postoperative analgesia after LSG

1. Postoperative pain management after
laprascopic sleeve gastrectomy
(LSC)
Dr.Radhwan Hazem Alkhashab
consultant anaesthesia & ICU

2. Definitionofacutepain
 Acute pain has been defined as “the normal, predicted, physiological
response to an adverse chemical, thermal, or mechanical stimulus.”
 Acute pain is self-limited discomfort that typically lasts from a few
moments to several weeks but less than 3 to 6 months.

3. Effects of pain
Acute postoperative pain is a normal response to surgical intervention and is a
cause of delayed recovery and many complications. Which includes:
1. Decreased Respiratory function.
2. Myocardial ischemia.
3. Sodium and water retention.
4. Increased catabolic state.
5. Postoperative hypercoagulable state.
6. Immunosuppression
7. Poor wound healing
8. Prolonged paralytic ileus

4. ElementsofPainpathway
1. Transduction- :
event whereby noxious thermal, chemical, or
mechanical stimuli are converted into an
action potential.
2. Transmission:
when the action potential is conducted
through the nervous system via the first
,second &third-order neurons, which have cell
bodies located in the dorsal root ganglion,
dorsal horn, and thalamus

5. 3. Modulation :
Modulation of pain transmission
involves altering afferent neural
transmission along the pain pathway.
The dorsal horn of the spinal cord is
the most common site for modulation
of the pain pathway.
Modulation can involve either
inhibition or augmentation of the pain
signals
4. Perception :
Perception of pain is the final common
pathway, which results from the
integration of painful input into the
somatosensory and limbic cortices

6. ApproachsforPostoperativepain relief
1. Single drug approach :
Opioids remain the cornerstone of the management of surgical pain,
despite their potential side effects , and can be given through IV,
intramuscular, oral, or transdermal routes. IV opioids provide rapid and
effective analgesia for patients with moderate to severe pain.

7. 2. Multimodal approach:
Recognizing the pathophysiology of surgical pain uses several agents
to decrease pain receptor activity and diminish the local hormonal
response to injury.
For example:
 Local anesthetics can directly block pain receptor activity,
 Antiinflammatory agents can decrease the hormonal response to
injury.
 Drugs such acetaminophen, ketamine, clonidine,
dexmedetomidine, gabapentin, and pregabalin can produce
analgesia by targeting specific neurotransmitters.

8. Principlesofamultimodalstrategyinclude:
Multimodal analgesia is a strategy that reduces reliance on opioids
through the use of non-opioid analgesics that have different mechanisms
of action.
Multimodal analgesia is directed toward 3 goals:
(1) Improvement in the patient experience through better pain control.
(2) Reduction in postoperative morbidity and mortality.
(3) Reduction in healthcare costs.

9. Methodsofacutepainrelief
Mltimodal approach includes combinations of local
and/or regional analgesic techniques and non-
opioid analgesics (eg, acetaminophen,
nonsteroidal anti-inflammatory drugs [NSAIDs],
cyclooxygenase [COX]-2–specific inhibitors) and
analgesic adjuncts (eg, dexamethasone,
gabapentinoids).
Multimodal approachs can be administer through
many methods , one of these is patient
controlled analgesia (PCA).

10. WHAT IS A PCA DEVICE?
 PCA was first described by Austin et al. in
1980.
 It is a device that allows the patient to
control the intake of pain killers to himself
through the pressure of a button. It is a
small device installed in the canula after the
bariatric surgeries, and it lasts for two or
three days at the most.
 The PCA is based on the idea of a negative
feedback loop. When the patients
experience pain, they self-administer
medication, and once the pain is reduced,
they stop giving themselves medication.

11. Many studies have demonstrated the efficacy, safety, and patient
satisfaction with PCA intravenously.
One of these study done among patients who received IV‐PCA, 36%
experienced moderate to severe pain in the first 24 h after surgery
when compared to 67% of important painful experience among
patients who received intramuscular opioids (*)
(*)Dolin SJ, Cashman JN, Bland JM. Effectiveness of acute postoperative pain
management: I. Evidence from published data. Br J Anaesth 2002;89:409–23

12. Mechanism of action of PCA
All PCA modes contain the following variables:
1. Initial loading dose.
2. Demand dose.
3. Lockout interval.
4. Background infusion rate.
The lockout interval is a set period in which the equipment does not
perform a new infusion of demand. During the interval lockout, if the
patient triggers the button, he will not receive the medication.
The lockout interval has the primary function of security by preventing
the administration of an overdose of analgesic drugs.

