Category: Focused Concept Reviews
-
Train of Four Ratio: Quantifying Paralysis
by
Train-of-Four ratio explained: T4:T1 fade, depth-of-block staging, and why ≥0.9 is the threshold defining adequate recovery from neuromuscular blockade.
-
Cardiac Output: Quantification of Heart Performance
Cardiac Output: Quantification of Heart Performance Stroke Volume vs. Heart Rate, and the Four Determinants That Make or Break Perfusion Cardiovascular Physiology · Hemodynamics · Preload & Afterload · Anesthetic Management Background: The concept of measuring blood flow as a product of the heart’s rate and ejection volume traces back to Adolf Fick in 1870,…
-
Capnography & ETCO₂: Visualizing Ventilation
by
Capnography & ETCO₂: Visualizing Ventilation The Waveform, the Number, and What Each Phase Actually Tells You Respiratory Monitoring · CO₂ Transport · Waveform Analysis · Airway Safety TL;DR In practice, ETCO₂ is best understood as a real-time window into three coupled physiologic systems: metabolism, circulation, and ventilation, all read through the imperfect lens of a…
-
MAC: How Anesthetic Potency is Defined
by
MAC: How Anesthetic Potency is Defined MAC-awake vs. MAC-intubation, and the Patient Factors That Shift the Curve Pharmacokinetics · Volatile Agents · Anesthetic Potency · Dose-Response Background: Minimum Alveolar Concentration (MAC): the end-tidal concentration of an inhaled anesthetic that prevents purposeful movement to a standardized surgical stimulus in 50% of unpremedicated subjects. It can be…
-
Bispectral Index (BIS): Monitoring the Brain Under Anesthesia
by
Bispectral Index (BIS): Monitoring the Brain Under Anesthesia EEG Signal Processing, Spectral Analysis, and the 0–100 Scale as a Proxy for Hypnotic Depth M&I · Neuromonitoring · EEG · Anesthetic Depth Background: The Bispectral Index is a processed EEG-derived algorithm that attempts to quantify hypnotic depth on a dimensionless 0–100 scale. Raw EEG is captured…