Correlation of end-tidal carbon dioxide with arterial carbon dioxide among patients in neurosurgical intensive care unit
10.3760/cma.j.issn.1001-8050.2015.09.015
- VernacularTitle:神经外科重症监护病房患者呼气末与动脉血二氧化碳分压的相关性
- Author:
Lei WANG
;
Jin LEI
;
Junfeng FENG
;
Qing MAO
;
Guoyi GAO
;
Jiyao JIANG
- Publication Type:Journal Article
- Keywords:
Craniocerebral trauma;
Capnography;
Blood gas monitoring,transcutaneous;
Ventilators,mechanical
- From:
Chinese Journal of Trauma
2015;31(9):814-819
- CountryChina
- Language:Chinese
-
Abstract:
Objective To examine the correlation between end-tidal carbon dioxide (PetCO2) and arterial CO2 (PaCO2) among patients admitted in neurosurgical intensive care unit (NICU) and the factors affecting the PaCO2-PetCO2 [P (a-et) CO2].Methods Thirty-two intubated or cut-trachea patients who presented in the NICU were enrolled.Arterial blood gas test was done at seven every morning,and values of PetCO2 were compared with simultaneously recorded PaCO2.The normal gap of P (a-et) CO2 was defined as-5 mmHg to 5 mmHg.Concordance between PaCO2 and PetCO2 was analyzed using the Bland-Altman plot.Parameters between the normal and high P(a-et) CO2 groups were compared to identify the factors affecting the P(a-et) CO2,including Glasgow Coma Scale(GCS),blood pressure (BP),heart rate (HR),respiration rate (RR),body temperature (BT),and pulse oxygen saturation (SpO2).Results Allvalues of PaCO2 and PetCO2 were in accordance with normal distribution (r =0.668,P < 0.01) and concordance between PaCO2 and PetCO2 was 69.8%.Patients who had high P(aet) CO2 showed lower initial GCS,lower instant GCS,BT,as well as pH and higher actual bicarbonate (AB) and PetCO2 than the patients with normal P (a-et) CO2.Correlation between PaCO2 and PetCO2 rapidly declined when positive end expiratory pressure(PEEP) was greater than 5 mmH2O(r =0.229,P < 0.01).Conclusions PetCO2 correlates well with PaCO2 and appears to be a useful monitor of respiratory function of the patients consecutively.Initial GCS,BT,AB and PEEP have an impact on P(a-et) CO2,so those factors should be considered when attempting to monitor the hyperventilation with PetCO2.