Pharmacology: Volatile agents

Contents: How do anaesthetic agents work? MAC and oil gas partition coefficient and Meyer-Overton Hypothesis Blood gas partition coefficient Metabolism Comparison tables Ideal inhaled anaesthetic agent References How do anaesthetic agents work? Different theories – none completely explains it. Meyer Overton Hypothesis and membrane expansion theory – Lipid soluble anaesthetic agents enter the cell membranes…

Pharmacology: Nitrous oxide and Xenon

Nitrous oxide Fast facts: Method of action = N-methyl-D-aspartate receptor antagonist Manufacture = Heating ammonium nitrate to 250◦C: NH4NO3 → N2O + 2H2O. Impurities include NO, HNO3, N2, NO2, NH3, and are removed through scrubbers, water and caustic soda Appearance = Clear colourless gas, sweet smelling at room temperature Critical temperature = 36.5 degrees celcius…

Airway: Simple airway manoeuvres and facemask ventilation

Contents of this page: Have a look at our airway anatomy page here too, just to help understand the structures we’re talking about on this page. Have a look at our airway assessment page to revise the risk factors for difficult facemask ventilation and how to make a strategy Head tilt, chin lift and jaw…

Pharmacology: Drugs affecting the renin-angiotensin-aldosterone system

Physiology of RAAS Classification of drugs Direct renin inhibitors ACE inhibitors Angiotensin II receptor antagonists Aldosterone antagonists References Physiology of RAAS and angiotensin can be found here. Classification of drugs The simplest way would be to classify drugs that affect the RAAS is to divide them into drugs that inhibit renin, angiotensin converting enzyme or…

Physiology: Renin-angiotensin-aldosterone system

Renin Renal blood flow Measurement of renal blood flow Renal autoregulation When do juxtaglomerular cells release renin? The renin angiotensin aldosterone system Eicosanoids and their relation to the kidney References Renin = hormone released from granular cells of the juxta-glomerular apparatus. The juxtaglomerular cells form part of the afferent arteriole as it enters the glomerulus…

Airway: Awake tracheal intubation (ATI)

Indications and contraindications Consent Preparation Oxygenation Sedation Topicalisation Performance of technique References Indications and contraindications Indications: Patients with head and neck pathology eg. malignancy and previous radiotherapy, who often have reduced mouth opening, limited neck extension, OSA, morbid obesity, and/or progressive airway compromise Absolute contraindications: Patient refusal Relative contraindications: Local anaesthetic allergy, airway bleeding, uncooperative…

Paediatrics: Paediatric airway and breathing considerations

Paediatric airway anatomical differences to adult and how to overcome them Airway assessment Preoperative considerations, planning and emergency preparation Induction of anaesthesia in a patient with a potentially difficult airway Congenital syndromes that have specific airway considerations Calculations and formulas for airway devices References Paediatric airway differences to adult and how to overcome them If…

Physics: Integration

Syllabus: PC_BK_04 Integration The following description of integration and differentiation is from the website Math is Fun! 🙂 This is most likely all you will need to know about the subject for the FRCA. A one liner explanation for what it is – it is a mathematical method of determining the area under a curve….

Physics: SI units and commonly used derived units

Syllabus: PC_BK_07, PC_BK_08 This page covers commonly used SI units and derived units, an exam favourite! Definitions The acronym for the SI units is SMMACKK – Second, meter, mole, ampere, candela, kilogram and kelvin. Second – time The second (s) is defined by taking the fixed numerical value of the cesium frequency ∆νCs, the unperturbed ground-state hyperfine…