Clinical Anesthesia Mastery Form
for Anesthesia Technician Students - Adult Patients (3rd Edition)
This application is designed as an educational training support tool for anesthesia technicians and trainees.
⚠️ Operating Room Safety Agreement
- Wear appropriate attire: scrubs, head cover, and slippers
- Stay quiet and maintain a professional demeanor
- Do not touch anything unless explicitly permitted
- Always ask permission before assisting
- Wash your hands regularly and follow sterile protocols
1
Make Introductions
2
Ask for Observation Spot
3
Quietly Enter the OR
4
Observe Equipment Functionality Check
5
Observe Anesthesia Machine & Circuits
6
Observe Medication Preparation
Anesthesia Medication Categories:
📚 The Six A's of Pre-Anesthetic Medications:
- Anxiolysis: Reducing patient anxiety and fear before surgery using benzodiazepines like midazolam, diazepam, or lorazepam
- Amnesia: Providing lack of memory of events surrounding surgery (secondary effect of anxiolytics like lorazepam or scopolamine)
- Antiemetic: Preventing postoperative nausea and vomiting (PONV) using metoclopramide or ondansetron
- Antacid: Reducing gastric acidity to minimize aspiration risk (oral sodium citrate, ranitidine, or omeprazole)
- Anti-autonomic: Blocking unwanted reflexes - drying secretions (glycopyrrolate) or managing HR/BP (beta-blockers)
- Analgesia: Preemptive pain relief with opioids (morphine, pethidine, or fentanyl)
7
Patient Arrival & Assessment
👤 Patient Information
Medical History:
8
Physical Examination
Focus Areas:
📚 Mallampati Classification System:
Used to predict difficulty of intubation based on visibility of pharyngeal structures with mouth fully open and tongue protruded:
- Class I: Soft palate, fauces, uvula, and anterior & posterior tonsillar pillars visible - Easy intubation
- Class II: Soft palate, fauces, and uvula visible - Usually easy intubation
- Class III: Soft palate and base of uvula visible - Moderate difficulty
- Class IV: Only hard palate visible - Difficult intubation likely
3-3-2 Rule for Airway Assessment:
- 3 fingers: Mouth opening (inter-incisor distance) - should accommodate 3 fingers (≥4cm)
- 3 fingers: Hyoid-mental distance (thyromental distance) - ≥3 fingers (≥6cm)
- 2 fingers: Hyoid-thyroid cartilage distance - ≥2 fingers (≥4cm)
Vital Signs (Pre-Induction):
Basic Investigations:
Additional Assessments:
9
Initial Surgical Position
📚 Common Surgical Positions:
10
Cannula Insertion & Fluid Therapy
📚 IV Cannula & Fluid Therapy Details:
Note:
NS (Normal Saline) is preferred for blood transfusions. RL (Ringer's Lactate) is avoided with blood due to calcium content causing clotting. For maintenance, balanced solutions like RL or Plasma-Lyte are often preferred over NS to reduce risk of hyperchloremic acidosis.
11
Patient Preparation & Reassurance
12
Monitor Attachment
13
Pre-Anesthesia Communication
14
Starting Anesthesia
15
Induction Phase
16
Final Patient Position
17
Post Induction Vital Signs (Very Important)
Vital Signs (Post-Induction):
18
Maintenance Phase (if General Anesthesia)
Ventilation Settings:
📚 Mechanical Ventilation Modes:
19
End of Procedure
20
Recovery Phase
Vital Signs (Recovery):
21
Handoff Protocol
22
Prepare for Next Patient
23
Observed Complications & Management
Did you observe any complications and how they were managed?
24
Anesthesia Documentation
25
Leaving OR
Core Ventilator Parameters
Each setting controls one thing. It also changes another, depending on the patient lungs. Know what each one does before you change it.
Tidal Volume (VT)6–8 mL/kg PBW
The amount of air given with each breath. Always calculate from Predicted Body Weight (PBW) — not actual weight. Too much air causes high pressure and can injure the lungs.
↑ Increased
Higher pressures. Risk of lung injury. Always use PBW to set VT.↓ Decreased
Lower pressures. Risk of not ventilating enough if the volume is too small.⚠ Always target VT to PBW. A 120 kg patient with 70 kg PBW should receive 420–560 mL, not 720–960 mL.
