The purpose of study is to verify the predictability of TV Chalange test during laparoscopic abdominal surgery for early postoperative AKI and intra-operative hypotension.

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The number and scope of laparoscopic surgery are increasing. Now almost every abdominal organ seems suitable for laparoscopic surgery. Laparoscopy may be considered potentially risky because it may involve extreme changes in the patient's position, prolonged intra-abdominal insufflation and carbon dioxide (CO2) degassing, unexpected visceral damage, and difficulty in assessing blood loss. The anesthesiologist must select the appropriate anesthesia management technique, conduct proper monitoring, and be aware of potential complications. Early detection and reduction of possible intra-operative problems can prevent postoperative complications and early complications.

Laparoscopic injection of CO2 or N2O can cause cardiovascular depression . Insufflation at a high flow rate can also exacerbate cardiovascular sequelae, including hypotension and bradycardia, and cause cardiac arrest . Intra-operative hypotension caused by rapid laparoscopic inflation is caused by the vagal-mediated cardiovascular reflex caused by the rapid expansion of the peritoneum. It can also be attributed to the reduction in preload and venous return associated with the pneumo-peritoneum (PP) .

During the period of elevated intra-abdominal pressure, there are three different mechanisms of renal insufficiency, including hypercapnia caused by CO2 insufflation, elevated intra-abdominal pressure and renin-angiotensin-aldosterone system (RAAS) .

In another study, the incidence of AKI after laparoscopic abdominal surgery was 35.9%, which was higher than the previous study .

Patients with low-volume status are susceptible to AKI due to ischemic acute tubular necrosis due to renal insufficiency, and predisposed by hypotension as a pre-renal cause.

Although low volume status has a major role in post-operative AKI .Yet, there are rising theories explaining the increased incidence of AKI in patients undergoing laparoscopic surgeries to increased renal resistive index (RRI) by increased intra-abdominal pressure Intra-operative volume status indicators are variable, including inferior vena cava (IVC), carotid artery ratio (JCR), stroke volume change (SVV) and pulse pressure change (PPV). These indicators may be reliable, but complex, time-consuming, and require trained personnel and high-tech equipment .

The Tidal Volume Challenge (TVC) test is a new tool which is used to assess the volume status and it has been approved as a reliable tool in neurosurgery patients . However, as far as we know, it has not been used to predict hypotension and AKI in laparoscopic surgeries. We hypothesis that mimicking the effect of increased intra-abdominal pressure transiently for a short period of time by TVC test could contribute in detecting patients at high risk of developing post-operative AKI.

TVC test/ abdominal insufflation adverse consequences can be also explained mainly by reduced venous compliance in some patients leading to mobilization of blood to peripheral venous system, with reduced venous elasticity the passive blood recoil to the heart maintaining hemo-dynamic stability and organ perfusion will be diminished, aggravating the effect of increased intra-abdominal or intra-thoracic pressure. That mechanism has been studied in orthostatic hypotension The purpose of study is to verify the predictability of TVC test during laparoscopic abdominal surgery for early postoperative AKI and intra-operative hypotension.

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Inclusion Criteria:

• Gender both males and females
• ASA Class I and II
• Age 18-65 years
• Patients undergoing elective laparoscopic surgery under general anaesthesia

Exclusion Criteria:

• Kidney dysfunction
• Cardiac arrhythmias and valvular heart disease
• Chronic obstructive pulmonary disease
• Right ventricular failure
• Intracranial hypertension
• Airway asthma or a long history of smoking
• Those who are on NSAID for 1 week prior to surgery.

The study will be conducted in Kasr Alainy Hospital of Cairo University.