TTSS Helps Triage Isolated Thoracic Trauma to ICU Care
Key Takeaways
- Among 100 adults with isolated thoracic trauma treated at two tertiary referral centers in Muscat, Oman, the Thorax Trauma Severity Score (TTSS) showed significant discrimination for ICU admission.
- Higher TTSS was significantly correlated with longer ICU stay and longer duration of mechanical ventilation.
- TTSS did not significantly discriminate in-hospital mortality in this cohort, which included only 3 deaths.
- TTSS also did not discriminate the need for surgical intervention, suggesting that its utility in this small cohort was greater for ICU-related outcomes than for mortality or operative decisions.
In a retrospective observational cohort study, investigators evaluated 100 adults with isolated thoracic trauma treated at Sultan Qaboos University Hospital and Khoula Hospital between January 2014 and December 2024. Overall, 77% of patients were male, mean age was 41.3 years, and mean TTSS was 4.28 ± 3.35.
The TTSS incorporates five components: PaO2/FiO2 ratio, rib-fracture burden, extent of pulmonary contusion, pleural involvement, and age, producing a total score ranging from 0 to 25. In this cohort, observed scores ranged from 0 to 15. Investigators categorized patients into TTSS groups of 0–5, 6–10, and 11–15 and examined in-hospital mortality as the primary outcome. Secondary outcomes included ICU admission, length of stay, mechanical ventilation, surgical procedures, and emergency department disposition.
TTSS significantly discriminated ICU admission, with an area under the receiver operating characteristic curve of 0.788 (95% CI, 0.696–0.879; P < .001). Higher TTSS was also moderately correlated with longer ICU stay and longer duration of mechanical ventilation, with Spearman ρ = 0.443 for both outcomes (P < .001).
Higher TTSS groups generally reflected greater thoracic injury severity and greater need for intensive care and respiratory support. Because pulmonary contusion and pleural involvement are themselves components of the TTSS, their increasing severity in higher TTSS strata should be interpreted as part of the score's construction rather than as independent evidence that these injuries predict worse outcomes. TTSS did not significantly discriminate in-hospital mortality, with an area under the curve of 0.643 (95% CI, 0.382–0.903; P = .402). Only 3 deaths occurred in the 100-patient cohort, limiting the precision and statistical power of the mortality analysis. Although deaths occurred more frequently in higher TTSS strata, the study did not establish significant mortality discrimination.
TTSS likewise showed essentially no discrimination for surgical intervention, with an area under the curve of 0.503 (95% CI, 0.382–0.625; P = .956). Operative decisions after thoracic trauma may depend on specific injuries and other clinical considerations that are not captured by the overall TTSS.
The findings should be interpreted within the study's limitations. This was a retrospective analysis of a relatively small cohort from two tertiary referral centers in Muscat, and only 3 deaths occurred. Restriction to isolated thoracic trauma also limits generalizability to patients with multisystem trauma. In addition, ICU admission and some treatment decisions may be influenced by institutional practice patterns and resource availability.
In this cohort, TTSS was more informative for ICU admission and measures of ICU and respiratory-support burden than for mortality or surgical intervention. The findings support further evaluation of TTSS for risk stratification in isolated thoracic trauma but do not establish a validated treatment threshold or demonstrate that TTSS-based decision-making improves patient outcomes.
Clinician Questions
How was isolated thoracic trauma evaluated in this TTSS cohort? The study included adults with isolated thoracic trauma presenting within 48 hours of injury to two tertiary referral centers in Muscat, Oman. The analysis was designed to focus on thoracic injury rather than outcomes primarily driven by major extra-thoracic trauma.
Which variables make up the Thorax Trauma Severity Score? TTSS incorporates five components: PaO2/FiO2 ratio, rib-fracture burden, extent of pulmonary contusion, pleural involvement, and age. Component scores are summed to produce a total score ranging from 0 to 25, with higher scores reflecting greater thoracic injury severity.
What did higher TTSS indicate in this Omani thoracic trauma cohort? Higher TTSS was associated with greater ICU-related and respiratory-support burden. The score significantly discriminated ICU admission and was moderately correlated with both ICU length of stay and duration of mechanical ventilation. These associations do not, however, establish that TTSS itself causes worse outcomes or that a particular score should determine ICU admission.
Why was TTSS less informative for mortality and surgery? TTSS did not significantly discriminate either mortality or surgical intervention in this cohort. The mortality analysis was particularly limited by the small number of events, with only 3 deaths among 100 patients. Surgical decisions can also depend on lesion-specific and clinical factors that are not fully represented by the composite TTSS. These results should therefore not be interpreted as establishing that TTSS has no mortality value in other populations; rather, this study did not demonstrate significant mortality discrimination in its small isolated-thoracic-trauma cohort.