OR ExampleTall male patient, 185 cm: PBW ≈ 81 kg. Target VT = 7 mL/kg PBW = 567 mL. Set flow to achieve a smooth waveform.
Respiratory Rate (RR)10–16 bpm
How many breaths the machine gives each minute. Together with VT, it controls CO₂ removal. Higher rate = less time to breathe out each breath.
↑ Increased
More CO₂ removed. Less time to breathe out. Risk of air trapping in asthma or COPD.↓ Decreased
CO₂ builds up. More time to breathe out. Useful in asthma and COPD.OR ExampleETCO₂ 55 mmHg intraoperatively — first increase RR (e.g., 12 to 16) before increasing VT to avoid volutrauma.
PEEP5–8 cmH₂O routine
Pressure kept in the lungs at the end of each breath. It keeps the small air sacs open. Without PEEP, air sacs collapse between breaths. Always use at least 5 cmH₂O routinely.
↑ Increased
Better oxygen by keeping air sacs open. Risk of over-inflation and low blood pressure at very high levels.↓ Decreased
Risk of alveolar collapse, atelectasis, and low oxygen. PEEP is commonly used to keep lungs open. Zero PEEP may be used depending on the clinical situation.OR ExampleRoutine laparoscopy in Trendelenburg: apply PEEP 5 cmH₂O. If SpO₂ falls despite FiO₂ 0.6, trial PEEP 8–10 with lung recruitment manoeuvre.
Peak Inspiratory Pressure (PIP)Alarm < 30–35 cmH₂O
The highest pressure in the airway during a breath. In VCV mode, PIP is a result — you do not set it directly. A sudden rise in PIP means something is wrong.
↑ Increased
Causes: blocked tube, bronchospasm, wrong tube position, pneumothorax, secretions, stiff lungs. Always investigate.↓ Decreased
Causes: leak in circuit, deflated cuff, patient relaxing (lungs softer), or tube moving out.OR ExamplePIP rises from 22 to 40 cmH₂O after repositioning — check ETT tip (main-stem migration in Trendelenburg). Withdraw 1–2 cm if suspected.
FiO₂0.21 – 1.0
The percentage of oxygen in each breath. Use the lowest level that keeps SpO₂ above 94%. Start at 40–50% for routine surgery. Use 100% only when needed.
↑ Increased
Better oxygenation margin. Absorptive atelectasis risk above 0.6. Oxygen toxicity with prolonged FiO₂ >0.8.↓ Decreased
Risk of hypoxaemia in V/Q mismatch, shunt, one-lung ventilation. Never reduce if SpO₂ marginal.OR ExamplePreoxygenation: FiO₂ 1.0. Maintenance: 0.4–0.5 targeting SpO₂ ≥97%. Emergency desaturation: immediately go to 1.0 and investigate.
Inspiratory Time / I:E RatioI:E = 1:2 typical
Ti is the time spent breathing in. Normal ratio is 1:2 — one second in, two seconds out. If expiration is too short, air gets trapped in the lungs.
↑ Ti (shorter I:E)
Longer inspiration. Shorter expiration — risk of gas trapping, especially with high resistance.↓ Ti (longer I:E)
Shorter insp, longer exp — essential in obstructive disease to prevent gas trapping.OR ExampleAsthmatic patient: I:E 1:3 or 1:4. Confirm expiratory flow returns to zero on the flow–time waveform before the next breath begins.
Flow (VCV)40–60 L/min
How fast air enters the lungs in VCV mode. Higher flow = shorter breath and higher PIP. If the patient is fighting the machine, try increasing flow first.
↑ Increased
Shorter Ti, higher PIP, longer Te. Can reduce WOB if patient demands more flow than set.↓ Decreased
Longer Ti, lower PIP. If too low in spontaneously breathing patient: scooped (concave) pressure waveform = flow starvation.OR ExampleConcave pressure waveform in VCV — patient is fighting the ventilator demanding more flow. Increase from 40 to 60 L/min.
Rise Time (PCV / PSV)50–200 ms
How fast the machine raises pressure at the start of a breath. Shorter rise time = faster and more aggressive. Adjust to match the patient breathing effort.
↑ Increased (slower)
Softer pressure rise, lower initial flow. May feel too slow for the patient breathing pattern.↓ Decreased (faster)
Aggressive rise, very high initial flow. Double-triggering risk. Higher effective PIP at start of breath.OR ExamplePatient double-triggers in PCV — increase rise time from 0.05 to 0.15 s. Observe pressure waveform losing its sharp onset.
