Fat embolism

Definition: 

Fat emboli:

- a complication of trauma/ surgery that involve intrumentation of femoral intramedullary canal

- it is a response/ manisfestation of fat globules that may enter the blood stream

Fat embolism:

- a process by which fat emboli passes the bloodstream and lodges within the blood vessel

Fat embolism syndrome:

- serious manisfestation of fat embolism that causes multi system dysfunction

Causes: 

1. mechanical theory

- fat droplets from bone marrow enters the vessel

- increase of intramedullary pressure and cause fat/marrow to enter the bloodstream. which later could lodge in the lungs as emboli

- causes inflammation and local ischemia

2. metabolic theory

- stress from trauma that causes change to the chylomicron that causes formation of fat emboli

or

1. trauma related

- fracture at long bones: especially femur fractures

2. non trauma related

- liver disease, shock, bone tumor lysis

Symptoms:

- asymptomatic within the first 12-48 hours

Gurd's criteria: 2major 1 minor or 1major 4 minor

• Major: 

- hypoxemia, petechial rashes, neurological symptoms, pulmonary edema

• Minor: 

-tachycardia, fever, retinal changes/ renal changes/ fat macroglobinemia, jaundice, 

- drop in Hb, increase ESR, thrombocytopenia

Investigation: 

- FBC

- ABG

- RP/LFT

- CXR : ground glass appearance / snow storm appearance

Management:

- stabilise the patient

• Airway : no obstruction
• Breathing: oxygen support
• Circulation: two large branulla with fluid support 
• hemodynamically: Hb? any blood loss
• hydration: 3L/d

1. monitor vital signs : BP, PR, SPO2, temperature

2. inform 

- MO incharge, anaest (ventilator support)

- keep in view the need of doing CT brain to exclude other causes

3. rigid fixation of fracture within 24 hours

4. diagnosis of exclusion

5. DVT prophylaxis 

6. stress ulcer prophylaxis

Reference: 

1. https://www.orthobullets.com/basic-science/9055/fat-embolism-syndrome

Fluid and Resus common QnA for HO

Part 1: Fluid and its components

Q1. What are the common cause of fluid loss in surgery?

• apparent loss: diarrhea, vomiting and high output stoma
• 3rd space loss: 
• loss of water, electrolyte and colloid particles into interstitial space
• which could contribute to edema
• Intestinal obstruction, pancreatitis and ascites
• others: insensible fluid loss (hyperventilation/pyrexia), stress response

Q1a. How patient loss fluids from IO?

• apparent loss: vomiting
• 3rd space loss: 
• increased secretions
• bowel obstruction will cause bowel to secrete a lot of secretion to overcome the obstruction. 
• mucosal edema, so fluid not absorbed
• so there will be a lot of accumulation of fluid that leads to third space loss
• fluid accumulation in bowel can reach up to 6L
• that could lead to hypovolemic shock

Q1b. How patient loss fluid from pancreatitis?

• systemic inflammation 
• inflammation causing release of inflammatory cytokine and other pro-inflammatory mediators,
• leading to capillary leakage
• thus loss of circulatory albumin and fluids to interstitium
• capillary leakage cause fluid shift to third space and then hypotension leads to hypovolemic shock.

Q2. What is the main difference between crystalloid and colloid?

• molecular size
• affects shifting of fluid where low molecular size - low tonicity

Q3. How does fluid moves in human body?

• from low concentration to high concentration 
• big molecules fluid (colloids) 
• has ability to pull fluids from other compartments : oncotic pressure
• opposite of oncotic pressure: hydrostatic pressure

** not through pressure gradient / osmosis

Q4. What is isotonic?

• a solution concentration that is similar to plasma
• the osmolarity of plasma is around 300 mosm/L
• Normal saline: 308
• Half saline: 154 (hypotonic)
• 3% saline: 1026 (hypertonic)

Q5. What is the difference between Normal Saline (NS) and Hartmann(HM) solution?

• Hartmann has additional potassium, lactate, calcium
• the most "physiological" solution

Q5a. What is the function of lactate in HM

• lactate will be metabolised by liver to HCO3, thus acting as buffer
• especially in met acidosis

Q5b. Can we use HM as resuscitation fluid?

• No
• usually when patient needs resuscitation, already with multiple organ failure or impairment
• so although Hartmann has lactate that could help as buffer, the liver is unable to convert lactate to bicarbonate, which could lead to accumulation
• the accumulation of lactate will worsen the metabolic acidosis
• and Pt in acidosis usually has hyperkalemia, Hartment contains K+ which would further worsen the situation

Q5b. So when do we use hartmann?

• as maintanence, especially in those who need replace electrolyte loss (diarrhea and vomiting)

Q6. What is the function of Dextrose 5%?

