Arterial oxygen saturation

Initial stabilization requires achievement of adequate arterial oxygen saturation and content. 

Respiratory alkalosis is associated with low partial pressure of02 (25 to 35 mm Hg) and alkaline pH, but normal bicarbonate. The first two values are measured by arterial blood gas, which also yields partial pressure of carbon dioxide and arterial oxygen saturation. Circulating arterial oxygen saturation can also be measured by an oximeter, which is a noninvasive method that is fairly accurate and useful at the patient s bedside. 

Tissue hypoxia occurs within 4 minutes of failure to deliver adequate supply. Hyperventilation due to carotid chemoreceptor stimulation becomes noticeable when P02 falls to 5.3. Arterial oxygen saturation should be between 95-100%. This patient has a good saturation figure of 99.6%. 

A pulmonary artery (Swan-Ganz) catheter can be used to determine central venous pressure (CVP) pulmouary artery pressure CO aud pulmonary artery occlusive pressure (PAOP), an approximate measure of the left ventricular eud-diastolic volume aud a major determinaut of left veutricular preload. CO (2.5 to 3 L/min) and mixed venous oxygeu saturatiou (70% to 75%) may be very low in a patient with extensive myocardial damage. Respiratory alkalosis is associated with low partial pressure of O2 (25 to 35 mm Hg) and alkaline pH, but uormal bicarbouate. The first two values are measured by arterial blood gas, which also yields partial pressure of carbon dioxide and arterial oxygen saturation. Circulating arterial oxygen saturation can also be measured by an oximeter, which is a noninvasive method that is fairly accurate and useful at the patient s bedside. 

Patients with acute severe asthma should receive supplemental oxygen therapy to maintain arterial oxygen saturation above 90% (above 95% in pregnant women and patients with heart disease). Significant dehydration should be corrected urine specific gravity may help guide therapy in young children, in whom assessment of hydration status may be difficult. 

Felodipine is a dihydropyridine derivative with diuretic properties (1). Its diuretic properties are not unique but are shared by other dihydropyridines. Its vasodilator-related adverse effects include flushing, headache, and tachycardia (2,3). Reduced arterial oxygen saturation has been seen in patients given intravenous felodipine for pulmonary hypertension (4,5). Along with amlodipine, but unlike other calcium channel blockers, felodipine may be safer in severe chronic heart failure accompanied by angina or hypertension. 

However, reducing the volume of local anesthetic (1.5% mepivacaine) from 40 to 20 ml, and applying proximal digital pressure, did not reduce the incidence or intensity of diaphragmatic paralysis during interscalene block in 20 patients, in whom arterial oxygen saturation fell significantly (53). 

Although the recommended dose of ipratropium is 2 puffs four times a day, there is evidence for a dose-response, so the dose can be titrated upward often to 24 puffs a day. Ipratropium has been shown to increase maximum exercise performance in stable COPD patients with doses of 8 to 12 puffs prior to exercise but not with doses of 4 puffs or less. " During sleep, ipratropium also has been shown to improve arterial oxygen saturation and sleep quality. Ipratropium is well tolerated. Themostfrequent patientcomplaints are dry mouth, nausea, and an occasional metallic taste. 

General GCS Record hourly initially, decrease frequency as neurologic status stabilizes Vital signs (BP, HR, RR, temperature) Record hourly initially, decrease frequency as neurologic status stabilizes Urine output Record hourly initially, decrease frequency as neurologic status stabilizes Arterial oxygen saturation Continuously while in intensive care unit... 

In utero the ductus arteriosis is kept open by low arterial oxygen saturation and elevated prostaglandin E2 (PGE2) levels. Functional closure occurs in the first 2 days of life due to increased oxygen saturation and decreased PGE2. 

Yoshiya I., Shimada Y., and Tanaka K. 1980. Spectrophotometric monitoring of arterial oxygen saturation in the fingertip. Med. Biol. Eng. Comput. 18 27. 

Mendelson Y. and Solomita M.V. 1992. The feasibility of spectrophotometric measurements of arterial oxygen saturation from the scalp utilizing noninvasive skin reflectance pulse oximetry. Biomed. Instrum. Technol. 26 215. 

In this way the measurement of the ratio of the fractional change in signal intensity of the two LEDs is used along with the empirically determined calibration equation to obtain a beat-by-beat measurement of the arterial oxygen saturation in a perfused tissue—continuously, noninvasively, and to an accuracy... 

---