Assessment Flashcard 9

D. Rationale: The very first step when performing the BLS assessment is to check for responsiveness.

C. Rationale: The waveform capnography device is connected directly to the endotracheal tube. Therefore, endotracheal intubation is required when measuring the end-tidal CO₂ pressure. The device is then connected to a cardiac monitor with capnography capabilities to display the end-tidal CO₂ output. The CO₂ detector, on the other hand, is a colorimetric device that changes color from yellow to purple in the presence of CO₂. It does not measure end-tidal CO₂ pressure.

C. Rationale: The S-100B blood marker can be used for prognosticating neurologic outcomes. However, studies have shown high false positive rates. S-100B is not specific for neuronal damage as it can also be increased in hemolysis, neuroendocrine tumors, myenteric plexus, and muscle and adipose tissue breakdown.

D. Rationale: Waveform capnography primarily measures end-tidal CO₂. This is the CO₂ pressure at the end of the expiratory phase of the respiratory cycle. With this information, providers can measure the gas exchange within the alveoli. If CPR quality is inferior, alveolar gas exchange will not work to expel enough carbon dioxide due to poor pulmonary blood flow and/or ventilation. Studies have shown that patients have poor survival rates if, after 20 minutes of CPR, the end-tidal CO₂ remains at 10 mm Hg or below. Hence, it is also a good prognostication tool for cardiac arrest patients.

D. Rationale: Sodium bicarbonate can temporarily correct metabolic acidosis. This is used while the clinician looks for the underlying cause of the patient’s metabolic acidosis.

A. Rationale: Pericardial tamponade is a reversible condition. Treatment includes pericardiocentesis for mild tamponade or emergency thoracotomy when cardiac tamponade is significant in size and volume. Other treatments for pericardial tamponade include volume infusion with a crystalloid solution. Pulmonary conditions such as tension pneumothorax and massive pulmonary embolism are reversible causes of cardiac arrest.

D. Rationale: Lividity is a sign of irreversible death.

B. Rationale: The four universal steps to operating an AED are: 1) power on the AED; 2) attach the electrodes; 3) analyze the rhythm; and 4) press the SHOCK button (after clearing the patient).

A. Rationale: The mnemonic for the BLS assessment that ensures a systematic approach to addressing patients with cardiac arrest is DRS ABCD = danger, response, shout, airway, breathing, circulation, defibrillation. The A-B-C-D sequence is used because we are unsure that the patient is in cardiac arrest and are attempting to provide first aid at this time. When the patient is unresponsive, without pulse or normal breathing, then we shift the sequence to concentrate our efforts to the circulation, airway, breathing sequence.

B. Rationale: Waveform capnography reading of 10 mm Hg or less after 20 minutes of CPR is predictive of futility despite the prolongation of CPR. It can be used as one of the factors in determining discontinuation of CPR.