BLOCKBOX — PAC / AIRWAY

1. Adult or Pediatric Patient

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Select Patient Population *

2. Assessment Context

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Choose Assessment Context *

Choose the clinical environment to see context-appropriate screening tools.

3. Patient Details & Surgery

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Case Identifier / Name *

Age *

Sex *

Weight (kg) *

Height (cm) *

Surgery Type *

Urgency *

Prior Anesthesia

Fasting Status *

Comorbidities

Allergies

4a. Physical Examination Indices

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Mallampati *

Mouth Opening *

Thyromental Dist. *

Sternomental Dist.

Neck Extension *

Dentition

Jaw Protrusion

C-Spine Issues

Radiation/Mass/Burn in Neck

Beard

Obesity (BMI>30) / Large Neck

OSA / Snoring

Receding Mandible (Wilson)

4c. Context Tools

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Select Clinical Scoring System *

5a. CLINICAL SCORES

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ASA PHYSICAL STATUS

ASA-PS Class Add “E” suffix for emergency in the PAC note

REVISED CARDIAC RISK INDEX (RCRI)

Tick each criterion present. Score ≥3 = high perioperative MACE risk.

High-risk surgery (intraperitoneal, intrathoracic, or suprainguinal vascular) Ischaemic heart disease (Hx MI, positive stress test, nitrate use, Q-waves, or ischaemic CP) Congestive heart failure (Hx CHF, pulmonary oedema, PND, bilateral crackles, or S3) Cerebrovascular disease (history of stroke or TIA) Insulin-dependent diabetes mellitus Preoperative creatinine >2.0 mg/dL (177 µmol/L)

SPECIAL POPULATION & AIRWAY HISTORY

Patient Population Flag

History of Difficult Intubation

5. Pre-op & Medical Review

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Hb (g/dL)

Creatinine (mg/dL)

ECG Status

Echo/CXR

Effort Tolerance (METs)

Anticoagulants

Active Conditions relevant to Anesthesia

T2DM/Diabetes Hypertension CAD/Ischemic Heart COPD/Asthma CKD/Renal Severe GERD/Reflux

📊 AIRWAY TOOL ACCURACY — Quick Reference

Tap to expand

Meta-analysis comparative data. No single tool is sufficient — combined multiparameter assessment achieves best accuracy.

TOOL	THRESHOLD	SENSITIVITY	SPECIFICITY	AUC
EL-GANZOURI	≥4	65–76%	68–82%	0.74–0.79
LEMON	≥4	55%	85%	0.70
WILSON	≥2	42%	89%	0.68
MALLAMPATI III/IV	Class III/IV	49%	86%	0.67
THYROMENTAL <6 cm	<6 cm	20%	94%	0.62
COMBINED TESTS	Multiparameter	75–85%	60–75%	0.80–0.85

⚠ All individual scores underperform. Awake intubation is indicated when combined multiparameter assessment suggests high risk.

Assessment Results

Confidence: High

✓ Saved

Mask Ventilation

Low

Intubation / Laryngoscopy

Low

Aspiration Risk

Low

Backup / Escalation

Standby

Preparation Checklist

Clinical Notes

Standardized PAC Summary Note

→ Continue planning in 🔪 OT — case guide 🏥 ICU — monitoring 🎯 REGIONAL — block

Saved Cases

Case ID	Date	Conf.	Mask	Intub.	Asp.	Bkp

Difficult Airway Predictors

LEMON — Intubation/Laryngoscopy

Look externally · Evaluate 3-3-2 rule · Mallampati III/IV · Obstruction · Neck mobility restricted

ROMAN — Difficult Mask Ventilation

Radiation/Restriction · Obesity/OSA · Mallampati III-IV / Mask seal (beard) · Age >55 · No teeth

MACOCHA — ICU/Critical

Mallampati III/IV · Apnoea syndrome · Cervical immobility · Mouth opening <3cm · Coma · Severe hypoxaemia · Non-anaesthetist. Score ≥3 → high risk.

STOP-Bang — OSA screen

Snoring · Tired · Observed apnoea · Pressure (HTN) · BMI >35 · Age >50 · Neck >40cm · Gender male. Score ≥5 → high OSA risk.

