MS-III Introductory Lectures in Anesthesiology

1. MS-III Introductory Lectures in Anesthesiology Basic Anesthesia Monitoring in the Operating Room

2. American Society of Anesthesiology (ASA) Standards for Basic Intraoperative Monitoring

3. ASA Standards Applies to all anesthesia care except labor and pain management Certain criteria may be waived in extenuating circumstances should document circumstances in chart potential criteria highlighted in future slides Definitions Continually - repeated regularly and frequently Continuous - without interruption

4. Standard I Qualified personnel shall be present in the operating room throughout all: General Anesthetics Regional Anesthetics Monitored Anesthesia Care Temporary Absence Exceptions hazardous conditions for anesthesia provider provide for remote monitoring emergency situations

5. Standard II During all anesthetics the following parameters will be continually monitored: oxygenation ventilation circulation temperature

6. Oxygenation Objective ensure adequate oxygen concentration in inspired gas and blood Methods inspired gas oxygen analyzer with alarms (GA) pulse oximetry illumination and exposure to assess color

7. Pulse Oximetry Theory two wavelengths (660 and 960 nm) calculates functional saturation (physiologic saturation) Limitations dyes or other hemoglobin species (carboxy, met, fetal, etc) motion low perfusion states electrocautery ambient light

8. Pulse Oximetry Optical plethysmography detects pulsatile changes in blood volume Spectrophotometry measures pulsatile hemoglobin saturation Assumptions all pulsation is arterial light passes through pulsatile beds

9. Ventilation qualitative clinical signs chest excursion observation of reservoir bag auscultation of breath sounds quantitative measurement end tidal carbon dioxide volume of expired gas continuous circuit disconnect monitor for mechanical ventilation

10. Ventilation General Anesthesia qualitative clinical signs adequate quantitative methods encouraged endotracheal tube or laryngeal mask placement continual end tidal carbon dioxide identification continuous disconnect alarm mandatory during controlled ventilation Regional Anesthesia and Monitored Anesthesia Care continual qualitative clinical signs (minimum)

11. Capnography Theory main or sidestream sampling several technical methods available IR, raman gas scattering, mass or photoacoustic spectroscopy Applications confirmation of intubation monitoring for circuit disconnection identification of airway obstruction rebreathing/metabolic monitoring

12. Circulation Objective ensure adequacy of circulatory function Methods continuous electrocardiogram monitoring arterial blood pressure and heart rate q 5 min during GA one additional continual parameter

13. Temperature Objective aid in maintaining appropriate body temperature Application readily available method to continuously monitor temperature if changes are intended, anticipated or suspected Methods thermistor temperature sensitive chemical reactions location

14. Intra-arterial Blood Pressure Equipment transducer and pressure monitor Monitoring location upper extremity lower extremity superficial temporal Technique

15. Noninvasive Blood Pressure Methodology oscillometric algorithms automated reproducible Limitations cuff size oversize erroneously low measurements to small erroneously high

16. Electrocardiogram 3 vs. 5 electrode system three versus seven leads for diagnostic purposes Heart rate measurement R wave counting (any lead) Ischemia Monitoring lead II and V5 are 90% sensitive lead II, V5 and V4 up to 98% sensitive Arrhythmia monitoring lead II or esophageal for supraventricular arrhythmias all leads for ventricular arrhythmias

17. Neuromuscular FunctionEvaluation of Reversal of Blockade Clinical Criteria head lift > 5 seconds sustained hand grip negative inspiratory force at least -55 cmH2O for adults at least -32 cmH2O for children vital capacity 15 ml/kg absence of nystagmus or diplopia Evoked Response Criteria 1-2 twitches prior to reversal sustained tetanus to 50 Hz supra-maximal stimulus no fade on DBS

18. Neuromuscular Blockade Site of Stimulation ulnar vs. facial vs. posterior tibial Characteristics of Electrical Stimuli supra-maximal, 0.2 msec, square wave Patterns of Stimulation