What is Pain?

A lot of people dread the bleep about pain management, and hopefully the above talk helps take some of the apprehension about managing pain away. 

So what is pain? 

IASP 2020

"An unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage”

So essentially this tells us that pain has both a sensory and emotional component, that may or may not be related to a physical problem. As a result pain is subjective, specific to an individual and this can make it very hard to manage at time.

However like everything else, start with a stepwise approach to assessment and management. 

Acute pain: 

Most of this page is going to focus on acute pain, as chronic pain is largely out of the scope of what you'll be expected to manage. 

So acute pain is generally pain which is recent in onset. It's usually a physiological response to a noxious stimuli and tends to be well localised, lasting <4 weeks. Chronic pain on the other hand tends to be more gradual in onset, poorly localised and symptoms tend to be persistent. Pain is deemed chronic after 3 months. 

So how do we manage acute pain? 

The straightforward answer is we start simple. Then build up using a multi-modal approach until analgesia is achieved. 

Take a look at the NICE guidance for a more indepth overview! 

WHO also has a simple stepwise approach which I'm sure you know well which you can review here - 

But as a general guide: 

1. Start simple - Paracetamol 

2. Add NSAIDS or weak opioids (if NSAID intolerant) alongside paracetamol.

3. Paracetamol, NSAID and a weak opioid 

In acute severe pain 

1. SC or IV opioids recommended

This is probably hard to give on a ward in actual practice, as staff generally aren't comfortable with it, and check with a senior before you do so. 

Things to consider: 

Patient specific: 

• Weight - Caution with paracetamol if <50kg 

• Renal function - Caution with opioids as they will accumulate in renal impairment

• Frailty or opioid naivity - reduce dose 

• Contraindications - can be absolute or relative 

  • Allergies

  • Intolerance 

  • Age - NSAIDs are more likely to cause issues in the elderly 

Therapy specific: 

• Have you reached the therapeutic dose before you stop it or switch to a different analgesic agent? 

• Consider the underlying cause? 

  • Is there another diagnosis that explains the pain which needs a different treatment 

• Did we do something? 

  • Are the doses appropriate? 

  • Are they post op? 

Other handy notes: 

• Cyclizine can cause agitation and distress when given to over 60's so generally avoid 

• Opioids make you nauseus - prescribe PRN antiemetics like ondansetron 

• Opioids make you itchy - prescribe PRN antihistamines like chlorphenamine 

• Opioids make you constipated - prescribe PRN laxatives 

• Opioids can be overdosed - prescribe naloxone for safety 

I've not really sold opioids there but they are very useful in the management of pain! Consider prescribing the above PRN's for patients on opioid therapy as it might save you a job later on down the line. 

Who can you call?

You don't have to manage pain alone. If you're struggling and nothing that you're doing seems to be working there are lots of options;

• Your seniors 

• Pharmacists 

• The pain team - via referral. 

• Palliative care team (if the patient is known to them) 

• Anaesthetics 

What adjuncts might you come across? 

This is more for interest as you won't be expected to manage these. There are a number of adjuncts that can be utulised to improve a patients pain management.

PCAs 

• Patient controlled analgesia - A locked infusion pump with a button attached that the patient can press to deliver a bolus dose of analgesia. 

• Will usually be morphine or fentanyl IV. 

• Built in 5 minute lockout period for safety.

• Usually managed by pain team or anaesthetics.

PCEAs 

• Patient controlled epidural anaesthesia.

• Usually sited for major abdominal surgery.

• Delivers a background infusion of local anaesthetic usually with bolus dosing. 

• Again managed by pain team or anaesthetics.

Rectus Sheaths 

• Tend to be used for post op laparotomies, usually if the patient has had a spinal on board. 

• Generally sited by surgeons at the end of the procedure 

• Again deliver a background maintenance dose of local anaesthetic alongside bolus doses 

• Generally less effective than epidurals but can remain in situ for 3-5 days. 

Disclaimer:

This is a not for profit education resource designed for new resident doctors. All information serves as a guide to help doctors approach day to day life as an F1. It is not intended as a guide to patient care and should never be used as such or in place of advice of treating clinicians or published clinical guidelines. All cases are fictional and any resemblance is purely coincidental. Additionally all images are AI generated unless otherwise stated.