Diastolic Shock Index for Predicting Hemodynamic Instability During Continuous Renal Replacement Therapy (DSI-CRRT)

Continuous renal replacement therapy (CRRT) is commonly used in critically ill patients with acute kidney injury. A frequent complication of CRRT is a drop in blood pressure that requires treatment, known as CRRT-associated hemodynamic instability. This complication is linked to higher mortality and poorer kidney recovery.

The diastolic shock index (DSI) is a simple bedside measure calculated by dividing heart rate by diastolic blood pressure. It requires no additional devices, blood tests or invasive procedures, and higher values have been associated with vasopressor need and mortality in septic shock.

This prospective observational study aims to determine whether DSI measured before the start of CRRT can predict hemodynamic instability during CRRT in adult intensive care unit patients. The predictive performance of DSI will also be compared with the classic shock index, the modified shock index and mean arterial pressure. All data will be obtained from routine clinical monitoring; no additional intervention will be performed for the study.

Study Overview

• Status: Not yet recruiting
• Conditions: Critical Illness; Acute Kidney Injury; Hypotension (MeSH: D007022)
• Intervention / Treatment: Other: Diastolic Shock Index Assessment

Detailed Description

Background: CRRT-associated hemodynamic instability (CRRT-HI) complicates 19-43% of CRRT sessions and is independently associated with increased mortality and impaired renal recovery. The diastolic shock index (DSI = heart rate / diastolic arterial pressure) reflects both vascular tone (diastolic pressure) and neurohumoral compensation (heart rate) and has been proposed as an early marker of vasoplegia. Its predictive value for CRRT-HI has not been prospectively evaluated.

Objective: To evaluate the diagnostic performance of pre-CRRT bedside DSI in predicting CRRT-HI in critically ill adults.

Design and setting: Prospective observational cohort study conducted in the general intensive care units of Basaksehir Cam and Sakura City Hospital, Istanbul, Turkey. Approximately 70 adult patients (≥18 years) starting CRRT for acute kidney injury will be enrolled.

Definition of CRRT-HI: An event meeting at least one of the following criteria: mean arterial pressure below 65 mmHg; initiation of a new vasopressor or an increase of ≥20% in the norepinephrine dose; crystalloid fluid bolus exceeding 250 mL; or reduction or discontinuation of ultrafiltration.

Data collection: Demographic and clinical characteristics (APACHE II, SOFA-2, comorbidities, CRRT indication and AKI stage), CRRT settings (modality, blood flow, dialysate and replacement fluid rates, ultrafiltration rate, anticoagulation), and baseline laboratory parameters (arterial blood gas, lactate, complete blood count, renal and liver function tests, electrolytes, CRP, procalcitonin) will be recorded. Heart rate, systolic, diastolic and mean arterial pressures, vasopressor/inotrope use and doses will be recorded at CRRT initiation (T0) and at 15, 30, 60 and 180 minutes. DSI, the classic shock index (HR/SAP) and the modified shock index (HR/MAP) will be calculated from these routine monitoring data. No additional blood sampling, tests or invasive procedures will be performed for the study.

Statistical analysis: The predictive performance of DSI, the classic shock index, the modified shock index and mean arterial pressure will be assessed by ROC curve analysis and compared using the DeLong test. Optimal cut-off values will be determined by the Youden index, with corresponding sensitivity and specificity. Independent risk factors for CRRT-HI will be identified by multivariable logistic regression. Associations of DSI and CRRT-HI with 28-day mortality, ICU and hospital length of stay, duration of mechanical ventilation and renal recovery will be evaluated as secondary analyses.

Sample size: Assuming a CRRT-HI incidence of approximately 50% and an expected AUC of 0.75 for DSI, at least 60 patients are required (α = 0.05, power = 80%). Allowing for approximately 15% data loss, 70 patients will be enrolled.

• Study Type: Observational
• Enrollment (Estimated): 70

Contacts and Locations

• Study Contact: Name: mahmut baran kaşısarı, md; Phone Number: 905072225254; Email: barankasisari@hotmail.com

Study Locations

• Turkey (Türkiye)
  • Istanbul, Turkey (Türkiye)
    • Basaksehir Cam and Sakura City Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Consecutive adult patients (≥18 years) admitted to the general intensive care units of Basaksehir Cam and Sakura City Hospital, Istanbul, Turkey, in whom continuous renal replacement therapy is initiated for acute kidney injury.

Description

Inclusion Criteria:

• Age 18 years or older
• Admission to the general intensive care unit
• Initiation of continuous renal replacement therapy (CRRT) for acute kidney injury
• Standard CRRT indication determined by the attending physician (e.g., uremic complications, refractory fluid overload, hyperkalemia, metabolic acidosis)
• Written informed consent obtained from the patient or legal representative

Exclusion Criteria:

• Pregnancy
• Chronic kidney disease on a maintenance intermittent hemodialysis program before the study
• Significant arrhythmia that may affect diastolic shock index calculation and hemodynamic assessment (e.g., permanent atrial fibrillation, frequent ventricular extrasystoles)
• Permanent discontinuation of CRRT within the first hour due to technical reasons (e.g., catheter dysfunction, circuit clotting)
• Missing or inconsistent data on key hemodynamic parameters

Study Plan

How is the study designed?

