Shock Index in Patients Undergoing Elective and Emergency General Surgical Procedures: A Predictor of Morbidity Risk and Outcomes

Abstract

Introduction: Shock index (SI) has gained popularity as a quick and inexpensive screening tool for patients of trauma or obstetric hemorrhage to predict risk of mortality and morbidity especially transfusion requirement. It has further been studied for sepsis in recent times. Though not specific the shock index has been shown to be a sensitive tool in alerting physicians of patients that may require greater medical attention. It has not been studied in patients undergoing general surgical procedures either elective or emergency.
 Aims & Objectives: To assess the utility of shock index in patients undergoing both elective and emergency general surgical procedures and to assess outcomes of these patients.
 Place and duration of study: It was a retrospective cohort study of in-patient records of the Department of General Surgery, Sir Ganga Ram Hospital, Lahore. The duration of study was from 1st September 2021 till 30th November 2021. Material & Methods: From the medical records information was retrieved and the shock index was calculated by ‘heart rate divided by systolic blood pressure’ and was recorded for the following instances: (i)At admission (ii) Prior to induction of anesthesia (iii) In the immediate post-operative phase in the recovery unit (iv) post-operative Day 1 (v) at discharge. Patient’s outcomes and investigations were also recorded. SPSS version 24 was used for data entry and analysis
 Results: SI at admission and on post-operative Day 1 for emergency vs elective surgery was 0.82 and 0.72 vs 0.69 and
 0.68. Shock index prior to induction was higher in the emergency surgery group and this was statistically significant. A shock index value of 0.81 was 71.7% and 72% specific for post-operative morbidities. The optimum value for shock index in ER and Elective surgery varies for each morbidity.
 Conclusion: This is a simple tool and may increase appropriate resource allocation and increased observation for certain patients who are screened to be at higher risk of developing a specific morbidity post-operatively, especially in resource- limited countries like Pakistan.