The rationale for worldwide trauma care usually follows the Advanced Trauma Life Support (ATLS ^®) of the American College of Surgeons. These guidelines emphasize problems prioritizing and managing life-threatening conditions using systematic approaches consistent with primary and secondary surveys. The primary survey aimed to identify immediate life-threatening injuries and to provide appropriate resuscitation. By contrast, the secondary survey focused on diagnosing and detailing the injury to lead to a specific treatment. The secondary survey includes important history taking (AMPLE), head-to-toe examination, and diagnostic adjunct. ¹ However, there is still a risk of missed injury even if the secondary survey is complete, especially in patients with severe injury (Injury Severity Score [ISS] > 15), altered mental status, life-threatening injuries, requiring an emergent operation, or mechanical ventilation. ^{2 – 4} The missed injury rate after the initial evaluation was 1.3 – 39%. ⁵ Missed injuries could lead to morbidity and mortality, increase the length of hospital stays, and increase total care costs. The tertiary survey was developed in 1990 to reduce missed injuries, consisting of repeated head-to-toe examinations, reviewing previously conducted laboratory and radiology test results, and considering additional testing. ³ The previous studies showed that the tertiary survey significantly reduced missed injuries. ^{3 – 7} However, a study in 2014 showed no significant difference in missed injury rates before and after implementing the tertiary survey. ⁸

Missed injuries can be classified into two types: type I represents missed injuries that occurred after primary and secondary surveys and can be detected by a tertiary survey. Type II missed injury is an injury that cannot be detected by a tertiary survey and is presented late after discharge. ⁷ Most studies measured missed injury detection rates that were not equal to missed injury rates. The tertiary survey was effective in increasing the missed injury detection rate. ⁶ While it significantly decreased the missed injury rate. ^{3 – 7} This study aimed to compare the missed injury rate before and after implementing the tertiary survey in critically ill trauma patients and declare the benefits of the tertiary survey in morbidity and mortality.

This case-matched cohort study was conducted on critically ill trauma patients treated at Thammasat University Hospital (TUH). TUH is a tertiary medical school hospital in the central region of Thailand, mimicking a Level-1 trauma center in the US. The study compared two periods of time: before the implementation of the tertiary survey between April 2020 and July 2022, and after implementation between August 2022 and February 2023. The inclusion criteria were adult trauma patients (age at least 18 years), initial ISS >15, and admission to the Surgical Intensive Care Unit (SICU). The exclusion criteria were referred cases with time to be admitted >24 h after the injury.

The tertiary survey record form was created and validated before implementation, including demographic data, primary and secondary survey results, initial interventions, repeated head-to-toe examinations, review of previously conducted laboratory and radiology tests, injury diagnosis, and treatment module results. Our tertiary survey record form is available in the supplementary data. The attending physicians or investigators of the SICU were trained to use the record form before implementing the tertiary survey. Two tertiary surveys were conducted in all adults critically ill trauma patients with ISS > 15 admitted to the SICU. The first survey was performed within 24 h of admission, and the second was performed before SICU discharge. The missed injury detected with the first survey was defined as missed injury type I, which was detected with the second refers to missed injury type II. The comparison data before the implementation period were retrieved from the electronic medical records of TUH. Missed injuries in the pre-implementation era were mainly detected in the outpatient department after patient discharge and were defined as missed injury type II. We matched the comparison data before and after implementing the tertiary survey with the maximum regional Abbreviated Injury Scale (AIS) at a 4:1 ratio. After matching, the data were compared in terms of missed injury detection rate, missed injury type I, missed injury type II, interventions for missed injuries, and missed injury-related morbidity and mortality.

The Human Research Ethics Committee of Thammasat University (Medicine) approved this study (certificate project number MTU-EC-SU-1-080/65) and approved on August 4, 2022. This study was registered with the Thai Clinical Trials Registry (reference number TCTR20230625001).

All baseline characteristics and demographic data were assessed during the pre- and post-implementation periods. Percentages, means, and standard deviations (SD) were calculated from the numerical data of both groups. Dichotomous variables were analyzed using the χ ² or Fisher’s exact test. Continuous variables were calculated using the paired t-test. Statistical analysis was performed using STATA/SE 16.0 for Macs (Stata Corp LP, Tx, USA, available at https://www.stata.com), and p-values <0.05 were regarded as indicating statistically significant. The flow diagram of the cohort study is shown in Figure 1.

A total of 25 patients in the post-implementation period were included in this study, and the comparison data of 100 patients in the pre-implementation era were retrieved from the electronic medical records. The demographic data between the pre- and post-implementation groups showed no statistically significant differences, except for sex (96% and 81%; p = 0.004). AIS However, both groups were predominantly male. The maximum AIS in the two groups was 40% in the head and neck region, followed by the abdomen (28%), extremities (16%), chest (12%), and face (4%). Population characteristics are presented in Table 1.

