Can the delta shock index predict mortality and clinical outcomes in trauma centers, specifically in semi/rural areas of Malaysia, using the Pan-Asian Trauma Outcomes Study (PATOS) registry?

Delta Shock Index for Predicting Mortality and Clinical Outcomes in Malaysian Semi/Rural Trauma Centers: A Dissertation Proposal

Delta shock index (ΔSI) is an excellent dissertation topic for predicting mortality and clinical outcomes in Malaysian semi/rural trauma centers using the PATOS registry, as it has demonstrated superior predictive ability compared to traditional vital signs and could significantly improve trauma triage and management in resource-limited settings. 1

Background and Rationale

The delta shock index (ΔSI), defined as the change in shock index (SI) over time, has emerged as a powerful predictor of mortality and clinical outcomes in trauma patients. Recent evidence shows that ΔSI demonstrates significantly better discriminative ability for:

• Major injury identification
• Prolonged ICU stays
• In-hospital mortality
• Need for blood transfusions 1, 2

This makes it particularly valuable in semi/rural trauma centers where resources may be limited and accurate triage is critical.

Key Considerations for Malaysian Context

Population Characteristics

• Malaysia's trauma population differs from Western countries with unique demographics, mechanisms of injury, and healthcare infrastructure
• Rural/semi-rural areas face challenges including:
  • Longer transport times
  • Limited resources
  • Varied prehospital care quality

PATOS Registry Advantages

• Pan-Asian Trauma Outcomes Study provides standardized data collection
• Enables comparison across different Asian settings
• Allows for validation of ΔSI in Malaysian-specific population

Proposed Methodology

Study Design

• Retrospective cohort analysis using PATOS registry data from Malaysian semi/rural trauma centers
• Inclusion criteria: Adult trauma patients (≥18 years) admitted to participating centers
• Exclusion criteria: Pregnant patients, pediatric patients, incomplete vital sign data

Variables to Analyze

1. Primary exposure variable:

   • Delta Shock Index (ΔSI) calculated as:
     • Difference between prehospital SI and emergency department SI
     • Alternative calculation: Change in SI during ED stay 3

2. Primary outcome measures:

   • In-hospital mortality
   • 28-day mortality 4

3. Secondary outcome measures:

   • ICU admission and length of stay
   • Hospital length of stay
   • Need for blood transfusion
   • Need for life-saving interventions
   • Ventilator days 2, 4

Analytical Approach

1. Categorize ΔSI into clinically relevant groups:

   • ΔSI < -0.5
   • -0.5 ≤ ΔSI < -0.1
   • -0.1 ≤ ΔSI < 0.1
   • 0.1 ≤ ΔSI < 0.5
   • ΔSI ≥ 0.5 1

2. Statistical analysis:

   • Calculate area under receiver operating characteristic curve (AUROC) for ΔSI
   • Compare predictive ability of ΔSI versus:
     • Traditional shock index
     • Prehospital SI
     • ED SI
     • Other trauma scoring systems (ISS, TRISS) 5
   • Adjust for confounding variables (age, comorbidities, injury mechanism)
   • Subgroup analysis for elderly patients, as they have unique physiological responses 5, 6

Expected Significance and Innovation

Clinical Implications

• Triage optimization: ΔSI > 0.1 has been associated with 31% increased likelihood of death and 2x higher odds of requiring blood products 4
• Resource allocation: Identifying patients who need immediate intervention in resource-limited settings
• Special populations: Particularly valuable for elderly patients, where traditional vital signs may be unreliable 5

Unique Aspects

• First validation of ΔSI in Malaysian semi/rural trauma centers
• Potential to develop Malaysia-specific ΔSI thresholds
• Opportunity to examine the J-shaped relationship between ΔSI and mortality 1

Potential Challenges and Solutions

Data Quality

• Challenge: Missing prehospital data
• Solution: Develop protocols for calculating ΔSI within ED stay if prehospital data unavailable 3

Confounding Factors

• Challenge: Medications affecting vital signs (beta-blockers)
• Solution: Collect medication history and stratify analysis 5

Generalizability

• Challenge: Variation between centers
• Solution: Multi-center approach with standardized protocols

Conclusion

This dissertation will provide valuable insights into the utility of delta shock index as a predictor of mortality and clinical outcomes in Malaysian semi/rural trauma centers. The findings could lead to improved triage protocols, resource allocation, and ultimately better patient outcomes in resource-limited settings.