Respiratory Alterations of Acid-base Equilibrium: Acute and Chronic Renal Response

Not Applicable

• Conditions: Acute Respiratory Variations of Acid-base Equilibrium

• Registration Number: NCT01540916
• Lead Sponsor: Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico

Brief Summary

Alterations of acid-base equilibrium are very common in critically ill patients. Thus, understanding their pathophysiology and the possible compensatory mechanisms acting in different organs may play an important role in better set the consequent clinical treatment. The lung and the kidney are the two principal actors of such regulations. Although the respiratory response to acid-base alterations is well understood, less information are available for what the renal system is concerned. Such lack of information is partially due to: 1) the historical consideration of the kidney as a "slow" organ, in response to variations in acid-base equilibrium; 2) the lack of a monitoring system to closely assess renal response.

Our group has recently developed a monitoring system aimed at analyzing, in a quasi-continuous and non-invasive manner (every 10 min) the urinary profile in terms of urinary pH and electrolyte concentrations (sodium, potassium, chloride, ammonium).

The investigators hypothesize that the renal system reacts to large as well as to minimal variations of the acid-base equilibrium (especially induced by a variation in the respiratory function) in a very fast way, modifying the urinary concentration (and therefore the urinary excretion) of ammonium and some electrolytes (especially chloride).

Detailed Description

Primary aim:

To investigate the acute renal response to respiratory alterations of acid-base equilibrium in order to better understand the underlying physiological mechanisms and to evaluate the validity of a renal monitoring system to indirectly assess the effectiveness of the respiratory function.

Secondary aim:

To collect data on the chronic response of the renal system in patients affected by chronic obstructive pulmonary disease (COPD), as well as on the acute response to acute variation of the chronic respiratory acidosis characterizing patients affected by COPD exacerbation.

Study protol:

Mechanically ventilated patients will undergo controlled variation of the ventilatory setting (hyperventilation vs. hypoventilation) in order to induce a controlled reduction or increase in arterial partial pressure of carbon dioxide (and an increase or reduction of arterial pH), within normal range of pH (7.35 - 7.45) During the variations, urinary concentrations of electrolytes and pH will be monitored.

Study Timeline

• Study Start: 2012-02
• Study First Submitted: 2012-02-23
• Study First Submitted QC: 2012-02-28
• Study First Posted: 2012-02-29
• Status Verified: 2015-11
• Primary Completion: 2015-11
• Study Completion: 2015-11
• Last Update Submitted: 2015-11-07
• Last Update Posted: 2015-11-10

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 50

Inclusion Criteria

1. Presence of mechanical ventilation
2. Presence of arterial and central venous line
3. Presence of urinary catheter

Exclusion Criteria

1. acute or chronic renal failure with anuria
2. presence of continuous renal replacement therapy
3. hemodynamic instability
4. less than 16 years of age

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
Variations in urinary electrolyte concentrations and pH	From 0 to 4 hours

Trial Locations

Locations (1)

Terapia Intensiva Postoperatoria; Rianimazione Generale - Fondazione IRCCS Ca' Granda - Ospedale Maggiore Policlinico; 🇮🇹 Milan, Italy