• provide hydration
• the have glucose in solution not for calorie to avoid lysis and avoid hypotonic
• calorie in D5: 170/L
• it is just to render solution isotonic once infused in the circulation, once they reach liver will convert into free fluid
• - provide free water that can pass through membrane pores, expanding both intracellular and extracellular spaces

Part 2: Fluid and resuscitations

Q7. 60year old, 70kg man presents with diarrhea and vomiting for 1 week. brought in with hypovolemic shock
Outline your management for this man

- ABC

• assess airway
• breathing
• circulation
• check the vital signs: unstable/ stable

- insert 2 large bore needles and give IV NS

- run fast 1 pint NS

Q7a : If patient doesn't respond to fluid resus? 

• reaccess: if the volume is improved, but patient still hypotensive, he might have other component of shock
• for example: septicaemic shock --> we might need to start inotrope for vasoconstriction
• if cardiogenic shock / has underlying IHD --> get an ECG, and we might need to start with dopamine or dobutamine as the inotropic support. 
• if volume is still low, 
• can infuse COLLOID to hold the fluid in the circulation
• colloid has oncotic pressure that will hold the fluid intravascularly, thus maintain the BP

• So why we cant give colloid straight away for resus?
• Colloid causes shifting of fluid out of the cell, worsen the hypoperfusion
• in shock, circulation fails and tissue is hypoperfused, if we infuse hypertonic solution all fluid will move from the tissue into the intravascular system . 
• Therefore load with volume first (crystalloid)
• resume the circulation
• let them reach the heart, brain and kidney
• after that infuse colloid to hold the volume. 

Q8: Define shock

• must have 2 components
• circulatory failure: seen via vital signs
• inadequate tissue perfusion : seen via low SPO2
• sequelae of low perfusion
• multiorgan failure

Q9: Why we cant have central line when patient is in shock?

• it is about the catheter's caliber. the shorter the calibre, faster the infusion. 
• if central line, it has long calibre and the rate of infusion is slower
• insertion takes a lot of time
• in shock we need large supply of fluid for the patient 
• Poiseuille law

Q10: How do you know patient responded to your fluid resuscitation? what are your AIMS?

• vital signs 
• HR <90
• BP >90/60 , MAP >60
• SPO2 >95%
• RR <20
• u/o  >0.5ml/kg/hr

drug doses to know in medical

LIST of important drugs and doses

 IV hydrocot 200mg stat

S/c Fondaparinox 2.5mg OD/7.5mg OD

S/c Heparin 5000u BD/7500u BD

S/c Morphine 5mg/7.5mg TDS

S/c Clexane 40mg/60mg OD

T Ranitidine 150mg BD

IV Ranitidine 50mg TDS

Mist calminative 15mls TDS

Mist Na Citrate 15mls/30mls OD

T EES 400mg BD

T Zinnat 250mg BD

T Ponstan 500mg TDS

T Voltaren  50mg TDS

T Papase 11/11 TDS

T Gelusil 11/11 TDS

IV Maxolon 10mg TDS

C Celebrex 200mg BD /400mg OD

C Tramal 50mg/75mg TDS 

T Arcoxia 90mg OD

Syp MMT 15mls TDS

Syp Benadryl 15mls TDS

T Piriton 4mg/8mg TDS

IV hydrocortisone 200mg stat, 100mg QID

T Cilostazol (claudication pain) 100mg OD

T Aspirin 150mg OD/300mg STAT

IM nubain 20mg stat

T/IV Bisolvon 8mg TDS 

T Labetolol 100mg TDS 

T Adalat 10mg TDS

T Methyldopa 250mg TDS

Ural sachet 1/1 BD/TDS 

IV/T lasix 20/40/80 mg BD

IM/IV Pethidine 50mg

T Rocaltriol 0.25 mcg OD

T calcium lactate 600mg BD

T levenogestrel 1.5mg stat

Inj Ertapenem 1gm OD

Inj Piptaz 3.375g 

T/IV Tranexamic acid 500-1000mg TDS

IV Tramal 50 mg/75mg TDS

IV Maxolon 10 mg TDS

IV Cefuroxime 1.5 stat, 750mg TDS

IV Unasyn 1.5g STAT and TDS

IV Cefobid 2g stat, 1g BD

IV Ceftriaxone 2g stat, 2g/1g OD

IV Cefepime 2g stat, 1g BD

IV Meropenem 500mg tds/qid

IV Imipenem 500mg tds/qid

IV Ampicillin 2gm Stat 1gm QID

IV Cloxacillin 1g STAT, 1g/500mg QID

IV Flagyl 500mg TDS

IV Augmentin 1.2g STAT, TDS

T Augmentin 625 mg BD

T Unasyn 375mg BD

T Doxycycline 200mg stat, 100mg bd

T Cloxacillin 500mg QID

T Azithromycin 500mg OD

T Flagyl 400mg TDS

C Tramal 50mg/75mg TDS

T Maxolon 10mg TDS

T Doxazosin 4mg OD 

T Finasteride 5 mg OD

T Cardura 4mg ON

T Hytrin 4mg ON

T. Metoprolol 50mg BD

IV vancomycin 500mg QID/1g BD over 1hr40min - MRSA  

Cream chlophelamine 

T. Cetrizine 10mg stat and OD