Advanced Anaesthetic Monitoring Lecture Notes PDF

Advanced Anaesthetic Monitoring Lecture – Anaesthesia, Critical Care and Surgical Techniques (A6004C17) Week 12 –Tuesday 14th January 2025 Kat Hart MSc BSc(Hons) DipAVN CertAVN PgCTSLHE FHEA RVN 1 Learning Objectives Intended Learning Outcomes 1 and 2… 1. Evaluat...

Advanced Anaesthetic Monitoring Lecture – Anaesthesia, Critical Care and Surgical Techniques (A6004C17) Week 12 –Tuesday 14th January 2025 Kat Hart MSc BSc(Hons) DipAVN CertAVN PgCTSLHE FHEA RVN 1 Learning Objectives Intended Learning Outcomes 1 and 2… 1. Evaluate the triage, assessment, monitoring and care of the critical patient. 2. Appraise the veterinary nurse’s role in the management of patients across a range of veterinary practices in a variety of both simple and complex anaesthesia and surgical cases. ▪ Advanced monitoring techniques… ▪ Blood gas analysis. ▪ Blood pressure analysis. ▪ Electrocardiography. ▪ Capnography. 2  Blood Gas Analysis (BGA) 3 What does BGA measure? 3 primary parameters… ▪ Oxygenation (PO²). ▪ Ventilation (PCO²) ▪ Acid-base status (pH). +/- electrolytes, blood glucose, blood lactate, ionised calcium, % saturation of oxygen, base excess, bicarbonate concentration. 4 Why would you measure BGs? ▪ Aids in the diagnosis, treatment and management of many disease processes…. ▪ Used alone or in conjunction with other blood tests +/- diagnostics. 5 Sample collection and processing ▪ Venous or arterial sample…Which one is ‘gold standard’? Venous Arterial ▪ Easier to access, even in a ▪ Difficult to access, especially conscious patient. in a conscious patient. ▪ Can be painful. ▪ Can be painful + ▪ Aseptic technique. ▪ Strict aseptic technique + ▪ Directly from the vein ▪ Directly from the artery or (jugular) or a central venous central arterial line. line. ▪ May require local anaesthesia or EMLA cream for arterial puncture. 6 Venous sampling Single blood draw (‘off the needle’) Central line (in-situ) 7 Arterial sampling Single blood draw (‘off the needle’) Central line (in-situ) 8 Sample collection and processing ▪ Anaerobic technique Airtight syringe → to prevent inadvertent air entry. or Direct collection from a central line → discard first few drops of blood. ▪ Heparinised syringe Lithium heparin blood gas syringe (ready-made) or a lithium heparin coated syringe. If not using a heparinised syringe, analyse the sample immediately. The InSight® Arterial Blood Gas Syringes (Woodley) – link to product information. 9 BGA Machine ▪ Link to ‘how to’ video → using the EPOC BGA machine. ▪ Link to EPOC BGA product flyer → ▪ Link to EPOC BGA machine user manual. 10 Evaluation of findings Parameter Normal Value / Range PO2 5 x inspired % of oxygen PCO2 35 - 45 mmHg pH 7.35 - 7.45 HCO3- 22-36 mmol/l Base excess -4 to +4 12-25 mmol/l (dogs) Anion gap 13-27 mmol/l (cats) 11 Evaluation of findings Table 1. Quick reference findings in metabolic and respiratory dysfunction. 12 Oxygenation ▪ Would expect PO2 to be roughly 5 x % inspired oxygen. ▪ Severe at 45mmHg PCO2 = hypoventilation. ▪ < 35mmHg PCO2 = hyperventilation. Evaluation of findings 3-year-old female, neutered X- breed dog admitted collapsed and in shock, receiving 100% oxygen. 1. What is the PO2? 2. What is the pH? 3. What is the PCO2? 4. What is the HCO3-? 5. What is the base excess? 15 Patient Scenario – BGA Interpretation Mr. Bear is a 2-year-old Shiba Inu, who has presented to the hospital with a suspected pleural effusion. The veterinary surgeon has asked you to obtain and run a blood sample for blood gas and acid-base analysis. 1) Tutorial → explain how to obtain a blood sample for BGA, including the equipment required. As part of your answer, you should discuss the advantages and disadvantages of obtaining arterial and venous blood samples for BGA. 2) Prior to analysing his blood results (on the next slide), what do you think you may find based on the clinical information above? 16 Patient Scenario – BGA Interpretation Mr. Bear’s results Consider oxygenation, ventilation and acid-base balance… 17 The SVNs/RVNs role in BGA Everything, excluding diagnosis! ▪ Obtaining and processing the blood sample for analysis. ▪ Managing peripheral and central lines. ▪ Using and managing BGA equipment. ▪ Interpreting and recording the results. ▪ Responding to results (under the veterinary surgeon's instruction). ▪ Monitoring the patient for progression or deterioration. ▪ Obtaining and processing subsequent samples. 18  Break 10 minutes 19  Blood Pressure (BP) Analysis 20 Arterial Blood Pressure Cardiovascular status (+ tissue perfusion). ▪ Systolic arterial pressure (SAP) = 90-120mmHg (contraction). ▪ Diastolic arterial pressure (DAP) = 55-90mmHg (relaxation). ▪ Mean arterial pressure (MAP) = 60-100mmHg. For adequate organ perfusion, MAP should be >60mmHg. What happens if MAP =