Critical Care Exam 1 Review Flashcards

Vocabulary practice flashcards generated directly from Critical Care course lecture notes covering oxygen therapy, mechanical ventilation, ARDS, hemodynamics, ECG interpretation, analgesia/sedation, pacemakers, and acute coronary syndrome/valvular heart diseases.

Oropharyngeal Airway

An airway device that should only be used for patients who are unconscious or have an absent or decreased gag reflex.

Nasopharyngeal Airway

An airway device that is better tolerated by patients who are more awake and retain a gag reflex.

End-Tidal CO2 Detector

A diagnostic device attached to the end of an endotracheal tube (ETT) during placement verification that turns gold to confirm proper tube positioning in the trachea.

Obturator

A guide device that must be kept at the bedside for patients with a new tracheostomy to facilitate emergency re-insertion if accidental dislodgement occurs.

FiO2 (Fraction of Inspired Oxygen)

The percentage or fraction of oxygen delivered to a patient by a ventilator, ranging from $30\%$ to $100\%$.

Tidal Volume ($V_T$)

The volume of air delivered per breath, typically weight-based with an average of $500\text{--}600\,\text{mL}$ ($6\text{--}8\,\text{mL/kg}$).

Positive End-Expiratory Pressure (PEEP)

A ventilator setting that maintains positive pressure at the end of expiration to keep alveoli open, with a normal range of $5\text{--}20\,\text{cm H}_2\text{O}$.

Capnography

The continuous measurement of exhaled carbon dioxide levels, with a normal reference range of $35\text{--}45\,\text{mmHg}$.

Assist-Control (AC) / Continuous Mandatory Ventilation (CMV)

A ventilator mode used when the patient requires maximum support, controlling both rate and tidal volume so that spontaneous breaths receive the exact set tidal volume.

Synchronized Intermittent Mandatory Ventilation (SIMV)

A ventilator mode that delivers preset mandatory breaths at a set tidal volume while allowing spontaneous breaths to occur at the patient's own tidal volume.

Pressure Support (PS)

A ventilator mode that controls and delivers only inspiratory pressure to assist spontaneous breaths, requiring the patient to initiate all breaths.

Rapid Shallow Breathing Index (RSBI)

A measurement used to predict weaning success, calculated as respiratory rate divided by tidal volume ($\text{RSBI} = \text{RR} / V_T$); an $\text{RSBI} < 105$ indicates readiness for extubation.

Aspiration Pneumonitis

Inflammation and damage of lung tissue caused by the entry of abnormal substances (such as gastric contents or subglottic secretions) into the lower airways.

Virchow's Triad

The three primary factors predisposing a patient to thrombus and pulmonary embolism formation: hypercoagulability, vascular wall injury, and endothelial injury.

Hypoxemic Normocapnic Respiratory Failure (Type 1)

Acute respiratory failure characterized by severe arterial hypoxemia (low $PaO_2$) with normal arterial carbon dioxide levels (normal $PaCO_2$).

Hypoxemic Hypercapnic Respiratory Failure (Type 2)

Acute respiratory failure characterized by low arterial oxygen levels (low $PaO_2$) accompanied by elevated carbon dioxide levels (high $PaCO_2$).

Acute Respiratory Distress Syndrome (ARDS)

A severe inflammatory pulmonary disease characterized by widespread alveolar-capillary membrane damage, increased permeability, and noncardiogenic pulmonary edema.

ARDS Pathological Phases

The three sequential stages of ARDS: the Exudative phase (rapid onset, alveolar swelling, hypoxemia), Proliferative phase (type II cell proliferation and body healing attempt), and Fibrotic phase (remodeling, stiff lungs, low recovery chance).

Extracorporeal Gas Exchange (ECMO)

A mechanical support technique that diverts blood out of the patient into a machine that oxygenates it and returns it to the body, resting the lungs and reducing oxygen consumption.

PR Interval

The ECG interval representing the time from atrial depolarization to the onset of ventricular depolarization, normally measuring $0.12\text{--}0.20\,\text{seconds}$.

