Esophageal 24-Hour pH Impedance

24 hour pH monitoring combined with impedance of the esophagus represents the most advanced diagnostic procedure in the evaluation gastroesophageal reflux disease (GERD).Through the nose of respondents put special thin probe, which at its tip has a sensor for determining the pH value or more sensors to determine impedance (impedance is a measure of resistance to electrical conduction).In this way, besides the possibility of detection of acid reflux and reflux can detect any kind of contents into the esophagus, gas or weakly acidic or alkaline.Also may be determined and the composition of the reflux, with respect to whether it is a liquid, gaseous or mixed.Thanks for impedance sensors covering the entire length of the esophagus, it is possible to determine the level of the esophagus odsnono pharyngeal reflux to which the content returns.

24 Hour impedance / pHmetraija a very sophisticated diagnostic procedures which, if done correctly, allows virtually 100% sensitivity in assessing the presence of reflux.In addition, computer software that analyzes the results and the likelihood izračuvana connection symptoms of patients with reflux episodes.This is extremely useful in determining the specific drug therapy, or evaluation of antireflux surgical treatment.

For more details about the examination, as well as the specificity and sensitivity of the procedure please read below.

Esophageal 24-Hour pH Impedance

Multichannel intraluminal impedance (MII) is a new technique in the evaluation functional diseases of the esophagus.Impedance is the resistance of electricity passing liquid or gas bolus in the lumen and it can be quantified and provide evidence of upward transit through the esophagus or reflux.Multichannel intraluminal impedance (MII) is a diagnostic procedure that measures the impedance in the lumen of the esophagus.Intraluminal impedance monitoring (measuring impedance from multiple intraluminal registration system) to detect changes in resistance in flow of an alternating electric current between two electrodes, when a bolus of fluid and / or gas moving between them.The introduction of this method has been proven that there are three types of gastroesophageal reflux: liquid, gaseous and mixed.Refluxed liquid may be acidic and non-acidic, while a combination of the mixed gas and liquid.When the bolus liquid nature impedance decreases, while it increases when the bolus is composed of gas.Impedance is very sensitive for detecting small quantities of liquids, and when combined with pH monitoring allows the detection and characterization of (the acid or the acid-) all reflux episodes.False positive changes in impedance are rare, so the specificity of this diagnostic procedure is very high, with a sensitivity for the detection of reflux episodes by 99%.Basic clinical significance of MII is in the discovery non-acid and liquid reflux, primarily in patients with GERD and prolonged conservative treatment, or those with extreme sensitivity of mucous membranes of the esophagus.

Through the nose into the esophagus introduces a catheter that is used as an insulator between the two electrodes at its tip that intraluminal create circumferential electric field.Changes in impedance between pairs of electrodes are used for detection of direction bolus.Resistance conductivity load esophagus is relatively stable and intraluminal impedance is measured between 2000 and 4000 ohms (Ω).The liquid content in the lumen of the esophagus has extremely high conductivity, so that when the liquid comes into contact with the electrodes come to a sharp drop in the values ​​of impedance.The value of impedance remains low until the bolus is present in the esophagus, and only after his clearance impedance values ​​returning to normal.If the gas is present in the esophagus whose in whom enforce-ability is very weak, there is an increase impedance at about 5000 ohms, because there is no electrical contact with the esophageal mucosa.Multichannel system enables the measurement of the transit time of the bolus through the esophagus, but also has the possibility of detection of reflux contents into the esophagus, or it is possible to estimate the type of reflux (liquid, gaseous, mixed) and the level to which reflux in the esophagus due.Reflux episodes on multichannel impedance is verified as a decrease in the impedance values ​​starting from distal channels and going upwards.

A special form of diagnosis represents a combined MII and esophageal manometry (MII-EM).This diagnostic procedure is able to present highly accurate data on the bolus transit in the esophagus.In MII-EM in manometry catheter embedded sensors impedance so that this diagnosis is particularly useful in identifying non-specific motility disorders of the esophagus, which is the conventional manometry can not precisely define.

In addition to determining whether the reflux liquid, gaseous or mixed type, when combined with the pH metric measurements of MII provides an insight into the exact pH of reflux contents.24 h the pH of the mixed-impedance (MII-pH) expands the possibility of diagnosing refluksata the same independent of its pH, thereby allowing detection and non-acidnog acidnog of GER.Using MII-pH can be determined with certainty whether it is a purely acid reflux (median pH ≤ 4), or non-acidic (average pH> 4) which can be divided into low acidic (pH between 4 and 7), and poor reflux base (pH> 7).The indication for MII-pH are persistent reflux symptoms with acidosupresivnu therapy, chronic cough, suspected ruminaciju, excessive belching and reflux symptoms in ahlorhidije.The specificity associated with MII pH monitoring is big and amounts to about 99%.



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