NC1 SET 1

A patient with severe kyphoscoliosis is breathless lying flat. The nurse elevates the head of bed to 45°. Which physiologic effect best explains the improvement?

• Increased functional residual capacity with better alveolar recruitment

• Decreased anatomic dead space with reduced tidal volume needs

• Reduced pulmonary capillary wedge pressure from venous pooling

• Immediate increase in hemoglobin-oxygen affinity at the alveolar level

During septic shock, the nurse notes warm skin and bounding pulses early. Which hemodynamic change best explains this finding?

• Systemic vasodilation with decreased afterload and reflex tachycardia

• Primary myocardial depression with reduced stroke volume first

• Acute rise in venous return due to enhanced skeletal muscle pump

• Cerebral vasoconstriction with redistribution of cardiac output

A post-op patient on opioids has RR 8/min and PaCO₂ 60 mmHg. Which medullary mechanism is most depressed?

• Ventilatory response to hypercapnia in the central chemoreceptors

• Peripheral chemoreceptor response to hypoxemia exclusively

• Stretch receptor reflex that terminates inspiration

• Voluntary respiratory control originating in the motor cortex

While administering a 1 L NS bolus to a dehydrated adult, which vascular space expands first and most?

• Intracellular compartment volume predominantly

• Interstitial compartment with minimal change intravascularly

• Intravascular (plasma) compartment within the extracellular space

• Total body water with equal distribution across all spaces

A client has SIADH from small-cell lung cancer. Which lab pattern is the most consistent?

• Serum osmolality high, urine osmolality low, sodium high

• Serum osmolality low, urine osmolality high, sodium low

• Serum osmolality normal, urine osmolality low, sodium high

• Serum osmolality high, urine osmolality high, sodium high

During fast PRBC transfusion, the nurse monitors calcium. Which mechanism makes this physiologic check necessary?

• Citrate in stored blood chelates ionized calcium causing hypocalcemia

• Hemolysis of donor cells acutely increases serum calcium load

• Transfusion raises calcitonin secretion reducing bone resorption

• Transfusion lowers parathyroid hormone via volume expansion alone

A runner becomes orthostatic when standing quickly after bed rest. Which immediate physiologic response prevents syncope in most people?

• Baroreceptor-mediated sympathetic activation increasing SVR

• Increased atrial natriuretic peptide to expand plasma volume

• Reduced chemoreceptor firing decreasing ventilation rate

• Coronary vasoconstriction to preserve aortic pressure

A patient with COPD uses pursed-lip breathing. Which mechanic best explains reduced dyspnea?

• Raised small-airway pressure reduces premature airway collapse

• Lowered intrathoracic pressure draws air faster into alveoli

• Increased respiratory rate lowers dynamic hyperinflation

• Decreased expiratory time reduces gas trapping significantly

The nurse pre-oxygenates for rapid sequence intubation. Which statement best describes the physiologic goal?

• Increase alveolar oxygen reservoir by denitrogenation to prolong safe apnea time

• Increase dissolved oxygen content to equal bound oxygen on hemoglobin

• Induce metabolic alkalosis to improve hemoglobin affinity for oxygen

• Reduce cardiac output temporarily to decrease oxygen consumption

An older adult with heart failure develops pulmonary edema. Which mechanisms primarily cause fluid to accumulate in alveoli? Select all that apply.

• Increased hydrostatic pressure in pulmonary capillaries

• Impaired lymphatic clearance of interstitial fluid

• Reduced plasma oncotic pressure from hemoconcentration

• Increased capillary permeability from endothelial injury

• Decreased alveolar surfactant production lowering surface tension