Which client finding should the practical nurse (PN) report to the registered nurse (RN) immediately?

A. Ineffective pain management reported while using morphine PCA is concerning but may not be immediately life-threatening. B. Inability to void after discontinuing an indwelling catheter should be addressed but might not require immediate attention. C. Oral ice chips eaten after vomiting postoperatively might need monitoring, but it's not typically an urgent issue. D. Coffee-ground secretions draining via nasogastric tube suction could indicate bleeding in the upper gastrointestinal tract, which requires immediate attention due to the potential for severe bleeding.