cancer practical proceedures

Question 1

what are the indications for thoracocentesis?

Answer 1

investigate the cause of a pleural effusion

symptom relieve for breathlessness

• urgent decompression can relieve respiratory distress
• repeated pleural tap can be used in palliative care however in such cases pleurodesis is indicated

Question 2

what are the contraindications of thoracocentesis?

Answer 2

very small volume of fluid
coagulopathy
mechanical ventilation - risk of pneumothorax is pleura is punctured

Question 3

describe how thoracocentesis is performed?

Answer 3

sit patient upright
percuss to determine level of fluid

conventional site = posteriorly, 10cm lateral from spine and 1-2 intercostal spaces below upper level of fluid. Also can use location = 5th intercostal space, mid clav line

avoid intercostal nerves and vessels - go immediately above the rib. intercostal vessels run just below rib

separate fluid into different pot - MC&S, cytology, biochem etc

if fluid is being removed for breathlessness, remove larger amount of fluid and give O2 and measure sats throughout.

Question 4

what are the complications of thoracocentesis?

Answer 4

pain
pneumothorax
persistent air leak 
bleeding 
empyema

Question 5

how can we investigate pleural aspirate?

Answer 5

MC&S - gram stain, acid fast bacilli, culture and sensitivity
biochem - LDH, protein, pH, glucose, complement levels
cytology

Question 6

what is paracentesis? ascitic tap?

Answer 6

removing fluid from ascites

ascetic tap = diagnostic, small amounts of fluid removed for analysis
paracentesis = large amounts remove, therapeutic

Question 7

what are the indications for paracentesis?

Answer 7

diagnostic - determine aetiology

therapeutic - relieve respiratory distress or abdominal discomfort

Question 8

how is pleural fluid analysed?

Answer 8

MCS, cytology, biochem
is it transudate/ exudate
infection? - neutrophil count >250 cells/ mm3
Serum ascites albumin gradient (SAAG)

Question 9

how is paracentesis performed?

Answer 9

first use USS to confirm fluid and location

supine position with head elevated so fluid will accumulate in lower abdomen

insert needle 5cm above and medial to asis and syringe off fluid.

Question 10

what are the complications of paracentesis?

Answer 10

bleeding
infection
bowel perforation
hypoNa
hepatic encephalopathy 

withdrawing 5L or more can precipitate post-paracentesis circulatory dysfunction (PPCD) - hypoNa, AKI, increased renin in plasma.

Question 11

what are the contraindications to paracentesis?

Answer 11

skin infection at puncture site
coagulopathy
severe bowel distension 
pregnancy
distended bladder

Question 12

what is a hickman line?

Answer 12

type of central venous catheter

Question 13

how is hickman line inserted and checked?

Answer 13

insertion via USS guidance

check with Xray

Question 14

what are the indications for hickman line?

Answer 14

to give treatment - Abx, chemo, blood transfusion, TPN

to sample blood

Question 15

how are hickman lines managed?

Answer 15

clean exit site once a week and flush with saline.
cap at end of central line changed once a week.
can shower and bath with central lines but avoid swimming and strenuous exercise due to infection/ dislodging

Question 16

what are the complications of hickman lines?

Answer 16

infection
thrombosis of vein at end of line
air emboli

Question 17

what is apheresis?

Answer 17

blood passed through apparatus and components are separated using centrifuge
used to separate donor blood.

therapeutically:

• LDH apheresis - removal of LDH in familial hyperlipidaemia
• plasma exchange - remove liquid portion of blood to remove harmful substances
• leukocytopharesis - remove WCC that are malignant in leukaemia patient

Question 18

how can bone marrow be examined?

Answer 18

aspiration

bone marrow biopsy = trephine

examined by lifht microscopy, flow cytometry, chromosome analysis

Question 19

how is bone marrow aspiration carried out?

Answer 19

patient lies prone or on their side.
use posterior iliac crest for aspiration site/ biopsy
apply anaesthetic locaaly and needle is pushed through skin until it reaches a bone. (use large needle for biopsy and small needle for aspiration

after lie flat for 5 to 10 mins to put pressure on the site

Question 20

what are the sites for bone marrow aspiration/ biopsy?

Answer 20

usually posterior iliac crest
also sternum
in children up to 2yrs we can use tibia.

Question 21

what are the contraindications to bone marrow aspiration/ biopsy?

Answer 21

not many contraindications

bleeding disorders are NOT a contraindication
don’t use site where infection is over the bone.

Question 22

compare bone marrow aspiration and biopsy..

Answer 22

aspiration is quick, looks at relative quantities of cells and can study molecular genetics and flow cytology. but does not represent all cells.

biopsy gives cell and stroma constitution / architecture. represents all cells. takes longer.