Type of test Photodiagnostic

Normal findings

 ≥ 95%

Possible critical values

 ≤ 75%

Test explanation and related physiology

 Oximetry is a noninvasive method of monitoring arterial blood oxygen saturation (Sao2 ). The Sao2 is the ratio of oxygenated hemoglobin to the total amount of hemoglobin. The Sao2 is expressed as a percentage; for example, a saturation of 95% indicates that 95% of the total hemoglobin attachments for oxygen have oxygen attached to them. The Sao2 is an accurate approximation of oxygen saturation obtained from an arterial blood gas study. By correlating the Sao2 and the patient’s physiologic status, a close estimate of the partial oxygen pressure (Po2 ) can be obtained.

Oximetry is typically used for monitoring the patient’s oxygenation status during the perioperative period (or any time of heavy sedation) and for patients receiving mechanical ventilation. This test is used in many clinical situations, such as pulmonary rehabilitation programs, stress testing, and sleep laboratories. Oximetry can be used to assess the body’s response to various drugs, such as theophylline (which causes bronchodilation) and methacholine (which evokes bronchospasm in people with asthma). This test is commonly used to titrate levels of oxygen on hospitalized patients.

O2 levels can also be measured in various body tissues. For example, monitors that continuously measure tissue O2 partial pressures can be attached to a small catheter placed in the brain, heart, or peripheral muscle. Brain tissue oxygen testing and monitoring is the most common use of this technology. It is used to monitor the condition of the brain after severe head trauma by measuring cerebral blood flow and pulmonary oxygenation. It is more accurate than intracranial pressure for indicating brain injury.

Procedure and patient care

Before

* Explain the procedure to the patient.

* Tell the patient that no fasting is required.

During

 • Rub the patient’s earlobe, pinna (upper part of the ear), or fingertip to increase blood flow.

• Clip the monitoring probe or sensor to the ear or finger. A beam of light passes through the tissue, and the sensor measures the amount of light the tissue absorbs (Figure 1).

• Note that this study is usually performed by a respiratory therapist or nurse at the patient’s bedside in a few seconds.

* Tell the patient that no discomfort is associated with this study.

Fig1. Oximetry. The pulse oximeter passes a beam of light through the tissue. The amount of light absorbed by the oxygen saturated hemoglobin is measured by the sensor.

After

 • Note that no special aftercare is needed.

Abnormal findings

Increased levels

- Increased inspired O2

- Hyperventilation

Decreased levels

- Inadequate O2 in inspired air

- Hypoxic lung diseases

- Hypoxic cardiac diseases

- Severe hypoventilation states

اخر الاخبار

اخبار العتبة العباسية المقدسة

العتبة العباسية المقدسة تواصل عقد مجلس عزائها بذكرى وفاة السيدة زينب (عليها السلام)

جمعية العميد تصدر الكتاب الأول من الموسوعة التربوية في نهج البلاغة

قسم صناعة الشبابيك يباشر أعمال إدامة الشباك القديم لمرقد الإمامين العسكريين (عليهما السلام)

صحن مرقد أبي الفضل العباس (عليه السلام) يشهد إقامة مجلس عزاء بذكرى وفاة السيدة زينب (عليها السلام)

المزيد

الآخبار الصحية

طبيب يكشف أفضل مكمل غذائي لتحسين المزاج ودعم الصحة النفسية

دراسة جديدة تكشف أضرار الأطعمة الجاهزة على القلب ؟

6 أطعمة طبيعية تهدئ الزكام دون أدوية.. تعرف عليهم

ماذا يحدث لأعراض الزكام عند تناول الثوم بانتظام؟

المزيد

الآخبار التكنلوجية

ابتكار ثوري في بطاريات السيارات الكهربائية.. سعة أعلى 4 مرات

ماذا يحدث لجسمك عند شرب الماء الساخن يوميا؟

7 فوائد "خفية" لشرب شاي الكركديه كل يوم

دراسة تكشف قدرة الحيتان على سماع الأصوات منخفضة وعالية التردد من مسافة بعيدة

المزيد

مواضيع ذات صلة

5′-nucleotidase

neutrophil gelatinase–associated lipocalin (NGAL, Lipocalin-2)

neutrophil antibody screen (Granulocyte antibodies, Polymorphonucleocyte antibodies [PMN ab], Antigranulocyte antibodies, Antineutrophil antibodies, Neutrophil antibodies, Leukoagglutinin)

Myoglobin

metal testing (lead, arsenic, mercury)

Clinical Molecular Biology: Diagnosis of Susceptibility

Laboratory diagnosis of SARS-CoV-2 : Point of Care Molecular Test

Laboratory diagnosis of SARS-CoV-2 : Real-time PCR

marijuana (THC) test (Cannabinoid or cannabis testing, Tetrahydrocannabinol [THC] testing)

lung cancer molecular testing (AKT1, ALK, BRAF, Epidermal growth factor [EGFR], HER2, KRAS, MEK1, MET, NRAS, PIK3CA, RET, and ROS1)

kidney stone analysis (Urinary stone analysis, Renal calculus analysis)

Variability and Standardization of CSF Examination