Predictors of chest drainage complications in trauma patients

Objective: to identify predictors of chest drainage complications in trauma patients attended at a University Hospital. Methods: we conducted a retrospective study of 68 patients submitted to thoracic drainage after trauma, in a one-year period. We analyzed gender, age, trauma mechanism, trauma indices, thoracic and associated lesions, environment in which the procedure was performed, drainage time, experience of the performer, complications and evolution. Results: the mean age of the patients was 35 years and the male gender was the most prevalent (89%). Blunt trauma was the most frequent, with 67% of cases, and of these, 50% were due to traffic accidents. The mean TRISS (Trauma and Injury Severity Score) was 98, with a mortality rate of 1.4%. The most frequent thoracic and associated lesions were, respectively, rib fractures (51%) and abdominal trauma (32%). The mean drainage time was 6.93 days, being higher in patients under mechanical ventilation (p=0.0163). The complication rate was 26.5%, mainly poor drain positioning (11.77%). Hospital drainage was performed in 89% of cases by doctors in the first year of specialization. Thoracic drainage performed in prehospital care presented nine times more chances of complications (p=0.0015). Conclusion: the predictors of post-trauma complications for chest drainage were a procedure performed in an adverse site and mechanical ventilation. The high rate of complications demonstrates the importance of protocols of care with the thoracic drainage.


Original Article A B S T R A C T
Objective: to identify predictors of chest drainage complications in trauma patients attended at a University Hospital.Methods: we conducted a retrospective study of 68 patients submitted to thoracic drainage after trauma, in a one-year period.We analyzed gender, age, trauma mechanism, trauma indices, thoracic and associated lesions, environment in which the procedure was performed, drainage time, experience of the performer, complications and evolution.Results: the mean age of the patients was 35 years and the male gender was the most prevalent (89%).Blunt trauma was the most frequent, with 67% of cases, and of these, 50% were due to traffic accidents.The mean TRISS (Trauma and Injury Severity Score) was 98, with a mortality rate of 1.4%.The most frequent thoracic and associated lesions were, respectively, rib fractures (51%) and abdominal trauma (32%).The mean drainage time was 6.93 days, being higher in patients under mechanical ventilation (p=0.0163).The complication rate was 26.5%, mainly poor drain positioning (11.77%).Hospital drainage was performed in 89% of cases by doctors in the first year of specialization.Thoracic drainage performed in prehospital care presented nine times more chances of complications (p=0.0015).Conclusion: the predictors of post-trauma complications for chest drainage were a procedure performed in an adverse site and mechanical ventilation.The high rate of complications demonstrates the importance of protocols of care with the thoracic drainage.

RESULTS
Of the 68 patients studied, 89% were male, with an average age of 35 years.The Revised Trauma Scores (RTS) had a median of 7.84 and the Trauma and Injury Severity Score (TRISS), of 98.The predominant trauma mechanism was the blunt one (67% of cases), the motorcycle event being the most prevalent, with 22%.
Penetrating gunshot and stabbing injuries accounted for 16% of individual cases.When grouped together, the traffic events (motorcycling accidents, automobile accidents and running over) corresponded to 50% of the casuistry.
Isolated thoracic lesions occurred in 14 patients, and the most frequent associated lesion was abdominal trauma, in 32% of cases, followed by head trauma and long bone fractures, each with 10%.The involvement of more than two body segments was present in 26% of the patients.Pulmonary contusion and rib fracture were the most frequent thoracic injuries (Figure 1).In 56 patients, thoracic drainage was carried out in a hospital setting, and in 89% (50 patients), performed by physicians in the first year of surgical specialization.
The thoracic drainage rate in the PHC setting was 17.6% (12 patients), and presented a risk of complications nine times higher when compared to those performed in a hospital environment, with p=0.0015 (Table 1).The overall complication rate was 26.5% (18 patients), and the malposition of the drain, with the need for new drainage, was the most frequent complication, with eight cases (Table 2).These occurred due to the position of the last drain hole outside the pleural cavity (n=4) and due to drainage introduced into the subcutaneous (n=2) or into the abdominal cavity (n=2).The mean length of hospital stay was 20 days.
One death (1.5%) occurred due to multiple complications and the severity of the associated lesions.

