Clinical Reasoning and Surgical Procedures

Clinical Reasoning

• Integrate clinical and contextual factors to make diagnostic and treatment decisions.
• Pattern recognition, intuition, more error-prone.
• Problem-solving approach: system, location, lesion.

Surgical Procedures

• SOAP (Subjective, Objective, Assessment, Plan) for procedure documentation.
• Important Surgical Principles: THA (Tissue Handling Approach), TAPE (Tissue handling, assessment, preserving blood supply, eliminating dead spaces, accurate tissue apposition, tension-free), HEAP (History, Exam, Assessment)

Pharmacology

• International Non-proprietary Names (INN) are used as generic names for drugs.
• Classification of drugs by properties (physiochemical, mechanism of action [MoA]).
• Prescription involves patient assessment for diagnosis, prescribing according to the identified diagnoses.
• Drug absorption is dependent on properties such as solubility, hydrophobicity, and diffusion.
• Drug distribution is related to plasma proteins (bound to protein or free), and distribution between body compartments.
• Drug metabolism changes drug structure to be more readily excreted.
• First-pass effect (drug is first metabolised by liver or gut) before reaching the systemic circulation.
• Drugs are eliminated through metabolism and excretion by the kidneys, liver, and other pathways.

Pharmacodynamics

• Drug-target interaction modulates biological function/effect.
• Structure-activity relationship (SAR) describes relationship between drug structure and its biological effect.
• Direct action: acts directly on target. Indirect action: drug acts upon a different target (sometimes endogenous release, inhibiting endogenous reuptake/metabolism)
• Agonist acts like a signal (stimulates).
• Antagonist blocks a signal (prevents)
• Dose/concentration-response relationship demonstrates the relationship between dose/concentration and the magnitude of effect of a drug, resulting in sigmoidal curve.
• Drug potency refers to the amount of drug required to exert a defined effect.
• Drug selectivity relates to the ability of the drug to only target the desired target.
• ADRs denote adverse drug reactions of a drug, type A = dose-dependent
• Therapeutic index (TI) relates dose of a drug that causes toxicity to the dose that elicits a therapeutic effect

Pharmacokinetics

• Drug clearance depends on factors such as drug concentration in plasma, total elimination & its bioavailability.
• Steady-state concentration is reached when drug absorption is equal to elimination rates
• First-pass effect: oral drugs are metabolised in the gut and liver.
• Volume of distribution describes the theoretical volume that is needed to dilute the total drug in the body to achieve the measured plasma concentration.
• Bioavailability is the fraction of administered drug that reaches the systemic circulation.
• Kinetic = – Zero order = constant amount for drug given per unit of time – First order= given as a constant fraction of the drug per unit time – Drug elimination half-life = time to reduce drug plasma concentration by 50%.

Clinical Preparation

• Premed (pre-operative medication) to ↓anxiety & catecholamine release and ↓ ANS activation

Anaesthetic Agents

• TIVA (total IV anaesthesia) = simultaneous IV injection & inhalant anaesthetics for maintaining anaesthesia.
• Induction agents rate can influence the rate of the rate of induction
• Ketamine (phencyclidine derivative)= rapid onset, and has dissociative effects
• Propofol = rapid IV induction and emergence
• Etomidate = rapid onset, less CV effects than other induction agents, not for CRI
• Inhalational agents = direct action on body . Oil/gas partition coefficient = anaesthetic potency . MAC (Minimum Alveolar Concentration): concentration of anaesthetic agent at which 50% of patients fail to respond to a noxious stimulus.

Anesthetic Systems & Equipment

• Various anesthetic systems exist = rebreathing vs Non rebreathing
• Gas supply, O2 delivery systems, P regulators/o2 concentrators for low P, & Flowmeters
• Proper use of components to prevent complications
• Understanding of different parts and proper function, & how to troubleshoot, and how to use for care/pre cautions

Surgical Instruments

• Description of different components and their uses – scalpel, scissors, forceps
• Special focus on different types of forceps & scissors (ex. haemostatic forceps, tissue forceps, scissors)
• Appropriate choice based on the tissues being manipulated.

Wound Healing and Management

• Inflammation (0-48hrs), Prolif (days 5-21), and Maturation phase (days 21+)
• Factors affecting wound healing (contamination, location, concurrent trauma, etc)
• Debridement (tissue removal)
• Wound closure methods based on exudate/infection presence
• Appropriate dressings and wound management techniques
• Understanding of different terms (laceration, degloving, abrasion, puncture, contusion, crush)
• Complications with wound healing (infection)

Antibiotics

• Classification of antibiotics based on mechanism of action.
• Indications (Gram +/-, anaerobic) to use ABs
• Time-dependent antibiotics: effectiveness relies on concentration above the minimum inhibitory concentration (MIC)
• Concentration-dependent antibiotics: effectiveness increases proportionally with the difference in concentration above the minimum inhibitory concentration (MIC)

Radiography and Radiation Safety

• X-ray dose management to limit radiation exposure to client & personnel
• Understanding of image qualities, positioning, & artifacts.

Ultrasonography

• Use of sound waves to create images, including probe type(linear array, curved), and limitations
• Interpretation of different imaging findings (e.g. fluid, lesions)

Pain Management

• Importance of assessing and managing pain throughout all surgical care.
• Use of systemic (system-wide pain meds), local, regional, & topical analgesics.

Other topics

This list is not exhaustive but includes other topics that the previous lists include, or could be included in the list of notes from similar material as above