Surgical Patient

Question 1

What are the common choices of anti-emetics for post operative care?

Answer 1

Ondansetron (5HT3 receptor antagonist)
Metoclopramide (Dopamine receptor antagonist)
Dexamethasone (Corticosteroid)
Haloperidol (Butyrophenone antipsychotic)
Cyclizine (Antihistamine)

Question 2

How does metoclopramide work?

Answer 2

Blocks dopamine receptors in the brain. It has an MHRA warning due to increased risk of neurological AE’s (EPS and TD)

Question 3

Who would not be prescribed metoclopramide or haloperidol?

Answer 3

Parkinson’s disease pts

Question 4

How does haloperidol work?

Answer 4

Reduces dopamine transmission in the brain but is very effective as an antiemetic as it acts on the chemoreceptor trigger zone blocking dopamine and reducing feelings of sickness

Question 5

How does ondansetron work?

Answer 5

It works specifically on 5HT3 receptors in the GI tract and in the CNS. it causes dystonic reactions and also prolongs the QT interval

Question 6

What is a prolonged QT interval and what can it lead to?

Answer 6

An ECG shows a lengthened QT period and is a risk in people with known long-QT syndrome (inherited disease) or those taking medications that prolong this interval.

it can lead to sudden death syndrome and is a life threatening arrhythmia.

Question 7

What are other drug classes that can prolong the QT interval?

Answer 7

• Macrolides
• Antifungals (fluconazole)
• Anti-arrhythmics (amiodarone, sotalol)
• Methadone
• Antipsychotics
• Antidepressants (Citalopram, Amitriptylline)
• Antiemetics (Domperidone, Ondansetron)

Question 8

How does Cyclizine work?

Answer 8

has anticholinergic activity. it can affect level of consciousness and hallucinations especially in elderly. may increase risk of falls

Question 9

How does Dexamethasone work?

Answer 9

It is a corticosteroid with high glucocorticoid activity
but would only be advised for short-term use

also beneficial for reducing inflammation post op

steroids can increase risk of infection (long term use SE)

Question 10

Why is Domperidone not routinely used in peri-operative care?

Answer 10

Cardiac side effects, avoid where there is risk of QT prolongation/when using CYP3A4 inhibitors or where there is pre-existing cardiac disease

Question 11

what are the benefits of dopmeridone and how should it be given?

Answer 11

works on chemoreceptor trigger zone but much less likely to cause sedation/dystonic movement disorders as it does not cross the blood brain barrier easily

use lowest dose for shortest period of time. suitable for PD patients, use PRN as alternative to dex if that doesn’t control post op sickness

Question 12

Why is constipation common post op?

Answer 12

• Dehydration
• Opiate use
• Antihistamine related anti-emetics (cyclizine)
• Immobility
• Dislike of hospital food
• Post op ileus

Question 13

How to treat constipation post op?

Answer 13

• Diet advice - ensure adequate fibre intake

- Laxatives

Question 14

Name examples of osmotic laxatives

Answer 14

Movicol, lactulose

Question 15

Name an example of stimulant laxatives

Answer 15

Senna

Question 16

Name an example bulk forming laxatives

Answer 16

Isphagula husk

Question 17

What other types of laxatives are there?

Answer 17

PR meds like enemas

suppositories (glycerine)

Question 18

Which laxative would be prescribed if there was hard, dry stool?

Answer 18

Stool softener plus glycerine suppository

Question 19

which laxative would be prescribed for post-op ileus/opioid induced/soft stool?

Answer 19

stimulant lax plus osmotic

avoid bulk formers as this could cause intestinal obstruction which could lead to perforation and peritonitis

Question 20

What if the first line laxatives didn’t work?

Answer 20

Manual evacuation/enema

Question 21

Describe lactulose

Answer 21

Sugar so not suitable for diabetics/intolerance and takes at least 48 hours to work

Question 22

Why should laxatives be reviewed on discharge

Answer 22

can lead to diarrhoea
bowel atony
hypokalaemia

Question 23

Why is thromboprophylaxis needed after post op?

Answer 23

to reduce the incidence of DVT and PE

Question 24

What is the INR target for those who have DVT/PE?

Answer 24

2-3

Question 25

What is the INR target for those who have recurring DVT/PE?

Answer 25

3.5

Question 26

What to do if the pt is already on Warfarin for recurrent PE during surgery?

Answer 26

1. Stop warfarin pre-op 5 days before
2. Offer bridging therapy with full dose Tinzaparin/unfractionated heparin once INR subtherapeutic
3. INR checked day before surgery and if necessary give vit K if INR is greater than 1.5
4. STOP heparin 4-6hrs before surgery (on basis of bleeding risk vs clotting risk)
5. unfractionated heparin good choice is major risk of bleeding as it can be reversed with protamine
6. post op start heparin/Tinzaparin once homeostasis achieved/up to 48 hrs post surgery in high risk procedures
7. warfarin can be restarted at usual maintenace dose on evening of op or next day
8. Compression stockings!

Question 27

What if the pt is not taking an anticoag after hip surgery?

Answer 27

still need thromboprophylaxis
options include
1. Tinzaparin 10 days post op followed by aspirin 75mg OD for further 28 days
2. 28 days tinzaparin plus stockings
3. Rivoroxaban (apixaban/dabigatran = alternatives)

Question 28

What if the pt is not taking an anticoag after knee surgery?

Answer 28

still need thromboprophylaxis 
options include 
1. aspirin 75-150mg OD for 14 days 
2. Tinzaparin for 14 days plus stockings 
3. Rivoroxaban

Question 29

Which antibiotics are given for post orthopaedic surgery?

Answer 29

Gentamicin and Teicoplanin
due to range of potential contaminants that could infect new prosthesis

stat dose of each enough but if hip/knee needs revision surgery after failed implant/infection give 7 days of abx prophylaxis
and monitor genatmicin levels as it can accumulate and in renal impairment

Question 30

what are the main risks following hip/knee surgery?

Answer 30

Infection
VTE
Constipation
Hospital acquired infection e.g. pneumonia
dehydration
AKI
neausea/vom
pain
sepsis
haemorrhage 
cardiac evvents e.g. heart attack