DAS Airway Framework — Plans A → D

Plan A — Direct/Video laryngoscopy. Optimise position (RAMP), pre-O₂ to EtO₂ >0.9. Max 3 attempts total.

Plan B — Supraglottic airway (SGA). Second-generation device (iGel/LMA ProSeal). Max 3 attempts.

Plan C — Facemask oxygenation. If successful → wake patient. If not →

Plan D (CICO) — Emergency front-of-neck access (eFONA). Scalpel–bougie–tube (6.0 cuffed). Do not delay.

Key Decision Points

Declare difficulty early — say it out loud.
Call for help before the airway is lost.
Limit total intubation attempts to avoid trauma & oedema.
Consider awake technique if predicted CICO risk at baseline.

Aspiration Prevention

RSI triggers: Inadequate fast · Emergency urgency · Severe GERD · Gastric outlet obstruction · Late pregnancy.

Modified RSI: Gentle BMV allowed if SpO₂ falls before ETT confirmed — use <20 cmH₂O.

RSI sequence: Pre-O₂ → Suction ready → Cricoid (controversial) → Induction agent + Suxamethonium/Rocuronium → No mask vent → Confirm tube → Release cricoid.

Known Limitations

This is a rule-based clinical decision aid, not a formally validated diagnostic model or medical device. It maps clinical inputs to standard guidelines (e.g., DAS, ASA) to assist in pre-operative planning and airway preparation.

Does not replace clinical judgment: Algorithm outputs must be verified against real-world patient context.
Hard-coded thresholds: The application categorizes risks rigidly. Borderline cases are typically escalated for safety.
Local Storage only: Data saved to this app never leaves the user's browser, meaning it cannot sync between devices or integrate with hospital EMRs via API.

Logic Assumptions & Major Thresholds

Mask Ventilation (ROMAN-informed)

High Risk: Previous neck pathology/radiation OR ≥3 positive predictors.
Moderate Risk: 1-2 positive predictors.

Laryngoscopy / Intubation (LEMON-informed)

Dominant Overrides (Forces High Risk): Prior known difficult airway, Severe Mouth Opening Restriction (<3 fingers), or Fixed C-Spine Limitation (Trauma / Ankylosing Spondylitis).
High Risk: ≥3 positive predictors.
Moderate Risk: 1-2 positive predictors.

Aspiration

High Risk: Inadequate Fasting status, Emergency urgency, or ≥2 predictors (Severe GERD, Severe Obesity, PONV Hx).

Backup / Escalation

Dominant Overrides: Combined High/Moderate Mask + Intubation concern independently forces an immediate 'High Backup' need.
High Need: Anticipated Difficult Intubation alone automatically triggers senior help/backup stand-by.

Missing Information

1. Adult or Pediatric Patient

2. Assessment Context

3. Patient Details & Surgery

4a. Physical Examination Indices

4b. Radiological Indices

4c. Context Tools

Advanced Documentation & Ultrasound Reference

Upper Airway Ultrasound (Adjunctive Reference)

4d. Intubation Adjuncts

Stylets

Introducers / Bougies

Airway Exchange Catheters / Guides

5a. CLINICAL SCORES

5. Pre-op & Medical Review

📊 AIRWAY TOOL ACCURACY — Quick Reference

Assessment Results

Assessment Incomplete

Mask Ventilation

Low

Intubation / Laryngoscopy

Low

Aspiration Risk

Low

Backup / Escalation

Standby

Preparation Checklist

Clinical Notes

Standardized PAC Summary Note

Saved Cases

Case-Specific Notes

Difficult Airway Predictors

LEMON — Intubation/Laryngoscopy

ROMAN — Difficult Mask Ventilation

MACOCHA — ICU/Critical

STOP-Bang — OSA screen

DAS Airway Framework — Plans A → D

Key Decision Points

Aspiration Prevention

Known Limitations

Logic Assumptions & Major Thresholds

Mask Ventilation (ROMAN-informed)

Laryngoscopy / Intubation (LEMON-informed)

Aspiration

Backup / Escalation

Sample Cases (10 Built-in)