Doppler Ultrasound Renal Arterial Resistive Indices As Predictor Of Multiorgan Failure In Patients With Acute Hypoxic Respiratory Failure Admitted To Respiratory Intensive Care Unit (Cryptic Shock Index- RICU)

University of Modena and Reggio Emilia30 enrolled

Overview

Patients with de novo respiratory failure undergoing non invasive ventilation (NIV) present failure rates of mechanical ventilation ranging from 4 to 50%. Causes for NIV treatment failure are various but the onset of septic shock and subsequent multi-organ failure (MOF) seem play a critical role. Recent data show that the 37% of patients admitted to intensive care unit for de novo respiratory failure without any other organ failure experience multiple organ failure within the first days from admission. Early identification of hypoxic patients at major risk for MOF seems critical. Physiological studies have demonstrated that the underlying mechanisms for organ damage preceding MOF are those involved in the oxygen consumption (VO2)/oxygen delivery (DO2) mismatch. Doppler ultrasound indices of renal arteria resistance are directly correlated tot he VO2/DO2 mismatch. With this study we aim at investigating the correlation between Doppler ultrasound indices of renal arteria resistance in patients with de novo respiratory failure admitted to ICU and the onset of MOF within the first 7 days form admission.

Study Type

OBSERVATIONAL

Enrollment

Conditions

Respiratory Failure Multi Organ Failure

Interventions

A high frequency probe will be used together with the use of color or power Doppler to help vessel localization. As resistance to blood flow progressively increases from the hilar arteries toward the more peripheral parenchymal vessels, renal arteria resistive index (RRI) will be done at the level of the arcuate or interlobar arteries, adjacent to medullary pyramids. Measurements will be repeated in different parts of both organs (superior, median, and lower) when at least three reproducible waveforms have been obtained. An RRI will be calculated with the following formula: (peak systolic velocity - end diastolic velocity)/peak systolic velocity, and the mean value of three measurements at each kidney is usually considered. An RRI value 0.60 ± 0.01 (mean ± SD) is usually taken as normal with a value of 0.70 being considered the upper normal threshold

Eligibility

Sex: ALLMin age: 18 YearsMax age: 85 Years

Medical Language ↔ Plain English

Inclusion Criteria: * patients with de novo respiratory failure admitted to the respiratory intensive care unit of the university hospital of Modena Exclusion Criteria: * age lower than 18 or higher than 85 * presence of organ failure apart form lung failure at the time of admission in the respiratory intensive care unit * pregnancy * difficult or unreliable ultrasound window for renal arterial resistive index assessment

Outcomes

Primary Outcomes

Onset of shock

Shock will be clinically identified by a vasopressor requirement to maintain a mean arterial pressure of 65 mm Hg or greater and serum lactate level greater than 2 mmol/L (\>18 mg/dL) in the absence of hypovolemia

Time frame: 7 days from Respiratory Intensive Care Unit admission