Mannitol Versus Nitroglycerin for Kidney Injury Prevention in Robotic-assisted Radical Prostatectomy or Cystectomy

NCT ID: NCT06408597

Last Updated: 2026-01-12

Basic Information

• Recruitment Status: ACTIVE_NOT_RECRUITING
• Clinical Phase: NA
• Total Enrollment: 90 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2024-05-12
• Study Completion Date: 2026-02-28

Brief Summary

Laparoscopic and minimally-invasive robotic access has transformed the delivery of urological surgery. While associated with numerous desirable outcomes including shorter post-operative stay and faster return to preoperative function, these techniques have also been associated with morbidity such as reduced renal blood flow and post-operative renal dysfunction. The mechanisms leading to these renal effects complex are multifactorial, and have not been fully elucidated. However they are likely to include direct effects from raised intra-abdominal pressure, and indirect effects secondary to carbon dioxide absorption, neuroendocrine factors and tissue damage from oxidative stress. It is well documented that pneumoperitoneum places profound stress on the cardiovascular, respiratory and gastrointestinal systems; it also places strain on the renal system.

During robotic surgery, continuous pneumoperitoneum and continuous rising of intra-abdominal pressure causes transient oliguria. Moreover, kidney function, estimated by the GFR, deteriorates during elevated intra abdominal pressure (IAP), and most of the studies identified decrease in renal blood flow (RBF) and renal cortical perfusion.

Studies conducted to assess the contribution of the nitric oxide (NO) system to the renal hemodynamic/function alterations during pneumoperitoneum, concluded that these adverse effects are probably related to interference with the NO system, and could be partially ameliorated by pretreatment with nitroglycerine.

Mannitol is an osmotic diuretic and a renal vasodilator that promotes tubular flow, prevents intratubular cast formation, decreases postischemic cellular swelling, and might serve as a free radical scavenger. Mannitol has traditionally been administered before renal surgeries to minimize perioperative renal dysfunction according to preclinical animal studies and clinical experience with renal transplantation. However, high-level clinical data in support of this belief are not available.

The aim of this study is to characterize the effects of increased intra-abdominal pressure on renal perfusion and function in cases undergoing robotic lower tract urologic surgeries, and to assess the contribution of either mannitol or nitroglycerin infusion to the renal hemodynamic/function alterations during pneumoperitoneum.

Conditions

Prostate Cancer; Bladder Cancer; Surgery; Renal Impairment; Renal Injury, Acute

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: SUPPORTIVE_CARE
• Blinding Strategy: DOUBLE

Study Groups

Control group

Standard Fluid Therapy group

Group Type: ACTIVE_COMPARATOR

Fluid Regimen

Intervention Type: PROCEDURE

Patients will take the standard fluid chart, as the patient will receive the estimated maintenance & deficit requirements according to 4/2/1 rule.

In case of hypotension, (defined as 20% decrease from the baseline), administration of a fluid bolus of 200 ml ringer will be done.

Blood loss more than 10% of estimated blood volume will initiate blood transfusion using 1:1 ratio. Additional fluids may be administered postoperatively according to the patient's volume status.

Nitroglycerin group

Nitroglycerin Infusion group

Group Type: EXPERIMENTAL

Nitroglycerin Infusion

Intervention Type: PROCEDURE

Nitroglycerin prepared using a vial (50 mg nitroglycerin) transferred into a 500 ml glass bottle of sodium chloride injection (0.9%), this yields a concentration of 100 mcg/ml.

Patients in the nitroglycerin group will receive nitroglycerin infusion at a rate of 0.25 mic/kg/min all through the surgery, to be discontinued in the PACU.

Fluid Regimen

Intervention Type: PROCEDURE

Patients will take the standard fluid chart, as the patient will receive the estimated maintenance & deficit requirements according to 4/2/1 rule.

In case of hypotension, (defined as 20% decrease from the baseline), administration of a fluid bolus of 200 ml ringer will be done.

