(34 days)
No
The document describes a standard critical care analyzer using optical fluorescence and scattering for measurements. There is no mention of AI, ML, or related concepts in the device description, intended use, or performance studies.
No
The device is used for measurement and analysis of various substances in blood and other fluids, providing diagnostic information rather than directly treating a condition.
Yes
The device measures multiple analytes (pH, PCO2, PO2, sodium, potassium, ionized calcium, chloride, glucose, urea (BUN), total hemoglobin content and oxygen saturation) in biological samples, which are used to provide information for diagnosis or monitoring of a patient's condition. The "Intended Use / Indications for Use" states it measures these parameters "in samples of whole blood, serum, plasma or dialysate".
No
The device description explicitly states it is a "small instrument" and details its physical dimensions and weight, indicating it is a hardware device. It also describes using optical fluorescence and scattering for measurements, which are hardware-based technologies.
Yes, this device is an IVD (In Vitro Diagnostic).
Here's why:
- Intended Use: The intended use explicitly states that the device is used for the "measurement of pH, PCO2, PO2, sodium, potassium, ionized calcium, chloride, glucose, urea (BUN), total hemoglobin content and oxygen saturation in samples of whole blood, serum, plasma or dialysate". These are all biological samples taken from the body, and the analysis is performed in vitro (outside the body).
- Device Description: The description details how the device analyzes these biological samples using optical fluorescence and scattering.
- Clinical Testing: The description of clinical testing confirms that the device is used to analyze "remnant from patient specimens of both whole blood and plasma".
All of these points align with the definition of an In Vitro Diagnostic device, which is used to examine specimens derived from the human body to provide information for diagnostic, monitoring, or screening purposes.
N/A
Intended Use / Indications for Use
The AVL OPTI Critical Care Analyzer is intended to be used for the measurement of pH, PCO2, PO2, sodium, potassium, ionized calcium, chloride, glucose, urea (BUN), total hemoglobin content and oxygen saturation in samples of whole blood, serum, plasma or dialysate in either a traditional blood gas, clinical laboratory setting or point-of-care locations by personnel minimally qualified to perform and report these results.
Product codes
75 CEM, 75 JFP, 75 JGS, 75 CGZ, 75 CHL, 81 GKR, 81 GLY, 75 KHP, 75 CDS, 75 CGA
Device Description
The AVL OPTI Critical Care Analyzer is a small [4.9 x 14.3 x 9.8 in, 10 lbs], instrument using optical fluorescence for the measurement of pH, PCO2, sodium, potassium, ionized calcium, choride. glucose and urea (BUN) of whole blood, plasma, serum or dialysate as appropriate. In addition, it uses scattering for the measurement of total hemoglobin and oxygen saturation. A disposable, single-use cassette containing six optical fluorescence sensors is packaged in a sealed foil pouch which bears a bar-coded label with calibration and identification information. The OPTI can perform up to 8 tests on a single sample, determined by the type of disposable cassette used.
Mentions image processing
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Mentions AI, DNN, or ML
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Input Imaging Modality
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Anatomical Site
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Indicated Patient Age Range
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Intended User / Care Setting
personnel minimally qualified to perform and report these results in either a traditional blood gas, clinical laboratory setting or point-of-care locations.
Description of the training set, sample size, data source, and annotation protocol
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Description of the test set, sample size, data source, and annotation protocol
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Summary of Performance Studies
Non-clinical tests: The AVL OPTI Critical Care Analyzer has been tested and found to comply with EN 50081-1, FCC Class B, EN 50081-2 and IEC 1010-1.
Precision: Typical Within-Run (Swr), Between-Day (Sdd) and Total (ST) precision were determined from two runs per day with 2 replicates per run for 20 days on two AVL OPTI instruments using samples: serum, reduced bovine hemoglobin solution and three levels of aqueous quality control solution.
Linearity: Linearity for the OPTI measurement has been established against reference materials or methods. Linearity for pH of whole blood is established by measurement of blood specimens which were tonometered to various CO2 values, and measured on an AVL 995 pH/Blood Gas Analyzer standardized to N.I.S.T. traceable pH buffers, and on OPTI Critical Care Analyzers.
