A nurse is caring for a client following his first hemodialysis treatment. The client reports a headache, nausea, and restlessness. The nurse should identify these findings as manifestations of which of the following complications?

Choice A rationale Septicemia is a systemic infection of the blood characterized by high fever, chills, tachycardia, and hypotension. It occurs if pathogens enter the bloodstream, often via a contaminated dialysis catheter or access site. While it is a serious complication of hemodialysis, it does not typically present with the specific cluster of neurological symptoms like headache and restlessness immediately after a first treatment unless a severe infectious process was already established or introduced rapidly during the procedure. Choice B rationale Peritonitis is an inflammation of the peritoneum, the lining of the abdominal cavity. This complication is most commonly associated with peritoneal dialysis rather than hemodialysis, occurring when bacteria are introduced into the peritoneal space through the dialysis catheter. Symptoms include abdominal pain, rebound tenderness, and cloudy dialysate outflow. Since this client is receiving hemodialysis, which involves filtering blood through an external machine, peritonitis is not the expected complication for the reported neurological and gastrointestinal symptoms. Choice C rationale Dialysis disequilibrium syndrome is a rare but serious complication occurring during or after the first few hemodialysis treatments. It results from the rapid removal of solutes like urea from the blood, creating an osmotic gradient that shifts water into the brain cells, causing cerebral edema. Manifestations include headache, nausea, restlessness, vomiting, and confusion. This fits the client's profile perfectly as they are undergoing their first treatment, making them highly susceptible to these rapid osmotic shifts in the brain. Choice D rationale An air embolism occurs when air enters the venous system and travels to the heart or lungs, potentially causing cardiovascular collapse. In hemodialysis, this can happen if air is introduced into the extracorporeal circuit. Clinical manifestations usually include sudden dyspnea, chest pain, hypotension, and a "mill-wheel" heart murmur. It is an acute emergency that presents with respiratory and circulatory distress rather than the gradual onset of headache, nausea, and restlessness seen in this client following their dialysis session.