An observational study in Nephrectomy / Methods, Intraoperative Hypothermia and Hyperlactatemia, sponsored by Beyzanur Aydoğdu. Recruiting at 1 site in Turkey (Türkiye). Open to participants aged 18 Years to 90 Years. Per ClinicalTrials.gov, last updated 2026-07-14.
Sponsored by Beyzanur Aydoğdu · Observational
The goal of this observational study is to learn whether warming patients before surgery, called "prewarming," affects blood lactate levels (a marker of how well tissues are getting oxygen) and recovery in adults having planned (elective) kidney removal surgery (nephrectomy).
The main questions this study aims to answer are:
Researchers will compare two groups of adults having this surgery. One group receives brief active warming before anesthesia (the "prewarming" group). The other group does not receive this warming (the "control" group). The anesthesia team decides whether to use prewarming and for how long, as part of routine care; the study does not change this decision. Researchers will compare the two groups to see whether prewarming is linked to lower lactate levels and better recovery.
Participants will:
This study does not add any extra tests, procedures, or blood draws beyond routine clinical care.
Nephrectomy is a major surgical procedure, performed via open or laparoscopic approaches, that is associated with a substantial physiological stress response. Reduced tissue perfusion and increased anaerobic metabolism during major surgery can raise serum lactate levels, and maintaining perioperative metabolic stability is an important goal in these patients.
Prewarming refers to active warming of a patient's body surface before induction of anesthesia, with the aim of reducing intraoperative core-temperature drop and its downstream effects on tissue perfusion and oxygenation. Clinical practice regarding the use and duration of prewarming varies among anesthesiologists, and there is no fixed institutional protocol dictating whether, or for how long, it should be applied.
This is a prospective, single-center, observational study conducted over a one-year period. Consecutive adult patients undergoing elective nephrectomy who meet the eligibility criteria will be enrolled and followed as part of routine clinical care (see Eligibility Criteria for full details). Whether a given patient receives prewarming, and for how long (typically 10-15 minutes when used), is determined solely by the anesthesia team providing care in the operating room; the study does not intervene in this clinical decision or modify usual care in any way. Outcomes will be compared between patients who receive prewarming and those who do not.
For each patient, a range of preoperative and postoperative physiological and laboratory parameters is recorded as part of routine perioperative monitoring (see Outcome Measures for the specific parameters and their timing). In addition, length of stay in the intensive care unit, need for blood transfusion, and the occurrence and type of postoperative complications are documented. All data are obtained from existing anesthesia records, nursing charts, laboratory results, intensive care information systems, and patient files, and are transcribed onto a predefined case report form; the study does not add any invasive procedures, blood draws, or deviations from routine clinical protocol.
Continuous variables will be compared between the prewarming and control groups using the independent-samples t-test or Mann-Whitney U test, as appropriate, and categorical variables will be compared using the chi-square test or Fisher's exact test. Regression analysis will be used to examine associations between prewarming and outcomes. A p-value \<0.05 will be considered statistically significant. A power analysis (G*Power v3.1.9.2), assuming a medium effect size (Cohen's d=0.5) for the primary between-group lactate comparison, indicated that at least 64 participants per group (128 total) would be needed to achieve 80% power at α=0.05.
50 studies on the registry are indexed under Hyperlactatemia; 7 are open to participants now.
This study's planned enrollment of 128 is close to the median of 136 across 17 observational studies indexed under Hyperlactatemia.
Browse Hyperlactatemia studies →This is the only study on the registry with Beyzanur Aydoğdu as lead sponsor.
Counted across the registry records on this site, refreshed daily.
Adult patients aged 18-90 years, ASA I-III, undergoing elective nephrectomy (open or laparoscopic) at the study site, enrolled consecutively over a one-year period.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
ASA physical status
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Patients who receive active preoperative warming, applied by the anesthesia team during operating room preparation, typically for approximately 10-15 minutes before induction of anesthesia, as part of routine clinical care.
Device: Preoperative active warming (prewarming)
Patients who do not receive active preoperative warming before induction of anesthesia, per the routine practice of the anesthesia team providing care. All patients receive standard intraoperative and postoperative warming per usual care.
Application of an active warming device to the patient's body surface during operating room preparation, before induction of anesthesia, for approximately 10-15 minutes at the discretion of the anesthesia team. The decision to apply prewarming, and its duration, follows routine clinical practice and is not standardized by the study protocol.
Also known as: Active preoperative warming
Change in Serum Lactate Concentration
Change in serum lactate concentration from the preoperative assessment to the postoperative assessment, compared between the prewarming and control groups.
Time frame: From the preoperative assessment to 24 hours after surgery
Change in Systolic and Diastolic Blood Pressure
Changes in systolic and diastolic arterial blood pressure from the preoperative assessment to the postoperative assessment, compared between the prewarming and control groups.
Time frame: From the preoperative assessment to 24 hours after surgery
Change in Heart Rate
Change in heart rate from the preoperative assessment to the postoperative assessment, compared between the prewarming and control groups.
Time frame: From the preoperative assessment to 24 hours after surgery
Change in Body Temperature
Change in body temperature from the preoperative assessment to the postoperative assessment, compared between the prewarming and control groups.
Time frame: From the preoperative assessment to 24 hours after surgery
Change in Hemoglobin Level
Change in hemoglobin concentration from the preoperative assessment to the postoperative assessment, compared between the prewarming and control groups.
Time frame: From the preoperative assessment to 24 hours after surgery
Change in Hematocrit
Change in hematocrit from the preoperative assessment to the postoperative assessment, compared between the prewarming and control groups.
Time frame: From the preoperative assessment to 24 hours after surgery
Change in Serum Osmolality
Change in serum osmolality from the preoperative assessment to the postoperative assessment, compared between the prewarming and control groups.
Time frame: From the preoperative assessment to 24 hours after surgery
Length of Intensive Care Unit Stay
Duration of stay in the intensive care unit, compared between the prewarming and control groups.
Time frame: Up to 48 hours after surgery
Need for Blood Transfusion
Proportion of patients requiring blood transfusion and the total number of units transfused during the first 48 hours after surgery, compared between the prewarming and control groups.
Time frame: During the first 48 hours after surgery
Incidence of Postoperative Complications
Presence and type of postoperative complications (respiratory, cardiac, renal, infectious, hematologic, or other), compared between the prewarming and control groups.
Time frame: From surgery to 24 hours after surgery
Plan to share: No
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