Interferences: Representative samples taken the published guidelines for evaluation of interference substances and identified from literature were evaluated.
Clinical tests: Clinical testing was conducted to demonstrate the correlation of AVL OPTI Critical Care Analyzer to predicate devices in a clinical setting, operated by personnel trained to perform and report these analyses. Specimens analyzed in these tests were remnant from patient specimens of both whole blood and plasma collected for routine analysis on existing instrumentation.
In all evaluations, there was no significant difference in mean values (P
§ 862.1345 Glucose test system.
(a)
Identification. A glucose test system is a device intended to measure glucose quantitatively in blood and other body fluids. Glucose measurements are used in the diagnosis and treatment of carbohydrate metabolism disorders including diabetes mellitus, neonatal hypoglycemia, and idiopathic hypoglycemia, and of pancreatic islet cell carcinoma.(b)
Classification. Class II (special controls). The device, when it is solely intended for use as a drink to test glucose tolerance, is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 862.9.
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DEC I 6 1999
Image /page/0/Picture/2 description: The image shows a logo with the letters "AVL" in a stylized, bold, sans-serif font. The letters are interconnected, forming a single, unified shape. The logo is black against a white background, creating a high-contrast visual. The overall design is modern and geometric.
510(k) Summary
- Submitter's name, address (a) (1) AVL Scientific Corporation 235 Hembree Park Drive Roswell, GA 30076
Date of preparation of this summary:
Contact Person Randy Byrd Director, Quality Assurance 770.576.5000 x 631
11 November 1999
Device trade or proprietary name:
AVL OPTI Critical Care Analyzer
Device common or usual name or classification name
pH, Blood Gas, Electrolyte, hemoglobin and oxygen saturation analyzer
| PRODUCT NOMENCLATURE | REGULATION | NUMBER | CLASS | PANEL |
|---|---|---|---|---|
| ELECTRODE, ION-SPECIFIC, POTASSIUM | 862.1600 | 75 CEM | II | CHEMISTRY |
| ELECTRODE, ION-SPECIFIC, CALCIUM | 862.1145 | 75 JFP | II | CHEMISTRY |
| ELECTRODE, ION-SPECIFIC, SODIUM | 862.1665 | 75 JGS | II | CHEMISTRY |
| ELECTRODE, ION-SPECIFIC, CHLORIDE | 862.1170 | 75 CGZ | II | CHEMISTRY |
| ELECTRODE, BLOOD GASES (PCO2, PO2) AND pH | 862.1120 | 75 CHL | II | CHEMISTRY |
| SYSTEM, HEMOGLOBIN, AUTOMATED | 864.5620 | 81 GKR | II | HEMATOLOGY |
| OXIMETER, WHOLE BLOOD | 864.7500 | 81 GLY | II | HEMATOLOGY |
| ACID, LACTIC ENZYMATIC METHOD | 862.1450 | 75 KHP | II | CHEMISTRY |
| ELECTRODE, ION-SPECIFIC, UREA NITROGEN | 862.1770 | 75 CDS | II | CHEMISTRY |
| GLUCOSE OXIDASE, GLUCOSE | 862.1345 | 75 CGA | II | CHEMISTRY |
Substantial Equivalence (3)
The AVL OPTI is substantially equivalent in function, safety and efficacy to a number of currently marketed devices known as 'Combi Analyzers' and 'Point of Care' analyzers, Specifically: NOVA Biomedical STAT Profile [K981426], Chiron 865 [K946206], AVL OMNI [K990092], SenDx 100 [954482], Diametrics IRMA [981270], I-STAT 200 [940918], as well as electrolyte analyzers such as AVL 9181 [972763] and IL 943 Flame Photometer JK8234801. The OPTI Critical Care Analyzer is an improved design of the AVL OPTI 1 pH/Blood Gas Analyzer [K944089, K961161, K974784, 984299].
