B recommendation, moderate level of
certainty).

23. OTHER STUDIED USES OF
KETAMINE

24. N = 10
ECT for severe depression
Methods:
 Patients served as their own controls
 Treatment groups:
1) Etomidate 0.3 mg/kg
2) Ketamine 1.0 mg/kg
Results :
 Group 2 had less impairment of short-term memory loss
Conclusion:
 The effect of ECT on memory is mediated by glutamate at NMDA
receptors
 NMDA receptor antagonists may offer protection from memory
dysfunction

25. ONCLUSION…

26. Ketamine is a unique IV anesthetic with analgesic-like
properties that has been used as an analgesic adjunctive.
Adjunctive use of small dose ketamine appears to be
associated with opioid-sparing effects and a less frequent
incidence of adverse events and greater patient and physician
acceptance.

27. REFERENCES
[1] A. Johansen, L. Romundstad, C. S. Nielsen, H. Schirmer,
and A. Stubhaug, “Persistent postsurgical pain in a general
population: prevalence and predictors in the Tromso
study,” Pain, vol. 153, no. 7, pp. 1390–1396, 2012.
[2] N. Katalinic, R. Lai, A. Somogyi, P. B. Mitchell, P. Glue, and
C. K. Loo, “Ketamine as a new treatment for depression: a
review of its efficacy and adverse effects,” The Australian and
New Zealand Journal of Psychiatry, vol. 47, no. 8, pp. 710–727,
2013.