Airway management for anaesthsia resident and definition of difficult mask ventilation and DSA protocol explained in simple terms and steps with diagrams

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I now have everything needed for a complete, well-illustrated guide. Here is the full answer:

Airway Management for the Anaesthesia Resident

A practical, step-by-step guide covering preoperative assessment, difficult mask ventilation, and the DAS protocol.

PART 1: Preoperative Airway Assessment

Before every anaesthetic, you must assess the likelihood of these six problems:

Difficult patient cooperation/consent
Difficult mask ventilation (DMV)
Difficult supraglottic airway (SGA/LMA) placement
Difficult laryngoscopy
Difficult intubation
Difficult surgical airway (front-of-neck access)

Use two mnemonics together: LEMON (for difficult intubation) and ROMAN (for difficult mask ventilation).

LEMON - Predicts Difficult Intubation

Letter	What to Check
L - Look externally	Gestalt: facial trauma, large tongue, beard, obesity
E - Evaluate 3-3-2 rule	Mouth opening = 3 fingers; Chin-to-hyoid = 3 fingers; Hyoid-to-thyroid notch = 2 fingers
M - Mallampati	Class I/II = easy; Class III = moderate; Class IV = likely difficult
O - Obstruction/Obesity	Supraglottic mass, Ludwig's angina, severe obesity
N - Neck mobility	Can they flex/extend? Fixed cervical spine = difficult

The 3-3-2 rule: if a patient has a receding jaw and high larynx, direct laryngoscopy will be very difficult because you cannot displace the tongue adequately to see the cords.

Mallampati Classes (mouth open, tongue out, no phonation)

Class	What you see	Meaning
I	Soft palate, uvula, anterior and posterior pillars	Easy
II	Soft palate, uvula	Usually easy
III	Soft palate, base of uvula only	Likely difficult
IV	Hard palate only	Very difficult

PART 2: Definition of Difficult Mask Ventilation (DMV)

Definition (ASA): Mask ventilation is "difficult" when it is inadequate, unstable, or requires more than one provider, despite optimized position and use of adjuncts (oral/nasal airway), OR when it is impossible - meaning no CO2 is detected and no perceptible chest rise occurs.

In practical terms, DMV means the anaesthetist cannot maintain SpO2 >90% with 100% O2 by face mask when the pre-induction SpO2 was >90%.

Prevalence: ~5% in general surgical populations; impossible mask ventilation is rare (~1:10,000).

ROMAN - Predicts Difficult Mask Ventilation

Use this before you give the muscle relaxant!

Letter	Risk Factor	Why it matters
R - Radiation/Resistance	History of neck radiation; severe asthma, COPD, ARDS	Stiff lungs need high pressures
O - Obstruction/Obesity/OSA	Supraglottic mass, BMI >35, obstructive sleep apnoea	Redundant pharyngeal tissue collapses
M - Mallampati/Mask seal/Male	Class III-IV; beard, facial trauma (poor seal); male sex	Poor seal = air leak; males have larger tongues
A - Age >55	Physiological aging, loss of pharyngeal tone	Harder to ventilate
N - No teeth (edentulous)	Teeth support the mask seal	"Teeth out to intubate, teeth IN to ventilate"

Practical tip: If a patient is edentulous, leave their dentures in for mask ventilation and only remove them for laryngoscopy.

Similarly, for difficult SGA placement, use RODS:

R - Restricted mouth opening or Resistance
O - Obstruction/Obesity/OSA
D - Distorted anatomy
S - Short thyromental distance

PART 3: The ASA Difficult Airway Algorithm

This is the foundational algorithm from the American Society of Anesthesiologists. The central question after a failed intubation attempt is: "Can I ventilate this patient by mask?"

ASA Difficult Airway Algorithm - Morgan & Mikhail's Clinical Anesthesiology 7e

Reading the algorithm in plain steps:

Before induction - decide: Awake intubation vs. intubation after induction?
- If you predict a truly difficult airway (e.g., massive neck mass, predicted CICO) → Awake intubation (preserve spontaneous breathing while you secure the airway)
- If anticipated normal/mildly difficult → intubate after induction
After induction, if intubation attempt fails:
- Can you mask ventilate? YES → Non-emergency pathway: call for help, try alternative approaches (videolaryngoscope, bougie, different blade, LMA as conduit)
- Can you mask ventilate? NO → Try SGA
  - SGA works → Emergency Non-invasive pathway
  - SGA also fails → EMERGENCY PATHWAY = CICO (Can't Intubate, Can't Oxygenate)
CICO = Life-threatening emergency → Emergency front-of-neck access (surgical cricothyrotomy) immediately

PART 4: The DAS Protocol (Difficult Airway Society 2015)

The DAS guidelines are the gold-standard in UK/international anaesthetic practice for unanticipated difficult intubation. They use a structured 4-Plan approach.

DAS Overview

DAS Difficult Airway Guidelines - Overview

DAS Detailed Plans

DAS Management of Unanticipated Difficult Tracheal Intubation in Adults 2015

Plan A - Facemask Ventilation + Tracheal Intubation

Goal: Secure the trachea on the FIRST attempt.

Steps:

Optimize head and neck position (ramping for obese patients)
Pre-oxygenate (EtO2 >80% or 3 min of tidal breathing or 8 vital capacity breaths)
Ensure adequate neuromuscular blockade
Use direct or video laryngoscopy - maximum 3 + 1 attempts (3 by the same operator, 1 by a more experienced colleague)
Use adjuncts: external laryngeal manipulation (BURP), remove cricoid pressure, use a bougie
Maintain oxygenation between attempts
Always confirm intubation with capnography (waveform ETCO2)

If Plan A fails → Declare failed intubation (say it out loud)

Plan B - Maintaining Oxygenation: SAD Insertion

Goal: Oxygenate the patient via a supraglottic airway device.