We identified 55 type II missed injuries in 39 of 100 cases before implementation, 20 type I missed injuries in 14 patients, and 1 type II missed injury in 1 of 25 patients after implementation of the tertiary survey. The pre-implementation group had the highest number of missed injuries in the extremities (29.09%), followed by the chest (27.27%), abdomen (20%), head and neck (14.54%), face (9.09%), and external regions (1.81%). After implementation, we discovered that 25% of missed injury type I was located in the external regions and extremities, including the pelvis; 20% on the chest; and 10% on the head and neck, face, and abdomen. An additional 1 case of missed type II injuries was found in the extremities, including the pelvis. Details of the missed injuries in both the groups are presented in Table 2.

Three missed injuries required surgical intervention in the pre-implementation group, such as an intracerebral artery dissection, which was treated with cerebral angiography with balloon angioplasty; a femur fracture that was treated with open reduction internal fixation with a reconstruction locking plate and headless screw; and a patellar fracture that required open reduction and internal fixation with a locking compression plate. After implementing the tertiary survey, one patient with missed injury type I (tongue laceration) underwent suturing under general anesthesia. Additionally, there was one missed type II injury, specifically an ulnar fracture that required open reduction and internal fixation with a locking plate.

Three morbidities were related to missed injury type II in the preimplementation group. Two individuals exhibited visual impairment from traumatic optic neuropathy, while the other had upper-extremity weakness related to brachial plexus injury. Conversely, in the post-implementation group, only one patient had visual impairment resulting from traumatic optic neuropathy, which was the missed injury type I. Fortunately, there was no mortality related to missed injury in either group. However, both groups showed no statistically significant differences in morbidity and mortality rates owing to missed injuries. After conducting a tertiary survey, the missed injury type II rate declined from 31% to 4% (OR, 0.36; 95%CI 0.15-0.86). Additionally, the missed injury detection rate was 56%. The differences between the missed injury rates and missed injury detection rates in both groups are shown in Table 3.

Previous studies have demonstrated that altered levels of consciousness, ^{2 , 3 , 9 , 10} other life-threatening injuries, ² the requirement for immediate operative intervention, ^{3 , 4} and intubated patients ² have a high likelihood of missed injuries. The two groups of population baseline characteristics showed no statistically significant differences. We cannot conclude which factors may be related to the development of missed injuries.

In 2004, Walter and colleagues ⁴ discovered that implementing a tertiary survey reduced missed injuries from 2.4% to 1.5% in the overall population and from 5.7% to 3.4% in trauma intensive care unit patients. Additionally, a meta-analysis conducted by Shahab ⁵ in 2015 demonstrated fewer missed injuries and higher missed injury detection rates following the implementation of a tertiary survey. Corresponding to our results, the missed injury type II rate significantly decreased from 31% to 4% after the implementation of the tertiary survey, with a missed injury detection rate of up to 56%. However, only one patient underwent operative intervention, while two patients experienced morbidity and no deaths resulted from missed injuries in our population.

Traumatic optic neuropathy (TON) is the most common morbidity related to missed injuries. TON is likely to be a missed diagnosis because symptoms are difficult to recognize and may cause permanent disability, such as blindness. ¹¹ Early detection may lead to better outcomes. Our tertiary survey record form focuses on this condition and may be beneficial in the early recognition of TON.

This study has some limitations. First, this study was conducted within a single institution, which may restrict the generalizability of the findings. Second, the small number of participants in the study may limit the statistical significance of any observed differences between the pre- and post-implementation groups. Third, the medical record review was partially limited because of the incompleteness of some portions of medical documentation.

Based on our research, implementing tertiary surveys in patients experiencing severe trauma can effectively decrease the missed injury rates from 31% to 4%. Additionally, tertiary surveys can result in missed injury detection rates of as high as 56%. Tertiary surveys are recommended as a routine aspect of severely traumatized patient care. Nonetheless, it is still unclear whether implementing this practice results in improved outcomes, such as decreased morbidity and mortality rates, as further studies with larger sample sizes are required to determine this effect.

The Human Research Ethics Committee of Thammasat University (Medicine) approved the study with the certificate project number MTU-EC-SU-1-080/65 and approved on August 4, 2022. Written Informed consent was obtained from all enrolled patients who were asked by investigators or research assistants. Investigators will ask for reconsent if the research participant regains consent capability if the investigator asks for consent from a legally authorized representative. The investigator will ask the impartial witness to witness the consent process of an illiterate participant.