Monitoring in Anesthesia พญ.เพชรรัตน์ วิสุทธิเมธีกร พ.บ., ป. ชั้นสูงสาขาวิสัญญีวิทยา, วว.(วิสัญญี) ภาควิชาวิสัญญีวิทยา วิทยาลัยแพทยศาสตร์กรุงเทพมหานคร และวชิรพยาบาล

Topic module 1.รู้วัตถุประสงค์และความสำคัญในการเฝ้าระวัง 2.รู้จักข้อบ่งชี้และขัอห้ามในการใช้เครื่องเฝ้าระวัง 3.สามารถใช้และแปรผลค่าที่ได้จากเครื่องเฝ้าระวัง ( NIBP , SpO2 , ECG , ET-CO2 )

Contents Introduction What is monitoring? Which, Why and How to monitor? Level of monitoring Standards for basic intraoperative monitoring ( ASA) Systematic monitoring Conclusion

Monitoring: A Definition ... interpret available clinical data to help recognize present or future mishaps or unfavorable system conditions ... not restricted to anesthesia (change “clinical data” above to “system data” to apply to aircraft and nuclear power plants)

What is monitoring? to monere (การเฝ้าระวัง, การเตือนภัย) Physiologic parameter & Patient safety parameter Clinical skills & Monitoring equipment Data collection, interpretation, evaluation, decision Problem seeking, Severity assessment, Therapeutic assessment, Evaluation of Anesthetic interventions

Patient Monitoring and Management Involves … Things you measure (physiological measurement, such as BP or HR) Things you observe (e.g. observation of pupils) Planning to avoid trouble (e.g. planning induction of anesthesia or planning extubation) Inferring diagnoses (e.g. unilateral air entry may mean endobronchial intubation) Planning to get out of trouble (e.g. differential diagnosis and response algorithm formulation)

Level of monitoring Standards for basic intraoperative monitoring Routine / Specialize / Extensive Non-equipment / Non-invasive / Minimally invasive / Penetrating / Invasive / Highly invasive Systematic Respiratory / Cardiovascular / Temperature/Fetal Neurological / Neuro-muscular / Volume status & Renal Standards for basic intraoperative monitoring ( ASA)

Standards for basic intraoperative monitoring ( ASA : American Society of Anesthesiologists) Standard I Qualified anesthesia personnel shall be present in the room throughout the conduct of all GA, RA, MAC Standard II During all anesthetics, the patient’s respiratory (ventilation, oxygenation), circulation and temperature shall be continually evaluated

Monitoring in the Past Visual monitoring of respiration and overall clinical appearance Finger on pulse Blood pressure (sometimes)

Monitoring in the Past Finger on the pulse

Harvey Cushing Not just a famous neurosurgeon … but the father of anesthesia monitoring Invented and popularized the anesthetic chart Recorded both BP and HR Emphasized the relationship between vital signs and neurosurgical events ( increased intracranial pressure leads to hypertension and bradycardia )

Examples of Multiparameter Patient Monitors

Some Specialized Patient Monitors Transesophageal Echocardiography Depth of Anesthesia Monitor Evoked Potential Monitor Some Specialized Patient Monitors

Cardiovascular monitoring Routine monitoring Cardiac activity Non-invasive blood pressure ( NIBP ) Electrocardiography ( ECG ) Advanced monitoring Direct arterial blood pressure Cardiac filling pressure monitor Central venous pressure Pulmonary capillary wedge pressure

Cardiovascular monitoring Electrocardiography Cardiac activity Arrhythmia: Lead II Myocardial ischemia: ECG criteria Electrolyte imbalance Pacemaker function

Cardiovascular monitoring การบ้าน ECG 1. การติด lead II, modified V5 2. การแปรผล สาเหตุ การรักษา -arrhythmia : bradycardia, tachycardia, AF, PVC, VT, VF -Myocardial ischemia -electrolyte imbalance

Cardiovascular monitoring Non-invasive blood pressure (NIBP) Cuff: width 120-150 % limb diameter, air bladder includes more than halfway around limb Manometer: aneroid, mercury Detector: manual, automated การบ้าน หลักการทำงาน หลักการเลือกขนาด ค่าที่ได้ ค่าใดถูกต้องและเชื่อถือได้มากที่สุด สถานะการณ์ใดรบกวนการวัดและรบกวนอย่างไร

Cardiovascular monitoring Non-invasive blood pressure Inaccurate: cuff size, inflated pressure, shivering, cardiac arrhythmia, severe vasoconstriction Proper application Narrow cuff Loose cuff

Cardiovascular monitoring Direct arterial pressure monitor Indications Continuous blood pressure monitor: anticipated cardiovascular instability, direct manipulation of cardiovascular system, inability to accurate measurement directly Frequent arterial blood sampling: ABG, Acid-base / electrolyte / glucose disturbance, Coagulopathies

Cardiovascular monitoring Direct arterial pressure monitor Contraindications Local infection Impaired blood circulation: Raynaud’s phenomenon, DM Risks of thrombosis: hyperlipidemia, previous brachial artery cannulation Modified Allen’s test ??? ( การบ้านข้อที่เท่าไรแล้วคะ)

Cardiovascular monitoring Direct arterial pressure monitor Complications Direct trauma: AV-fistula, Aneurysm Hematoma Infections Thrombosis Embolization Massive blood loss