DISCUSSION
Urban violence predominates in developing countries.In Brazil the death rate due to homicides in the age group of 15 to 29 years is 20 times higher than the rate of European countries 11 .In a study of the University Hospital in Damascus, Syria, with 888 patients with thoracic trauma, traffic accidents were the main cause, in areas outside the conflict zones.Accidents were the most frequent mechanism (40% of cases), male gender was the most prevalent (89% of cases), mean age was 31 years and associated lesions occurred in 36% of patients, with predominance of upper and lower limbs(19% of cases), followed by abdominal and craniocerebral trauma (13% and 8% of the cases, respectively) 12 , This differs from our study, in which abdominal trauma was the lesion most of air leakage and radiographic examination with pulmonary expansion.They also point out that drainage withdrawal reduces morbidity, complications and reduces hospitalization time 15  points to perform thoracic drainage and revealed that 45% did not identify the correct site, the most common error being the very low insertion error (20%).They concluded that these are avoidable complications 17 .
A study involving four teaching hospitals in Nigeria evaluated the level of resident doctors' experience and knowledge in thoracic drainage and found that 10% of the interviewees had never performed the procedure, and 77% performed it for the first time in the first year of residence training.He also identified that 40% had never placed the chest drain in connection with continuous aspiration.Only 30% examined the patient again and gave a simple chest X-ray examination after drainage.
They concluded that, since this is a simple and salvage procedure in critical situations, the training of medical surgeons should be done at the beginning of the surgical career, with adequate supervision 18 .In the present study, 89% of in-hospital drainage was performed by a resident physician in the first year of surgical specialization.
There was no statistical relation of greater complications between this group and the one drained by doctors with higher level of experience.
In Drainage in the surgical center was associated with reduced empyema, pneumonia and surgical wound infection.The study emphasizes that pleuropulmonary complications prior to the implementation of CPDT did not meet acceptable international parameters, ranging from 11% to 31%, and that there was a decline to 6.5% 19 .
Prehospital drainage, trauma mechanism, need for mechanical ventilation and injuries in other body segments are some of the predictors of chest drainage complications observed in the present study and listed in the literature 12 .These are variables that reveal the severity of the patient and the need for specific care.Therefore, the understanding of these variables will influence the management and evolution of patients submitted to thoracic drainage.
The mortality rate in patients hospitalized for isolated chest injury is between 4% and 8%.When there We conclude that the predictive factors of complications of post-traumatic thoracic drainage were adverse site to perform the procedure, such as in the prehospital care setting, and mechanical ventilation, which determines a longer drainage time.Our complication rate is close to the upper limit of the literature, which demonstrates the importance of elaborating care protocols with patients submitted to thoracic drainage.
. The criteria used in the Discipline of Trauma Surgery -Unicamp for the removal of the posttraumatic chest drain are: flow less than 100 milliliters in 24 hours, absence of air leakage, full lung expansion by simple chest X-ray and physical examination.The present study demonstrated that drainage withdrawal in patients under mechanical ventilation was late, with statistical significance (p=0.0163).Aylwin et al. evaluated the thoracic drainage performed in PHC and in the hospital by a trauma team according to the ATLS precepts.A sample of 57 patients presented an overall complication rate of 14%.Of these 31% were by poorly positioned tubes, and 17% had to be submitted to a new drainage.They concluded that there was no difference in the risk of drainage complications in the PHC and in-hospital, and that the in-hospital complication rates due to failures in the technique were high, which called attention to the adequate formation and training of the team 16 .In the present study, 17.6% were drained in the PHC, one case being in a primary health unit.This group of patients had a nine-fold greater risk of complications than the group submitted to thoracic drainage in our Service, with p=0.0015.The PHC environment is adverse and several local and external factors may contribute to the increase in the rate of complications, such as site contamination, climatic variation (rain, wind), inadequate positioning, and limited material and resources.Kesieme et al. performed an evaluation among surgery resident physicians of the first year on anatomical

Table 1 .
Incidence of complications after thoracic drainage according to the environment where it was performed.
MendesPredictors of chest drainage complications in trauma patients 3 Rev Col Bras Cir.2018; 45(2):e1543 associated with thoracic trauma (32 % of cases) and the most prevalent event was motorcycling.The Revised Trauma Score (RTS) is a physiological index of the patient at admission, based on three parameters: neurological level (Glasgow Coma Scale -GCS), systolic blood pressure and respiratory rate, the higher the value, the better the prognosis.The Injury Severity Score (ISS) is an anatomical index that classifies the severity of the lesions in each body segment.Trauma and The complication rate of 26.5% was due to poorly positioned drains and residual hemothorax and pneumothorax, which may also be related to drains that are poorly positioned in the pleural cavity, folded or directed to the diaphragm, which makes it difficult for air and liquids to escape.Residual hemothorax occurred in 2.9% of our cases and the treatment was performed by thoracoscopy.Post-trauma residual hemothorax in the work of Navsaria et al. occurred in 4.4% of patients submitted to thoracic drainage.Video-assisted thoracoscopic surgery (VATS) was successful in the hygiene of the pleural space in 80% of cases and failed in 20% due to the presence of pulmonary incarceration, requiring thoracotomy 13 .A study by Rezende Neto et al. emphasizes that residual hemothorax contributes to an increase in hospitalization time, costs and morbidity, At the trauma center at the University of Medical Sciences in Iran, Abbasi et al. demonstrated that it is safe to withdraw the drain in patients under mechanical ventilation, provided that the following criteria are met: flow rate less than 300 milliliters in 24 hours, absence

Table 2 .
Complications of thoracic drainage.
Thoracoscopy was indicated in two patients: one for empyema (gastric perforation by the drain in one patient with traumatic diaphragmatic hernia) and another for residual hemothorax.The empyema patient evolved with incarceration and the need for pleurostomy.
Rev Col Bras Cir.2018; 45(2):e1543 is another body segment involved, it increases to 10% to 25%, and reaches 35% when there is compromise of multiple organ systems 20 .In the present study, 18 patients (26%) presented lesions in more than two body segments, and one death occurred due to multiple organ lesions.