Perfusion Index Derived from Pulse Oximetry, Serum actate, its Surrogates and Beta Type Natriuretic Peptide (Bnp) for Outcome Prediction in Poly-Traumatized Patients. A Prospective Observational Cohort Study

Introduction: Perfusion index (PI) is a non-invasive numeric value of peripheral perfusion; gained from pulse Oximeters. No study researched the predictive value of perfusion index in poly-traumatized patients. Patients and methods: Fifty adult poly-traumatized patients with blunt injury without head injury studied. Perfusion index compared to serum lactate lactate clearance, base deficit and beta Natriuretic peptide (BNP) in survivors and non-survivors and their predictability of mortality in a prospective observational study up to 48 hours in Assuit University tertiary hospital. Results: Perfusion index showed a significant difference between survivors and non-survivors after the first 6 hours, post resuscitation (p< 0.001). ROC analysis showed the ideal cutoff point for predicting mortality ≤ 0.75 with AUC 0.93, sensitivity 97% and specificity 82%. Non-survivors had significantly higher serum lactate than survivors (p< 0.001). ROC analysis showed the ideal cutoff point for predicting mortality ≥ 2.25 mmol/L with AUC 0.57, sensitivity 79% and specificity 69%. Survivors had significantly higher lactate clearance than non-survivors (p< 0.001). ROC analysis showed the ideal cutoff point for predicting mortality < 3.0 mmol/L/24 hours with AUC 0.97, sensitivity 97% and specificity 86%. Non-survivors had significantly higher beta Natriuretic peptide (BNP) at 48 hours than survivors (p< 0.001). ROC analysis showed the ideal cutoff point for predicting mortality ≥ 95.0 pg/ml with AUC less than 0.5, sensitivity 61% and specificity 32%. Conclusion: Perfusion index more than six hours after the injury is prognostic of mortality in adult poly-traumatized patients with blunt injury. Lactate clearance is prognostic of mortality. Serum lactate is a weak predictor of mortality in adult poly-traumatized patients with blunt injury. Beta Natriuretic peptide (BNP) has no prognostic value of mortality in adult poly-traumatized patients with blunt injury in this survey.