title: Earlobe arterialized capillary blood gas analysis in the intensive care unit: a pilot study.
abstract: BACKGROUND
  Earlobe arterialized capillary blood gas analysis can be used to estimate arterial gas content and may be suitable for diagnosis and management of critically ill patients. However, its utility and applicability in the ICU setting remains unexplored.
  
  
  METHODS
  A prospective observational validation study was designed to evaluate this technique in a cohort of mechanically ventilated adult critically ill patients admitted to a polyvalent ICU. Precision and agreement between capillary gas measures and arterial references was examined. Acute Respiratory Distress Syndrome (ARDS) diagnosis capabilities with the proposed technique were also evaluated. Finally, factors associated with sampling failure were explored.
  
  
  RESULTS
  Fifty-five patients were included into this study. Precision of capillary samples was high (Coefficient of Variation PO2 = 9.8%, PCO2 = 7.7%, pH = 0.3%). PO2 measures showed insufficient agreement levels (Concordance Correlation Coefficient = 0.45; bias = 12 mmHg; percentage of error = 19.3%), whereas better agreement was observed for PCO2 and pH (Concordance Correlation Coefficient = 0.94 and 0.93 respectively; depreciable bias; percentage of error 11.4% and 0.5% respectively). The sensitivity and specificity for diagnosing ARDS were 100% and 92.3% using capillary gasometric measures. Sampling was unsuccessful in 43.6% of cases due to insufficient blood flow. Age > 65 years was independently associated with failure (odds ratio = 1.6), however hemodynamic failure and norepinephrine treatment were also influencing factors.
  
  
  CONCLUSIONS
  Earlobe capillary blood gas analysis is precise and can be useful for detecting extreme gasometrical values. Diagnosis of ARDS can be done accurately using capillary measurements. Although this technique may be insufficient for precise management of patients in the ICU, it has the potential for important benefits in the acute phase of various critical conditions and in other critical care arenas, such as in emergency medicine, advanced medical transport and pre-hospital critical care.
authors.affiliation: Critical Care Center, Sabadell Hospital, CIBER Enfermedades Respiratorias, Parc Tauli University Institute, Parc Taulí 1, 08208 Sabadell, Spain.
authors.forename: Sergi
authors.initials: S
authors.lastname: Vaquer
authors.affiliation: Critical Care Center, Sabadell Hospital, CIBER Enfermedades Respiratorias, Parc Tauli University Institute, Parc Taulí 1, 08208 Sabadell, Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Masip
authors.affiliation: Critical Care Center, Sabadell Hospital, CIBER Enfermedades Respiratorias, Parc Tauli University Institute, Parc Taulí 1, 08208 Sabadell, Spain.
authors.forename: Gisela
authors.initials: G
authors.lastname: Gili
authors.affiliation: Critical Care Center, Sabadell Hospital, CIBER Enfermedades Respiratorias, Parc Tauli University Institute, Parc Taulí 1, 08208 Sabadell, Spain.
authors.forename: Gemma
authors.initials: G
authors.lastname: Gomà
authors.affiliation: Critical Care Center, Sabadell Hospital, CIBER Enfermedades Respiratorias, Parc Tauli University Institute, Parc Taulí 1, 08208 Sabadell, Spain.
authors.forename: Joan Carles
authors.initials: JC
authors.lastname: Oliva
authors.affiliation: Wyle GbmH, Albin Koebis Strasse 4, Cologne, Germany.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Frechette
authors.affiliation: Wyle GbmH, Albin Koebis Strasse 4, Cologne, Germany.
authors.forename: Simon
authors.initials: S
authors.lastname: Evetts
authors.affiliation: Centro de Microgravidade/FENG-PUCRS, Av. Ipiranga, 6681 - Partenon, 90619-900 Porto Alegre, (RS), Brazil.
authors.forename: Thais
authors.initials: T
authors.lastname: Russomano
authors.affiliation: Critical Care Center, Sabadell Hospital, CIBER Enfermedades Respiratorias, Parc Tauli University Institute, Parc Taulí 1, 08208 Sabadell, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Artigas
keywords: Acute respiratory failure; Arterialized; Capillary blood; Emergency medicine; Intensive care medicine; Mechanical ventilation
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