Peri-op care and prep before investigations

Question 1

complications of bowel preparation in colorectal surgery?

Answer 1

dehydration
perforation
liquefying bowel contents which are spilled during surgery
electrolyte loss, leading to seizures and hyponatraemia
higher rate of post-op anastamotic leakage

Question 2

importance of nutrition?

Answer 2

wound healing
reduced infections
faster recovery
reduced loss of muscle mass

Question 3

daily calorie requirement?

Answer 3

30kcal/Kg/day

Question 4

types of enteral feeding?

Answer 4

supplements
nasogastric tube
nasojejunal tube
percutaneous endoscopic gastrostomy
jejunostomy

Question 5

complications of enteral feeding?

Answer 5

aspiration

re-feeding syndrome

Question 6

complications of total parenteral nutrition?

Answer 6

line thrombosis
sepsis
metabolic imbalance, fluid o.load, electrolyte imbalance, liver damage
mechanical e.g. pneumothorax, e.g. with SC line

Question 7

describe re-feeding syndrome

Answer 7

Occurs in the severely malnourished
Hypophosphatemia
Cellular dysfunction
Cardiac arrhythmia
Prevent by close attention to K, PO, Mg

Question 8

3 components to consider in hypotensive ptnt post op?

Answer 8

reduction in circulating volume (preload)
reduction in CO- reduced myocardial contractility, arrhythmias, valvular dysfunction
vasodilatation (afterload)

Question 9

most common cause of hypotension after surgery?

Answer 9

hypovolaemia e.g. bleeding in surgery, continued bleeding, tissue damage causing oedema, or evaporation during prolonged surgery on body cavities e.g. abdomen and thorax.

Question 10

how is hypovolaemia post op diagnosed?

Answer 10

reduced peripheral perfusion- CRT >2s, cold clammy skin, in absence of fear, pain and hypothermia
tachycardia- PR>100bpm of poor volume
hypotension, and narrow pulse pressure- DBP elevated due to compensatory vasoconstriction
inadequate urine output- <0.5ml/kg/h, should be measured hrly with catheter.

Question 11

causes of a reduced urine output post op, other than hypovolaemia?

Answer 11

blocked catheter
hypotension
hypoxia
renal damage intraoperatively e.g. in AAA surgery or hysterectomy

Question 12

most common causes of oliguria and anuria?

Answer 12

oliguria- hypovolaemia

anuria- blocked catheter

Question 13

in which ptns might hypovolaemia post op not be detected?

Answer 13

young, fit ptnt who can lose up to 15% of blood volume without detectable signs
ptnt on beta blockers may not be seen as having tachycardia

Question 14

management of hypovolaemia post op?

Answer 14

ensure adequate oxygenation and ventilation
give IV fluid
X match blood
stop any external haemorrhage with direct pressure
monitor CVP if cardiac function is in question
arterial blood sample- lactic acidosis?

Question 15

why might a ptnt have adequate oxygen sat.s despite inadequate ventilation?

Answer 15

receiving O2 therapy

Question 16

features indicating L ventricular dysfunction post op?

Answer 16

tachypnoea
tachycardia
poor peripheral circulation- cold clammy hands, CRT>2s
distended neck veins, raised JVP
basal crepitations on lung auscultation
wheeze with productive cough
triple rhythm on heart auscultation

Question 17

management of L ventricular dysfunction post op?

Answer 17

sit ptnt upright
give 100% O2
monitor ECG, BP, and SpO2
can give fluid challenge if diganosis unclear, an improvement in circulatory status suggest hypovolaemia
if sure of diagnosis, can give a diuretic and restrict fluids initially
monitor CVP trends
care in critical care area
use of inotropes and vasodilators

Question 18

most common arrhythmia after anaesthesia and surgery?

Answer 18

sinus tachycardia (>100bpm)
usually result of pain or hypovolaemia
if assoc with pyrexia, may be early indication of sepsis

Question 19

what might development of an unexplained tachycardia post anaesthesia rarely be the 1st sign of?

Answer 19

malignant hyperthermia/hyperpyrexia

Question 20

tment of sinus tachycardia post-op?

Answer 20

give O2
analgesia
adequate fluid replacement
possible beta blocker if persists

Question 21

causes of sinus bradycardia post op?

Answer 21

inadequate dose of anticholinergic given with neostigmine to reverse NMB
excessive suction to clear pharyngeal or tracheal secretions
traction on viscera in surgery
excessive high spread of epidural or spinal anaesthesia
development of acute inferior MI
excessive beta-blockage preop or intraop

Question 22

medication used intraoperatively to reverse epidural or spinal aneasthesia induced hypotension?

Answer 22

ephedrine hydrochloride

Question 23

most common supraventricular tachycardia post op?

Answer 23

AF

usually due to IHD or presence of sepsis

Question 24

if ptnt has sinus bradycardia post op, and low BP, what medication should be given?

Answer 24

atropine, 0.5mg IV
consider adrenaline infusion if no response

O2 should also be given

Question 25

how is hypotesion secondary to regional aneasthesia corrected?

