ls /tmp/workspace/ 2>/dev/null || mkdir -p /tmp/workspace/nitrous-oxide && echo "workspace ready"

mkdir -p /tmp/workspace/nitrous-oxide && python3 << 'EOF' import matplotlib matplotlib.use('Agg') import matplotlib.pyplot as plt import matplotlib.patches as mpatches from matplotlib.patches import FancyBboxPatch, FancyArrowPatch import matplotlib.patheffects as pe fig, ax = plt.subplots(figsize=(14, 22)) ax.set_xlim(0, 14) ax.set_ylim(0, 22) ax.axis('off') fig.patch.set_facecolor('#F0F4FA') ax.set_facecolor('#F0F4FA') # ── helper functions ────────────────────────────────────────────────────────── def rounded_box(ax, x, y, w, h, text, facecolor, edgecolor, fontsize=10, bold=False, text_color='white', radius=0.35): box = FancyBboxPatch((x - w/2, y - h/2), w, h, boxstyle=f"round,pad=0.05,rounding_size={radius}", linewidth=2, edgecolor=edgecolor, facecolor=facecolor, zorder=3) ax.add_patch(box) weight = 'bold' if bold else 'normal' ax.text(x, y, text, ha='center', va='center', fontsize=fontsize, color=text_color, fontweight=weight, zorder=4, wrap=True, multialignment='center') def arrow(ax, x1, y1, x2, y2, color='#455A64'): ax.annotate('', xy=(x2, y2), xytext=(x1, y1), arrowprops=dict(arrowstyle='->', color=color, lw=2.2), zorder=5) def side_arrow(ax, x1, y1, x2, y2, color='#455A64'): ax.annotate('', xy=(x2, y2), xytext=(x1, y1), arrowprops=dict(arrowstyle='->', color=color, lw=1.8, connectionstyle='arc3,rad=0.0'), zorder=5) # ── colour palette ───────────────────────────────────────────────────────── C_TITLE = '#1A237E' # deep indigo C_HEAD = '#283593' # indigo C_STEP = '#1565C0' # blue C_NMDA = '#6A1B9A' # purple – NMDA arm C_OPT = '#00695C' # teal – opioid arm C_GABA = '#E65100' # orange-red – GABA/other arm C_EFFECT = '#2E7D32' # green – final effects C_WARN = '#B71C1C' # red – adverse / notes C_EDGE = '#263238' # dark # ═══════════════════════════════════════════════════════════════════════════ # ROW 1 – Title banner # ═══════════════════════════════════════════════════════════════════════════ banner = FancyBboxPatch((0.3, 20.7), 13.4, 1.1, boxstyle="round,pad=0.05,rounding_size=0.4", linewidth=2.5, edgecolor=C_TITLE, facecolor=C_TITLE, zorder=3) ax.add_patch(banner) ax.text(7, 21.25, 'MECHANISM OF ACTION OF NITROUS OXIDE (N₂O)', ha='center', va='center', fontsize=13.5, fontweight='bold', color='white', zorder=4) ax.text(7, 20.88, 'KD Tripathi – Essentials of Medical Pharmacology', ha='center', va='center', fontsize=9, color='#B3C7F7', zorder=4, style='italic') # ═══════════════════════════════════════════════════════════════════════════ # ROW 2 – Inhalation # ═══════════════════════════════════════════════════════════════════════════ rounded_box(ax, 7, 19.85, 7, 0.70, 'Inhalation of N₂O → Absorbed via lungs → Enters blood (low blood-gas solubility: λ = 0.47)', '#1A237E', C_EDGE, 9.5, bold=False, text_color='#E8EAF6') arrow(ax, 7, 19.5, 7, 18.85) # ═══════════════════════════════════════════════════════════════════════════ # ROW 3 – CNS distribution # ═══════════════════════════════════════════════════════════════════════════ rounded_box(ax, 7, 18.55, 7, 0.55, 'Rapid distribution to CNS (high lipid solubility → crosses BBB rapidly)', '#283593', C_EDGE, 9.5, bold=False, text_color='white') arrow(ax, 7, 18.27, 7, 17.65) # ═══════════════════════════════════════════════════════════════════════════ # ROW 4 – Three receptor targets label # ═══════════════════════════════════════════════════════════════════════════ ax.text(7, 17.55, '▼ Acts on