Trigger SensitivityFlow: 2–4 L/min
How hard the patient must breathe in before the machine helps. Too sensitive = machine triggers by itself. Too high = patient works too hard to start each breath.
More sensitive (↓ threshold)
Easier triggering — risk of auto-triggering from cardiac oscillations, circuit water, or cardiogenic artefact.Less sensitive (↑ threshold)
Higher effort required — patient may make visible breathing attempts without receiving assisted breaths.OR ExamplePatient making breathing efforts but breaths are not assisted — check for gas trapping on the flow waveform. Inform anaesthetist.
ETS — Expiratory Trigger Sensitivity25% (10–40%)
In PSV mode, the breath ends when flow drops to this percentage of peak flow. Higher ETS = shorter breath. Lower ETS = longer breath. Adjust for each patient.
↑ Increased (40%+)
Earlier cycling — shorter Ti. Risk: insufficient VT, premature termination, double-triggering in patients with high respiratory drive.↓ Decreased (10%)
Inspiration continues longer. Risk: patient begins to exhale before the ventilator has finished delivering the breath.OR ExampleCOPD patient on PSV: flow decay is slow (high resistance). Increase ETS to 40% to cycle earlier and provide longer Te for full exhalation.
Predicted Body Weight & Tidal Volume
One of the most common ventilation errors is sizing tidal volume to actual body weight. Always use PBW based on height.
Predicted Body Weight (PBW)Height-based formula
PBW uses height and sex to estimate a safe lung size. Lung size does not grow with body weight. An obese patient and a normal-weight patient of the same height need the same VT.
Male PBW (kg) = 50 + 0.91 × (height [cm] − 152.4)
Female PBW (kg) = 45.5 + 0.91 × (height [cm] − 152.4)
Target range
6–8 mL/kg PBW for routine OR ventilation. Use 7–8 mL/kg for most patients without lung problems.Why not actual weight?
The lungs of a 120 kg obese patient are the same size as those of a 70 kg patient of the same height. Oversized VT creates dangerously high pressures.⚠ Obesity example: Female, 165 cm, 110 kg actual weight.
PBW = 45.5 + 0.91 × (165 − 152.4) = 57 kg
Correct VT (8 mL/kg PBW) = 456 mL.
Using actual weight: 8 × 110 = 880 mL — nearly double. Always use PBW.
PBW = 45.5 + 0.91 × (165 − 152.4) = 57 kg
Correct VT (8 mL/kg PBW) = 456 mL.
Using actual weight: 8 × 110 = 880 mL — nearly double. Always use PBW.
OR RuleAlways calculate PBW before connecting the patient to the ventilator. Enter height and sex in the simulator panel to see the safe VT range automatically.
Waveform Interpretation
Every anaesthesia machine shows three waveforms at the same time. Learning to read them is one of the most important skills for an anaesthesia technician.
Pressure–Time
VCV: Linear rise to PIP, then drops to PEEP on expiration. With an inspiratory hold: pressure steps down from PIP to Pplat, showing the lung pressure alone.
PCV: Pressure ramps up to the set level then holds as a plateau. Rise time controls how quickly it reaches that level.
PSV: Brief dip below PEEP when patient triggers, then rapid rise to support level.
PCV: Pressure ramps up to the set level then holds as a plateau. Rise time controls how quickly it reaches that level.
PSV: Brief dip below PEEP when patient triggers, then rapid rise to support level.
Abnormal Patterns
High PIP: Bronchospasm, secretions, kinked ETT, or stiff lungs. Check with Pplat measurement to find the cause.
Leak: Pressure falls during expiration — ETT cuff issue or circuit disconnect.
Trigger dip: Patient is breathing spontaneously — inform anaesthetist.
Flow–Time
VCV: Constant positive flow during inspiration, then negative flow during expiration curving back to zero.
PCV / PSV: Inspiration starts with high flow then decelerates. Expiratory flow decays back to zero.
Key rule: If expiratory flow does not return to zero before the next breath, air is trapped.
PCV / PSV: Inspiration starts with high flow then decelerates. Expiratory flow decays back to zero.
Key rule: If expiratory flow does not return to zero before the next breath, air is trapped.
Abnormal Patterns
Gas Trapping: Expiratory flow does not reach zero before the next breath — air is not fully leaving the lungs.
