Part Two - general Flashcards
Breslow thickness
Tumour depth - Approximate five year survival
< 1mm - 95-100%
1-2mm - 80-96%
2.1-4mm - 60-75%
> 4mm - 50%
Dukes classification
Dukes’ A = invasion into but not through bowel wall - 90% five year survival
Dukes’ B = invasion through the bowel wall but not involving nodes - 70%
Dukes’ C = involvement of lymph nodes - 30%
Dukes’ D = distant metastases - <15%
Submandibular space
Anterior upper neck
Above investing layer of deep cervical fascia
Between hyoid and mandible to mucous membrane of floor of mouth
Contains:
- Mylohyoid muscle
- Sublingual gland above mylohyoid muscle
- Submandibular gland hooking around posterior border of mylohyoid
Cellulitis here = LUDWIG’S ANGINA
MAGIC trial
United Kingdom Research Council MAGIC Trial
503 patients with potentially resectable gastric (74%), distal oesophageal (11%) or OGJ adenocarcinomas (15%)
Surgery alone or surgery plus perioperative chemotherapy
Three preop and three post op cycles of epirubicin, cisplatin and infusional 5-fluorouracil
T2+ disease with no distant metastases or locally advanced inoperable disease as per CT, USS and laparoscopy
Only 42% could complete treatment
Five year survival improved from 23% to 36%
Problem - more T1/T2 tumours in chemotherapy group
CA 125
Cancer antigen 125
Large transmembrane glycoproteins derived from both coelomic (pericardium, pleura, peritoneum) and müllerian ( fallopian tubes, endometrium, endocervical) epithelia.
Elevated in malignant conditions:
- Ovarian carcinoma
- Fallopian tube carcinoma
- Primary serous peritoneal carcinoma
- Endometrial carcinoma
- Endocervical adenocarcinoma
- Pancreatic carcinoma
- Breast carcinoma
- Lymphoma
- Lung carcinoma
- Colorectal carcinoma
Elevated in benign conditions
- Endometriosis
- Cirrhosis
- Acute peritonitis
- Acute pancreatitis
- Acute PID
- First trimester of pregnancy
Describe Strasberg classification oh bile duct injury
Type A - Bile leak from cystic duct or minor hepatic ducts draining liver bed
Type B - Occlusion injury of aberrant right hepatic duct
Type C - Transection without ligation of proximal aberrant right hepatic duct
Type D - lateral injury to major bile duct
Type E - Transection of main duct
* E1 / Bismuth 1 - Injury >2cm from confluence
* E2 / Bismuth 2 - Injury <2cm from confluence
* E3 / Bismuth 3 - Injury at confluence, confluence intact
* E4 / Bismuth 4 - Destruction of biliary confluence
* E5 / Bismuth 5 - Injury to aberrant right hepatic duct and main duct
Define SIRS
SIRS = systemic inflammatory response syndrome
Clinically defined by two or more of:
- Temperature > 38 or < 36
- Pulse rate > 90
- WCC > 12 or < 4 x 10*9/L
- Respiratory rate > 20/min or PaCO2 <32 mmHg
Daily water turnover in the gut
Ingested 2.0L Endogenous secretions 7.0L - Salivary glands 1.2L - Stomach 2.5L - Bile 0.5L - Pancreas 1.5L - Intestine 1.0L Reabsorbed 8.8L - Jejunum absorbs > ileum > colon Faeces 0.2L
Define harmatoma
Disorganised but benign-appearing mass composed of cells indigenous to particular site
Define pseudopolyp
Inflammatory pseudo polyps are irregularly shaped islands of residual intact mucosa resultant from ulceration and regeneration in IBD.
How large do lymph nodes need to be on CT to suggest LN metastases?
Thorax & abdomen - 1cm in short axis
Supraclavicular - 0.5cm in short axis
Retrocrural - 0.6cm in short axis
What is metaplasia?
