How to Master One of the Hardest Parts of the IBSC FP-C Exam: Cardiopulmonary Emergencies

Ask IBSC FP-C candidates which part of the exam worried them most, and many will point to the cardiac questions. It isn’t the ECGs. It’s the balloon pump waveform, the pulmonary artery pressures, and the patient with a ventricular assist device and no palpable pulse.

Cardiopulmonary Emergencies is hard for a few reasons. It’s the largest domain on the outline. It tests devices that many ground and even flight medics see only a few times a year. And the questions usually ask you to interpret numbers and act on them, not just recall a definition.

We’ll walk you through the core concepts, common traps, two sample questions, and a focused study plan.

What Does the Cardiopulmonary Emergencies Domain Cover?

Cardiopulmonary Emergencies is Domain 6 of the FP-C Detailed Content Outline. The outline assigns it 25 of its 125 listed questions, or 20%, the most of any domain. (IBSC’s current exam has 110 scored questions, so read the outline count as relative weight.)

The domain has 13 subtopics, which fall into two halves:

Cardiac: Detailed cardiovascular assessment; recognizing acute MI, heart failure, cardiogenic shock, primary arrhythmias, and hemodynamic instability; invasive monitoring in transport; treatment; using and adjusting ventricular assist devices, transvenous pacemakers, and intra-aortic balloon pumps; electrical therapies; and cardiac medications.
Respiratory: Detailed respiratory assessment; recognizing ARDS, spontaneous pneumothorax, and pneumonia; monitoring with pulse oximetry, capnography, blood gases, and chest radiography; treatment; and respiratory medications.

Core Concepts You Need to Know

Hemodynamic Monitoring

Invasive monitoring lets you see what’s driving a patient’s shock. Start with the basic relationships:

Cardiac output (CO) = heart rate × stroke volume. Normal is about 4 to 8 L/min. Cardiac index (CI) adjusts for body size; normal is about 2.5 to 4.0 L/min/m².
Mean arterial pressure (MAP) ≈ (systolic + 2 × diastolic) ÷ 3. A MAP of at least 65 mmHg is a common perfusion target.
Preload is estimated by central venous pressure (CVP, about 2 to 6 mmHg) on the right and pulmonary artery occlusion pressure (PAOP or “wedge,” about 8 to 12 mmHg) on the left.
Afterload is estimated by systemic vascular resistance (SVR, about 800 to 1,200 dynes·sec/cm⁵).

Learn the classic shock profiles, because exam questions often hand you a set of numbers and ask what’s wrong:

Hypovolemic: Low CVP and PAOP, low CO, high SVR.
Cardiogenic: High PAOP, low CO/CI, high SVR.
Distributive (such as septic): Low SVR, with CO often normal or high early on.
Obstructive (tension pneumothorax, tamponade, massive PE): Low CO with signs of blocked flow, such as rising and equalizing filling pressures in tamponade.

For an arterial line, keep the transducer leveled at the phlebostatic axis (fourth intercostal space, mid-axillary line). A transducer that sits too low reads falsely high, and one that sits too high reads falsely low. Re-level and re-zero after moving the patient or after major altitude changes.

Intra-Aortic Balloon Pump (IABP)

The balloon sits in the descending thoracic aorta, with its tip about 2 cm below the left subclavian artery and its base above the renal arteries. It inflates in diastole and deflates just before systole, which does two things:

Diastolic augmentation: Inflation at the dicrotic notch (aortic valve closure) pushes blood back toward the coronary arteries and improves myocardial oxygen supply.
Afterload reduction: Deflation just before the ventricle ejects lowers the pressure it pumps against, reducing myocardial oxygen demand.

On an ECG trigger, inflation lines up with the middle of the T wave, and deflation happens at or just before the QRS. Know the four timing errors:

Early inflation: The balloon inflates before the aortic valve closes, which can close the valve early and increase afterload.
Late inflation: Augmentation is reduced because coronary perfusion time is lost.
Early deflation: Afterload reduction is lost, and coronary and carotid flow may reverse.
Late deflation: The ventricle ejects against a still-inflated balloon. On the waveform, the assisted aortic end-diastolic pressure is equal to or higher than the unassisted end-diastolic pressure.

Early inflation and late deflation are harmful errors because both increase the workload on the heart. Watch for migration as well. A weakened left radial pulse suggests the balloon has moved up toward the left subclavian, and a sudden drop in urine output suggests it has moved down over the renal arteries. Absolute contraindications include significant aortic insufficiency and aortic dissection.

Ventricular Assist Devices (VADs)

Most modern left ventricular assist devices (LVADs) provide continuous flow, so many patients have no palpable pulse and an unreliable pulse oximeter or automated blood pressure. A Doppler-based or arterial-line MAP is the usual assessment tool. Know the controller display (speed, flow, power, and pulsatility index), keep the driveline and power sources secure, and bring backup batteries and the controller.

Low flow alarms commonly point to hypovolemia, bleeding, right ventricular failure, or an obstruction such as thrombus. A suction event, where the ventricle collapses around the inflow cannula, often responds to fluid. Contact the patient’s VAD coordinator early, and follow device-specific and program protocols for cardiac arrest.