Description of the new device (4)
The AVL OPTI Critical Care Analyzer is a small [4.9 x 14.3 x 9.8 in, 10 lbs], instrument using optical fluorescence for the measurement of pH, PCO2, sodium, potassium, ionized calcium, choride. glucose and urea (BUN) of whole blood, plasma, serum or dialysate as appropriate. In addition, it uses scattering for the measurement of total hemoglobin and oxygen saturation. A disposable, single-use cassette containing six optical fluorescence sensors is packaged in a sealed foil pouch which bears a bar-coded label with calibration and identification information. The OPTI can perform up to 8 tests on a single sample, determined by the type of disposable cassette used.
(2)
000019
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(5) Intended use of the device
The AVL OPTI Critical Care Analyzer is intended to be used for the measurement of pH, PCO2, PO2, sodium, potassium, ionized calcium, chloride, glucose, urea (BUN), total hemoglobin content and oxygen saturation in samples of whole blood, serum, plasma or dialysate in either a traditional blood gas, clinical laboratory setting or point-of-care locations by personnel minimally qualified to perform and report these results.
(6) Technological characteristics of the device.
Principles of Measurement
The OPTI Critical Analyzer uses fluorescence optode technology similar to that used in commercially available products since late 1983 and is unchanged in principle of operation from the originally submitted 510(k) for this device. Additional parameters, sodium and potassium, ionized calcium, chloride, glucose and urea (BUN) are measured by fluorescence intensity and measurement of total Hemoglobin (ctHb) and oxygen saturation (SO2) is accomplished by optical scattering.
Calibration
A disposable, single-use cassette contains all the elements needed for calibration, QC sample measurement, patient sample measurement and waste containment. Calibration verification is performed with each cassette immediately prior to use. No other calibration is required for the usual operation of this device for the measurement of pH, PCO2, PO2, Na , K , Ca , Cl , Glucose, Urea (BUN). Total hemoglobin and SO2 are calibrated at 6month intervals.
(b) (1) Summary of non-clinical tests submitted with the premarket notification for the device.
The AVL OPTI Critical Care Analyzer has been tested and found to comply with EN 50081-1, FCC Class B, EN 50081-2 and IEC 1010-1.
Precision
Typical Within-Run (Swr), Between-Day (Sdd) and Total (ST) precision were determined from two runs per day with 2 replicates per run for 20 days on two AVL OPTI instruments using samples: serum, reduced bovine hemoglobin solution and three levels of aqueous quality control solution.
Linearity
Wherever possible, linearity for the OPTI measurement has been established against reference materials or methods. Linearity for pH of whole blood is established by measurement of blood specimens which were tonometered to various CO2 values, and measured on an AVL 995 pH/Blood Gas Analyzer standardized to N.I.S.T. traceable pH buffers, and on OPTI Critical Care Analyzers.
2
Interferences1
Representative samples taken the published guidelines for evaluation of interference substances and identified from literature were evaluated.
(b) (2) Summary of clinical tests submitted with the premarket notification for the device.
Clinical testing was conducted to demonstrate the correlation of AVL OPTI Critical Care Analyzer to predicate devices in a clinical setting, operated by personnel trained to perform and report these analyses. Specimens analyzed in these tests were remnant from patient specimens of both whole blood and plasma collected for routine analysis on existing instrumentation.
In all evaluations, there was no significant difference in mean values (P1 NCCLS. Interference Testing in Clinical Chemistry; Proposed Guideline. NCCLS Document EP7-P. NCCLS, 771 East Lancaster Avenue, Villanova, Pennsylvania 19085, 1986,
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Image /page/3/Picture/1 description: The image shows the seal of the Department of Health & Human Services (HHS) of the United States of America. The seal features a stylized eagle with three lines representing the three levels of health services: prevention, treatment, and rehabilitation. The text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" is arranged in a circular pattern around the eagle.
Food and Drug Administration 2098 Gaither Road Rockville MD 20850
DEC I 6 1999
Mr. Randy Byrd Director, Quality Assurance AVL Scientific Corporation 235 Hembree Park Drive Roswell, Georgia 30076
K993837 Re:
Trade Name: AVL OPTI Critical Care Analyzer Regulatory Class: II Product Code: CGA, CDS Dated: November 11, 1999 Received: November 12, 1999
Dear Mr. Byrd:
We have reviewed your Section 510(k) notification of intent to market the device referenced above and we have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration.
