A client is hospitalized for observation after suffering heat exhaustion during a marathon race. He complains of dizziness when he stands up, and the RN determines that he has postural hypotension. Based on the information, which of the following electrolyte imbalances could cause the client's symptoms?

Choice A reason: Fluid volume deficit is a condition in which the body loses more fluid than it gains, resulting in dehydration, hypotension, and electrolyte imbalances. It is not a complication of IV fluid therapy, but rather a reason for initiating it.

Choice B reason: Fluid volume excess is a condition in which the body retains more fluid than it needs, resulting in edema, hypertension, and heart failure. It is a potential complication of IV fluid therapy, especially in older adults who have reduced renal function and cardiac output. The nurse's assessment findings of crackles, shortness of breath, and jugular vein distention are indicative of fluid overload and pulmonary congestion.

Choice C reason: Speed shock is a systemic reaction that occurs when a substance is administered too rapidly into the bloodstream, causing adverse effects such as chest pain, dyspnea, hypotension, and cardiac arrest. It is not a complication of IV fluid therapy, but rather a risk associated with IV medication administration.

Choice D reason: Pulmonary embolism is a blockage of one or more pulmonary arteries by a blood clot, fat, or air, causing impaired gas exchange, chest pain, dyspnea, and hemoptysis. It is not a complication of IV fluid therapy, but rather a possible outcome of venous thromboembolism, which can be prevented by using anticoagulants and mechanical devices.

Choice A reason: Tachycardia is a physiological response to fear and anxiety. Tachycardia is a condition where the heart rate is faster than normal, usually above 100 beats per minute. Fear and anxiety can trigger the release of stress hormones, such as adrenaline and cortisol, that stimulate the sympathetic nervous system. This causes the heart to beat faster and stronger, increasing the blood flow and oxygen delivery to the muscles and organs. This prepares the body for the fight-or-flight response, which is a survival mechanism that helps the person to cope with a perceived threat or danger.

Choice B reason: Bronchial constriction is not a physiological response to fear and anxiety. Bronchial constriction is a condition where the airways in the lungs become narrow and inflamed, reducing the airflow and causing difficulty breathing. Bronchial constriction can be caused by various factors, such as asthma, allergies, infections, or irritants. Fear and anxiety can worsen the symptoms of bronchial constriction, but they are not the primary cause of it.

Choice C reason: Bradypnea is not a physiological response to fear and anxiety. Bradypnea is a condition where the breathing rate is slower than normal, usually below 12 breaths per minute. Bradypnea can be caused by various factors, such as brain injury, drug overdose, sleep apnea, or metabolic disorders. Fear and anxiety can increase the breathing rate, not decrease it, as the body needs more oxygen to cope with the stress.

Choice D reason: Pupillary constriction is not a physiological response to fear and anxiety. Pupillary constriction is a condition where the pupils in the eyes become smaller and less responsive to light. Pupillary constriction can be caused by various factors, such as eye injury, medication, aging, or neurological disorders. Fear and anxiety can cause pupillary dilation, not constriction, as the pupils widen to allow more light and improve the vision. This helps the person to see better and react faster to the situation.