Types of question DNB SS 2018 CET
Q1. ) What are natural killer cells?
a) Multinuclear monocytes
b) Special macrophages
c) Antibody presenting cells
d) Large granular lymphocytes?
Q2) What is the ideal suture is to wound length ratio for appropriate wound closure?
Q3. What should be the ratio of length : breadth in an elliptical incision
Q4 ) Blade used for arteriotomy?
a) No. 11
b) No. 22
c) No. 10
d) No. 23
Q5. Vascular anastomosis, preferable suture material
A. Non-absorbable, elastic
B. Non-absorbable, non-elastic
C. Absorbable, elastic
D. Absorbable, non-elastic
Q6 . In a critically ill patient best way to monitor cardiac output is by
A. Pulmonary artery catheter
B. Pulmonary vein catheter
C. Femoral artery catheter
D. Subclavian vein catheter
Q7 CT abdomen is equal to how many CXR
Q8) Hot air oven sterlization is done for:
b) Surgical instruments
c) Culture media
Q 9) Isotonic fluid solution is
A. Half normal saline
B. 1/5th normal saline
C. Ringer lactate
D. Dextrose in Normal saline
Q10 False in hemorrhagic shock
A. Low heart rate
B. Cold extremity
C. Due to fluid losses
D. Vascular resistance high
Accessory Question from AIIMS
Q) All are true about disinfectants in surgery except
A. Povidone iodine needs to dry up prior to its action
B. Alcohol disinfectants act against all organisms except clostridium difficile
C. Single dose of first generation cephalosporin should be givens prophylaxis for vascular
procedures and bladder catheterisation
D. Chlorhexidine is bactericidal, viricidal, fungicidal, and has rapid onset of action and persistent
Large granular lymphocytes
Natural killer cells are a part of lymphocytes called "null cells" These are large granular lymphocytes and the 1st line of defence against viruses and bacteria
They belong to null cells as they do not rely on specific match or memory.
They control both tumor and microbial spread in the body.
Unlike T cells ( which mature in thymus), natural killer cells develop in bone marrow. They identify the viruses and other harmful cells by lack of major histocompatibility complexes (MHC)
Antigen presenting cells are B cells
T cells are direct cyto toxic cells
Sabiston 20th page 601
For abdominal wall closure, the length of the suture material should be at least four times the
length of the wound to be closed to minimise the risk of abdominal dehiscence or later incisional hernia .
Transverse incisions are better than vertical incisions
Ref: Bailey 26th page 34
Elliptical incisions are most commonly used for melanomas, cosmetic and pre cancerous lesions.
They should be placed parallel to the langer's lines.
For an elliptical wound to close without tension the length is to breadth ratio should be 3:1
Ref Bailey 26th page 33
22 is used for abdominal incisions
11 for arteriotomy
15 for minor surgical procedures
Ref Bailey 26th page 33
For Vascular anastomoses- Non elastic Non absorbable suture is preferred
Bile duct - absorbable that has no tissue reaction
Bailey 26th page 5
Pulmonary artery catheter
Pulmonary artery catheters measure cardiac output and cardiac index as well as oxygen delivery to the tissues.
They are however invasive and can lead to complications such as arrythmias and pulmonary artery rupture.
Bailey page 259, 26th edition
Bailey 26th table 13.1
Hot air oven operate between 50 degree to 300 degree.They kill micro organisms by heat.
- 1.5 to 2 hours at 160 °C (320 °F)
- 6 to 12 minutes at 190 °C (374 °F)
They can only be used for things which do not get destroyed by heat such as glass, oily fluids, powders, flasks
Surgical instruments and endoscopes would loose their shape and are sterlized with cresol and glutareldehyde
Culture media- Tyndallisation
Ringer lactate and Normal saline are isotonic fluid. they are useful in replacing GI losses. Ringer lactate has a bit of potassium as well.
Body actually requires bicarbonate and not lactate. Lactate is the more stable form in IV solutions and is used, it is converted by liver into bicarbonates.
Half NS is used in replacing losses when sodium concentration is high in the body, mainly as maintenance fluid
1/5th NS is hardly used clinically
Dextrose in Saline or DNS is used for maintenance and is not isotonic
Answer to AIIMS Question
Povidone-iodine solution is used for surgical site preparation, it must be allowed to dry for microbicidal effect.
Chlorhexidine is a phenol which is used in concentrations of 0.5% to 4.0% alone or in lower concentrations in combination with an alcohol as a skin antiseptic. ....
Chlorhexidine has all actions, bactericidal, viricidal, and fungicidal, Its onset of action is slow but persistent
Alcohol hand cleansers are effective except against the spores of Clostridium difficile, which requires cleansing with soap and water.
Ref Sabiston page 244