If your device is classified (see above) into either class II (Special Controls) or class III (Premarket Approval), it may be subject to such additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 895. A substantially equivalent determination assumes compliance with the Current Good Manufacturing Practice requirements, as set forth in the Quality System Regulation (QS) for Medical Devices: General regulation (21 CFR Part 820) and that, through periodic OS inspections, the Food and Drug Administration (FDA) will verify such assumptions. Failure to comply with the GMP regulation may result in regulatory action. In addition, FDA may publish further announcements concerning your device in the Federal Register. Please note: this response to your premarket notification submission does not affect any obligation you might have under sections 531 through 542 of the Act for devices under the Electronic Product Radiation Control provisions, or other Federal laws or regulations.
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Page 2
Under the Clinical Laboratory Improvement Amendments of 1988 (CLIA-88), this device may require a CLIA complexity categorization. To determine if it does, you should contact the Centers for Disease Control and Prevention (CDC) at (770) 488-7655.
This letter will allow you to begin marketing your device as described in your 510(k) premarket notification. The FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and thus, permits your device to proceed to the market.
If you desire specific advice for your device on our labeling regulation (21 CFR Part 801 and additionally 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4588. Additionally, for questions on the promotion and advertising of your device, please contact the Office of Compliance at (301) 594-4639. Also, please note the regulation entitled, "Misbranding by reference to premarket notification"(21 CFR 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers Assistance at its toll-free number (800) 638-2041 or (301) 443-6597, or at its internet address "http://www.fda.gov/cdrh/dsma/dsmamain.html".
Sincerely yours,
Steven Sutman
Steven I. Gutman, M.D. M.B.A. Director Division of Clinical Laboratory Devices Office of Device Evaluation Center for Devices and Radiological Health
Enclosure
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510(k) Number: K993837
Device Name:
The AVL OPTI Critical Care Analyzer intended to be used for the measurement of pH, PCO2, PO2, ctHb, SO2, Na*, K*, Cl*, Cl*, glucose and BUN in whole blood, serum, plasma and aqueous dialysate solutions as appropriate by minimally trained personnel qualified to perform and to report these values in either a traditional blood gas, clinical laboratory setting or point-of-care locations by personnel minimally qualified to perform and report these results.
For Professional Use Only For In Vitro Diagnostic Use
Indications for Use1,2
DH
The pH value of the blood may be the single most valuable factor in the evaluation of the acid-base status of a patient. The pH value is an indicator of the balance between the buffer (blood), renal (kidnev) and respiratory (lung) systems, and one of the most tightly controlled parameters in the body. The causes of abnormal blood pH values are generally classified as:
- · primary bicarbonate deficit metabolic acidosis
- primary bicarbonate excess . metabolic alkalosis · primary hypoventilation respiratory acidosis
- · primary hyperventilation respiratorv alkalosis
An increase in blood, serum or plasma pH (alkalemia) may be due to increased plasma bicarbonate, or a feature of respiratory alkalosis due to an increased elimination of CO2 due to hyperventilation.
A decrease of pH value (acidemia) in blood, serum or plasma may occur due to an increased formation of organic acids, an increased excretion of H -ions in certain renal disorders, an increased acid intake such as in salicylate poisoning or loss of alkaline body fluids. Respiratory acidosis is the result of a decreased alveolar ventilation and may be acute, as the result of pulmonary edema, airway obstruction or medication, or maybe be chronic, as the result of obstructive or restrictive respiratory diseases.
The composition of serous body fluids: pleural, pericardial, ascitic and cerebrospinal fluid, is similar to serum and plasma in electrolyte content and pH. The AVL OPTI may be used for the analysis of these fluids, limited to a pH in the
1 Tietz, Norbert W., Ed., Clinical Guide to Laboratory Tests, 2nd Ed., (Philadelphia: W.B.Saunders, Co., 1990) p.436.
2 Burtis C, Ashwood E (Eds.), Tietz Textbook of Clinical Chemistry, 2nd Ed., (Philadelphia: W.B.Saunders, Co., 1994) pp.1354-1360,2180-2206.