Steps:

Insert a second-generation SAD (e.g., ProSeal LMA, LMA Supreme, i-gel)
- Second-generation devices have gastric drainage ports - better for airway protection
Maximum 3 attempts (change device type or size between attempts)
Confirm ventilation with capnography

If Plan B succeeds → STOP AND THINK (don't rush to intubate):

Option 1: Wake the patient up (safest if surgery is elective)
Option 2: Intubate the trachea through the SAD (using fiberoptic scope)
Option 3: Proceed with surgery under SAD anaesthesia (if safe/appropriate)
Option 4: Tracheostomy or cricothyroidotomy (planned)

If Plan B fails → Declare failed SAD ventilation

Plan C - Final Attempt at Facemask Ventilation

Goal: One last attempt to oxygenate before declaring CICO.

Steps:

If facemask ventilation was previously impossible → ensure full neuromuscular blockade (paralysis actually opens the airway)
Use two-person technique: one person holds the mask with both hands using a two-thumb jaw thrust, second person squeezes the bag
Use oropharyngeal + nasopharyngeal airways together

If Plan C succeeds → Wake the patient up

If Plan C fails → DECLARE CICO

Plan D - Emergency Front-of-Neck Access (eFONA)

This is the final rescue. CICO = immediate life threat. Do not hesitate.

DAS Plan D - Failed intubation, failed oxygenation in the paralyzed patient

The DAS-recommended technique is scalpel cricothyroidotomy (not needle):

Steps:

Call for help - say "CICO, I need the front of neck kit"
Continue 100% O2 via upper airway while setting up
Ensure complete neuromuscular blockade (relaxed muscles make the neck anatomy palpable)
Extend the neck
Laryngeal handshake - use thumb and middle finger to stabilize the larynx, index finger feels the cricothyroid membrane (CTM)
Palpable CTM:
- Transverse stab incision through skin and CTM
- Turn blade 90° (sharp edge caudally)
- Slide bougie along blade into trachea
- Railroad a lubricated 6.0mm cuffed tube over the bougie
- Ventilate, inflate cuff, confirm with capnography
- Secure the tube
Impalpable CTM (obese/distorted neck):
- 8-10 cm vertical midline skin incision
- Blunt finger dissection to find the larynx
- Then proceed as above

PART 5: Key Rules to Remember as a Resident

Rule	Explanation
Oxygen first, always	Give supplemental oxygen between every attempt
Do not repeat failure	Never do the same thing three times if it's failing - change your approach
Call for help early	Before you've used up all your attempts, not after
Video laryngoscopy first	ASA and DAS now recommend VL as the primary approach for anticipated difficulty
Maximum 3+1 intubation attempts	After 3 failed attempts by the same operator, one more by a more senior person
CICO is not a failure	Declaring CICO early and going to Plan D saves lives. Delay kills.
Capnography confirms intubation	Waveform ETCO2 is the gold standard. Do not rely on chest rise or "feeling" alone
Awake intubation for predicted impossible mask	If you predict you cannot mask ventilate AND cannot intubate, do NOT induce GA
Document and follow up	After any difficult airway, fill an airway alert form, inform the patient in writing, notify their GP

Quick Summary Card

PREOP ASSESSMENT:
LEMON (difficult intubation) + ROMAN (difficult mask ventilation)

INTRAOP - If intubation fails:

PLAN A (DAS): Laryngoscopy - max 3+1 attempts, optimized technique
       ↓ FAIL → Declare failed intubation
PLAN B (DAS): Second-generation SAD - max 3 attempts
       ↓ SUCCEED → STOP AND THINK (wake up / intubate via SAD / proceed)
       ↓ FAIL → Declare failed SAD
PLAN C (DAS): Final facemask ventilation (2-person technique, NMB)
       ↓ SUCCEED → Wake patient up
       ↓ FAIL → DECLARE CICO
PLAN D (DAS): Scalpel cricothyroidotomy - NOW, no further delay

Sources:

Morgan and Mikhail's Clinical Anesthesiology, 7e - Difficult Airway Algorithm (ASA)
DAS 2015 Guidelines (Frerk C et al., Br J Anaesth 2015;115(6):827-848) - reproduced in Morgan & Mikhail's
Rosen's Emergency Medicine, 9e - LEMON, ROMAN, RODS mnemonics
Scott-Brown's Otorhinolaryngology Head & Neck Surgery - prevalence data
Barash Clinical Anesthesia, 9e - pediatric and complex airway management

Create a visual pocket card PDF of the DAS 4-plan algorithm with equipment checklists

Reading File

Running Command

mkdir -p /home/daytona/workspace/das-pocket-card && ls /home/daytona/workspace/d…

Writing File

~/das-pocket-card/generate_das_card.py

"""
DAS 4-Plan Difficult Airway Algorithm - Visual Pocket Card PDF
A3 landscape, double-sided pocket card design using ReportLab
"""

from reportlab.lib.pagesizes import A4
from reportlab.lib import colors
from reportlab.lib.units import mm
from reportlab.platypus import SimpleDocTemplate
from reportlab.pdfgen import canvas
from reportlab.lib.colors import HexColor, white, black
import os

OUTPUT = "/home/daytona/workspace/das-pocket-card/DAS_Airway_Pocket_Card.pdf"

# ── Colour palette ──────────────────────────────────────────────────────────
NAVY       = HexColor("#1B3A6B")   # DAS dark blue
PLAN_A_BG  = HexColor("#1B3A6B")   # Plan A header
PLAN_B_BG  = HexColor("#1B6B3A")   # Plan B header - green
PLAN_C_BG  = HexColor("#6B4E1B")   # Plan C header - amber/brown
PLAN_D_BG  = HexColor("#8B0000")   # Plan D header - dark red (emergency)
CICO_RED   = HexColor("#CC0000")
SUCCEED_GREEN = HexColor("#2E7D32")
ARROW_RED  = HexColor("#D32F2F")
LIGHT_BLUE = HexColor("#E8F0FE")
LIGHT_GREEN= HexColor("#E8F5E9")
LIGHT_AMBER= HexColor("#FFF8E1")
LIGHT_RED  = HexColor("#FFEBEE")
BOX_GREY   = HexColor("#F5F5F5")
MID_GREY   = HexColor("#9E9E9E")
DARK_GREY  = HexColor("#424242")
STOP_BG    = HexColor("#FFF3E0")
STOP_BORDER= HexColor("#FF8F00")
WHITE      = white
BLACK      = black

