Troubleshooting in APS Moderator: Dr Wan Rohaidah Date: 11/7/13

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

Case scenario 32 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) Make sure patient on non opiod adjuvants (PCM, NSAID, tramadol, gabanoids) Ensure patient getting the most out of PCA Optimise PCA doseAdd ketamine infusionChange opioid

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 mg/kg/hr maximum mg/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 scenario 32 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?