Troubleshooting in APS

Moderator: Dr Wan RohaidahDate: 11/7/13

Content

• Case scenario• Troubleshooting: PCA• Troubleshooting: epidural• Other pain management• APS in chronic pain patient/ substance users• Role of oxynorm

Case scenario32 years old lady, G2P1 at 34 weeks. Presented with 1 episode of seizure and

drop in GCS. CT scan noted brain aneurysm. Admitted to ASW for further management. In ward, patient had episodes of intermittent tachycardia and hypertension, most likely due to pain contractions. Patient conscious but not obeying command, not intubated. Referred to APS for pain control, to prevent labile BP which can lead to bleeding of the aneurysm.

What is the best modality of APS to be used in this patient?

Content

• Case scenario• Troubleshooting: PCA• Troubleshooting: epidural• Other pain management• APS in chronic pain patient/ substance users• Role of oxynorm

Troubleshooting: PCA

• Inadequate analgesia• Nausea and vomiting• Sedation• Respiratory depression• Pruritus

PCA: Inadequate analgesia

• Check pump (Demand and good)– If high

• Increase bolus dose by 50%• Change types of opiods (opioid rotation)• Add ketamine infusion (0.1mg/kg/hour)- dilute 200mg in

50cc NS• Non opiods adjuvants (PCM, NSAIDs, tramadol,

gabanoids)• If bolus greater than standard (eg fentanyl 20mcg) and

use of fentanyl > 200mcg/hr;– Consider adding ketamine

PCA: Inadequate analgesia

– If low• Nausea when presses button?• Doesn’t understand how to use PCA–If cognitive impaired, change to NCA–If cognitive intact, encourage to use

PCA

PCA: Inadequate analgesia (stepwise approach)

Nausea and vomiting

• Consider changing to other opiods• Other aetiologies- bowel obstruction,

dehydration• PONV protocol

Nausea and vomiting (PONV protocol)

Nausea and vomiting

• Midazolam infusion– Give bolus 0.5mg or 1mg– Review after 30 mins– If improved, commenced and continue until PCA

removed• 10mg midazolam in 100cc NS, run at 0.5-1mg/hr

Sedation: PCA

• Monitor vital signs- RR, pulse oximetry, sedation score

• Ensure patient on oxygen• Check usage of PCA –consider reducing dose• Exclude other causes (intracranial pathology-

trauma history/neurosurgical)• Ensure patient not getting sedatives

Respiratory depression: PCA

• Monitor RR (if less than 6-8, be alarmed)• Apply oxygen• Check other signs of opiod toxicity- pupil size,

rousability• Stop PCA• Naloxone– Dilute 400mcg (1 ampoule) in 10mls– Give 1ml at a time and wait 2-3 minutes each time

Pruritus

• Centrally (intrathecal, epidural)- naloxone, ondansetron

• IV,s/c,oral- antihistamine first choice• Ondansetron or sc naloxone (100mcg 2 hourly

prn)• Change opioid• Low dose naloxone infusion (0.2 mcg/kg/min)

Content

• Case scenario• Troubleshooting: PCA• Troubleshooting: epidural• Other pain management• APS in chronic pain patient/ substance users• Role of oxynorm

Troubleshooting: Epidural

• Hypotension• Inadequate analgesia• Epidural haematoma/abscess

Epidural: hypotension

• Check other causes (haemorrhage, sepsis, cardiac event)

• Fluid loading• Check epidural– Extent- adjust accordingly (adjust rate)– Check tip- ensure not intrathecal

Epidural: Inadequate analgesia

• Causes (bleeding, compartment syndrome, cardiac event)

• Level of catheter insertion• Has it been effective at the first place?• Epidural site- dislodged, leakage• Extent of sensory block

No block/patchy block

Unilateral block

Block too high/ too low

Epidural haematoma/ abscess

Epidural abscess

• Routine inspection at epidural site D2 onwards

• If pain/erythema present, assess;– Extent, location, severity of pain– Extent of erythema– Neurological symptoms and signs– Recent or current pyrexia– Any predisposing factors (cancer, sepsis,

immunosuppressed)

Epidural abscess

Content

• Case scenario• Troubleshooting: PCA• Troubleshooting: epidural• Other pain management• APS in chronic pain patient/ substance users• Role of oxynorm

Other pain management:Ketamine infusion

• Useful for;• Opiod tolerance (reduces tolerance)• Pain that is poorly responsive to opioids (eg phantom

limb pain)• Neuropathic pain

• Starting rate 0.05-0.1mg/kg/hr maximum 0.5-0.6mg/kg/hr

• Dilution: 200mg in 50cc NS

Content

• Case scenario• Troubleshooting: PCA• Troubleshooting: epidural• Other pain management• APS in chronic pain patient/ substance users• Role of oxynorm

APS in Chronic pain patients and substance users

• Do not assume pain complaints stem from opiod tolerance, drug seeking, behavioural issues- can be genuine surgical complications.

• Ensure they are getting the usual opioid requirement (this is their background requirement) and be given along with PCA/regional

• Consider adding ketamine infusion or increase dose by 50%

Opiod conversion table

Opioid conversion table

• Eg:– Conversion of SC morphine to transdermal

fentanyl patch, patient using 10mg 4 hrly= 60mg per day

– Conversion factor: divide by 1.2– 60 divide 1.2= 50mcg per hour

Case scenario32 years old lady, G2P1 at 34 weeks. Presented with 1 episode of seizure and

drop in GCS. CT scan noted brain aneurysm. Admitted to ASW for further management. In ward, patient had episodes of intermittent tachycardia and hypertension, most likely due to pain contractions. Patient conscious but not obeying command, not intubated. Referred to APS for pain control, to prevent labile BP which can lead to bleeding of the aneurysm.

What is the best modality of APS to be used in this patient?