PAGE_W, PAGE_H = A4  # 595.27 x 841.89 points  (portrait A4)

# We'll create 2 pages: Page 1 = main algorithm, Page 2 = equipment checklists

def draw_rounded_rect(c, x, y, w, h, r, fill_color=None, stroke_color=None, line_width=1):
    """Draw a rounded rectangle."""
    c.saveState()
    if fill_color:
        c.setFillColor(fill_color)
    if stroke_color:
        c.setStrokeColor(stroke_color)
        c.setLineWidth(line_width)
    else:
        c.setStrokeColor(colors.transparent)
    p = c.beginPath()
    p.roundRect(x, y, w, h, r)
    if fill_color and stroke_color:
        c.drawPath(p, fill=1, stroke=1)
    elif fill_color:
        c.drawPath(p, fill=1, stroke=0)
    elif stroke_color:
        c.drawPath(p, fill=0, stroke=1)
    c.restoreState()

def draw_arrow_down(c, x, y, length=14, color=ARROW_RED, width=2):
    """Draw a downward arrow from (x, y)."""
    c.saveState()
    c.setStrokeColor(color)
    c.setFillColor(color)
    c.setLineWidth(width)
    # shaft
    c.line(x, y, x, y - length + 4)
    # arrowhead
    p = c.beginPath()
    p.moveTo(x - 4, y - length + 5)
    p.lineTo(x + 4, y - length + 5)
    p.lineTo(x, y - length)
    p.close()
    c.drawPath(p, fill=1, stroke=0)
    c.restoreState()

def draw_arrow_right(c, x, y, length=20, color=SUCCEED_GREEN, width=2):
    """Draw a rightward arrow from (x, y)."""
    c.saveState()
    c.setStrokeColor(color)
    c.setFillColor(color)
    c.setLineWidth(width)
    c.line(x, y, x + length - 4, y)
    p = c.beginPath()
    p.moveTo(x + length - 5, y - 4)
    p.lineTo(x + length - 5, y + 4)
    p.lineTo(x + length, y)
    p.close()
    c.drawPath(p, fill=1, stroke=0)
    c.restoreState()

def wrap_text_in_box(c, text_lines, x, y, w, h, font_name, font_size, text_color, line_height=None):
    """Draw wrapped text lines centred vertically in a box."""
    if line_height is None:
        line_height = font_size + 2
    total_h = len(text_lines) * line_height
    start_y = y + h/2 + total_h/2 - font_size
    c.setFont(font_name, font_size)
    c.setFillColor(text_color)
    for i, line in enumerate(text_lines):
        c.drawCentredString(x + w/2, start_y - i * line_height, line)

def draw_plan_block(c, plan_label, plan_title, steps, outcome_text,
                    bx, by, bw, bh,
                    header_color, body_bg, outcome_color,
                    fail_label=None, succeed_label=None,
                    stop_think=None):
    """Draw one plan block with header, steps, and outcome."""
    header_h = 22
    margin = 6
    
    # Header
    draw_rounded_rect(c, bx, by + bh - header_h, bw, header_h, 4,
                      fill_color=header_color, stroke_color=None)
    c.setFillColor(WHITE)
    c.setFont("Helvetica-Bold", 9)
    c.drawCentredString(bx + bw/2, by + bh - header_h + 7, f"{plan_label}: {plan_title}")

    # Body background
    draw_rounded_rect(c, bx, by, bw, bh - header_h, 4,
                      fill_color=body_bg, stroke_color=header_color, line_width=1)

    # Steps
    c.setFont("Helvetica", 7.5)
    c.setFillColor(DARK_GREY)
    ty = by + bh - header_h - margin - 8
    for step in steps:
        if step.startswith("**") and step.endswith("**"):
            c.setFont("Helvetica-Bold", 7.5)
            txt = step[2:-2]
        else:
            c.setFont("Helvetica", 7.5)
            txt = step
        # word-wrap simple
        max_chars = int(bw / 4.2)
        if len(txt) > max_chars:
            # split at space near midpoint
            mid = max_chars
            while mid > 0 and txt[mid] != ' ':
                mid -= 1
            line1 = txt[:mid]
            line2 = txt[mid+1:]
            c.drawString(bx + margin, ty, "• " + line1)
            ty -= 9
            c.drawString(bx + margin + 6, ty, line2)
        else:
            c.drawString(bx + margin, ty, "• " + txt)
        ty -= 10

    # Outcome arrow label (succeed →)
    if succeed_label:
        c.setFont("Helvetica-BoldOblique", 7)
        c.setFillColor(SUCCEED_GREEN)
        c.drawCentredString(bx + bw/2, by + 4, succeed_label)

def draw_page1(c):
    """Draw Page 1: DAS 4-Plan Algorithm."""
    W, H = PAGE_W, PAGE_H
    margin = 10 * mm

    # ── Background ──
    c.setFillColor(HexColor("#FAFAFA"))
    c.rect(0, 0, W, H, fill=1, stroke=0)

    # ── Top header banner ──
    c.setFillColor(NAVY)
    c.rect(0, H - 28*mm, W, 28*mm, fill=1, stroke=0)

    c.setFillColor(WHITE)
    c.setFont("Helvetica-Bold", 16)
    c.drawCentredString(W/2, H - 14*mm, "DAS DIFFICULT AIRWAY ALGORITHM")
    c.setFont("Helvetica", 9)
    c.drawCentredString(W/2, H - 22*mm, "Management of Unanticipated Difficult Tracheal Intubation in Adults  |  DAS Guidelines 2015")

