title: [Value of transcutaneous monitoring of CO2 pressure in the diagnosis and treatment of sleep and breathing disorders].
abstract: OBJECTIVE
  To evaluate the clinical value of transcutaneous carbon dioxide (TcPCO2) measurement during sleep respiratory monitoring.
  
  
  METHODS
  A total of 29 patients were prospectively recruited. Their age range was (49.5 ± 12.9) years and body mass index (BMI) (28.2 ± 3.6) kg/m(2). All of them underwent polysomnography (PSG) at Sleep Center, Peking University People's Hospital during the period of January-August 2013. TcPCO2 signal was entered into PSG systems and TcPCO2 (TCM4, Radiometer,Demark) measured simultaneously. Arterial blood gas (ABG) analysis for arterial pressure of CO2 (PaCO2) was undertaken to validate TcPCO2 measurement. The data were statistically analyzed by Pearson's product-moment correlation. Dynamic change of TcPCO2 was monitored during rapid eye movement (REM) and non-rapid eye movement (NREM) sleep stages. The effect of noninvasive positive airway pressure ventilation (NPPV) treatment on TcPCO2 during sleep was also observed.
  
  
  RESULTS
  TcPCO2 (44.2 ± 4.0) mmHg (1 mmHg = 0.133 kPa) was highly correlated with PaCO2 (43.2 ± 4.7) mmHg (Pearson's correlation, r = 0.896, P = 0.000), TcPCO2 (45.8 ± 5.4) mmHg level during wakefulness correlated significantly with that during N1, N2, N3 and REM sleep stages (r = 0.658, 0.871, 0.898,0.775; P = 0.009, 0.000, 0.003, 0.000). TcPCO2 levels during different sleep stages were all higher than that of wakefulness.However, TcPCO2 levels did not differ between two sleep stages. During both NREM and REM, elevated TcPCO2 returned to the level during wakefulness on NPPV treatment.
  
  
  CONCLUSIONS
  Continuous monitoring of PCO2 is well-tolerated during PSG testing. And the signal is stable. During whole night sleep, TcPCO2 monitoring provides more accurate and clinically acceptable estimation of PaCO2 so that it helps to titrate the NPPV pressure levels.
authors.affiliation: Department of Respiratory Medicine and Intensive Care Unit, People's Hospital, Peking University, Beijing 100044, China.
authors.forename: Yanan
authors.initials: Y
authors.lastname: Liu
authors.forename: Xiaosong
authors.initials: X
authors.lastname: Dong
authors.forename: Wei
authors.initials: W
authors.lastname: Zhou
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Pei
authors.initials: P
authors.lastname: An
authors.forename: Long
authors.initials: L
authors.lastname: Zhao
authors.forename: Zhancheng
authors.initials: Z
authors.lastname: Gao
authors.affiliation: Email: hanfang1@hotmail.com.
authors.forename: Fang
authors.initials: F
authors.lastname: Han
mesh_terms: D000328:Adult; D000368:Aged; D001785:Blood Gas Monitoring, Transcutaneous; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011175:Positive-Pressure Respiration; D011446:Prospective Studies; D012891:Sleep Apnea Syndromes / Q000097:blood* / Q000175:diagnosis / Q000628:therapy; D012894:Sleep Stages; D012893:Sleep Wake Disorders / Q000097:blood* / Q000175:diagnosis / Q000628:therapy; D055815:Young Adult