Correlation of End tidal and Arterial carbon dioxide in mechanically ventilated children

All intubated children with post intubation Xray will be assessed for eligibility. Informed Consent will be obtained from the parents of the study participants ,Children who Satistied inclusion criteria will be taken up for the study. Indication for ICU admission and mechanical ventilation will be noted . Whenever Arterial blood gas done as a part of standard protocol of treatment, simultaneously Etco2 will be recorded. Continuous mainstream Etco2 monitoring probe, Philips Capnostat M2501A gas analyser will be attached to endotracheal tube for recording Simultaneous Etco2 and PaCo2 measurements will be recorded in a bedside datasheet. At least two readings will be taken from each patient with a minimum gap of 24 hours as a part of standard protocol of treatment , these values help in assessment of patient status and guide in further management.  At the time of data collection, the following ventilator parameters will be recorded: Respiratory rate, Fractional inspired oxygen concentration (Fio2), expiratory tidal volume, peak inspiration pressure (PIP), positive end-expiratory pressure (PEEP), Oxygen saturation(spo2). Inspiratory time (Ti) and I:E ratio.  Severity of lung disease will be calculated using Ventilation index (VI), Oxygenation Index and P/F ratio. PF ratio will be calculated using the formula Pao2/Fio2, where Pao2 is Partial pressure of arterial Oxygen tension, Fio2 is Fraction of inspired Oxygen. PIF ratio <200 is considered as abnormal. Ventilation index will be calculated using equation VI = (Paco2 X PIP]X RR, where paco2 is partial pressure of co2 and PIP is Peak inspiratory pressure, RR is respiratory rate of mechanical ventilator VI for > 20 is considered as high. Oxygenation Index: Ol= FIO2 X MAP/Paco2  (Mean airway pressure)  Ol >16: Severe ARDS.   data obtained will be analysed using the Statistical Package for Social Sciences (SPSS) version 23.0. Descriptive will be expressed as frequencies and percentages. Mean and standard deviation will be computed for the variables following normal distribution curve while median and inter-quartile range will be Computed for nonparametric data Fisher exact test will be used to test categorical variables. Student t-test or Mann Whitney test will be used to compare mean or median value of parameter between 2 groups. Pearson bivariate Correlation will be used to study the linear correlation, Coefficient of determination will be calculated by applying the linear regression with Paco2 as the dependent and Etco2 as the independent variable The cut-off p-value for the significance test will be <0.05