IRCT201503089759N6 IRCT 2015-06-14 vice chancellor for research, Hamadan University of Medical Sciences Effect of aromatherapy on physiological indicators and intensity of pain Effect of inhalation aromatherapy with lavender essence versus placebo on physiological indicators and intensity of venipuncture pain in hospitalized preschool children in pediatric unit: a single blinded non randomized clinical trial 2015-04-30 anticipated 60 Complete https://irct.ir/trial/10294 interventional Randomization: Not randomized, Blinding: Single blinded, Placebo: Used, Assignment: Parallel, Purpose: Supportive, Other design features: Sampling is conventional and eligible children to enter the study in two separate stages on two experimental and control groups will be entered in the study. N/A pain. Intervention 1: Intervention1: the physiological indicators of children will be measured in half an hour before entering into the venipuncture room and the children inhale 5 drops of lavender essence 2% which was poured onto 10×10 cm gauze attached to collar of children shirt in 20 minutes. Then, physiological indicators will be measured immediately after fixation of catheter and in minutes of 5 and 10 after exiting of venipuncture room. Intensity of pain will be measured in times of immediately, 5 and 10 after exiting of venipuncture room. Intervention 2: Intervention2: The physiological indicators of children will be measured in half an hour before entering into the venipuncture room and the children inhale 5 drops of distilled water (placebo) which was poured onto 10×10 cm gauze attached to collar of children shirt in 20 minutes. Then, physiological indicators will be measured immediately after fixation of catheter and in minutes of 5 and 10 after exiting of venipuncture room. Intensity of pain will be measured in times of immediately, 5 and 10 after exiting of venipuncture room.