Trigger effort: Small negative spike — patient is making breathing efforts. Inform anaesthetist.
Volume–Time
Normal: Rises during inspiration to VT peak, then returns completely to zero during expiration. Complete return = no air trapping.
VCV: Linear rise (constant flow). PCV/PSV: Curved rise — fast initially as flow peaks, then slowing near the end of inspiration.
PCV-VG: Pressure adjusts breath-to-breath — VT stays consistent, but the pressure waveform height visibly changes.
VCV: Linear rise (constant flow). PCV/PSV: Curved rise — fast initially as flow peaks, then slowing near the end of inspiration.
PCV-VG: Pressure adjusts breath-to-breath — VT stays consistent, but the pressure waveform height visibly changes.
Abnormal Patterns
Gas Trapping: Volume does not return fully to zero before the next breath — air is accumulating in the lungs.
Leak: Volume does not return to baseline — exhaled VT less than inhaled VT. ETT cuff leak, circuit disconnect.
Plateau Pressure & Driving Pressure
Measuring Pplat helps identify whether a pressure problem is coming from the airway or from the lungs. Report abnormal values to the anaesthetist.
Inspiratory Hold → Pplat → Driving PressurePplat < 28–30 cmH₂O
During an inspiratory hold, airflow stops for a moment. The pressure then falls to Plateau Pressure (Pplat). This shows the true pressure in the lungs, without the effect of airway resistance.
How to read it
High PIP, normal Pplat → Airway problem (bronchospasm, secretions, kinked ETT)High PIP and high Pplat → Lung is stiff (pneumothorax, pulmonary oedema, surgical position)
Both readings together help the anaesthetist find the cause.
What to do
High PIP with normal Pplat → check the airway: listen for bronchospasm, check ETT position, suction if needed.High Pplat → inform anaesthetist immediately. Do not adjust settings independently.
In the Simulation tab, use the Measure Pplat button in VCV mode to perform a simulated inspiratory hold. The result shows Pplat and Driving Pressure.
Ventilation Modes
Each mode fixes one thing and lets another change with the patient lung condition. Know which is which.
VCV — Volume Control Ventilation
Volume & flow controlled · Pressure variable
ControlledVT Flow Rate
VariablePIP — rises with R or falls with C
HoldUse the Measure Pplat button to perform an inspiratory hold. Shows Pplat and Driving Pressure — helps identify whether a pressure problem is from airway or lungs.
Key RiskBarotrauma if compliance falls acutely while VT is fixed.
WaveformP: linear rise to PIP (plateau visible if hold set). F: square constant. V: linear rise.
PCV — Pressure Control Ventilation
Pressure controlled · Volume variable
ControlledPdrive Ti Rate
VariableVT — changes with compliance and resistance
Rise TimeControls ramp slope to target pressure. Slower rise = lower initial flow and lower PIP. Faster rise = higher initial flow.
Key RiskHypoventilation if compliance drops — VT decreases silently. Monitor VT closely.
WaveformP: ramped rise to square plateau. F: decelerating exponential. V: curved rise.
PCV-VG — Volume Guaranteed
Hybrid: pressure delivery + volume target
ControlledTarget VT — auto-adjusts Pdrive each breath
VariablePdrive — changes by max 3 cmH₂O per breath
AdaptationSystem converges over 5–10 breaths. The pressure waveform visibly changes height breath-to-breath — key visual feature.
Key RiskOvershoot on sudden compliance increase (e.g. muscle relaxant) — momentary high VT before system adjusts.
WaveformSame as PCV shape. Pressure peak height changes breath-to-breath.
PSV — Pressure Support Ventilation
Spontaneous · Patient-triggered · Flow-cycled
ControlledPS level PEEP ETS%
VariableVT, RR, Ti — all set by patient drive
TriggerPatient effort creates flow/pressure change exceeding threshold — ventilator opens support valve. If effort < threshold: missed trigger (dip visible, no support).
Key RiskApnoea — no mandatory backup rate. Always confirm apnoea backup is enabled. Inform anaesthetist if patient stops triggering.
WaveformP: brief sub-PEEP dip (trigger), rapid rise to support level, gradual decay. F: high initial peak (decelerating), abrupt cut at ETS%.
Waveform Pattern Recognition
Seven essential patterns for OR technician practice. Focus on the shape — not just the numbers. P = Pressure, F = Flow, V = Volume.
