Chest Tubes

Approval for the study obtained from the relevant ethics committee at the University of Mazandaran, Sari, Iran. Before the beginning of the study, written informed consent was obtained from each patient.
This randomized, observer-blind, prospective experimental study was conducted during February-March 2013 in the Mazandaran Heart Center. The subjects include 80 patients underwent open heart surgery. The sample size was determined based on a similar study[2 (link)] with a 0.99% confidence coefficient. Based on mean and standard deviation of pain intensity immediately after CTR in experimental and control groups, respectively, 3.85 ± 1.75, and 5.6 ± 1.94, the sample size was calculated 30 in each group (intervention and control) that according to effect size of 1.33 the samples increased to 40 in each group.
Data collection tools included a demographic questionnaire and Visual Analogue Scale (VAS) to evaluate pain. VAS comprised a 100-mm baseline that is indicative a continuum with the ends marked “0 = no pain” and “100 = unbearable pain”.[24 ] Reliability and validity of this scale is approved internationally.[25 (link)26 (link)] Various researches have used this scale to rate pain severity in patients underwent CABG surgery.[27 (link)]
Inclusion criteria included: Willingness to participate, upper 18-years old, full consciousness, ability to understand visual analog pain scale, first-time experience with CABG and chest tube, BMI less than 30 kg/m^{218 (link)} and having two chest tubes for 24 hours at least (one mediastinal tube and one left pleural). Exclusion criteria included unwillingness to participate, oversensitivity to cold, received mechanical ventilation support, visual or auditory defects, received opioid analgesic during less than 4 hours before intervention and drug dependency.
On the first day after operation, the researcher offered some explanation about the procedure to patients eligible to participate in study. Patients randomly were assigned to groups by Rand between function in Excel software (this function used to generate random numbers). As the participants in the study had two chest tubes, the act of assignment in intervention groups was done twice (one assignment for each tube). The case group was divided to seven bulks comprising 6 cases and within each bulk 6 cards were divided to 1-2 then randomly selected (three indicated by cod[1 (link)] for left pleural cold therapy- mediastinal relaxation and three cod number[2 (link)] considered for left pleural relaxation- mediastinal cold therapy). So each chest tube of patient assigned in one group and finally patients were divided randomly in the groups of cold therapy, relaxation, or control.
After the first assignment, the subjects were taught to rate the pain intensity by using VAS and got enough information about CTR procedure. In addition, we presented some information about cold application and relaxation for experimental groups that was repeated just before the CTR process.
All above procedures are supervised by a physician. For every group subjects’ all tight clothes were loosened, they were placed in semi-fowler position and a pillow was set below their head and knees in order to ensure their comfort. The usual intervention, as used for the control group, was nothing more than acetaminophen pills each 6 hours. All subjects received the intervention. In cold therapy group, cooling gel packs with 0°C temperature (made in Iranian Bespar Javidan Ghostar company) was used to reduce the body temperature around the chest tube during undressing. The bandage was removed from chest area and body temperature measured and recorded by an infrared thermometer at the same time by non-contact infrared thermometers UNI-T 912 (Hong Kong) then three cooling packs (8 × 10 cm) twisted in gauze was placed around the tube so that it would locate in the center. The packs would remain in their position, after 10 minutes till the temperature reached 13°C.[28 29 ] At this moment, all packs were removed and the tube was exit according to the usual method. The temperature was recorded immediately and 15 minutes after extubation. According to the evidence, effectiveness of cooling treatments sustains around 30 minutes.[30 (link)31 ] There is no other evidence to confirm the effectiveness time duration for relaxation. Therefore, 1 hour after cooling therapy and extubation-related tube, the next tube extubated while patients exposed to relaxation technique. In the relaxation group, patients were encouraged to breathe calmly and deeply. In this exercise, they should inhale calm and deep through their nose and exhale calm through semi-closed lips, all with closed eyes for 15 minutes.[5 (link)] The tube was removed after 5 minutes of exercising.
In control group, the tubes of the first patient were removed randomly with 1-hour intervals. Then the procedure was repeated for all patients in the control group as routine. The chest tubes in all groups were removed by the same nurse and procedure lasted on 1-2 minutes. The pain intensity was recorded by a nurse who trained to record VAS and was blind to the conducted different CTR procedure. The pain severity was recorded in three phases (before, immediately, and 15 minutes after CTR).

There are two thoracic surgery teams in our hospital. All thoracic surgeons receive similar training programmes and the operative equipment is the same. Patients with chest injuries admitted to our hospital were equally distributed to the two thoracic surgical teams. The first group comprised patients admitted on odd-numbered dates and the other group comprised patients admitted on even-numbered dates. The first group underwent thoracoscopy for treating pleural collections only by the ‘evacuation’ method. This method focuses on the management of pleural collections without repair of lung lesions. All patients underwent a tube thoracostomy at the ER and the incision was made along the anterior axillary line at the fifth intercostal space. A 0° angle, 10-mm thoracoscope was used. Another thoracostomy was made along the mid axillary line at the seventh intercostal space. Pleural effusion and blood clots were removed by suction tube, referred to as the evacuation procedure. This procedure focuses on adequate drainage and re-expansion of the collapsed lungs. After these processes were performed, two new chest tubes were placed; 32-Fr straight and curved chest tubes were usually used. Continuous suction of the chest tubes with −15 cmH₂O was performed and they were removed when there was no air leakage or if the amount of drainage from the chest tube was <100 ml per day.
The second group underwent thoracoscopy that had small differences from the former, referred to as the ‘evacuation with suture-resection’ method. As for the first group, another thoracostomy was made at the seventh intercostal space along the mid axillary line. After this drainage, thorough inspection of the lung surface was done to look for lacerations noted at the previous chest CT, especially the lung surface attached to the site of fractured ribs. When these lesions were found under thoracoscopic vision, the previously used 10.5 mm 0° angle scope was changed to a 5 mm 0° angle thoracoscope. A 5-mm Endo-clinch grasper was applied parallel to the thoracoscope through the same site. When the lesions were checked again, both edges of the lacerated lung were grasped and repaired using an endoscopic auto-stapler (Specialist Surgical Product, Covidien Taiwan Limited) inserted through the previous thoracostomy (usually in the fifth intercostal space, anterior axillary line). As in the previous intervention for the first group, 32-Fr straight and curved chest tubes were placed.
All patients were admitted to the ICU postoperatively for close observation, with the duration of ventilator usage recorded. Patients were weaned off the ventilator when their vital signs were stable along with normal oximeter readings. The chest tubes were connected to continuous low-pressure suction and the volume of chest tube drainage was recorded daily. The chest tube was removed when the pleural effusion in the past 24 h amounted to <100 ml, without continuous air leakage. All patients enrolled were followed up at our outpatient clinics for 1 year.

Our surgical team including senior and resident surgeons went the rounds of our patients in the morning every day. We argued whether air leakage was found or not at the rounds. The chest drain was removed when air leakage stopped in the standardized management group, regardless of the fluid volume or the surgeon’s preference on postoperative day 1 or later. However, from July 2021, we started early removal of chest drain on postoperative day 0 for a patient undergoing thoracoscopic segmentectomy when air leakage was not detected in the sealing test at the end of operation and postoperatively for 2–4 hours, The patients receiving early removal of chest drain on postoperative day 0 were included in the standardized management group. In the non-standardized management group, the tube was usually removed when air leakage stopped or the daily pleural effusion amount fell below 500 mL (on postoperative day 1 or later); however, tube removal was at the surgeon’s discretion. After discharge, postoperative follow-up using chest X-ray in outpatient ward was performed for any patient on around postoperative day 10 and 30.