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range between 6.8 and 7.7, as long as care is taken to ensure the specimen to be analyzed is clear of fibrin clots or other debris which may block the sample transport in the cassette.
Pleural fluid3
The pH measurement of pleural fluid can be a clinically useful tool in the management of patients with parapneumonic effusions. Patients with pneumonia may develop effusions when the infectious process extends to the visceral pleura, causing exudation of fluid into the pleural space. Fluids are divided into potentially benign and complicated effusions on the basis of pH. Fluids with a pH greater than 7.30 resolve spontaneously, whereas a pH less than 7.20 is an indication of tube drainage.
PCO2
The PCO2 value of arterial blood is used to assess how well the body eliminates carbon dioxide in relation to the metabolic rate of CO2 production.
An arterial PCO2 below the normal range is termed respiratory alkalosis and indicates hypocapnia, a condition caused by increased alveolar ventilation such as hyperventilation. An arterial PCO2 above the normal range is termed respiratory acidosis and indicates hypercapnia, a sign of hypoventilation and failure, resulting from cardiac arrest, chronic obstructive lung disease, drug overdose, or chronic metabolic acid-base disturbances.
PCO2
The PO2 value of arterial blood has become the primary tool for the evaluation of arterial oxygenation status. Values below the normal arterial PO2 (arterial hypoxemia) are usually caused by pulmonary, circulatory, or respiratory abnormalities (e.g. bronchial obstruction, vascular problems, decrease in cardiac output, increased oxygen demand, anatomical heart defect, low inspired O2 content). Generally, PO2 levels above 100 mmHg do not contribute significantly to the oxygen content since, with normal hemoglobin concentrations, 80 - 100 mmHg, PO2 provides a 97 % saturation level, and a level greater than 100 % cannot be achieved.
Sodium
Sodium is the major cation of extracellular fluid. Its primary functions in the body are to chemically maintain osmotic pressure and acid-base balance and to transmit nerve impulses. Sodium functions at the cell membrane level by creating an electrical potential between different cell membranes causing the transmission of nerve impulses and neuromuscular excitability to be maintained. Sodium is involved in some enzyme catalyzed reactions as a cofactor. The body has a strong tendency to maintain a total base
3 Kaplan LA. Pesce AJ. Clinical Chemistry: Theory, analysis and correlation. 2nd Ed. (St.Louis: C.V.Mosby Co. 1989) p 590-591.
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content, and only slight changes are found even under pathologic conditions.
Low sodium values, hyponatremia, usually reflect a relative excess of body water rather than a low total body sodium. Reduced sodium levels may be associated with: low sodium intake; sodium losses due to vomiting or diarrhea with adequate water and inadequate salt replacement, diuretics abuse, or salt-losing nephropathy; osmotic diuresis, metabolic acidosis; adreocortical insufficiency; congenital adrenal hyperplasia; dilution type due to edema, cardiac failure, hepatic failure; and hypothyroidism.
Elevated sodium values, hypernatremia, are associated with conditions with water loss in excess of salt loss through profuse sweating, prolonged hyperpnea, severe vomiting or diarrhea. diabetes insipidus or diabetic acidosis; increased renal sodium conservation in hyperaldosteronism, Cushing's syndrome; inadequate water intake because of coma or hypothalamic diseases; dehydration; or excessive saline therapy.
The sodium value obtained may be used in the diagnosis or monitoring of all disturbances of the water balance, infusion therapies, vomiting, diarrhea, burns, heart and kidney insufficiencies, central or renal diabetes insipidus, endocrine disturbances and primary or secondary cortex insufficiency of the adrenal gland or other diseases involving electrolyte imbalance.
Potassium
Potassium is the major cation in the intracellular fluid and functions as the primary buffer within the cell itself. Ninety percent of potassium is concentrated within the cell, and damaged cells release potassium into the blood. Potassium plays an important role in nerve conduction, muscle function, and helps maintain acid-base balance and osmotic pressure.