Answer 25

give fluids use of vasopressors e.g. ephedrine or combination of both give O2

Question 26

minimum criteria for discharge from recovery area?

Answer 26

fully conscious and able to maintain own airway adequate breathing stable CVS, with minimal bleeding from surgical site adequate pain relief warm

Question 27

presentation of post op confusion?

Answer 27

agitation disorientation attempts to leave hosp, esec. at night

Question 28

how to treat post op confusion?

Answer 28

gently reassure patient may need sedation to examine them- midazolam, or haloepridol reassure relatives that it is common, and reversible

Question 29

tests in hypoxic/dyspnoeic ptnt post op?

Answer 29

FBC- pneumonia ?rasied WCC ABG CXR- fluid overload ECG- MI, PE- R axis deviation, RBBB sit up ptnt and give O2 pulse oximetry

Question 30

most common form of infection post op?

Answer 30

wound infection

Question 31

types of infections post op?

Answer 31

``` wound infection peritonism chest infection UTI cannula site eryhtema menigism endocarditis ```

Question 32

common causative organisms of post op wound infections?

Answer 32

``` staph aureus pseudomonas aeruginosa E coli staph epidermidis enterococcus faecolis ```

Question 33

tment of anuria post op?

Answer 33

most likely due to blocked catheter, so flush or replace catheter

Question 34

tment of oliguria post op?

Answer 34

increase fluid input

Question 35

how is urine output monitored and managed post op?

Answer 35

review fluid chart and examine for signs of volume depletion= fast pulse rate, cold and pale extremities, CRT>2s, low BP examine for palpable bladder- urinary retention common establish normovolaemia- may use CVP line, may need 1L/h IVI for 2-3hr, a colloid bolus over 30 min may also help catheterise bladder for accurate monitoring, checks Us and Es refer to nephrologist early if IRF suspected

Question 36

why is metoclopramide NOT used to treat PONV?

Answer 36

due to its prokinetic property

Question 37

recent concern over anti-muscarinic drugs e.g. atropine?

Answer 37

dementia

Question 38

effect of aspirin on risk of GI bleeding?

Answer 38

75mg aspirin daily increases risk of GI bleeding 2-fold

Question 39

surgical presentations in ptnts on COCP?

Answer 39

``` DVT/PE mesenteric venous thrombosis ischaemic colitis hepatic adenomas progesterone only increases risk of pregnancy being ectopic ```

Question 40

drug causes of pancreatitis?

Answer 40

``` Alcohol Azathioprine Aminosalicylates ACE inhibitors Frusemide/thiazides L-aspariganase Metroniadazole 6-mecaptopurine Oestrogens Steroids Sulphonamides Tamoxifen Tetracyclines Valproic acid ```

Question 41

drug causes of diarrhoea?

Answer 41

``` ß-blockers Misoprostol Antibiotics Iron Metformin ACE-inhibitors Statins Olsalazine Mefenamic acid Laxatives (acute) ```

Question 42

drug causes of constipation?

Answer 42

``` opioids chronic laxative use antimuscarinics mebeverine gaviscon iron ```

Question 43

how is risk of small bowel enteropathy affected by NSAID use?

Answer 43

Small bowel enteropathy (hypoalbuminaemia and iron deficiency) risk is increased 7-fold in NSAI users

Question 44

drug causes of colitis?

Answer 44

``` Antibiotics Mefenamic acid Other NSAIs may cause relapse of ulcerative colitis Methyldopa Gold (oral) Penicillamine ```

Question 45

is aspirin stopped before surgery?

Answer 45

no | cardio and cerebroprotrective effects outweigh risk of bleeding

Question 46

are statins stopped before surgery?

Answer 46

no | reduce perioperative mortality

Question 47

why are beta blockers not stopped before surgery?

Answer 47

if IHD, sudden cessation can cause rebound angina/infarction

Question 48

risk if oral hypoglycaemics given on day of surgery?

Answer 48

intraoperative hyoglycaemia

Question 49

when should oral contracetive pills be stopped before surgery and why?

Answer 49

at least 4wks before as 5X increased risk of DVT restart 2 wks post op same for HRT,, increases risk by 1.5X

Question 50

tment of addisonian crisis if sudden cessation of steroids?

Answer 50

?100mg hydrocortisone every 6 to 8 hrs

Question 51

why is ptnt on warfarin?

Answer 51

AF previous DVT/PE prosthetic heart valve

Question 52

are herbal medicines stopped before surgery?

Answer 52

yes, 2 wks before | as may affect platelet function

Question 53

problem with metformin and use of iodine containing contrast media?

Answer 53

risk of renal failure | so STOP METFORMIN ON DAY OF PROCEDURE, CHECK U&E’s AT 48-72 hrs AND DECIDE WHETHER SAFE TO RESTART METFORMIN.

Question 54

recovery times of GI tract post surgery?

Answer 54

small bowel= 0-24 hrs stomach= 24-48 hrs colon= 48-72 hrs

Question 55

in emergency surgery, why is a bolus of Vit K not used to reverse warfarin if ptnt can wait at least 3hrs before surgery?

Answer 55

causes cardiac arrest | so give 1-5mg SLOWLY IV over 30 mins

Question 56

ptnts having what type of surgery should not receive LMWH prophylactically?

Answer 56

neck surgery

Question 57

if continuing opioid for more than 3 days post op, what must also be prescribed?

Answer 57

laxative e.g. senna

Question 58

prochlorperazine (stemetil) can be prescribed for nausea and vomiting. what problem can this cause and how is it reversed?

Answer 58

acute dystonia | treat with procyclidine, an anti-muscarinic, 5mg IV

Question 59

caution in prescribing NSAIDs post op?

Answer 59

ptnts with renal impairment

Question 60

define pain

Answer 60

an unpleasent sensory and emotional experience resulting from a stimulus causing tissue damage or likely to cause tissue damage, or expressed in terms of that damage.

Question 61

effects of pain on body?

Answer 61