    # ── Sub-header: key rule ──
    draw_rounded_rect(c, margin, H - 35*mm, W - 2*margin, 6*mm, 3,
                      fill_color=HexColor("#FFF9C4"), stroke_color=HexColor("#F9A825"), line_width=1.5)
    c.setFont("Helvetica-Bold", 8)
    c.setFillColor(HexColor("#E65100"))
    c.drawCentredString(W/2, H - 32*mm, "⚠  If in difficulty at ANY point — CALL FOR HELP immediately  ⚠")

    # ── Layout constants for the 4 plan boxes ──
    col_w = (W - 2*margin - 3*4*mm) / 4   # 4 equal columns with 4mm gaps
    box_h = 95*mm
    box_y = H - 35*mm - 4*mm - box_h
    gap = 4*mm

    plans = [
        {
            "label": "PLAN A",
            "title": "Facemask + Intubation",
            "header": PLAN_A_BG,
            "body": LIGHT_BLUE,
            "steps": [
                "**Optimise head/neck position**",
                "Pre-oxygenate (EtO₂ >80%)",
                "Adequate neuromuscular blockade",
                "Direct OR video laryngoscopy",
                "Max 3+1 attempts total",
                "Use bougie as primary adjunct",
                "External laryngeal manipulation",
                "Remove cricoid pressure if view poor",
                "Maintain oxygenation between attempts",
                "**Confirm with waveform capnography**",
            ],
            "fail": "▼ Declare FAILED INTUBATION",
            "succeed": "✓ Confirmed intubation → PIM",
        },
        {
            "label": "PLAN B",
            "title": "SAD Insertion",
            "header": PLAN_B_BG,
            "body": LIGHT_GREEN,
            "steps": [
                "**2nd-generation SAD recommended**",
                "(i-gel, ProSeal LMA, LMA Supreme)",
                "Max 3 attempts",
                "Change device or size if fails",
                "Confirm ventilation with capnography",
                "Oxygenate and ventilate",
            ],
            "fail": "▼ Declare FAILED SAD ventilation",
            "succeed": "✓ Succeed → STOP & THINK (see box)",
        },
        {
            "label": "PLAN C",
            "title": "Facemask Ventilation",
            "header": PLAN_C_BG,
            "body": LIGHT_AMBER,
            "steps": [
                "**Final attempt — oxygenate**",
                "Ensure full NMB (paralysis opens airway)",
                "2-person technique:",
                "  Person 1: Both hands on mask",
                "  Two-thumb jaw thrust grip",
                "  Person 2: Squeeze bag",
                "Oropharyngeal + nasopharyngeal airway",
                "Increase fresh gas flow",
            ],
            "fail": "▼ DECLARE CICO",
            "succeed": "✓ Succeed → Wake the patient",
        },
        {
            "label": "PLAN D",
            "title": "Emergency FONA",
            "header": PLAN_D_BG,
            "body": LIGHT_RED,
            "steps": [
                "**CICO = ACT NOW, no delay**",
                "Continue O₂ via upper airway",
                "Ensure full NMB",
                "Extend the neck",
                "**Laryngeal handshake:**",
                "Stabilise larynx, feel CTM",
                "**Scalpel cricothyroidotomy:**",
                "Transverse stab incision CTM",
                "Turn blade 90° (sharp edge down)",
                "Bougie into trachea → 6mm tube",
                "Inflate cuff, confirm capnography",
            ],
            "fail": None,
            "succeed": None,
        },
    ]

    for i, plan in enumerate(plans):
        bx = margin + i * (col_w + gap)
        by = box_y

        # Header bar
        draw_rounded_rect(c, bx, by + box_h - 20, col_w, 20, 4,
                          fill_color=plan["header"], stroke_color=None)
        c.setFillColor(WHITE)
        c.setFont("Helvetica-Bold", 8.5)
        c.drawCentredString(bx + col_w/2, by + box_h - 13, plan["label"])
        c.setFont("Helvetica", 7)
        c.drawCentredString(bx + col_w/2, by + box_h - 22, plan["title"])

        # Body
        draw_rounded_rect(c, bx, by + 18, col_w, box_h - 20, 4,
                          fill_color=plan["body"],
                          stroke_color=plan["header"], line_width=1.2)

        # Steps text
        c.setFont("Helvetica", 7.2)
        c.setFillColor(DARK_GREY)
        ty = by + box_h - 30
        for step in plan["steps"]:
            if step.startswith("**") and step.endswith("**"):
                c.setFont("Helvetica-Bold", 7.2)
                txt = "• " + step[2:-2]
                c.setFillColor(BLACK)
            else:
                c.setFont("Helvetica", 7.2)
                txt = "  " + step if step.startswith(" ") else "• " + step
                c.setFillColor(DARK_GREY)
            # simple wrap
            max_w = col_w - 8
            # Estimate char width ~4pt per char at 7.2
            max_chars = int(max_w / 3.9)
            if len(txt) > max_chars:
                mid = max_chars
                while mid > 0 and txt[mid] != ' ':
                    mid -= 1
                if mid == 0:
                    mid = max_chars
                c.drawString(bx + 5, ty, txt[:mid])
                ty -= 8.5
                c.drawString(bx + 10, ty, txt[mid:].lstrip())
            else:
                c.drawString(bx + 5, ty, txt)
            ty -= 9.5
            if ty < by + 22:
                break

        # Succeed label (green, bottom right area)
        if plan["succeed"]:
            c.setFont("Helvetica-Bold", 6.5)
            c.setFillColor(SUCCEED_GREEN)
            c.drawCentredString(bx + col_w/2, by + 22, plan["succeed"])

        # Fail label below box
        if plan["fail"]:
            c.setFont("Helvetica-Bold", 7)
            c.setFillColor(CICO_RED)
            c.drawCentredString(bx + col_w/2, by + 10, plan["fail"])