Transvenous Pacing

Transvenous pacing problems fall into a few categories:

Failure to capture: Pacer spikes without a QRS after them. Increase the output (mA), check connections, and consider lead displacement.
Undersensing (failure to sense): The pacer fires regardless of the patient’s own beats, so spikes can land on T waves. Increase sensitivity by lowering the mV setting.
Oversensing: The pacer mistakes other signals for beats and doesn’t fire. Decrease sensitivity by raising the mV setting.

Vibration and patient movement in an aircraft make lead displacement more likely, so secure the generator and leads before you move.

Respiratory Emergencies and Blood Gases

ARDS is defined by the Berlin criteria: onset within one week, bilateral opacities not fully explained by effusion or collapse, respiratory failure not fully explained by heart failure or fluid overload, and a PaO2/FiO2 ratio of 300 or less on at least 5 cmH2O of PEEP. Lung-protective ventilation uses about 6 mL/kg of predicted body weight with a plateau pressure of 30 cmH2O or less, and PEEP and FiO2 are titrated together.

Normal blood gas values are pH 7.35 to 7.45, PaCO2 35 to 45 mmHg, and HCO3- 22 to 26 mEq/L. Identify the primary disorder first, then check for compensation. Remember that ETCO2 usually runs a few mmHg below PaCO2, but the gap widens with dead space, as in a large PE, low cardiac output, or ARDS.

A spontaneous pneumothorax is also a flight physiology problem. By Boyle’s law, trapped gas expands as pressure falls, so a stable pneumothorax can become a tension pneumothorax at altitude.

Common Cardiopulmonary Traps on the FP-C

Giving fluid by reflex: In cardiogenic shock with a high wedge pressure, a large fluid bolus worsens pulmonary edema. Read the PAOP before you reach for fluid.
Mixing up the IABP’s two jobs: Inflation helps supply. Deflation reduces demand. Many questions hinge on which one a timing error affects.
Chasing a pulse on an LVAD patient: No palpable pulse is expected. Use MAP, mental status, skin signs, and device data.
Backward sensitivity changes: A lower mV number means a more sensitive pacer.
Relying on ETCO2 alone: In low-flow states, ETCO2 can significantly underestimate PaCO2. Confirm with a blood gas when you can.

Sample Scenarios: How to Reason Through Cardiopulmonary Questions

Scenario 1: A Balloon Pump Waveform

Consider a question where you’re transporting a patient with cardiogenic shock on a 1:2 IABP. The arterial waveform shows an assisted aortic end-diastolic pressure higher than the unassisted end-diastolic pressure. The options include early inflation, late inflation, early deflation, and late deflation.

The key clue is the assisted end-diastolic pressure. When deflation works, the balloon empties just before systole, so pressure dips below the patient’s own end-diastolic value. A pressure that stays higher means the balloon was still inflated when the ventricle began to eject. The answer is late deflation, which increases afterload and should be corrected by moving deflation earlier.

Scenario 2: A Hemodynamic Profile

Now imagine a patient two days after an anterior MI. The blood pressure is 84/56 mmHg, heart rate is 118, PAOP is 24 mmHg, CI is 1.8 L/min/m², and SVR is 1,700 dynes·sec/cm⁵. Crackles are present bilaterally. The options include a 1-liter fluid bolus, a vasodilator to lower afterload, vasopressor and inotropic support per protocol with preparation for mechanical support, or morphine and transport only.

A high wedge, low index, and high SVR suggest cardiogenic shock. More fluid will worsen the pulmonary edema, and a vasodilator alone will drop an already low blood pressure. The best answer supports pressure and contractility with vasopressors and inotropic agents per protocol and prepares for mechanical support such as an IABP.

How Cardiopulmonary Emergencies Connect to the Rest of the FP-C Exam

Flight Physiology: Altitude affects pneumothoraces, ETT cuffs, and oxygenation, and vibration causes monitor artifact and lead displacement.
Advanced Airway and Ventilation Management: ARDS ventilation strategy and capnography interpretation overlap both domains.
Trauma and Burn Emergencies: Thoracic trauma brings tension pneumothorax, tamponade, and hemorrhagic shock profiles.
Perinatal and Pediatric Emergencies: Pediatric shock, congenital heart defects, and dysrhythmias apply the same principles to smaller patients.
General Medical Patient: Invasive monitoring also applies here, along with AAA and GI bleeding as causes of shock.

A Focused Study Plan for Cardiopulmonary Emergencies

Memorize the numbers. Make a one-page sheet of normal hemodynamic values, blood gas ranges, and the four shock profiles, and rewrite it from memory until it’s automatic.
Draw the IABP waveform. Sketch normal timing and each of the four errors, labeling assisted and unassisted pressures.
Build device cards. For VADs, transvenous pacers, and balloon pumps, list how each works, normal settings, alarms, and what you’d do first.
Read the source chapters. Use the cardiac and respiratory sections of an IBSC-recommended text, such as Critical Care Transport or Air and Surface Patient Transport.
Practice in focused sets, then mix. Use Pocket Prep’s Build Your Own Quiz to drill cardiac and respiratory questions, then check yourself in a mixed Timed Quiz a few days later.
Close the loop. Review every explanation, revisit misses with the Missed Questions quiz, and let the Weakest Subject quiz tell you when a related area needs work.

Start Preparing for the IBSC FP-C Exam With Pocket Prep

Pocket Prep’s IBSC FP-C exam prep offers 1,000 practice questions with detailed explanations and a full-length mock exam, so you can practice hemodynamic and device questions under exam conditions. With consistent studying, you’ll be ready to earn the FP-C.