Cardiovascular monitoring Cardiac filling pressure monitor Frank-Starling curve: optimum Preload maximize ventricular performance (Stroke volume, CO.) Preload = Myocardial fiber length (2.2 micron) LV Preload  LVEDV  LVEDP  LAP  PCWP  PAP  RVP  RAP  CVP Myocardium function, LV compliance, Mitral valve, Airway pressure, Pulmonary vascular resistance, Pulmonic valve, Tricuspid valve

Cardiovascular monitoring Cardiac filling pressure monitor LV Preload  LVEDV  LVEDP  LAP  PCWP  PAP LVEDP  RVEDP  RAP  CVP

Cardiovascular monitoring Cardiac filling pressure monitor PCWP: Pulmonary capillary wedge pressure CVP: Central venous pressure

Cardiovascular monitoring PCWP: Pulmonary capillary wedge pressure CVP: Central venous pressure Fluid Challenge test to optimize preload and maximize Cardiac performance

Respiratory monitoring Ventilatory monitoring Oxygenation monitoring Machine and Circuit monitoring Clinical skills Monitoring devices

Ventilatory monitoring Clinical skills Direct observation: rate, rhythm, volume of respiration Auscultation: precordial, esophageal stethoscope Palpation: reservoir bag movement Monitoring devices Spirometer Airway pressure manometer Circuit disconnection alarm

Ventilatory monitoring Capnometer (End-tidal CO2 analysis) relationship with PaCO2 : ETCO2 < PaCO2 ~ 3-6 mmHg mainly depends on dead space ventilation normal value 30 – 35 mmHg Infrared absorption spectrography Main-stream VS. Side-stream

Ventilatory monitoring Capnogram : normal curve 1. Dead space air (no CO2) 2. Mixed bronchus & alveolus air (CO2 upstroke) 3. Alveolus air (CO2 plateau) Inspiration 3 ETCO2 2 1

Ventilatory monitoring Capnometer (End-tidal CO2 analysis) Most useful in detection of Esophageal intubation, airway or circuit disconnection Useful in CO2 rebreathing, partial recovery of neuro-muscular blockade, good predictor of successful CPR

การบ้าน (เขียน waveform of ET-CO2 และสาเหตุ) Capnograph -esophageal intubation -bronchial intubation -airway obstruction -circuit disconnect -circuit leakage -partial rebreathing -spontaneous breathing (recovary of neuromuscular blockade) -hypoventilation

Oxygenation monitoring Clinical skills Direct observation: impaired mental function, sympathetic overactivities, appearance(+ cyanosis) Auscultation: wheezing, crepitation Monitoring devices Arterial blood gas analysis Percutaneous O2 measurement Pulse oximeter

Oxygenation monitoring Pulse oximeter Percent of oxyhemoglobin / total hemoglobin Oxyhemoglobin absorp 940 nm. Deoxyhemoglobin absorp 660 nm. Caution: SpO2  PaO2

Oxygenation monitoring Pulse oximeter SpO2 correlates with PaO2 as in Oxygen-hemoglobin dissociation curve SpO2 90  PaO2 60 mmHg (moderate hypoxemia) 75  40 mmHg (mixed venous oxygen sat.) 50  27 mmHg (P50)

Oxygenation monitoring Pulse oximeter artifacts Abnormal hemoglobin: COHb, MetHb, HbF Dye: Methylene blue Anemia Ambient light Arterial saturation Blood flow Motion Nail polish Electro-cautery

การบ้าน Wave form Pulse oximeter Pulse oximeter artifacts กระทบต่อการแปรผลอย่างไร Cause of Rt-Lt shift of oxygen-hemoglobin dissociation curve

Machine & circuit monitoring Safety system DISS, PISS, Quick disconnection adaptor Oxygen fail-safe valve, Oxygen supply failure alarm Oxygen analyzer Airway gas composition Clinical skills: flowmeters, vaporizers Monitoring devices: Infrared spectrometer

Depth of Anesthesia Clinical Signs EEG monitoring eye signs respiratory signs cardiovascular signs CNS signs EEG monitoring Facial EMG monitoring (experimental) Esophageal contractility (obsolete)

Neurologic monitoring Depth of anesthesia ( BIS ) EEG Evoked potentials Cerebral blood flow Intracranial pressure

Neuromuscular monitoring Clinical skills Monitoring device : PERIPHERAL NERVE STIMULATOR

Volume status and renal monitoring Estimate blood loss Urine output Hemodynamic stability

Volume status and renal monitoring Estimate blood loss Urine output Hemodynamic stability

Electrolyte / Metabolic monitoring Fluid balance Sugar Electrolytes Acid-base balance

Coagulation Monitoring PT / PTT / INR ACT Platelet counts Factor assays TEG Clinical sign

Temperature monitoring 4 mechanism of heat loss Perioperative hypothermia (BT<36) Core temperature : nasopharynx, esophageal, tympanic membrane, pulmonary a. catheter, bladder, rectum

Temperature Monitoring Rationale for use detect/prevent hypothermia monitor deliberate hypothermia adjunct to diagnosing MH monitoring CPB cooling/rewarming

Temperature monitoring Deleterious effects of hypothermia -cardiac dysrhythmia -increased PVR -Lt. shift of the Oxygen-hemoglobin dissociation curve -reversible coagulopathy (platelet dysfunction) -postoperative protein catabolism and stress response -altered mental status -impaired renal function -decreased drug metabolism -poor wound healing

Conclusion การบ้านกี่ข้อแล้วคะ มีเครื่องมือเยอะจัง ไม่ได้อย่า out ต้องรู้ NIBP,ECG,ET-CO2,SpO2