    # ── Downward arrows between plans ──
    for i in range(3):
        ax = margin + (i+1) * (col_w + gap) - gap/2
        ay = box_y + box_h/2 + 8
        draw_arrow_right(c, ax - 3, ay, length=gap + 4, color=ARROW_RED, width=1.5)

    # ── STOP AND THINK box ──
    stop_x = margin
    stop_y = box_y - 52*mm
    stop_w = (W - 2*margin) * 0.48
    stop_h = 46*mm

    draw_rounded_rect(c, stop_x, stop_y, stop_w, stop_h, 5,
                      fill_color=STOP_BG, stroke_color=STOP_BORDER, line_width=2)
    # Header
    c.setFillColor(STOP_BORDER)
    c.setFont("Helvetica-Bold", 9)
    c.drawCentredString(stop_x + stop_w/2, stop_y + stop_h - 10, "🛑  STOP AND THINK  (After successful Plan B)")
    c.setFont("Helvetica", 7.5)
    c.setFillColor(DARK_GREY)
    options = [
        "Consider risks & benefits carefully before next step:",
        "1.  Wake the patient up  (safest if elective surgery)",
        "2.  Intubate trachea via SAD (with fiberoptic scope)",
        "3.  Proceed with surgery under SAD anaesthesia",
        "4.  Planned tracheostomy or cricothyroidotomy",
        "",
        "Do NOT rush to intubate. Oxygenation is secured.",
    ]
    oy = stop_y + stop_h - 22
    for opt in options:
        c.setFont("Helvetica-Bold" if opt.startswith("Consider") else "Helvetica", 7.5)
        c.setFillColor(HexColor("#BF360C") if opt.startswith("Do NOT") else DARK_GREY)
        c.drawString(stop_x + 8, oy, opt)
        oy -= 9.5

    # ── CICO box ──
    cico_x = stop_x + stop_w + 4*mm
    cico_y = stop_y
    cico_w = W - 2*margin - stop_w - 4*mm
    cico_h = stop_h

    draw_rounded_rect(c, cico_x, cico_y, cico_w, cico_h, 5,
                      fill_color=HexColor("#FFCDD2"), stroke_color=CICO_RED, line_width=2.5)
    c.setFillColor(CICO_RED)
    c.setFont("Helvetica-Bold", 11)
    c.drawCentredString(cico_x + cico_w/2, cico_y + cico_h - 13, "⚡ CICO DECLARED")
    c.setFont("Helvetica-Bold", 8)
    c.drawCentredString(cico_x + cico_w/2, cico_y + cico_h - 24, "Can't Intubate, Can't Oxygenate")
    c.setFont("Helvetica-Bold", 8)
    c.setFillColor(DARK_GREY)
    cico_steps = [
        "→ CALL FOR HELP (shout loud)",
        "→ Continue O₂ via upper airway",
        "→ Declare to team: 'This is CICO'",
        "→ Proceed IMMEDIATELY to Plan D",
        "→ Scalpel cricothyroidotomy NOW",
        "→ No further intubation attempts",
    ]
    cy = cico_y + cico_h - 36
    for s in cico_steps:
        c.setFont("Helvetica-Bold" if "NOW" in s or "IMMEDIATELY" in s else "Helvetica", 7.5)
        c.setFillColor(CICO_RED if "NOW" in s or "IMMEDIATELY" in s else DARK_GREY)
        c.drawCentredString(cico_x + cico_w/2, cy, s)
        cy -= 9.5

    # ── Key Principles footer ──
    fp_y = stop_y - 28*mm
    draw_rounded_rect(c, margin, fp_y, W - 2*margin, 24*mm, 4,
                      fill_color=HexColor("#E3F2FD"), stroke_color=NAVY, line_width=1)
    c.setFont("Helvetica-Bold", 8)
    c.setFillColor(NAVY)
    c.drawCentredString(W/2, fp_y + 18*mm, "KEY PRINCIPLES")
    principles = [
        ("Oxygen always", "Supplement O₂ throughout — never stop trying to oxygenate"),
        ("Never repeat failure", "Change technique, device, or provider — not the same thing again"),
        ("Confirm with ETCO₂", "Waveform capnography is the gold standard for tube confirmation"),
        ("Max 3+1 attempts", "3 by same operator + 1 by senior; no more laryngoscopy after that"),
        ("Awake if CICO predicted", "If mask ventilation + intubation both predicted impossible → awake fibreoptic"),
        ("Post-event follow-up", "Airway alert form + written info to patient + notify GP"),
    ]
    px = margin + 5
    py = fp_y + 14*mm
    col_width = (W - 2*margin - 10) / 3
    for idx, (title, desc) in enumerate(principles):
        col = idx % 3
        row = idx // 3
        tx = px + col * col_width
        ty2 = py - row * 10*mm
        c.setFont("Helvetica-Bold", 7.5)
        c.setFillColor(NAVY)
        c.drawString(tx, ty2, f"▸ {title}:")
        c.setFont("Helvetica", 7)
        c.setFillColor(DARK_GREY)
        c.drawString(tx + 2, ty2 - 8, desc)

    # ── Footer ──
    c.setFont("Helvetica", 6.5)
    c.setFillColor(MID_GREY)
    c.drawCentredString(W/2, 8*mm, "Based on DAS 2015 Guidelines (Frerk C et al. Br J Anaesth 2015;115:827-848)  |  For educational use only  |  Always refer to current institutional protocols")
    c.drawCentredString(W/2, 5*mm, "Page 1 of 2  —  DAS Algorithm")


def draw_checklist_box(c, x, y, w, h, title, items, header_color, body_color, col_count=1):
    """Draw an equipment checklist box."""
    hh = 16
    draw_rounded_rect(c, x, y, w, h, 4, fill_color=header_color, stroke_color=None)
    c.setFillColor(WHITE)
    c.setFont("Helvetica-Bold", 8)
    c.drawCentredString(x + w/2, y + h - 11, title)

    draw_rounded_rect(c, x, y, w, h - hh, 4,
                      fill_color=body_color, stroke_color=header_color, line_width=1.2)