1 — Normal VCVBaseline
P
F
V
ShapeSquare pressure peaks, constant inspiratory flow, volume rises linearly then returns fully to zero.
MeansNormal ventilation — all components working as expected.
Do First
Verify VT, RR, and PIP are within expected range for this patient. Compare to baseline at start of case.
2 — Normal PCVBaseline
P
F
V
ShapePressure ramps then plateaus. Flow starts high and decelerates. Volume rises steeply at first, then slows near peak.
MeansNormal pressure-controlled ventilation. VT will change if compliance or resistance changes.
Do First
Monitor VT closely — it is not guaranteed. Alert anaesthetist if VT drops or rises significantly.
3 — High ResistanceObstruction
P
F
V
ShapePIP is elevated (large PIP–Pplat gap in VCV). Expiratory flow decays slowly — the key sign. Volume baseline may drift up.
MeansAirway obstruction — bronchospasm, secretions, ETT kinked or bitten.
Do First
Auscultate chest. Check ETT for kinking. Suction if secretions suspected. Inform anaesthetist immediately.
4 — Low ComplianceStiff Lung
P
F
V
ShapeBoth PIP and Pplat are high. The step down from PIP to Pplat is small — both pressures remain elevated. Flow and volume shape are normal.
MeansLung is stiff — pneumothorax, atelectasis, pulmonary oedema, surgical pressure on chest, or main-stem intubation.
Do First
Check bilateral air entry with stethoscope immediately. Inform anaesthetist urgently — this pattern requires rapid diagnosis.
5 — DisconnectionEmergency
P
F
V
ShapeAll three traces go flat. Pressure falls to zero or near zero. Low-pressure alarm sounds.
MeansCircuit disconnect, accidental extubation, or complete breathing circuit failure.
Do First
Trace the circuit from patient to ventilator immediately. Reconnect. If not resolved in seconds — hand-ventilate with BVM and call for help.
6 — Gas TrappingAuto-PEEP
P
F ★
V
ShapeFlow (★) does not return to the dashed zero line before the next breath. Volume baseline drifts upward. Pressure trace can look deceptively normal.
MeansIncomplete exhalation — RR too high, resistance too high, or expiratory time too short.
Do First
Reduce RR to lengthen expiratory time. Check for bronchospasm. Do NOT add PEEP — it will increase total alveolar pressure further. Inform anaesthetist.
7 — Trigger DipSpontaneous Effort
P ★
F ★
V
ShapeBrief downward deflection on pressure (★) just before each breath — dips below the PEEP baseline. Small negative spike on flow trace just before inspiration.
MeansPatient making spontaneous breathing efforts. Neuromuscular blockade may be wearing off, or depth of anaesthesia lightening.
Do First
Inform anaesthetist immediately. Do not adjust ventilator — this is a patient-level finding. Anaesthetist will assess NMB level and depth of anaesthesia.💨 ETCO₂ — End-Tidal CO₂
Mandatory monitoring for all intubated patients. The ETCO₂ value (normally 35–45 mmHg) reflects how much CO₂ is being exhaled. A normal capnogram rises at the start of exhalation, forms a near-flat plateau, then drops to zero with the next breath.
Four signs to recognise:
- Sudden drop to zero → Disconnection, oesophageal intubation, or cardiac arrest. Treat as emergency.
- Gradual rise → Under-ventilation or rising CO₂ production. Increase RR as directed.
- Baseline above zero → CO₂ rebreathing. Check absorber and valves.
- Slanted plateau → Obstructive disease (asthma). Same cause as the slow expiratory flow trace.
Full capnography waveform simulation will be available in the upcoming Enki Scalar OR & ICU module.
Patient
🧍 Anthropometrics
Sex
Height (cm)
Actual Wt (kg)
⚠ VT = mL/kg PBW
—
PBW— kg
Safe VT (6–8 mL/kg)—
VT targets PBW, not actual weight.
Mode
Lung Mechanics
Presets
⚠ Gas Trapping — Incomplete Exhalation
Intrinsic PEEP
0.0 cmH₂O
+ Applied PEEP
0 cmH₂O
Total Alveolar PEEP
0.0 cmH₂O
Flow has not returned to zero — air is not fully leaving the lungs. Reduce RR, lower resistance, or extend expiratory time. Inform the anaesthetist.
PressurecmH₂O
FlowL/min (+ insp / − exp)
VolumemL above end-expiratory baseline
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