multiple receptor systems ▼', ha='center', va='center', fontsize=9.5, color='#37474F', style='italic', zorder=4) # Branch lines down to three columns # Left: NMDA Centre: Opioid Right: GABA / K+ channels ax.plot([7, 7], [17.38, 17.15], color='#455A64', lw=2, zorder=3) ax.plot([2.8, 11.2], [17.15, 17.15], color='#455A64', lw=2, zorder=3) ax.annotate('', xy=(2.8, 16.85), xytext=(2.8, 17.15), arrowprops=dict(arrowstyle='->', color='#455A64', lw=2), zorder=5) ax.annotate('', xy=(7, 16.85), xytext=(7, 17.15), arrowprops=dict(arrowstyle='->', color='#455A64', lw=2), zorder=5) ax.annotate('', xy=(11.2, 16.85), xytext=(11.2, 17.15), arrowprops=dict(arrowstyle='->', color='#455A64', lw=2), zorder=5) # ═══════════════════════════════════════════════════════════════════════════ # THREE COLUMNS (left=NMDA, centre=Opioid, right=GABA/K+) # ═══════════════════════════════════════════════════════════════════════════ # Column X centres XL, XC, XR = 2.8, 7.0, 11.2 CW = 3.8 # column box width # ----- Column headers ----- rounded_box(ax, XL, 16.5, CW, 0.60, '① NMDA Receptor\nAntagonism', C_NMDA, C_EDGE, 9.5, bold=True) rounded_box(ax, XC, 16.5, CW, 0.60, '② Opioid Receptor\nActivation', C_OPT, C_EDGE, 9.5, bold=True) rounded_box(ax, XR, 16.5, CW, 0.60, '③ GABA-A / K⁺ Channels\n& Other Targets', C_GABA, C_EDGE, 9.5, bold=True) # ----- NMDA column ----- arrow(ax, XL, 16.2, XL, 15.65) rounded_box(ax, XL, 15.35, CW, 0.57, 'Non-competitive block of\nNMDA (glutamate) receptors\n(↓ Ca²⁺ influx into neuron)', '#7B1FA2', C_EDGE, 9, text_color='white') arrow(ax, XL, 15.07, XL, 14.52) rounded_box(ax, XL, 14.22, CW, 0.56, '↓ Excitatory neurotransmission\n(Glutamate pathway blocked)', '#9C27B0', C_EDGE, 9, text_color='white') arrow(ax, XL, 13.94, XL, 13.4) rounded_box(ax, XL, 13.1, CW, 0.55, 'Sedation • Amnesia\nAnti-nociception\n(Dissociative analgesia)', '#AB47BC', C_EDGE, 9, text_color='white') # ----- Opioid column ----- arrow(ax, XC, 16.2, XC, 15.65) rounded_box(ax, XC, 15.35, CW, 0.57, 'Stimulates release of\nendogenous opioid peptides\n(met-enkephalin / β-endorphin)', '#00796B', C_EDGE, 9, text_color='white') arrow(ax, XC, 15.07, XC, 14.52) rounded_box(ax, XC, 14.22, CW, 0.56, 'Activation of μ & κ opioid\nreceptors in spinal cord\n& supraspinal sites', '#00897B', C_EDGE, 9, text_color='white') arrow(ax, XC, 13.94, XC, 13.4) rounded_box(ax, XC, 13.1, CW, 0.55, 'Potent Analgesia\n(↑ pain threshold)\nAnxiolysis / euphoria', '#26A69A', C_EDGE, 9, text_color='white') # note: NOT reversed by naloxone (incomplete) ax.text(XC, 12.78, '* Not fully reversed by naloxone', ha='center', fontsize=7.5, color='#004D40', style='italic') # ----- GABA / K+ column ----- arrow(ax, XR, 16.2, XR, 15.65) rounded_box(ax, XR, 15.35, CW, 0.57, 'Weak potentiation of\nGABA-A receptors\n(↑ Cl⁻ influx)', '#BF360C', C_EDGE, 9, text_color='white') arrow(ax, XR, 15.07, XR, 14.52) rounded_box(ax, XR, 14.22, CW, 0.56, 'Activation of two-pore domain\nK⁺ channels (TREK-1)\n→ neuronal hyperpolarisation', '#D84315', C_EDGE, 9, text_color='white') arrow(ax, XR, 13.94, XR, 13.4) rounded_box(ax, XR, 13.1, CW, 0.55, 'Sedation • Muscle relaxation\nImmobility (contribution to MAC)\nAnti-anxiety', '#E64A19', C_EDGE, 9, text_color='white') # ═══════════════════════════════════════════════════════════════════════════ # Merge arrow → COMBINED EFFECTS # ═══════════════════════════════════════════════════════════════════════════ ax.plot([XL, XL], [12.82, 12.35], color='#455A64', lw=2, zorder=3) ax.plot([XC, XC], [12.82, 