    # Items in columns
    item_count = len(items)
    per_col = -(-item_count // col_count)  # ceil divide
    col_w = (w - 8) / col_count
    start_y = y + h - hh - 5

    for idx, item in enumerate(items):
        col = idx // per_col
        row = idx % per_col
        ix = x + 4 + col * col_w
        iy = start_y - row * 9.5
        # checkbox
        c.setStrokeColor(header_color)
        c.setLineWidth(0.8)
        c.rect(ix, iy - 1, 6, 6, fill=0, stroke=1)
        c.setFont("Helvetica", 7)
        c.setFillColor(DARK_GREY)
        c.drawString(ix + 8, iy, item)


def draw_page2(c):
    """Draw Page 2: Equipment checklists + assessment tools."""
    W, H = PAGE_W, PAGE_H
    margin = 10 * mm

    # Background
    c.setFillColor(HexColor("#FAFAFA"))
    c.rect(0, 0, W, H, fill=1, stroke=0)

    # Header
    c.setFillColor(NAVY)
    c.rect(0, H - 22*mm, W, 22*mm, fill=1, stroke=0)
    c.setFillColor(WHITE)
    c.setFont("Helvetica-Bold", 14)
    c.drawCentredString(W/2, H - 12*mm, "DAS AIRWAY POCKET CARD — EQUIPMENT & ASSESSMENT")
    c.setFont("Helvetica", 8)
    c.drawCentredString(W/2, H - 19*mm, "Checklists for Plans A–D  |  LEMON  |  ROMAN  |  Cricothyroid Membrane Landmark")

    # Layout: two columns
    col_w = (W - 2*margin - 4*mm) / 2
    left_x = margin
    right_x = margin + col_w + 4*mm
    top_y = H - 26*mm

    # ── PLAN A Equipment ──
    plan_a_items = [
        "Laryngoscope (Mac 3 & 4, Miller)",
        "Video laryngoscope (e.g. C-MAC, McGrath)",
        "ETT sizes 6.0, 7.0, 8.0 (cuffed)",
        "Gum elastic bougie",
        "10mL syringe (cuff inflation)",
        "Magill's forceps",
        "Stylet/introducer",
        "Tape/tube tie for securing ETT",
        "CO₂ detector / waveform capnograph",
        "Suction (Yankauer) — working",
        "Pre-oxygenation mask + circuit",
        "NMB agent (suxamethonium/rocuronium)",
        "Stethoscope",
        "Monitoring: SpO₂, ETCO₂, ECG, NIBP",
    ]
    a_h = 52*mm
    draw_checklist_box(c, left_x, top_y - a_h, col_w, a_h,
                       "PLAN A — Intubation Equipment", plan_a_items,
                       PLAN_A_BG, LIGHT_BLUE, col_count=2)

    # ── PLAN B Equipment ──
    plan_b_items = [
        "i-gel (sizes 3, 4, 5)",
        "ProSeal LMA or LMA Supreme",
        "Classic LMA (backup)",
        "Lubricant (water-based)",
        "Syringe for cuff inflation",
        "Gastric drainage tube (60mL syringe)",
        "Tape to secure SAD",
        "Capnograph connection",
    ]
    b_h = 33*mm
    draw_checklist_box(c, left_x, top_y - a_h - 4*mm - b_h, col_w, b_h,
                       "PLAN B — SAD / Supraglottic Airway Equipment", plan_b_items,
                       PLAN_B_BG, LIGHT_GREEN, col_count=2)

    # ── PLAN C Equipment ──
    plan_c_items = [
        "Face mask (correct size)",
        "Oropharyngeal (Guedel) airways: sizes 3, 4",
        "Nasopharyngeal airway + lubricant",
        "Self-inflating bag (Ambu)",
        "2nd operator for 2-person technique",
        "Oxygen source (100%)",
    ]
    c_h = 28*mm
    draw_checklist_box(c, left_x, top_y - a_h - 4*mm - b_h - 4*mm - c_h, col_w, c_h,
                       "PLAN C — Facemask Ventilation Equipment", plan_c_items,
                       PLAN_C_BG, LIGHT_AMBER, col_count=2)

    # ── PLAN D Equipment ──
    plan_d_items = [
        "Scalpel — No. 10 blade",
        "Bougie (gum elastic, 60cm)",
        "Cuffed ETT 6.0mm ID",
        "10mL syringe (cuff inflation)",
        "Lubricant for tube",
        "Tape/tie for securing tube",
        "Capnograph (confirm position)",
        "Suction available",
        "Skin prep / swabs",
        "Assistant + good lighting",
    ]
    d_h = 40*mm
    draw_checklist_box(c, left_x, top_y - a_h - 4*mm - b_h - 4*mm - c_h - 4*mm - d_h, col_w, d_h,
                       "PLAN D — Emergency FONA / Scalpel Cricothyroidotomy", plan_d_items,
                       PLAN_D_BG, LIGHT_RED, col_count=2)

