ABSTRACT
Diffusing capacity of the lung for nitric oxide (DLNO), otherwise known as the transfer factor, was first measured in 1983. This document standardises the technique and application of single-breath DLNO This panel agrees that 1) pulmonary function systems should allow for mixing and measurement of both nitric oxide (NO) and carbon monoxide (CO) gases directly from an inspiratory reservoir just before use, with expired concentrations measured from an alveolar "collection" or continuously sampled via rapid gas analysers; 2) breath-hold time should be 10â s with chemiluminescence NO analysers, or 4-6â s to accommodate the smaller detection range of the NO electrochemical cell; 3) inspired NO and oxygen concentrations should be 40-60â ppm and close to 21%, respectively; 4) the alveolar oxygen tension (PAO2 ) should be measured by sampling the expired gas; 5) a finite specific conductance in the blood for NO (θNO) should be assumed as 4.5â mL·min-1·mmHg-1·mL-1 of blood; 6) the equation for 1/θCO should be (0.0062·PAO2 +1.16)·(ideal haemoglobin/measured haemoglobin) based on breath-holding PAO2 and adjusted to an average haemoglobin concentration (male 14.6â g·dL-1, female 13.4â g·dL-1); 7) a membrane diffusing capacity ratio (DMNO/DMCO) should be 1.97, based on tissue diffusivity.
Subject(s)
Blood Volume , Nitric Oxide/blood , Pulmonary Alveoli/blood supply , Pulmonary Diffusing Capacity/standards , Adolescent , Adult , Aged , Aged, 80 and over , Capillary Permeability , Carbon Monoxide/blood , Female , Hemoglobins/analysis , Humans , Linear Models , Male , Middle Aged , Oxygen/blood , Young AdultABSTRACT
Lung diffusing capacity for nitric oxide (DLNO) is used to measure alveolar membrane conductance (DMNO), but disagreement remains as to whether DMNO=DLNO, and whether blood conductance (thetaNO)=infinity. Our previous in vitro and in vivo studies suggested that thetaNOSubject(s)
Capillary Permeability
, Cell Membrane Permeability
, Erythrocytes/metabolism
, Lung/blood supply
, Lung/metabolism
, Nitric Oxide/blood
, Pulmonary Circulation
, Pulmonary Diffusing Capacity
, Animals
, Blood Substitutes/pharmacology
, Blood Volume
, Capillary Permeability/drug effects
, Carbon Monoxide/blood
, Cell Membrane Permeability/drug effects
, Dogs
, Erythrocytes/drug effects
, Exchange Transfusion, Whole Blood
, Hemoglobins/pharmacology
, Hemolysis
, Lung/drug effects
, Male
, Models, Cardiovascular
, Pulmonary Diffusing Capacity/drug effects
, Time Factors
ABSTRACT
A 63-year-old previously healthy woman developed a severe systemic infection 5 days after returning from a holiday to Southern Portugal. She subsequently died, and polymerase chain reaction of a blood sample was positive for Rickettsia conorii ssp israeliensis. The prevalence of severe forms of this illness in the Mediterranean Basin is discussed.