``` tachycardia hypertension inability to deep breathe or cough nausea poor appetite poor mobility stress response- Na+ and water retention, oedema inability to work, depression, insomnia, illness behaviour ```

Question 62

caution with use of tramadol in elderly?

Answer 62

can cause confusion

Question 63

paracetamol dosage?

Answer 63

adults 20mg/kg, typically 1g 4-6hrly, and children=15mg/kg 4 hrly, PO, PR or IV

Question 64

dose of diclofenac, commonly prescribed NSAID?

Answer 64

100 mg pr 16hrly in adults, 50mg po 8 hrly

Question 65

example of a selective COX-2 inhibitor?

Answer 65

celecoxib

Question 66

dose of codeine prescribed?

Answer 66

0.5-1mg/kg | 30-60mg 6hrly in adults

Question 67

active metabolite of morphine that accumulates in renal failure?

Answer 67

morphine-6-glucuronide

Question 68

initial dose of morphine?

Answer 68

0.1-0.2mg/kg

Question 69

which places do the LA and opioid act when an epidural is given?

Answer 69

LA on nerve roots | opioid on SC

Question 70

what score is a measure of hypoxia?

Answer 70

the SpO2, measured via pulse oximetry

Question 71

what score provides a measure of how much O2 is able to cross the alveolar membrane?

Answer 71

PaO2 measured via ABG, =dissolved O2 in blood

Question 72

characteristics of O2 given via venturi mask?

Answer 72

fixed O2 concentration | often used in COPD ptnts

Question 73

drug that can be used post op to treat hypertension?

Answer 73

labetalol- mixed alpha beta adrenergic antagonist

Question 74

problem with Ryles (nasogastric) tubes if left in nose for >7-10 days?

Answer 74

can cause pressure sores around nose

Question 75

why does electrolyte imbalance occur with parenteral nutrition?

Answer 75

bypassing liver so lose liver's protective function against toxicity

Question 76

how do opioids increase risk of post op chest infection?

Answer 76

reduce cough reflex

Question 77

min time for IV Vit K to work?

Answer 77

6hrs

Question 78

why might elderly ptnts be more suitable to use of fentanyl or oxycodone to mangage post op pain rather than morphine?

Answer 78

prinicpal metabolite of morphine= morphine-6-glucuronide has potent opioid effects, and may accumulate in ptnts with renal failure, causing toxicity. fentanyl and oxycodone have less active metabolites and a faster onset of action.

Question 79

why might elderly ptnts be more suitable to use of fentanyl or oxycodone to mangage post op pain rather than morphine?

Answer 79

prinicpal metabolite of morphine= morphine-6-glucuronide has potent opioid effects, and may accumulate in ptnts with renal failure, causing toxicity. fentanyl and oxycodone have less active metabolites and a faster onset of action.

Question 80

entonox is a weak analgesic with sedative properties, what does it contain and when should it NOT be used?

Answer 80

50% NO and 50% O2 | avoided if pneumothorax as NO may diffuse into gas-filled space, increasing the volume.

Question 81

entonox is a weak analgesic with sedative properties, what does it contain and when should it NOT be used?

Answer 81

50% NO and 50% O2 | avoided if pneumothorax as NO may diffuse into gas-filled space, increasing the volume.

Question 82

what must be considered pre-op in ptnts with regular opioid use?

Answer 82

any current opioid med should be continued on admission to prevent withdrawal much larger doses of opioid than normal may be required explain that toxicity from high opioid dose is very unlikely reassure that addiction is not a concern

Question 83

what must be considered pre-op in ptnts with regular opioid use?

Answer 83

any current opioid med should be continued on admission to prevent withdrawal much larger doses of opioid than normal may be required explain that toxicity from high opioid dose is very unlikely reassure that addiction is not a concern.

Question 84

difference between oramorph and zomorh?

Answer 84

``` oramorph= immediate release, usually used for acute pain where opioid requirement unknown or changing rapidly zomorph= modified release over 12 or 24hr,, useful if opioid tment prolonged and for gradually weaning down dose at end of tment ```