    # RIGHT COLUMN ──────────────────────────────────────────────────────────

    # ── LEMON ──
    lemon_items_text = [
        ("L", "Look externally",
         "Gestalt: facial trauma, beard, large tongue, obesity, small mouth"),
        ("E", "Evaluate 3-3-2",
         "3 fingers between incisors | 3 fingers floor of mouth | 2 fingers hyoid-to-notch"),
        ("M", "Mallampati",
         "Class I/II = easy  |  Class III = moderate  |  Class IV = predicted difficult"),
        ("O", "Obstruction/Obesity",
         "Supraglottic mass, Ludwig's, tonsil, obese (BMI >35), OSA"),
        ("N", "Neck mobility",
         "Can they flex/extend? Fixed C-spine, halo, collar = very difficult"),
    ]
    lemon_h = 48*mm
    draw_rounded_rect(c, right_x, top_y - lemon_h, col_w, lemon_h, 4,
                      fill_color=NAVY, stroke_color=None)
    c.setFillColor(WHITE)
    c.setFont("Helvetica-Bold", 8.5)
    c.drawCentredString(right_x + col_w/2, top_y - 12, "LEMON  —  Predict Difficult Intubation")
    draw_rounded_rect(c, right_x, top_y - lemon_h, col_w, lemon_h - 16, 4,
                      fill_color=HexColor("#E8EAF6"), stroke_color=NAVY, line_width=1)
    ly = top_y - 26
    for letter, title, desc in lemon_items_text:
        # Letter badge
        draw_rounded_rect(c, right_x + 5, ly - 4, 12, 12, 2,
                          fill_color=NAVY, stroke_color=None)
        c.setFillColor(WHITE)
        c.setFont("Helvetica-Bold", 8)
        c.drawCentredString(right_x + 11, ly + 1, letter)
        c.setFont("Helvetica-Bold", 7.5)
        c.setFillColor(NAVY)
        c.drawString(right_x + 20, ly + 4, title)
        c.setFont("Helvetica", 6.8)
        c.setFillColor(DARK_GREY)
        c.drawString(right_x + 20, ly - 4, desc)
        ly -= 14

    # ── ROMAN ──
    roman_items = [
        ("R", "Radiation/Resistance",
         "Neck radiation hx | Asthma/COPD/ARDS (high pressures needed)"),
        ("O", "Obstruction/Obesity/OSA",
         "Supraglottic mass | BMI >35 | OSA (redundant pharyngeal tissue)"),
        ("M", "Mallampati/Mask seal/Male",
         "Class III-IV | Beard/facial trauma (seal failure) | Male sex"),
        ("A", "Age >55",
         "Physiological ageing, decreased pharyngeal tone"),
        ("N", "No teeth (edentulous)",
         "'Teeth IN to ventilate, teeth OUT to intubate'"),
    ]
    roman_h = 48*mm
    ry = top_y - lemon_h - 4*mm
    draw_rounded_rect(c, right_x, ry - roman_h, col_w, roman_h, 4,
                      fill_color=PLAN_B_BG, stroke_color=None)
    c.setFillColor(WHITE)
    c.setFont("Helvetica-Bold", 8.5)
    c.drawCentredString(right_x + col_w/2, ry - 12, "ROMAN  —  Predict Difficult Mask Ventilation")
    draw_rounded_rect(c, right_x, ry - roman_h, col_w, roman_h - 16, 4,
                      fill_color=HexColor("#E8F5E9"), stroke_color=PLAN_B_BG, line_width=1)
    ry2 = ry - 26
    for letter, title, desc in roman_items:
        draw_rounded_rect(c, right_x + 5, ry2 - 4, 12, 12, 2,
                          fill_color=PLAN_B_BG, stroke_color=None)
        c.setFillColor(WHITE)
        c.setFont("Helvetica-Bold", 8)
        c.drawCentredString(right_x + 11, ry2 + 1, letter)
        c.setFont("Helvetica-Bold", 7.5)
        c.setFillColor=PLAN_B_BG
        c.setFillColor(HexColor("#1B5E20"))
        c.drawString(right_x + 20, ry2 + 4, title)
        c.setFont("Helvetica", 6.8)
        c.setFillColor(DARK_GREY)
        c.drawString(right_x + 20, ry2 - 4, desc)
        ry2 -= 14

    # ── Cricothyroid Membrane Landmark Diagram ──
    ctm_y = ry - roman_h - 4*mm
    ctm_h = 62*mm
    draw_rounded_rect(c, right_x, ctm_y - ctm_h, col_w, ctm_h, 4,
                      fill_color=HexColor("#FCE4EC"), stroke_color=PLAN_D_BG, line_width=1.5)
    c.setFillColor(PLAN_D_BG)
    c.setFont("Helvetica-Bold", 8)
    c.drawCentredString(right_x + col_w/2, ctm_y - 11,
                        "CTM LANDMARK — Laryngeal Handshake")

    # Simple neck diagram
    cx = right_x + col_w/2
    cy_base = ctm_y - ctm_h + 10

    # Neck outline (simple rectangle)
    c.setStrokeColor(HexColor("#795548"))
    c.setLineWidth(1.5)
    c.roundRect(cx - 22, cy_base + 2, 44, 40, 5, fill=0, stroke=1)
    c.setFillColor(HexColor("#FFCCBC"))
    c.roundRect(cx - 22, cy_base + 2, 44, 40, 5, fill=1, stroke=1)

    # Thyroid cartilage label
    c.setFillColor(HexColor("#6D4C41"))
    c.setFont("Helvetica-Bold", 7)
    c.drawCentredString(cx, cy_base + 37, "Thyroid Cartilage")

    # CTM zone (coloured)
    c.setFillColor(HexColor("#FF5722"))
    c.rect(cx - 12, cy_base + 22, 24, 8, fill=1, stroke=0)
    c.setFillColor(WHITE)
    c.setFont("Helvetica-Bold", 6.5)
    c.drawCentredString(cx, cy_base + 27, "CTM")

    # Cricoid label
    c.setFillColor(HexColor("#6D4C41"))
    c.setFont("Helvetica-Bold", 7)
    c.drawCentredString(cx, cy_base + 17, "Cricoid Cartilage")

    # Tracheal rings
    for i in range(3):
        c.setStrokeColor(HexColor("#795548"))
        c.setLineWidth(0.8)
        c.rect(cx - 10, cy_base + 5 + i*3, 20, 3, fill=0, stroke=1)

