Blood gases and oxygen saturation

In acute exacerbations of COPD, white blood cell count, vital signs, chest x-ray, and changes in frequency of dyspnea, sputum volume, and sputum purulence should be assessed at the onset and throughout the exacerbation. In more severe exacerbations, arterial blood gases and oxygen saturation should also be monitored. 

Since infection may cause RDS, a sepsis work-up is needed, i.e., WBC with differential, and blood culture. Arterial blood gases and oxygen saturation monitors can be used to evaluate for adequate oxygenation. 

Treatment for the respiratory damage involves oxygen supplements, intubation, and artificial ventilation when indicated, as well as the use of a hyperbaric chamber to remove carbon monoxide, if needed. Any restriction to the chest owing to burned skin is removed surgically. The nurse must monitor arterial blood gases and oxygen saturation levels to determine the effectiveness of treatment. In addition, the nurse should monitor for signs of acidosis and related acid-base imbalances. <3 ... 

B. Other useful laboratory studies include electrolytes, glucose, BUN, creatinine, serum lactate, ECG, arterial blood gases and measured arterial and venous oxygen saturation (see Cyanide, p 177), and methemoglobin level. 

Evlauation Close monitoring of pulmonary status, blood gases (if indicated), oxygen saturation, chest x-ray, blood and sputum cultures, CBC, bronchoscopy with lavage (if needed)... 

Blood pressure, arterial blood gases, oxygen saturation, cyanide and thiocyanate concentrations, anion gap, lactate levels... 

Solutions include different combinations in which a solid, liquid, or gas acts as either solvent or solute. Usually the solvent is a liquid. For instance, sea water is an aqueous solution of many salts and some gases such as carbon dioxide and oxygen. Carbonated water is a saturated solution of carbon dioxide in water. Solutions are common in nature and are extremely important in all life processes, in all scientific areas, and in many industrial processes. The body fluids of all forms of life are solutions. Variations in concentrations of our bodily fluids, especially those of blood and urine, give physicians valuable clues about a person s health. Solutions in which the solvent is not a liquid are also common. Air is a solution of gases with variable composition. Dental fillings are solid amalgams, or solutions of liquid mercury dissolved in solid metals. Alloys are solid solutions of solids dissolved in a metal. 

Arterial oxygen pressure (Pa02) and saturation (Sa02) may be measured invasively by obtaining an arterial blood sample. Arterial blood gases measured by conventional arterial sampling are considered... 

B. Other laboratory tests include CBC, electrolytes, glucose, BUN, creatinine, arterial blood gases, amylase/llpase and liver transaminases, chest x-ray, and ECG monitoring. In addition, obtain serum lactate and mixed venous oxygen saturation if cyanide poisoning is suspected (see p 177). 

Because resting hypoxemia is not always evident and because severe exercise-induced hypoxemia may go undetected, it is important to consider exercise testing with serial measurement of arterial blood gases (or measurement of oxygen saturation by pulse oximetry). Arterial oxygen desaturation, a failure to decrease dead space appropriately with exercise (i.e., a high ratio), and an excessive increase in respiratory rate with a lower than expected recmitment... 

Raised metHb levels can falsely elevate the calculated oxygen saturation on arterial blood gas analysis. A saturation gap wiU occur when there is a difference between the O2 saturation measured on pulse oximetry and the O2 saturation calculated on arterial blood gases which may indicate methaemoglobinaemia. 

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