Intake and Output

Intake and output (I&O) is a running record of measurable fluid entering and leaving the patient. It helps the nurse detect changing renal perfusion, fluid retention, dehydration, and response to treatment, but it is not a complete measurement of body-fluid change: water lost through the skin and respiration is not charted. A positive or negative balance therefore requires clinical interpretation rather than an automatic treatment response. The most reliable bedside picture combines accurate I&O with consecutive daily weights, vital-sign trends, lung and peripheral-edema findings, mental status, mucous membranes, and ordered laboratory results. A missed daily weight weakens the trend, and a single shift total can mislead. On the NCLEX-PN Test Plan effective April 2026, nutrition and oral hydration are included under Basic Care and Comfort within Physiological Integrity, so practical-nurse questions may connect fluid measurement with safety, prioritization, and patient teaching. For a US LPN/LVN, collecting and recording measurable volumes may be assigned or delegated according to state law and employer policy. Interpreting what the pattern means, assessing the patient, teaching, and deciding when to escalate require nursing judgment.