The reversible replacement of one differentiated cell type with another mature differentiated cell type
Subclavian artery
Divided into three parts by saclenus anterior
1st part medial with three branches
- Vertebral artery
- Internal thoracic artery
- Thyrocervical trunk
- Inferior thyroid artery
- Inferior laryngeal artery
- Ascending cervical artery
- Superficial cervical artery
- Suprascapular artery
2nd part behind muscle with two branches
- Costocervical trunk
- Deep cervical
- Superior intercostal
- Dorsal scapular artery
3rd part lateral to muscle with no branchesAxillary artery
Continuation from SCA beginning lateral border 1st rib and terminating lower border terries major
Divided into three parts by pec minor
1st part medial to muscle with one branch
- Superior thoracic artery
2nd part behind muscle with two branches
- Thoracoacromial trunk - CHAP branches
- Lateral thoracic artery
3rd part lateral to muscle with three branches
- Subscapular -> thoracodorsal & circumflex scao
- Anterior circumflex humeral
- Posterior circumflex humeral
Indications for the open abdomen
1 - prevention or treatment of ACS
2- damage control for life-threatening intra-abdominal bleeding
3 - management of severe intra-abdominal sepsis
Define abdominal hypertension
Sustained pathologic increase in intra-abdominal pressure greater than or equal to 12mmHg
Define abdominal compartment syndrome
Sustained pathologic increase in intra-abdominal pressure greater than 20mmHg that is associated with new organs dysfunction/failure
What is abdominal perfusion pressure (APP)?
= MAP - IAP
Is a measure of the net pressure available for perfusion of intra-abdominal organs
Target APP associated with appropriate perfusion is 60mmHg
Analogous to cerebral perfusion pressure
Principles of managing IAP
- Serial monitory of IAP
- Optimisation of systemic perfusion and organ function in the patient with increased IAP
- Institution of specific medical procedures to reduce IAP
- Prompt surgical decompression for refractory IAH
Risk factors for IAH/ACS
Four categories of risk factors:
- Diminished abdominal wall compliance
- Increased intraluminal content
- Increased abdominal contents
- Capillary leak / fluid resuscitation
Specific examples:
- > 5L crystalloid within 24 hours
- > 10U packed red cells within 24 hours
- Hypothermia < 33
- Acidosis with BE < -14 and/or pH 30
- Burns:
- TBSA > 30% risk factor for IAH
- TBSA >50% risk factor for ACS
- Inhalation risk factor for ACS
How do you measure intra-abdominal pressure?
Bladder pressures. Instill 25mL saline via a foley catheter attacher to a pressure transducer zeroed at the MAL in the supine position. Take the reading at end-expiration.
How does warfarin work?
Coumarin derivative with structure similar to vitamin K. It causes the production of inactive vitamin K dependent coagulation factors - II, VII, IX and X.
How is warfarin reversed?
Cease for 5 days Vitamin K 1-10mg Prothrombinex 50IU/kg FFP 30ml/kg Recombinant factor VIIa 15-90units/kg
What is Prothrombinex?
Sterile, freeze-dried powder containing purified human coagulation factors II, IX and X and low levels of factors V and VII.
What is dabigatran?
A direct thrombin inhibitor that is renal excreted and difficult to reverse. Only known effective measure for reducing effect is haemodyalysis
How do you test the effect of dabigatran?
HEMOCLOT and ecarin clotting time are specific assays but not generally available.
If TCT and aPTT are normal there is probably no significant drug presence but if they are elevated they do not correlate well with affect
How do you reverse dabigatran?
Haemodialysis only method.
Support measures may include:
- Keep good UO as renal excreted
- Platelets if 80 or less and/or on anti-platelet agent
- Oral charcoal if ingested within two hours
- Replace calcium if low
- Tranexamic acid IV (15-30mg/kg) +/- continuous infusion (1mg/kg/hr)
- Consider Prothrombinex +/- rFVII
How does heparin work?
It is an indirect thrombin inhibitor which increases the efficacy of antithrombin III such that thrombin is aggressively inactivated. Also inactivates factors IIa, IXa, Xa, XIa, XIIa.
Enoaxaparin just inhibits Xa.
How is heparin reversed?
Because of short half life, just ceasing administration may be enough. Else protamine: - 1mg per 100mg UFH within 3 hours -------fully reversed - 1mg per 1mg LMWH with 8 hours -------up to 80% reversed
What defines massive blood loss?
- Loss of entire blood volume within 24 hours
- Loss of 50% within 3 hours
- Ongoing blood loss of 150ml/min
- Ongoing blood loss of a.5ml/kg/min
- Rapid blood loss leading to circulatory failure
Define shock
Inability of the body to maintain adequate end organ perfusion
How is haemorrhagic shock classified?
Into four classes based on amount of blood lost, HR, BP, PP, RR, UO and CNS.
15/30/40/>40
140
Define massive transfusion
10+ PRBCs within a 24 hour period
Damage control resuscitation strategies
For patients with overwhelming injury burden and massive blood loss
Includes:
Permissive hypotension
Aggressive 1:1:1 ratio transfusion
Selective use of haemostatic adjuncts
What is permissive hypotension?