Elevated potassium levels, hyperkalemia, can be found in oligouria, anemia, urinary obstruction, renal failure due to nephritis or shock, metabolic or respiratory acidosis. renal tubular acidosis with the K /H exchange and hemolysis of the blood. Low potassium levels, hypokalemia, can be found in excessive loss of potassium through diarrhea or vomiting, inadequate intake of potassium, malabsorption, severe burns and increased secretion of aldosterone. High or low potassium levels may cause changes in muscle irritability, respiration and myocardial function.
The potassium value obtained may be used to monitor electrolyte imbalance in the diagnosis and treatment of infusion therapies, shock, heart or circulatory insufficiency, acid-base imbalance, therapy with diuretics, all kinds of kidney problems, diarrhea and hyper- and hypo-function of adrenal cortex and other diseases involving electrolyte imbalance.
lonized Calcium
Calcium in blood is distributed as free calcium ions (50%) bound to protein, mostly albumin (40%) and 10% bound to anions such as bicarbonate, citrate, phosphate
8
and lactate. However, only ionized calcium can be used by the body in such vital processes as muscular contraction, cardiac function, transmission of nerve impulses and blood clotting. The OPTI CCA measures the ionized portion of the total calcium. In certain disorders such as pancreatitis and hyperparathyroidism, ionized calcium is a better indicator for diagnosis than total calcium.
Elevated calcium, hypercalcemia, may be present in various types of malienancy. and calcium measurements may serve as biochemical markers. In general, while ionized calcium may be slightly more sensitive, either ionized or total calcium measurements have about equal utility in the detection of occult malignancy. Hypercalcemia occurs commonly in critically ill patients with abnormalities in acidbase regulation and losses of protein and albumin, which gives a clear advantage to monitoring calcium status by ionized calcium measurements.
Patients with renal disese caused by glomular failure often have altered concentrations of calcium, phosphate, albumin, magnesium and pH. Since these conditions tend to change ionized calcium independently of total calcium, ionized calcium is the preferred method of accurately monitoring calcium status in renal disease 19.
Ionized calcium is important for diagnOosis or monitoring of: hypertension management, parathyroidism, renal diseases, malnutrition, kidney stoes, multiple myeloma and diabetes mellitus.
Chloride
Chloride is an anion that exists predominantly in extracellular spaces. It maintains cellular integrity through its influence on osmotic pressure. It is also significant in monitoring acid-base balance and water balance. In metabolic acidosis, there is a reciprocal rise in chloride concentration when the bicarbonate concentration drops.
Decreased levels are found in severe vomiting, severe diarrahea, ulcerative colitis, pyloric obstruction, severe burns, heat exhaustion, diabetic acidosis, Addison's disease, fever and acute infections such as pneumonia.
Increased levels are found in dehydration, Cushing's syndrome, hyperventilation, eclampsia, anemia, cardiac decompensation.
Glucose
Hyperglycemia can be due to a number of causes which can be sub-divided into those due to diabetes mellitus or those due to non-diabetic causes. Diabetes mellitus is a syndrome of chronic hyperglycemia which is due to either absolute insulin deficiency or reduced tissue response to insulin, or both. It is a common condition which is diagnosed according to strict criteria that rely upon measurement of the blood glucose level. Nondiabetic causes of hyperglycaemia include
19 Burritt MF, Pierides AM, Offord KP: Comparative studies of total and ionized scrum calcium values in normal subjects and in patients with renal disorders. Mayo Clinic Proc. 55:606. 1980.
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postprandial (occurs immediately after a carbohydrate-containing meal), factitious (blood taken from an arm where glucose is being infused), drugs (produce a tissue insensitivity to insulin), non-pancreatic endocrine disease (excessive production of anti-insulin hormones), pancreatic disorders (secondary diabetes mellitus), and stress (physical and psychogenic types causing excess secretion of cortisol and catecholamines.