Design Details

• Observational Models: COHORT
• Time Perspectives: PROSPECTIVE

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

Critically Ill Adults Receiving CRRT; Adult patients (≥18 years) admitted to the general intensive care units of Basaksehir Cam and Sakura City Hospital who are initiated on continuous renal replacement therapy (CRRT) for acute kidney injury. The diastolic shock index (heart rate / diastolic arterial pressure) will be calculated from routine bedside monitoring before and during CRRT, and patients will be followed for the development of CRRT-associated hemodynamic instability. No study-specific intervention will be performed.

Other: Diastolic Shock Index Assessment; Bedside calculation of the diastolic shock index (heart rate / diastolic arterial pressure) from routine hemodynamic monitoring at CRRT initiation and at 15, 30, 60 and 180 minutes. No additional procedure is performed.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Diagnostic Performance of Pre-CRRT Diastolic Shock Index for Predicting CRRT-Associated Hemodynamic Instability	Area under the receiver operating characteristic curve (AUC) of the diastolic shock index (heart rate / diastolic arterial pressure) measured immediately before CRRT initiation for predicting CRRT-associated hemodynamic instability. CRRT-associated hemodynamic instability is defined as at least one of the following: mean arterial pressure <65 mmHg; initiation of a new vasopressor or ≥20% increase in norepinephrine dose; crystalloid fluid bolus >250 mL; or reduction or discontinuation of ultrafiltration. The optimal cut-off value will be determined by the Youden index, with corresponding sensitivity and specificity.	From CRRT initiation to 180 minutes

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Comparison of Diastolic Shock Index With Other Bedside Hemodynamic Indices	AUC of the diastolic shock index compared with the classic shock index (heart rate / systolic arterial pressure), modified shock index (heart rate / mean arterial pressure) and mean arterial pressure for predicting CRRT-associated hemodynamic instability, compared using the DeLong test.	From CRRT initiation to 180 minutes
Incidence of CRRT-Associated Hemodynamic Instability	proportion of patients developing CRRT-associated hemodynamic instability as defined in the primary outcome.	From CRRT initiation to 180 minutes
28-Day All-Cause Mortality	All-cause mortality within 28 days of CRRT initiation, compared according to diastolic shock index values and the occurrence of CRRT-associated hemodynamic instability.	28 days after CRRT initiation

Collaborators and Investigators

• Sponsor: Istanbul University - Cerrahpasa
• Investigators: Principal Investigator: mahmut baran kaşısarı, md, Başakşehir Çam & Sakura City Hospital

Publications and helpful links

General Publications

• Ospina-Tascon GA, Teboul JL, Hernandez G, Alvarez I, Sanchez-Ortiz AI, Calderon-Tapia LE, Manzano-Nunez R, Quinones E, Madrinan-Navia HJ, Ruiz JE, Aldana JL, Bakker J. Diastolic shock index and clinical outcomes in patients with septic shock. Ann Intensive Care. 2020 Apr 16;10(1):41. doi: 10.1186/s13613-020-00658-8.
• Chazot G, Bitker L, Mezidi M, Chebib N, Chabert P, Chauvelot L, Folliet L, David G, Provoost J, Yonis H, Richard JC. Prevalence and risk factors of hemodynamic instability associated with preload-dependence during continuous renal replacement therapy in a prospective observational cohort of critically ill patients. Ann Intensive Care. 2021 Jun 14;11(1):95. doi: 10.1186/s13613-021-00883-9.

Study record dates

Study Major Dates

• Study Start (Estimated): November 15, 2026
• Primary Completion (Estimated): January 31, 2027
• Study Completion (Estimated): February 1, 2027

Study Registration Dates

• First Submitted: November 1, 2026
• First Submitted That Met QC Criteria: November 1, 2026
• First Posted (Actual): November 5, 2026

Study Record Updates

• Last Update Posted (Actual): November 5, 2026
• Last Update Submitted That Met QC Criteria: November 1, 2026
• Last Verified: November 1, 2026

More Information

Terms related to this study

• Keywords: diastolic shock index; Intradialytic Hypotension; Hemodynamic Instability; Shock Index; Continuous Renal Replacement Therapy CRRT
• Additional Relevant MeSH Terms: Urogenital Diseases; Vascular Diseases; Cardiovascular Diseases; Pathologic Processes; Male Urogenital Diseases; Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Disease Attributes; Renal Insufficiency; Pathological Conditions, Signs and Symptoms; Critical Illness; Acute Kidney Injury; Hypotension
• Other Study ID Numbers: E-96317027-514.10-321013232

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No