Blood loss more than 10% of estimated blood volume will initiate blood transfusion using 1:1 ratio. Additional fluids may be administered postoperatively according to the patient's volume status.

Mannitol group

Mannitol Infusion group

Group Type: EXPERIMENTAL

Mannitol Infusion

Intervention Type: PROCEDURE

Mannitol will be prepared through diluting 100 ml of the 20% solution with 180 ml of sodium chloride injection (0.9%).

Patients in the mannitol group will receive an infusion bolus of mannitol 20% 0.5gm/kg added to the standard fluid chart via centeral line.

Mannitol intake will be started directly after induction of anaesthesia and before intra-peritoneal gas insufflation, as an infusion over 15 minutes.

Fluid Regimen

Intervention Type: PROCEDURE

Patients will take the standard fluid chart, as the patient will receive the estimated maintenance & deficit requirements according to 4/2/1 rule.

In case of hypotension, (defined as 20% decrease from the baseline), administration of a fluid bolus of 200 ml ringer will be done.

Blood loss more than 10% of estimated blood volume will initiate blood transfusion using 1:1 ratio. Additional fluids may be administered postoperatively according to the patient's volume status.

Interventions

Nitroglycerin Infusion

Nitroglycerin prepared using a vial (50 mg nitroglycerin) transferred into a 500 ml glass bottle of sodium chloride injection (0.9%), this yields a concentration of 100 mcg/ml.

Patients in the nitroglycerin group will receive nitroglycerin infusion at a rate of 0.25 mic/kg/min all through the surgery, to be discontinued in the PACU.

Intervention Type: PROCEDURE

Mannitol Infusion

Mannitol will be prepared through diluting 100 ml of the 20% solution with 180 ml of sodium chloride injection (0.9%).

Patients in the mannitol group will receive an infusion bolus of mannitol 20% 0.5gm/kg added to the standard fluid chart via centeral line.

Mannitol intake will be started directly after induction of anaesthesia and before intra-peritoneal gas insufflation, as an infusion over 15 minutes.

Intervention Type: PROCEDURE

Fluid Regimen

Patients will take the standard fluid chart, as the patient will receive the estimated maintenance & deficit requirements according to 4/2/1 rule.

In case of hypotension, (defined as 20% decrease from the baseline), administration of a fluid bolus of 200 ml ringer will be done.

Blood loss more than 10% of estimated blood volume will initiate blood transfusion using 1:1 ratio. Additional fluids may be administered postoperatively according to the patient's volume status.

Intervention Type: PROCEDURE

Eligibility Criteria

Inclusion Criteria

• ASA class I - III
• Normal renal functions or Mild renal disease (GFR < 60 ml/min &/or presence of albuminuria > 30 mg/dl)

Exclusion Criteria

• BMI > 40
• Previous renal surgery
• Moderate (GFR 30 - 59 mg/dl) & severe (GFR 15 - 29 mg/dl) renal impairment
• Decompensated cardiac disease: New York Heart Association (NYHA) class 3 or 4
• Allergy to mannitol or nitroglycerin

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 70 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Nazmy Edward Seif

OTHER

Sponsor Role: lead

Responsible Party

Nazmy Edward Seif

Clinical Professor

Responsibility Role: SPONSOR_INVESTIGATOR

Principal Investigators

Ashgan R Ali, MD

Role: STUDY_CHAIR

Kasr Al-Ainy Hospital, Faculty of Medicine, Cairo University

Nazmy S Mikhael, MD

Role: PRINCIPAL_INVESTIGATOR

Kasr Al-Ainy Hospital, Faculty of Medicine, Cairo University

Manar H Mohamed

Role: STUDY_DIRECTOR

Kasr Al-Ainy Hospital, Faculty of Medicine, Cairo University

Locations

Cairo University Hospitals

Cairo, , Egypt

Countries

Egypt

Other Identifiers

MVTKIPRARPC

Identifier Type: -

Identifier Source: org_study_id