To associate medications, anesthetic techniques, and clinical conditions that interfere in the time of patient approval in the safety protocol for thirst management.A quantitative, analytical, and longitudinal study conducted in Southern Brazil.A nonprobabilistic sample, of 203 adult patients in the immediate postoperative period, evaluated every 15 minutes for 1 hour.A general prevalence of thirst of 67.7%, and mean intensity of 6.38. Fentanyl, morphine, rocuronium, and sevoflurane increased lack of approval in the protocol within 30 minutes (P.05). General anesthesia (P.0001) and level of consciousness (95.4%) presented the highest nonapproval rates.Anesthetics and general anesthesia delayed protocol approval; however, after 30 minutes, 75.4% of patients had been approved. Level of consciousness was the main criterion of disapproval. The protocol identified crucial clinical conditions that made it impossible for the patient to receive thirst relief strategies and demonstrated that thirst can be satiated precociously with safety.