Pathophysiology pearls Flashcards
DIC
Complement activation pathways and cascade
Diagnosis of chylothorax and chylous ascites
Milky fluid
Presence of chylomicrons
Triglygeride greater than 2mmol/L (and often >10mmol/L)
Nutrition screening tool
MUST screening tool, 5 step process
- Obtain BMI
- >20=0, 18.5-20=1, <18.5=2
- Percentage of unplanned weight loss
- <5=0, 5-10=1, >10=2
- Disease effect
- acute illness AND has been or likely to be poor intake >5 days
- Calculate score
- 0 low risk
- 1 medium risk- observe intake 3/7
- 2 high risk- needs intervention
- Make and undertake a plan
What is the Fearon- Vogelstien model?
Grading and parameters of haemorrhagic shock
What is an MTP
What are the constituents
What monitoring is recommended
A system designed to rapidly replace blood products at an approximate 1:1:1 ratio in a patient who is exsanguinating.
- The exact protocol differs between centres
At our centre the MTP is activated by a clinician who thinks it is warranted.
- Additional markers for triggering the MTP include:
- loss of half of estimated blood volume,
- use of 10 packed red cell units, or
- a score of 2 or more in the ABC trauma score
- 1 point each for penetrating trauma, HR >100, SBP <90, or positive FAST
Our protocol is:
- The first box contains
- 2 units of RCC and 2 units of FFP
- The second box contains
- 4U RCC + 4U FFP + 3U cryoprecipitate
- The third box contains
- 4U RCC + 4U FFP + 1U platelets
- Box Four is the same as the second box and these keep rotating.
The patient should receive 1g of TXA on arrival
The patient’s coagulation status should be continuously monitored with TEG, ROTEM, or coags as well as calcium and an ABG
Some centres use recombinant VIIa, although this is not widespread practice.
ABC trauma score
1 point each for:
- Penetrating trauma
- HR >100
- SBP <90
- Positive FAST
A score of 2 or more is an indication to commence the MTP
PTEN
Tumour suppressor gene
- Regulates cell cycle
- Widely expressed in most tissues
Associated conditions
- Cowden syndrome/Cowden-like syndrome
- Breast cancer (at least partly Cowden)
- Lung cancer
- Prostate cancer
- Head and neck SCC
- Thyroid Cancer
- Esp follicular cancer
Cowden syndrome and Cowden-like syndrome
Autosomal dominant
These conditions are characterized by the growth of multiple hamartomas and cancers,
- Lipomas, papillomas
- Breast cancer
- Thyroid cancer (follicular)
- Endometrial cancer
Cowden syndrome and Cowden-like syndrome are considered to be part of PTEN hamartoma tumor syndrome
Li-Fraumeni Syndrome
TP53 tumour suppressor gene mutation
Risk of malignancy developing in childhood and early adulthood
- lifetime malignancy risk of ~100%
- Some studies have used annual whole body MRI for surveillance which is effective but trade off with high rates of incidenatalomas
Autosomal dominant
Classical cancers
- Breast (lifetime risk 50%)
- Soft tissue and bone sarcomas (but not Ewings)
- Brain tumours
- Adrenocortical carcinomas
Less common cancers:
- Leukemias
- Adrenocortical carcinoma
- Pancreatic
- Bowel
- Many others
High association with radiation induced malignancies-
- Avoid RTx where possible
Pathognomonic histology:
“Leaf like stroma”
Phyllodes tumour
Pathognomonic histology:
“Orphan Annie Eyes”
Papillary Thyroid Cancer
Pathognomonic histology:
Psammoma body
Arise from papillary infaction and calcification in papillary forms of cancer
- Thyroid
- Papillary thyroid cancer
- Pancreas
- Somatostatinoma
- Glucagonoma
- Kidney
- Papillary RCC
- Gynae
- Ovarian and endometrial cancer
What are the phases of wound healing
- Haemostasis
- Inflammation
- Proliferation
- Maturation
These phases overlap significantly
VINDICATE
Vascular
Infectious/inflammatory
Neoplastic
Degenerative
Iatrogenic/Intoxication
Congenital
Autoimmune
Trauma
Endocrine/Metabolic
How to compose an answer to a question you do not have the answer for
In A Surgeons Gown Physicians May Make Some Progress
Incidence
Age
Sex
Geography
Pathogenesis/Precipitation
Macroscopic features
Microscopic features
Spread
Prognosis
The two hit model of tumourigenesis
First hit
- Inherited germ line mutation in a gene which would otherwise suppress malignancy
Second hit
- Sporadic mutation in the remaining functional copy of that gene in a single cell
- Clonal expansion and tumour development
Peutz-Jeghers
GI hamartoma syndrome
STK11 mutation (aka LKB1)
Pigmented mucosal lesions
Panenteric hamartomas
Very elevated risks for gastrointestinal cancers:
- Colorectal
- Stomach
- Small intestine
- Pancreas
Also breast and ovarian cancers
- Recommend increased/early surveilllance for these cancers
Hereditary diffuse gastric cancer syndrome
Germline cadherin 1 gene mutation (CDH1)
Susceptibility to diffuse, highly invasive gastric cancer
- also called:
- signet ring carcinoma
- isolated cell-type carcinoma
Also Lobular breast cancer
- Some pathogenic types this may be as high as 50%
- Generally risk reducing mastectomy not warranted unless strong family history to suggest a breast cancer pathogenic variant
PALB2
Partner and localizer of BRCA2 (PALB2)
- breast cancer susceptibility gene that encodes a BRCA2-interacting protein
- monoallelic PALB2 pathogenic variant have a risk of breast cancer by age 70 of 33 to 58% depending on family history
- the upper risk range can overlap with BRCA2 risks,
- PALB2 is considered to be a moderate to high-risk gene associated with hereditary breast cancer
- initiate annual mammography with tomography and annual breast MRI, starting at age 30 years.
- RRM may be an appropriate option for some patients
- Other cancers
- Pancreatic
- prostate cancer
- medulloblastoma
- ovarian
Tools used in recognising sepsis:
SIRS criteria
Not specific for sepsis but helpful in recognising the unwell patient
Four parameters
- Pulse
- >90
- <50
- Temp
- >38
- <35
- WCC
- >12
- <4
- Resp rate
- >20
- <8