Equivalency between the shock index and subtracting the systolic blood pressure from the heart rate: an observational cohort study

Abstract

Background Although the shock index is known to predict mortality and other severe outcomes, deriving it requires complex calculations. Subtracting the systolic blood pressure from the heart rate may produce a simple shock index that would be a clinically useful substitute for the shock index. In this study, we investigated whether the simple shock index was equivalent to the shock index. Methods This observational cohort study was conducted at 2 tertiary care hospitals. Patients who were transported by ambulance were recruited for this study and were excluded if they were aged < 15 years, had experienced prehospital cardiopulmonary arrest, or had undergone inter-hospital transfer. Pearson’s product-moment correlation coefficient and regression equation were calculated, and two one-sided tests were performed to examine their equivalency. Results Among 5429 eligible patients, the correlation coefficient between the shock index and simple shock index was extremely high (0.917, 95% confidence interval 0.912 to 0.921, P < .001). The regression equation was estimated as sSI = 258.55 log SI. The two one-sided tests revealed a very strong equivalency between the shock index and the index estimated by the above equation using the simple shock index (mean difference was 0.004, 90% confidence interval 0.003 to 0.005). Conclusion The simple shock index strongly correlated with the shock index.

Management of Pericardial Effusion in Patients with Solid Tumor

“…SI is the ratio of heart rate to systolic blood pressure and has been shown to be predictive of transfusion needs, risk of death, and injury severity in trauma patients and of ruptured ectopic pregnancy in obstetric patients 8,15,16 . sSI is the difference between heart rate and systolic blood pressure 9 . This nomogram, which can be easily implemented in any hospital setting, can function as a clinical decision-making tool to aid in the selection of intervention and to identify patients who require closer monitoring postintervention in the ICU.…”

“…8,15,16 sSI is the difference between heart rate and systolic blood pressure. 9 This nomogram, which can be easily implemented in any hospital setting, can function as a clinical decision-making tool to aid in the selection of intervention and to identify patients who require closer monitoring postintervention in the ICU. Though the incidence of PHI is lower in patients undergoing IR percutaneous drainage, selection of intervention should be decided on a case-by-case basis, as surgical intervention may be preferable for patients with recurrent or loculated pericardial effusions or where a tissue biopsy is necessary.…”

“…1 Representative vital signs (ie, heart rate, systolic blood pressure, and diastolic blood pressure) before the intervention were collected. Shock index (SI; the ratio of heart rate to systolic blood pressure) 8 and simple shock index (sSI; the difference between heart rate and systolic blood pressure) 9 were calculated.…”

Effects of growth trajectory of shock index within 24 h on the prognosis of patients with sepsis

“…An increase in SI indicates an increase in heart rate and a decrease in systolic blood pressure ( 26 ), suggesting that the patient has acute hypovolemia and circulatory failure ( 27 ), all of which will increase the patient’s risk of death. The initial level of the patients in class 5 was at a relatively high stage of 1.86, indicating that the patients had severe circulatory failure at the beginning ( 28 ). Although the trend decreased in the later stage, the prognosis remained poor.…”