RRT-ACCS cheat sheet

P/F ratio = PaO2 ÷ FiO2. Berlin ARDS thresholds (applied with PEEP ≥5 cmH2O): 200-300 mild, 100-200 moderate, <100 severe.

Alveolar gas equation: PAO2 = FiO2 × (Patm − 47) − (PaCO2 ÷ 0.8). A-a gradient = PAO2 − PaO2; normal ≤15-20 mmHg in a young adult on room air.

Static compliance = VT ÷ (Pplat − total PEEP); normal adult 60-100 mL/cmH2O. Airway resistance = (PIP − Pplat) ÷ inspiratory flow; normal intubated adult roughly 5-15 cmH2O/L/s.

Ventilator targets: plateau pressure ≤30 cmH2O, driving pressure (Pplat − PEEP) <15 cmH2O, endotracheal cuff pressure 20-30 cmH2O.

Auto-PEEP = total PEEP measured on an end-expiratory hold − set PEEP. Confirm with expiratory flow that fails to return to zero before the next breath.

Dead space by Bohr equation: Vd/Vt = (PaCO2 − PECO2) ÷ PaCO2; normal 0.2-0.3, elevated in PE, ARDS, and overdistension. Shunt: Qs/Qt = (CcO2 − CaO2) ÷ (CcO2 − CvO2).

Weaning predictors: RSBI (RR ÷ VT in liters) <105, MIP/NIF more negative than −20 to −30 cmH2O, vital capacity >10-15 mL/kg.

ROX index = (SpO2 ÷ FiO2) ÷ respiratory rate; ≥4.88 at 2, 6, and 12 hours predicts high-flow nasal cannula success, <3.85 predicts failure.

ScvO2 <70% or lactate ≥2 mmol/L indicates oxygen delivery is inadequate relative to demand; trend both rather than relying on a single value.

ARDSNet lung-protective strategy: VT 6 mL/kg predicted body weight (range 4-8), plateau ≤30 cmH2O, pH goal 7.30-7.45; accept hypercapnia before exceeding plateau limits.

Predicted body weight: male = 50 + 2.3 × (height in inches − 60); female = 45.5 + 2.3 × (height in inches − 60). Tidal volume is always set from PBW, not actual weight.

Initial invasive settings: FiO2 1.0 titrated to SpO2 88-95%, VT 6-8 mL/kg PBW, rate 12-16/min, PEEP 5 cmH2O, inspiratory flow 40-60 L/min.

ARDSNet FiO2/PEEP pairs: 0.3-0.4 → 5-8; 0.5 → 8-10; 0.6 → 10; 0.7 → 10-14; 0.8 → 14; 0.9 → 14-18; 1.0 → 18-24 cmH2O.

Prone positioning at least 12-16 hours daily for P/F <150 on FiO2 ≥0.6 and PEEP ≥5. Recruitment maneuver: 30-40 cmH2O for 30-40 seconds followed by PEEP titration.

NIV settings: COPD exacerbation EPAP 4-6 with IPAP 8-12 cmH2O; cardiogenic pulmonary edema CPAP 5-10 cmH2O. Avoid with unprotected airway, active vomiting, or hemodynamic instability.

ECMO physiology: blood flow rate governs oxygenation; sweep gas flow governs CO2 removal. Ventilator settings during ECMO are reduced to lung-rest values.

Weaning: spontaneous breathing trial 30-120 minutes on pressure support 5-7 cmH2O and PEEP ≤5 or T-piece. Extubate when the SBT is tolerated and cough, secretions, and cuff leak are adequate.

High-flow nasal cannula: 30-60 L/min, FiO2 0.21-1.0, temperature 31-37 °C; generates roughly 0.5-1 cmH2O PEEP per 10 L/min with the mouth closed and washes out nasopharyngeal dead space.

Ventilator bundle: head of bed 30-45°, daily sedation interruption paired with a spontaneous breathing trial, oral care, DVT prophylaxis, stress ulcer prophylaxis, closed suction, cuff pressure 20-30 cmH2O.

CDC ventilator-associated event tiers: VAC = FiO2 increase ≥0.20 or PEEP increase ≥3 cmH2O sustained ≥2 days; IVAC adds temperature or WBC abnormality; PVAP requires positive culture or purulent secretions.

CLABSI prevention bundle: hand hygiene, maximal sterile barrier during insertion, chlorhexidine skin antisepsis, avoidance of the femoral site in obese adults, daily review of line necessity.

Reported quality metrics: unplanned extubation per 100 ventilator days, reintubation within 48 hours (benchmark roughly 10-15%), VAE rate, bundle compliance, and standardized mortality ratio.

WHO five moments of hand hygiene: before patient contact, before an aseptic task, after body fluid exposure risk, after patient contact, after touching patient surroundings.

ABCDEF bundle: Assess and treat pain, Both awakening and breathing trials, Choice of sedation (minimize benzodiazepines), Delirium monitoring with CAM-ICU, Early mobility, Family engagement.

FMEA is prospective, scoring each process step by severity × occurrence × detection; RCA is retrospective, examining system-level contributors after a sentinel event.

Just culture distinguishes human error (console), at-risk behavior (coach), and reckless behavior (sanction), supporting non-punitive reporting of events and near misses.

Surviving Sepsis hour-1 bundle: measure lactate, obtain blood cultures, give broad-spectrum antibiotics, give 30 mL/kg crystalloid for hypotension or lactate ≥4 mmol/L, start vasopressors to keep MAP ≥65 mmHg.