13. The background infusion rate is a given infusion rate in a continuous
manner, independent of the patient's wish (also called continuous
infusion).
Errors may occur in the drug administration, usually by programming
failures on infusion pump and they may result in inadequate pain
control, heavy sedation, respiratory depression, and, eventually,
death of the patient

14. Although intravenous PCA is the most studied route of PCA, alternative
routes have extensively been described in the literature. PCA by
means of peridural catheters and peripheral nerve catheters are the
most studied. Recently, transdermal PCA has been described.

15. THE PATIENT CONTROLLED ANALGESIA PCA OFFERS SEVERAL
BENEFITS INCLUDING:
1-The patient's reassurance even before entering the operation, as he will
not feel pain.
2-After the operation, the device electronically downloads accurate
quantities of the analgesic described by the doctor by weight, length
and condition of the patient.
3-The patient can get an additional dose of the analgesic within the allowed
limits and programmed in advance, simply and easily by pressing the
button.
4-The patient does not feel pain completely during the recovery period after
the operation.

16. DurgsusedinPCA
The major drugs used in this system are the opioid analgesics, such as
morphine, hydromorphone, fentanyl, sufentanil and tramadol.
1. Morphine:
Morphine is the most common opioid used for IV-PCA . Many side effects
associated with morphine include (nausea, vomiting, itching, urinary
retention, sedation and respiratory depression may occur, it have active
metabolite which is morphine‐6‐glucuronide. The usual morphine dose
are : demand dose: 1–2 mg; lockout period: 6–10 min; continuous basal
infusion dose: 0–2 mg/h.
2. Hydromorphone :
Hydromorphone is semisynthetic opioid & has been used in patients
with impaired renal function or with a history of allergy to morphine. It is
mainly metabolized by the liver and it is, approximately, five times more
potent than morphine.

17. 3. Fentanyl
Fentanyl is 80–100 times more potent than morphine and it may cause less
respiratory depression when compared with morphine. It has no active
metabolites. Doses and recommended parameters: demand dose: 20–50 µg;
lockout: 5–10 min; Basal continuous: 0–60 µg/h .
4. Sufentanil
Sufentanil is a fentanyl analog, being about 5–10 times more potent than
Fentanyl itself. The doses and the usual parameters are: demand dose: 4–
6 µg; lockout: 5–10 min; continuous baseline: 0–8 µg/h
5. Tramadol:
Tramadol acts on opioid receptors , tramadol is a safe and an effective option for
PCA, but with a higher incidence of nausea and vomiting . The
recommended doses are: demand dose: 10–20 mg; lockout: 6–10 min;
continuous baseline: 0–20 mg/h

18. 7. Acetaminophen:
Is an effective perioperative analgesic with efficacy for both pain control and opioid
reduction across all surgical specialties. The main problem is hepatotoxicity
which may occur above the maximum dosage of 4 g per 24 hours.
8. NSAID :
Nonsteroidal antiinflammatory drugs (NSAIDs) are commonly combined with
intravenous morphine patient-controlled analgesia to relieve postoperative pain.
NSAIDs have a documented 30-50% sparing effect on morphine consumption.
9. dexamethazone:Glucocorticoids reduce postoperative pain through
anti-inflammatory mechanisms and possess antiemetic properties,
serving as a key adjunct for PONV prophylaxis.

19. Roleofdexamethazoneinmultimodalpainmanagement
A 2013 meta-analysis demonstrated that postoperative patients have decreased
pain scores and opioid consumption when dexamethasone is included as a
multimodal adjunct.

20. Patient‐controlledregionalanalgesia
There are several techniques that use catheters for the purpose of
providing postoperative analgesia with little or no opioid use. In this
model of patient‐controlled regional analgesia, local anesthetics
(ropivacaine, bupivacaine or levobupivacaine) are normally
administered through a catheter located in perineural site,
intraarticular region or surgical incision site. Eventually, a
combination of local anesthetics and opioids can be administered
by the infusion pump

21. Pain assessment & management

22. Painratingscales
What is a pain scale, and how
is it used?
A pain scale is a tool that doctors use
to help assess a person’s pain. A
person usually self-reports their
pain using a specially designed
scale, sometimes with the help of
a doctor, parent,

23. Sitesofactionofanalgesics

24. WHO analgesic ladder