General Anaesthesia

General anesthesia (anaesthesia)

State of unconsciousness and loss of protective reflexes resulting from administration of 1 or more general anesthesia agent.

Theories of general anesthesia (put in simple term)


1. Lipid theory - Decrease membrane permeability -> interfere with brain function -> LOC

2. Ion channel theory - Effect brain's ion channel (Na+,K+) ->  interfere with brain function -> LOC

3. Receptor theory - Increase GABA effect -> interfere with brain function -> LOC

Stages of anesthesia


1. Sedation - administration of agent till LOC
2. Excitement - LOC till loss of eyelid reflex
3. Surgical Anesthesia - loss of eyelid reflex till respiratory depression
4. Overdose - respiratory depression - death

Components in GA

1. Loss of consciousness - The use of either intravenous or volatile (gas) GA agent
2. Muscle relaxant - Non depolarizaing / Depolarizing
3. Analgesia - Opioid

General anesthesia agent


- To be continued-


1. IV agent

- Barbiturate: thiopental

- Benzodiazepam: midazolam

- Phenol: Propofol

- Steroid: Ethomidate

- Imine: Ketamine

2. Volatile agent


- Sevoflurane
- Isoflurane
- Desflurane
- Halotane
- Enflurane

Muscle relaxant agent

1. Depolarizing

Suxamethonium

2. Nondepolarizing

Atracurium
Rucororium

Analgesia


Opioid

Reversal agent


Neostigmine
Atropine

Preoperative assessment

Preoperative assessment is done based on

1. History
2. Physical Examination
3. Investigation

1. History


- Presenting complain
- Medical condition: CV/Respiratory/effort tolerance
- Anesthesia history: previous complication/ side effect: difficult airway/nausea/headache
- Family history: malignant hyperthermia/ porphyria/ pseudocholinesterase deficiency 
- Drug history: Anti-hypertensive/ steroids/ OCPs/ anti-convulsion
- Allergy: drug/food/soy
- Social History: smoking/alcohol

2. Physical examination


General: hydration/ temperature
CVS: Pulse/ JVP/ BP/ Heart sound/ Murmur - AS(lean in front) /MS(lean laterally)
Respiatory: Cyanosis/ Auscultation of lungs
Airway: Mallampati score, thyromental distance, neck movement, facial symmetry, tongue size

Mallampati score
Grade 1- full opening
Grade 2- tongue touches tip of uvula
Grade 3- Tongue covering tip of uvula
Grade 4- Tongue covering everything

Thyromental distance (<7cm : suggest difficult airway)

3. Investigation


- FBC: all
- Urinalysis: all
- RF : hx of diarrhea/vomiting/ renal disease
- LFT: liver disease/ alcoholism / nutritional state
- Blood glucose: DM/ vascular disease/ corticosteroid 
- Coagulation profile: coagulation disorder/ chronic liver disease
- ECG: >45 CVS disease
- CXray: Respiratory problem/ Thyroid enlargement


American Society of Anesthesiologists grading (ASA)


Grade
1. Healthy
2. + Disease controlled/ non life threatening
3. + Disease uncontrolled/ non life threatening
4. +  Life threatening
5. Expect to die with or without surgery
6. Dead - for organ donation

Orthopedic emergency

This post will be explaining briefly, the common orthopedic emergencies, including its presentation investigations and managements.

EMERGENCY 1 : SEPTIC ARTHRITIS


Septic arthritis = infected joint. The infection will produce inflammation that kills the pathogen , but at the same time damages the cartilage.
The infection can either come from direct trauma or due to hematogenous spread from elsewhere in the body

Common organism: Staphylococcus Aureus (adult), H. influenza (child)

S&: FEVER, SWELLING, PAIN, WARM

Hx: Single joint, cant move (in pain), Hx of Trauma / URTI


Ix: FBC, C&S, (ultrasound in child), X-ray (effusion-widenning of joint space), crp

Mx: analgesic, fluid, paracetamol, aspirate, antibiotic
If Confirmed: (flush/ n aspirate), drain. immobilize


Complication: osteomylitis, deformity


EMERGENCY 2 : Crush Injury (reperfusion)


Crush injury will result in breakdown of muscle cells causing a delivery of its products (Myoglobin/Potassium/Creatine Phosphokinase) into the blood stream.
A release of the crushing pressure will allow these products to circulate freely in the blood causing systemic damage. (shock and renal failure)

Sign: hypovolemia

Investigation: ABG, Renal profile, full blood count

Management: Apply tourniquet , amputate , treat the shock and renal failure


-----Coming soon---- 


EMERGENCY 3 : Compartment Syndrome


EMERGENCY 4 : Fat Embolism


EMERGENCY 5 : Cauda Equina Syndrome

Fractures: principal and management

Intro:

Fracture is discontinuity of a bone

Describing a fracture:

Type : Close / Open
Nature : oblique / transverse / spiral / comminuted (more than 2 fragments)
Site : which bone, R / L
Displacement : angulation, overriding, translation, twisting

Fracture: can be divided into OPEN and CLOSED


- Open fx: fracture which communicates with a wound
- Closed: fracture with intact skin

Classification:

Gustilo classification for open fracture

Grade:
1 : CLEAN wound, less than 1 cm
2 : CLEAN wound, 1-10 cm
3 A : DIRTY wound, adequate soft tissue covering
   B : DIRTY wound, inadequate soft tissue covering
   C : Involve neuro/vascular injury


Management

The general rule is, fracture heals on its own. We manage fracture by aligning it so that i can fix itself correctly. The physiological process of fracture healing (HICCR):

H: Hematoma 
I  : Inflammation
C : Callus formation
C : Consolidate 
R : Remodeling


Time to heal:

Adult:
Upper limb:  3x2 (6 weeks)
Lower limb:  3x2x2 (12 weeks)



Management of Closed fractures:

Reduce: Close manipulation, Open reduction, mechanical traction
Hold: Traction - Fixed / Balance(skeletal / skin), Cast, Internal fixation (screw/wire/plates and screw/intermedulary nail, External fixator  (illizarof)
Exercise: to reduce oedema, restore muscle power

a. screw b. nail and plate c. intermedullary nail d. locked intermedullary nail e. dynamic hip screw

Management of Open fracture:

Debridement: clean wound
Antibiotic prophylaxis : prevent infection
Fracture stabilization: usually external fixation
Closure of wound: delayed primary closure, secondary closure


Complication of fracture

Early (Insanely Hot Nude Nice Fat Chick)
- Infection
- Heamarthosis
- Neuro/Vascular injury

- Fat embolism (explained in orthopedic emergencies)

- Compartment syndrome (explained in orthopedic emergencies)

Late (DAMN)
- Delayed union
- Avascular necrosis
- Malunion
- Non-union (hypertrophic / atrophic)

Introduction

New year's resolution no. 9: to STUDY more! and what better way to ensure that i study than blogging bout it!
*inspired by an old friend, JACK NAIM


Reference are/will be made from, textbooks, journals, lecturers and notes from others (etc. jack naim's)

Feel free to browse/read/copy and paste/reproduce any part of this blog

With the words of Bismillahirrahmanirrahim, allow me to begin.