With-hold of minimise fluids as long as cerebral perfusion is evidence and SBP remains above a threshold value of 70-80mmHg
What are massive transfusion protocols?
Institution based protocols activated in appropriate patients that standardise replacement of platelets and clotting factors in an optimum ratio to PRBCs and increases transfusion efficiency. Adjuncts of tranexamic acid, Prothrombinex and rFVIIa included
How do local anaesthetics work?
Drugs that prevent pain by reversible blockade of conduction along nerve fibres by sodium channel blockade. Small diameter fibres like pain fibres are the most sensitive
Lignocaine
Reversible sodium channel blocker
Acts rapidly 5 mins
Duration 2 hours
5 mg/kg without or 7mg/kg with adrenaline
Toxic dose 300mg without or 500mg with adrenaline
Bupivacaine
Reversible sodium channel blocker
Acts within 10mins
Duration 4 hours
2mg/kg without or 3mg/kg with adrenaline
Toxic dose 175mg without or 225mg with adrenaline
35ml without or 45ml with adrenaline in 0.5% mix
What is the risk of malignancy with CT?
1/200
1/400 fatal
How do you diagnose a chyle leak?
Increased drain output with enteral nutrition
Change in drain output from serous to milky
Triglyceride level >110mg/dL
Presence of chylomicrons
Treatment of chyle leak
Diagnosis then STEPWISE approach
NBM or high protein-low far oral diet with MCT supplements +/- somatostatin/ocreotide - 50% success
If no response within 5-14 days - ligation - 90% success
Consider early ligation if:
- Drain > 1L/day
- Younger adult patients at low risk of further complications
- After resection of a malignancy as less likely to respond to conservative management as leaking from collaterals that seldom heal spontaneously
Good technique for closure
Nonabsorbable monofilament
Continuous stitch
Suture length-to-incision ratio of 4:1 = 1cm of tissue at 1 cm intervals
WHO criteria for screening
RAIN ESCAPES
R = recognisable early stage of disease A = ability for continuous screening, not a one off I = important problem N = natural history known
E = evidence that early treatment beneficial S = sensitive, specific, simple, acceptable screening test C = cost effective A = adequate resources P = no psychological harm E = effective, safe, acceptable treatment S = strategy to identify those who should be screened
Explain the hypokalaemic hypochloraemia metabolic alkalosis with paradoxical aciduria
Vomit out HCl and KCl to a lesser extent-> alkalosis
K + exchanges for H+ -> exacerbating hypokalaemia
DT favours Na+/H+ over Na/K+ -> aciduria
Thereby aggravating the metabolic alkalosis in GOO
ABCs of non-surgical management
A - analgesia & antibiotics B - breathing optimisation C - catheter & consent D - DVT prophylaxis & drain E - electrolytes & emesis treatment F - fluids, food & ferrous G - gastric protection & glucose
ARDS
Clinical syndrome of pulmonary dysfunction resulting from infection, inflammation, tissue injury or cellular shock
Criteria for diagnosis of ARDS
- Hypoxaemia
- Bilateral pulmonary infiltrates
- Exclusion of heart failure
- Acute onset
Pathophysiology of ARDS
- Exudative phase - fucked type II pneumocytes
- Fibroproliferative phase - mesochymal cells = fibrosis
- Resolution phase - type II recover and fix fuckedness
Treatment ARDS
Supportive Prophylaxis Identify & treat underlying cause Omega three fatty acids Lung protective ventilation Prone positioning
Cardiopulmonary exercise testing
Accurate way to assess exercise tolerance which is the best predictor of post-operative complications.
Measures maximal oxygen consumption (VO2 max) which is a measure of level of work achieved on a static bike with increasing resistance via ECG and gas analyser.
>20ml/kg/min –> OK for surgery
not for surgery
Arista
MPH = microporous polysaccharde hemispheres derived from purified plant starch. Puff powered. Works in minutes and absorbs in 24 hours.
Controls capillary, venous and arteriolar bleeding when pressure, ligature and other conventional methods of haemostats are ineffective or impractical.
Eg - presacral vein bleeding, liver trauma
Surgicel
Absorbable haemostatic agent ORC = oxidised regenerated cellulose. Provides a matrix for platelet adhesion and aggregation. Absorbs in 7-14 days. Has anti-bacterial properties.
Proceed mesh
ORC, PDS, polypropylene.
Soft polypropylene mesh encapsulated by PDS