    # Arrow to CTM
    c.setStrokeColor(CICO_RED)
    c.setFillColor(CICO_RED)
    c.setLineWidth(1.5)
    c.line(cx + 30, cy_base + 26, cx + 14, cy_base + 26)
    # arrowhead
    p = c.beginPath()
    p.moveTo(cx + 14, cy_base + 23)
    p.lineTo(cx + 14, cy_base + 29)
    p.lineTo(cx + 10, cy_base + 26)
    p.close()
    c.drawPath(p, fill=1, stroke=0)
    c.setFont("Helvetica-Bold", 7)
    c.drawString(cx + 31, cy_base + 24, "← Incise here")

    # Handshake steps
    c.setFont("Helvetica-Bold", 7.5)
    c.setFillColor(PLAN_D_BG)
    c.drawString(right_x + 5, ctm_y - 18, "Laryngeal Handshake Technique:")
    steps_ctm = [
        "1. Thumb + middle finger grip thyroid cartilage",
        "2. Index finger slides down to feel CTM dip",
        "3. CTM = soft tissue between thyroid & cricoid",
        "4. Horizontal stab incision through CTM",
        "5. Bougie → 6mm tube → confirm with ETCO₂",
    ]
    c.setFont("Helvetica", 7)
    c.setFillColor(DARK_GREY)
    hy = ctm_y - 27
    for s in steps_ctm:
        c.drawString(right_x + 5, hy, s)
        hy -= 9

    # ── Mallampati guide ──
    mall_y = ctm_y - ctm_h - 4*mm
    mall_h = 36*mm
    draw_rounded_rect(c, right_x, mall_y - mall_h, col_w, mall_h, 4,
                      fill_color=HexColor("#F3E5F5"), stroke_color=HexColor("#7B1FA2"), line_width=1.2)
    c.setFillColor(HexColor("#7B1FA2"))
    c.setFont("Helvetica-Bold", 8)
    c.drawCentredString(right_x + col_w/2, mall_y - 11, "MALLAMPATI CLASSIFICATION")
    classes = [
        ("I",   "Soft palate, uvula, pillars all visible",       "✓ Easy",    HexColor("#2E7D32")),
        ("II",  "Soft palate + uvula visible",                   "✓ Usually easy", HexColor("#558B2F")),
        ("III", "Soft palate, base of uvula only",               "⚠ Likely difficult", HexColor("#E65100")),
        ("IV",  "Hard palate only — tongue fills mouth",         "✗ Very difficult", CICO_RED),
    ]
    my = mall_y - 24
    for cls, vis, pred, col in classes:
        draw_rounded_rect(c, right_x + 5, my - 3, 12, 10, 2,
                          fill_color=col, stroke_color=None)
        c.setFillColor(WHITE)
        c.setFont("Helvetica-Bold", 7)
        c.drawCentredString(right_x + 11, my + 2, cls)
        c.setFont("Helvetica", 6.8)
        c.setFillColor(DARK_GREY)
        c.drawString(right_x + 20, my + 3, vis)
        c.setFont("Helvetica-Bold", 6.8)
        c.setFillColor(col)
        c.drawString(right_x + 20, my - 4, pred)
        my -= 14

    # Footer
    c.setFont("Helvetica", 6.5)
    c.setFillColor(MID_GREY)
    c.drawCentredString(W/2, 8*mm, "Based on DAS 2015 Guidelines (Frerk C et al. Br J Anaesth 2015;115:827-848)  |  For educational use only  |  Always refer to current institutional protocols")
    c.drawCentredString(W/2, 5*mm, "Page 2 of 2  —  Equipment Checklists & Assessment Tools")


# ── Generate PDF ─────────────────────────────────────────────────────────────
c = canvas.Canvas(OUTPUT, pagesize=A4)
c.setTitle("DAS Difficult Airway Pocket Card")
c.setAuthor("Orris Medical Education")
c.setSubject("DAS 2015 Difficult Airway Algorithm – Anaesthesia Resident Reference")

draw_page1(c)
c.showPage()
draw_page2(c)
c.showPage()
c.save()

print(f"PDF generated: {OUTPUT}")
import os
size = os.path.getsize(OUTPUT)
print(f"File size: {size:,} bytes ({size/1024:.1f} KB)")

Running Command

cd /home/daytona/workspace/das-pocket-card && python generate_das_card.py 2>&1

Editing File

~/das-pocket-card/generate_das_card.py

Successfully replaced 1 instance(s) of the string in '/home/daytona/workspace/das-pocket-card/generate_das_card.py'

Running Command

cd /home/daytona/workspace/das-pocket-card && python generate_das_card.py 2>&1

Running Command

cd /home/daytona/workspace/das-pocket-card && python -c " from pypdf import PdfR…

Your DAS Airway Pocket Card is ready:

DAS Airway Pocket Card

PDF Document · PDF

What's inside (2 pages, A4)

Page 1 - DAS 4-Plan Algorithm

4 colour-coded columns side by side: Plan A (navy blue), Plan B (green), Plan C (amber), Plan D (dark red)
Each column shows the step-by-step actions with bold key steps highlighted
Red arrows connecting each failed plan to the next
STOP AND THINK box (appears after Plan B succeeds) listing the 4 options
CICO emergency box in red with immediate actions
Key Principles footer - 6 rules in a grid (oxygen always, never repeat failure, confirm with ETCO2, max 3+1 attempts, awake if CICO predicted, post-event follow-up)

Page 2 - Equipment Checklists + Assessment Tools

4 checklists with tick boxes: Plan A intubation equipment (14 items), Plan B SAD equipment (8 items), Plan C facemask equipment (6 items), Plan D scalpel cricothyroidotomy equipment (10 items)
LEMON mnemonic with letter badges and full explanations
ROMAN mnemonic with letter badges and clinical detail
CTM anatomy diagram with labelled laryngeal handshake technique and scalpel entry point
Mallampati classification with colour-coded difficulty predictions (I-IV)

Print double-sided on A4 card stock and laminate for a durable pocket reference.

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