12.35], color='#455A64', lw=2, zorder=3) ax.plot([XR, XR], [12.82, 12.35], color='#455A64', lw=2, zorder=3) ax.plot([XL, XR], [12.35, 12.35], color='#455A64', lw=2, zorder=3) ax.annotate('', xy=(7, 12.1), xytext=(7, 12.35), arrowprops=dict(arrowstyle='->', color='#455A64', lw=2.5), zorder=5) # ═══════════════════════════════════════════════════════════════════════════ # COMBINED PHARMACOLOGICAL EFFECTS # ═══════════════════════════════════════════════════════════════════════════ rounded_box(ax, 7, 11.75, 9.5, 0.60, 'COMBINED PHARMACOLOGICAL EFFECTS', C_EFFECT, C_EDGE, 10.5, bold=True) arrow(ax, 7, 11.45, 7, 10.88) # Effects grid (2 columns) effects = [ ('Analgesia', 'Sedation & Anxiolysis'), ('Amnesia (incomplete)', 'Euphoria / "Laughing gas"'), ('Anaesthesia (with 2nd agent)', '↓ MAC of volatile anaesthetics'), ('Maintains laryngeal reflexes', 'No significant muscle relaxation'), ] y0 = 10.75 for i, (left, right) in enumerate(effects): y_pos = y0 - i * 0.46 rounded_box(ax, 3.9, y_pos, 5.1, 0.37, left, '#388E3C', '#1B5E20', 8.5, text_color='white') rounded_box(ax, 9.9, y_pos, 5.1, 0.37, right, '#2E7D32', '#1B5E20', 8.5, text_color='white') # ═══════════════════════════════════════════════════════════════════════════ # Unique properties # ═══════════════════════════════════════════════════════════════════════════ y_uni = 8.9 arrow(ax, 7, 8.55, 7, 7.98) rounded_box(ax, 7, 8.72, 9.5, 0.55, 'UNIQUE PHYSICOCHEMICAL PROPERTIES AFFECTING MOA', '#0277BD', C_EDGE, 10, bold=True) props = [ '• Lowest blood-gas solubility (0.47) → ultra-rapid onset & offset', '• Second gas effect: ↑ uptake of co-administered volatile agents', '• Diffusion hypoxia (Fink effect): N₂O rapidly replaces alveolar O₂ on discontinuation', '• Non-flammable but supports combustion; colourless & odourless (sweet smell)', ] y_p = 7.82 for p in props: ax.text(7, y_p, p, ha='center', va='center', fontsize=8.5, color='#01579B', zorder=4) y_p -= 0.40 # ═══════════════════════════════════════════════════════════════════════════ # ADVERSE EFFECTS / CONTRAINDICATIONS # ═══════════════════════════════════════════════════════════════════════════ arrow(ax, 7, 6.25, 7, 5.68) rounded_box(ax, 7, 6.08, 9.5, 0.55, 'KEY ADVERSE EFFECTS & CONTRAINDICATIONS', C_WARN, C_EDGE, 10, bold=True) adv = [ '• Oxidises vit B₁₂ (methionine synthase inactivation) → megaloblastic anaemia / neuropathy', '• Expands air-filled cavities (pneumothorax, bowel obstruction, middle ear) – CONTRAINDICATED', '• Postoperative nausea & vomiting (PONV) • Diffusion hypoxia on cessation', '• Teratogenic risk (prolonged exposure) – avoid in 1st trimester • Abuse potential', ] y_a = 5.52 for a in adv: ax.text(7, y_a, a, ha='center', va='center', fontsize=8.5, color='#B71C1C', zorder=4) y_a -= 0.40 # ═══════════════════════════════════════════════════════════════════════════ # Footer # ═══════════════════════════════════════════════════════════════════════════ footer = FancyBboxPatch((0.3, 0.15), 13.4, 0.60, boxstyle="round,pad=0.05,rounding_size=0.3", linewidth=1.5, edgecolor='#78909C', facecolor='#ECEFF1', zorder=3) ax.add_patch(footer) ax.text(7, 0.45, 'Reference: KD Tripathi – Essentials of Medical Pharmacology, 9th Ed. ' '| Barash Clinical Anesthesia 9e | Miller\'s Anesthesia 10e', ha='center', va='center', fontsize=8, color='#546E7A', zorder=4, style='italic') plt.tight_layout(pad=0) plt.savefig('/tmp/workspace/nitrous-oxide/N2O_MOA_Flowchart.png', dpi=180, bbox_inches='tight', facecolor='#F0F4FA') plt.close() print("Saved!") EOF