Intervention
STERILE, COLD
Study intervention for all participants in all groups was implemented 15 min before CTR. In the cold compress group, the skin surrounding the chest tube insertion site was cleansed using alcohol and then, a cold compress with a temperature of – 5 °C was applied to the site for 15 min so that it covered an area of 10-cm diameter around the chest tube insertion site. A sterile gauze was placed between the skin and the cold compress in order to prevent the direct contact of the compress with the skin. In the TENS group, a TENS device named stimulator 615 k (made by Novin company, Isfahan, Iran) with two pads sized four by 6 cm was used. TENS electrodes were placed on the skin next to the chest tube insertion site and TENS was started at a frequency of 80–100 Hz, the mode of the device was on normal mode and the intensity of the device was set to 6 mA [