Hydrogen Sulfide as Prognostic Factor (H2S-1)

December 3, 2014 updated by: Podbregar Matej, University Medical Centre Ljubljana
Hydrogen sulfide (H2S), better known as a poisonous gas, has emerged as the third gaseous transmitter in mammals, next to nitric oxide (NO) and carbon monoxide (CO). Increased production and higher serum concentrations were shown in inflammatory diseases, septic shock and stroke. The investigators will test the hypothesis that higher serum H2S concentrations on admission to intensive care unit (ICU) are linked with higher mortality in patients with shock of any reason.

Study Overview

Status

Completed

Conditions

Detailed Description

Hydrogen sulfide (H2S), better known as a poisonous gas, has lately emerging as a third gaseous transmitter in mammals, next to nitric oxide (NO) and carbon monoxide (CO). H2S is present in most human tissues in concentrations up to 50 μM. Most of it is synthesized in brain, cardiovascular system, kidneys and liver. In human tissues H2S is synthesized from L-cysteine by two enzymes cystathionine-γ-lyase and cystathionine-β-synthase. H2S works by stimulating ATP sensitive potassium channels and is involved in regulation of vascular tone, myocardial contractility, insulin secretion and neurotransmission. In numerous animal models, H2S deficiency was shown in arterial and pulmonary arterial hypertension, Alzheimer's disease and liver cirrhosis. Increased production and higher serum concentrations were shown in inflammatory diseases, septic shock and stroke.

Most of studies so far were conducted on animals and already show some therapeutic potentials. In available literature there have been no studies in humans focused on H2S concentrations in critically ill and its prognostic value.

Hypothesis We will test the hypothesis that higher serum H2S concentrations on admission to ICU are linked with higher mortality in patients with shock of any reason.

Serum H2S concentrations are related to treatment support with vaso-active drugs (noradrenalin, epinephrine).

Material and methods In the study we will include adult patients admitted to medical ICU due to shock of any reason. Shock is defined as systemic arterial pressure lower than 90mmHg or drop for systemic arterial pressure at least 40mmHg for 15minutes or more with elevation of serum lactate value.

Patients will be included on basis of clinical appearance of shock - hypotension or need for vasopressors, brady- or tachycardia, signs of peripheral hypo perfusion, oliguria and changes in mental status.

Exclusion criteria: patient younger then 18years and patients not in shock

From blood samples drawn on admission to ICU we will measure H2S concentration. H2S concentration will be measured spectrophotometrically5 as first described in 19496 and further refined in 19657. Spectrophotometrical determination of H2S concentration in tissue and plasma was previously used by many researchers.3,8-11 Blood samples will be centrifuged as quickly after collection to obtain plasma. 200 μL of plasma will be mixed with pre-prepared solution of 100 μL 10% (wt/vol) trichloroacetic acid and 60 μL 1% (wt/vol) zinc acetate, to trap dissolved H2S. The mixture will be frozen at 20 C until further analysis.

After sufficient number of samples will be obtained, we will measure H2S concentration in series. 40µL 20 µM N,N-dimethyl-p-phenylenediamine sulfate in 7,2 M HCl and 40µL 30 µM FeCl3 v 1,2 M HCl will be added to unfrozen samples. After 10-20 min incubation at room temperature final mixtures will be centrifuged at 9000 rpm for 5 minutes to remove precipitate. After centrifugation absorption at 670 nm will be measured with spectrophotometer. All analysis will be done in duplicates.

Calibration curve of absorbance versus sulfide concentration will be obtained from known concentration of Na2S (0,699 µM - 69,93 µM) and concentrations of H2S in plasma calculated.

Impact of plasma H2S concentration on admission to ICU on ICU mortality will be observed trough nonparametric statistical analysis.

Expectations We hypothesize that higher serum H2S concentrations on admission to ICU in patients with shock of any cause are indicators of severity of shock and cardiovascular deterioration, related to treatment support with vaso-active drugs (noradrenalin, epinephrine). Thus higher serum H2S concentrations are expected to be better prognostic factor of ICU mortality in patients with shock than currently established lactic acid.

Study Type

Observational

Enrollment (Actual)

50

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Slovenia
      • Ljubljana, Slovenia, 1000
        • University Medical Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 95 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

Critically ill patients how are admitted in shock or hemodynamicaly unstable ino intensive care

Description

Inclusion Criteria:

  • shock ( systemic arterial pressure less then 120mmHg, elevated lactate > 2.5mmol/L)

Exclusion Criteria:

  • patients admitted due to intoxication with H2S

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
critically ill
Critically ill patients admitted to ICU

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Prognostic value of H2S
Time Frame: In hospital; ICU mortality 30days

relationship between H2S and mortality of patients during intensive care treatment,

comparison of H2S and lactate prognostic value
In hospital; ICU mortality 30days

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Correlation of H2S with vasopressor requirements
Time Frame: ICU treatmennt 30days
relationship between H2S and dose of vasopressors (noradrenaline, epinephrine) used
ICU treatmennt 30days

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University Medical Centre Ljubljana

Investigators

  • Principal Investigator: Matej Podbregar, MD PhD, University Medical Centre Ljubljana

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

January 1, 2010

Primary Completion (Actual)

January 1, 2012

Study Completion (Actual)

January 1, 2014

Study Registration Dates

First Submitted

March 12, 2010

First Submitted That Met QC Criteria

March 16, 2010

First Posted (Estimate)

March 17, 2010

Study Record Updates

Last Update Posted (Estimate)

December 5, 2014

Last Update Submitted That Met QC Criteria

December 3, 2014

Last Verified

December 1, 2014

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • H2S_1

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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