Monitoring the Anesthetized Patient 2023

Monitoring the Anesthetized Patient

Overview

  • Date and Presenter: October 24, 2023, Dr. Debbie Wilson

  • Focus Areas: Record keeping, equipment, common problems associated with anesthesia.

Objectives

  • Review of physiology related to respiration monitoring.

  • Discuss common anesthesia abnormalities and the role of capnographs.

  • Introduce the anesthetic record design at MSU.

  • Practice data entry and interpretation of monitored data.

Importance of Monitoring

  • Enhances Outcome: Monitoring is crucial to optimize patient safety and recovery.

  • Standard of Care: Adheres to guidelines set by organizations such as AAHA and ACVAA.

  • Client Expectations: Veterinary practices are held accountable to clients’ concerns regarding safety and care.

Anesthesia's Impact on Respiration

  • Pathologic Condition: Anesthesia can fundamentally alter respiratory functions, especially in different species (e.g., horses).

  • Common Respiration Problems:

    • Strange patient positions can lead to atelectasis and ventilation-perfusion (V/Q) mismatches.

    • Anesthetic drugs can reduce respiratory drive and hypoxic response.

Monitoring Tools and Techniques

  • Basic Monitoring Tools:

    • Physical Assessment: Use of hands, eyes, and ears for initial evaluations.

    • Circulation Assessment:

      • Pulse palpation at various arteries (femoral, pedal, lingual, etc.).

      • Esophageal stethoscope for heart sounds.

      • Pulse oximeter for oxygen saturation (SpO2) measurements.

      • EKG and blood pressure measurements (direct and indirect).

Practical Lung Function Assessment

  • Physical Indicators:

    • Chest excursion and reservoir bag movement.

    • Mucous membrane color to assess oxygenation.

    • Use of pulse oximeter and capnograph for oxygen and CO2 levels.

    • Arterial Blood Gas (ABG) analysis for detailed respiratory assessment.

Pulse Oximetry

  • SpO2 Measurement: Reflects %Hb saturation with thresholds set for normal (95-100%) to critical (<60%).

  • Components of Pulse Oximeter: LED transmitter, photodiode receiver.

  • Common Issues: Measurement errors due to pigmentation, motion artifacts, and poor perfusion.

Capnography in Anesthesia

  • Purpose: Monitors end-tidal CO2 (ETCO2) levels, critical for assessing ventilation efficiency.

  • Mainstream and Side-stream Analyzers: Types of equipment used to monitor CO2.

  • Capnogram Analysis:

    • Waveform characteristics: height (ETCO2), frequency, rhythm, baseline, and shape describe respiratory status.

    • Normal capnogram shows identifiable phases and values that reflect proper ventilation.

    • Abnormal capnograms may indicate conditions such as hypoventilation or rebreathing.

Anesthesia Record-Keeping

  • Importance of Documentation:

    • Serves as a standard of care and a legal document reflecting the level of care provided.

    • Tracks drug administration, dosages, physiological responses, and patient responses to interventions.

  • Key Components of the Anesthesia Record:

    • Patient details (weight, age, procedure)

    • Pharmacological interventions.

    • Monitoring results (HR, BP, SpO2, ETCO2, Temp).

Common Anesthetic Problems and Responses

  • Tachycardia or Tachypnea: Treatment includes assessing stimulus and administering agents to stabilize vital signs.

  • Hypoventilation: Managed by adjusting anesthetic depth or supporting with mechanical ventilation.

  • Hypotension: Requires evaluation of intravascular volume and possible use of inotropic agents.

  • Apnea: Immediate resuscitation and identification of underlying causes are crucial.

  • Esophageal Intubation: Confirm proper placement through physical cues and capnography.

Practice Scenarios and Record Exercises

  • Hands-on practice in recording vital signs, interpreting scenarios, and solving abnormalities based on monitoring data.

  • Education on the symbols and terminology used in the anesthesia record, enhancing understanding of patient status during procedures.

Conclusion

  • Continuous Monitoring: Crucial during anesthesia with ongoing patient assessments.

  • Simulation Feedback: Learn from mock cases to prepare for real-life application in anesthesia management.