Hypoglycemia is an acute medical condition with a number of characteristic signs and symptoms which are accompanied by biochemical hypoglycamia and which are relieved by the administration of glucose. The causes of hypoglycaemia can be divided into three groups: Medication/Toxins, Reactive Hypoglycemia; Fasting Hypoglycemia. Hypoglycemia due to excessive amounts of certain Medications or Toxins include insulin (insulin overdose is the commonest cause of hypoglycemia), oral hypoglycaemics or suphonylureas, ethanol and other drugs such as salicylate and propanalol. Reactive Hypoglycemia occur, within 5-hours of a carbohydrate meal in otherwise normal subjects, in patients with early adult-onset diabetes mellitus and in patients who have had gastric surgery. Fasting Hypoglycemia can be due to insulinomas, non-pancreatic tumors, endocrine disorders, liver failure, sepsis, renal failure or autoimmune disorders.
Urea Nitrogen
Urea is produced in the liver as a by-product from the breakdown of amino acids. These are transaminated and deaminated to ammonia which is a toxin. Detoxification of ammonia occurs in the urea cycle where two molecules of ammonia are joined to a molecule of carbon dioxide to form urea. Approximately 1120-1680 mg/dL of urea nitrogen are produced per day but the production depends upon protein intake and liver function. A wide variety of renal diseases with different permutations of glomerlular, tubular, interstitial or vascular damage can effect azotemia (increased urea concentration).
total Hemoglobin concentration (ctHb)
The hemoglobin is the main component of erythrocytes. It serves as the vehicle for transportation of oxygen within the bloodstream and each gram/dL of hemoglobin can carry 1.39 mL of oxygen. The oxygen combining capacity of the blood is directly proportional to the hemoglobin concentration rather than to the number of red blood cells (RBC), because some red cells contain more hemoglobin than the others.
Although oxygen transport is the main function of hemoglobin, it also serves as an important buffer in the extracellular fluid. Decreases in the amount of hemoglobin can come about as a result of a decreased concentration of hemoglobin in the erythrocytes, or a decreased number of erythrocytes that contain a normal concentration of hemoglobin.
Decreased levels are found in anemia states, hyperthyroidism, severe hemorrhage and hemolytic reactions due to transfusions of incompatible blood, reaction to
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chemical, infectious and physical agents as well as various systemic diseases. Increased levels are found in hemoconcentration of the blood, chronic obstructive pulmonary disease and congestive heart failure.
CtHb gives valuable information in an emergency situation if interpreted not in an isolated fashion but in conjunction with other pertinent laboratory data.
ctHb is used to screen for disease associated with anemia, to determine the severity of anemia, to follow the response to treatment for anemia and to evaluate polycythemia.
Oxygen Saturation (SO2%)
When each heme group of the hemoglobin molecule is associated with one molecule of oxygen, the hemoglobin is referred to as oxyhemoglobin (O2Hb). The amount of oxyhemoglobin, expressed as a fraction of the total available hemoglobin is termed, hemoglobin oxygen saturation (SO2). The largest portion (about 98%) of blood oxygen content is the oxygen bound to hemoglobin. The reference interval for arterial blood from healthy adults is typically 94 to 98%. Decrease in SO2 below the critical level necessary for tissue oxygen saturation is a grave clinical situation. Low oxygen saturation may be caused by many of the same factors responsible for arterial hypoxemia, as well as from unusually large amounts of non-functional hemoglobins, high concentrations of deoxyhemoglobin, chemically altered hemoglobin or factors affecting the affinity of hemoglobin for oxygen, including: temperature, pH, PCO2, 2,3-DPG concentration and type of hemoglobin. 3
4 Siggaard-Andersen O. Durst RA. Maas AHJ. IFCC/IUPAC approved recommendation (1984) on physicochemical quantities and units in clinical chemistry. J Clin Chem Clin Biochem. 25:369-391. 1987.
5 Burtis C, Ashwood E (Eds.), Tietz Textbook of Clinical Chemistry, 2nd Ed., (Philadelphia: W.B.Saunders, Co., 1994) pp.1354-1360,2180-2206.
Qian Cooper
I Laborator
(PLEASE DO NOT WRITE BELOW THIS LINE - CONTINUE ON ANOTHER PAGE IF NEEDED)
Concurrence of CDRH, Office of Device Evaluation (ODE)
Prescription Use \ (Per 21 CFR 801.109)
OR
Over-The-Counter Use
(Optional Format 1-2-96)
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