QRS Complex

The ECG waveform representing ventricular depolarization, normally measuring $0.04\text{--}0.12\,\text{seconds}$.

Supraventricular Tachycardia (SVT)

A rapid heart rhythm characterized by narrow QRS complexes without identifiable P or T waves; treated sequentially with vagal maneuvers, Adenosine ($6\,\text{mg}$ initial dose), and cardioversion.

Cardioversion

The delivery of a synchronized electrical shock timed directly to the QRS complex, performed under IV sedation to treat specific tachyarrhythmias.

Torsades de Pointes

A polymorphic form of ventricular tachycardia associated with a prolonged QT interval that displays alternating QRS amplitudes; treated with Magnesium Sulfate.

Pulseless Electrical Activity (PEA)

A cardiac arrest rhythm where an organized electrical pattern is visible on the ECG monitor, but no mechanical contraction or palpable pulse is present.

Critical-Care Pain Observation Tool (CPOT)

A behavioral pain monitoring scale for non-verbal ICU patients evaluated by comparing baseline rest behaviors with responses during invasive procedures.

Richmond Agitation-Sedation Scale (RASS)

A 10-point clinical scoring scale ranging from $+4$ (combative) to $-5$ (unarousable) used to titrate sedative medication infusions in critical care.

Flumazenil (Romazicon)

An injectable benzodiazepine receptor antagonist used as a reversal agent for benzodiazepine overdose.

Dexmedetomidine (Precedex)

A short-acting continuous infusion sedative with mild analgesic properties that does not cause respiratory depression, helping shorten delirium duration and weaning time.

CAM-ICU (Confusion Assessment Method for the ICU)

A standardized screening tool for delirium requiring an acute mental status change, inattention, and either altered level of consciousness or disorganized thinking.

Failure to Pace

A pacemaker malfunction where the generator fails to produce an electrical discharge spike despite an abnormally low intrinsic heart rate.

Failure to Capture

A pacemaker malfunction where an electrical pacer spike is generated but fails to depolarize the heart tissue, resulting in a spike unsupported by a P wave or QRS complex.

Oversensing

A pacemaker malfunction where non-cardiac signals or tall T-waves are misinterpreted as intrinsic heart beats, inappropriately inhibiting the pacemaker from firing.

Zones of Myocardial Infarction

The three zones of ischemic cardiac tissue during an MI: Zone of Infarction (dead necrotic tissue, pathologic Q waves), Zone of Hypoxic Injury (injured tissue, ST elevation), and Zone of Ischemia (outermost salvageable tissue, T wave inversion).

Beck's Triad

The classic set of three physical examination signs diagnostic of cardiac tamponade: hypotension, jugular venous distention (JVD), and muffled heart sounds.

B-type Natriuretic Peptide (BNP)

A neurohormone marker secreted in response to ventricular overstretching and volume overload; levels $< 100\,\text{pg/mL}$ indicate heart failure is improbable, whereas levels $> 400\,\text{pg/mL}$ indicate heart failure is likely.

Heart Failure with Reduced Ejection Fraction (HFrEF)

Systolic heart failure characterized by loss of functional myocardial cells resulting in an ejection fraction $< 40\%$.

Heart Failure with Preserved Ejection Fraction (HFpEF)

Diastolic heart failure characterized by impaired myocardial relaxation and filling despite maintaining an ejection fraction $\ge 50\%$.

Mitral Regurgitation

Incomplete closure of the mitral valve causing blood to leak backward into the left atrium during systole, resulting in left atrial enlargement, pulmonary hypertension, and heart failure.

Mitral Stenosis

A valvular disorder where thickened or fused mitral leaflets obstruct blood flow from the left atrium into the left ventricle during diastole.

Aortic Regurgitation

Incomplete closure of the aortic valve causing blood to flow back into the left ventricle during diastole, causing LV hypertrophy and forceful peripheral arterial pulsations.

Aortic Stenosis

Progressive narrowing of the aortic valve orifice obstructing left ventricular outflow, leading to LV hypertrophy, reduced cardiac output, and pulmonary congestion.