RRT-ACCS flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

P/F ratio

PaO2 divided by FiO2. With PEEP at least 5 cmH2O, values of 200-300 indicate mild ARDS, 100-200 moderate, and below 100 severe.

A-a gradient

Alveolar oxygen minus arterial oxygen. Alveolar oxygen equals FiO2 times 713 minus PaCO2 divided by 0.8; normal gradient on room air is about 15-20 mmHg.

Driving pressure

Plateau pressure minus applied PEEP. Values above 15 cmH2O in ARDS are associated with higher mortality independent of tidal volume and plateau pressure.

Auto-PEEP detection

Expiratory flow that does not return to zero before the next breath, plus a total PEEP on end-expiratory hold that exceeds the set PEEP.

Static compliance

Tidal volume divided by plateau pressure minus PEEP. Normal adult values are 60-100 mL/cmH2O; it falls with ARDS, pneumonia, atelectasis, and abdominal distension.

Airway resistance

Peak pressure minus plateau pressure, divided by inspiratory flow. Normal intubated adults are roughly 5-15 cmH2O/L/s; rises with bronchospasm and secretions.

Cuff pressure target

Maintain endotracheal cuff pressure at 20-30 cmH2O. Lower pressures permit microaspiration, while higher pressures risk tracheal mucosal ischemia and later stenosis.

ROX index

SpO2 divided by FiO2, then divided by respiratory rate. Values of 4.88 or higher at 2, 6, and 12 hours predict high-flow nasal cannula success.

Bohr equation dead space

Vd/Vt equals PaCO2 minus mixed expired CO2, divided by PaCO2. Normal is 0.2-0.3 and it rises in pulmonary embolism, ARDS, and alveolar overdistension.

Rapid shallow breathing index

Respiratory rate divided by tidal volume in liters, measured during unassisted breathing. A value below 105 predicts successful weaning from mechanical ventilation.

Maximum inspiratory pressure

Peak negative pressure generated against an occluded airway. A value more negative than minus 20 to minus 30 cmH2O suggests adequate respiratory muscle strength for weaning.

Lung-protective tidal volume

In ARDS, set tidal volume at 6 mL/kg predicted body weight, keep plateau pressure at or below 30 cmH2O, and accept pH down to 7.30.

Predicted body weight, male

50 plus 2.3 times the height in inches above 60. Ventilator tidal volumes in men are calculated from this value, not from actual body weight.

Predicted body weight, female

45.5 plus 2.3 times the height in inches above 60. Tidal volume of 6-8 mL/kg is set from this value regardless of actual body weight.

Prone positioning criteria

For ARDS with P/F ratio below 150 on FiO2 at least 0.6 and PEEP at least 5, prone at least 12-16 hours daily reduces mortality.

APRV T-low

A deliberately short expiratory time that ends before full exhalation, creating intentional auto-PEEP that maintains alveolar recruitment and oxygenation.

ECMO sweep gas

Sweep gas flow across the membrane oxygenator determines carbon dioxide removal, while blood flow rate primarily determines oxygen delivery.

Spontaneous breathing trial duration

A trial of 30-120 minutes with pressure support 5-7 cmH2O and PEEP of 5 or less, or a T-piece, assesses readiness for extubation.

Recruitment maneuver

A sustained airway pressure of 30-40 cmH2O for 30-40 seconds to reopen collapsed alveoli, which must be followed by adequate PEEP to keep them open.

NIV for COPD exacerbation

Bilevel support with EPAP 4-6 and IPAP 8-12 cmH2O reduces intubation rate and mortality; target an exhaled tidal volume of 6-8 mL/kg.

CPAP for cardiogenic pulmonary edema

Continuous positive airway pressure of 5-10 cmH2O improves oxygenation and reduces work of breathing, with strong evidence for reducing intubation in acute pulmonary edema.

High-flow nasal cannula

Heated, humidified oxygen at 30-60 L/min and FiO2 0.21-1.0, which washes out nasopharyngeal dead space and provides low-level positive airway pressure.

Ventilator-associated event

A CDC surveillance definition based on sustained increases in FiO2 or PEEP, tiered as ventilator-associated condition, infection-related complication, and possible pneumonia.

Ventilator bundle elements

Head of bed 30-45 degrees, daily sedation interruption with spontaneous breathing trial, oral care, DVT and stress ulcer prophylaxis, closed suction, and cuff pressure 20-30 cmH2O.

CLABSI prevention bundle

Hand hygiene, maximal sterile barrier at insertion, chlorhexidine skin antisepsis, appropriate site selection, and daily review of whether the central line is still needed.

Unplanned extubation rate

A safety metric reported as events per 100 ventilator days; it reflects sedation practice, restraint use, tube securement, and adequacy of weaning assessment.

Reintubation within 48 hours

A marker of extubation failure; rates above roughly 10-15 percent suggest premature extubation or an incomplete pre-extubation assessment.

Failure mode and effects analysis

A prospective team method that maps each process step and scores potential failures by severity, occurrence, and detectability to prioritize risk reduction.

Root cause analysis

A retrospective structured review after a sentinel event that identifies system-level contributing factors and produces actions intended to prevent recurrence.

Just culture

A framework that consoles human error, coaches at-risk behavior, and sanctions only reckless behavior, so that event and near-miss reporting remains non-punitive.

ABCDEF bundle

Assess and treat pain, Both awakening and breathing trials, Choice of sedation, Delirium monitoring with CAM-ICU, Early mobility, and Family engagement in the ICU.

WHO five hand hygiene moments

Before patient contact, before an aseptic task, after body fluid exposure risk, after patient contact, and after touching the patient surroundings.