We describe an opto-electronic device capable of measuring the hemoglobin concentration (Hgb) non-invasively and continuously, hence the percentage changes in blood volume (BV) during dialysis treatment by means of the optical absorption of monochromatic light by the blood in the arterial line. This method has been validated during several in ...

Changes in cerebral venous oxyhemoglobin saturation reflect changes in the balance between cerebral oxygen delivery and cerebral oxygen consumption. Invasive monitoring of cerebral venous saturation (CSVO2) has provided useful information in the management of critically ill adults at risk of cerebral hypoxia. This study describes the development and validation of ...

A standard of care for providing pulse oximetry monitoring for patients receiving conscious sedation during and after endoscopy has not been established. This study sought to clarify whether desaturation occurs after gastroscopy and colonoscopy and what characteristics are predictive of desaturation that does occur. The convenience sample consisted of 475 ...

Systemic venous oxygen saturation is clinically used as an indicator of a satisfactory oxygen supply demand balance on cardiopulmonary bypass (CBP). Cerebral desaturation has been associated with postoperative cognitive dysfunction and has an incidence of 17% to 23% on bypass. We tested the hypothesis that systemic venous saturation did not ...

It has been postulated that leukotriene B4 is involved in the pathogenesis of postischaemic cerebral oedema. We set out to determine if a relationship exists between jugular bulb leukotriene B4 and other indicators of cerebral ischaemia. No association could be demonstrated for either intracranial pressure, jugular bulb blood oxygen saturation ...

BACKGROUND: Monitoring the jugular venous oxygen saturation (SjVO2) and cerebral arteriovenous oxygen difference (AVDO2) is valuable in detecting cerebral ischemia. In the present study, we investigated the effect of mannitol on SjVO2 and AVDO2 in patients undergoing craniotomy. METHODS: We studied 25 ASA class II-III patients undergoing craniotomy. Anesthesia was ...

We describe a patient who had a cardiac arrest during anaesthesia, in whom regional cerebral oxygen saturation was being measured by near infrared spectroscopy and the auditory evoked responses (AER) were being recorded. Both of these monitors provided useful information on cerebral oxygenation during cardiac arrest. Changes in the AER ...

A prospective observational study was performed to assess the reliability of fibreoptic oximetric catheters and to identify the incidence and causes of jugular bulb oxygen desaturation in patients with acute closed head injury. There were twenty-five patients (30 +/- 16 years) with GCS < or = 8 in this study. ...

The aim of our study was to evaluate the reliability of pulse oximetry in detecting both hyper- and hypoxaemic states and to create clinically feasible alarm limits. A total of 792 readings of a pulse oximeter and corresponding values of arterial oxygen tension from 146 (79M, 67F) artificially ventilated preterm ...

Experimental surgery in animal models often requires prolonged periods of general anesthesia. Animals undergoing these procedures may have difficulty maintaining normal ventilation and oxygenation and therefore may require physiologic monitoring and endotracheal intubation to avoid hypoxia that could adversely affect the results of the investigation. Monitoring has traditionally included measurements ...

Continual improvement of oxygenators has been important in the growing demands of patient safety and support during cardiopulmonary bypass. The purpose of this study was to compare the Maxima 1380 oxygenator to the upgraded Maxima Plus oxygenator. Thirty-two adult patients were randomized to either the 1380 group or the Plus ...

Mixed venous oxygen saturation is generally accepted as an indicator of adequacy of systemic oxygen delivery; however, cardiopulmonary bypass (CPB) may alter this relationship. Major postoperative complications potentially secondary to inadequate oxygen delivery during CPB indicate that mixed venous oxygen saturation may not detect regional venous desaturation during CPB. We ...

1. The pulse oximeter measures blood oxygen saturation and provides rapid information about the onset of pulmonary complications. 2. Interpretation of the oximeter signal is complicated when inspired oxygen is increased and both inspired and oximeter oxygen values must be recorded. 3. If oxygen saturation is low, there is a ...

OBJECTIVE: To compare spectrophotometric saturation values of fetal blood sampling to the saturation readings by pulse oximetry. METHODS: During a clinical trial, fetal oxygen saturation was monitored during labor by a fetal oxisensor and a fetal pulse oximeter. Fifty-one fetal scalp blood samples were assessed because of abnormal fetal heart ...

The current parameters of oxygenation, arterial oxygen saturation and arterial oxygen pressure represent the availability of oxygen to the tissues. Venous oxygen saturation reflects oxygen extraction and could be a more useful indicator of tissue oxygenation. Therefore, we tested the feasibility and accuracy of a fiberoptic catheter, inserted into the ...

We compared in vitro oxyhaemoglobin saturations using two pulmonary artery catheters (catheter SO2), with oxyhaemoglobin saturations (SO2) measured by the IL282 co-oximeter and derived partial oxyhaemoglobin saturations (partial SO2) at different oxygen tensions (PO2) in six solutions: whole blood, 50:50 mixture of whole blood and Plasmalyte A (haemodiluted blood), 50:50 ...

A piglet model was used to evaluate the accuracy of a fiberoptic oximeter over a wide range of arterial oxygen saturation (SaO2) values. In eight anaesthetized piglets, the inspired oxygen concentration was varied from 30% to 6% resulting in a SaO2 range from 100% to 15%. Paired data of the ...

Placement of two different pulse oximeter probes, a finger (f) probe and a multisite (s) probe, was evaluated in six healthy, anesthetized beagles. Concurrent arterial blood gas values were compared to determine the most consistent (repeatable) and accurate (compared to calculated hemoglobin saturations) pulse oximeter probe and probe placement sites ...

Comatose patients run a high risk of developing cerebral ischaemia which may considerably influence final outcome. It would therefore be extremely useful if one could monitor cerebral blood flow in these patients. Since there is a close correlation between the arteriovenous difference of oxygen and cerebral blood flow, it was ...

Neonatal encephalopathy, plausibly related to hypoxia and ischaemia, remains one of the main problems in perinatal medicine. Efforts are necessary to find new non-invasive methods for assessing brain oxygenation. Near infrared spectroscopy (NIRS) provides information on the concentrations of the oxygenated and deoxygenated forms of haemoglobin, as well as of ...

Multi-wavelength photometers, blood gas analysers and pulse oximeters are widely used to measure various oxygen-related quantities. The definitions of these quantities are not always correct. This paper gives insight in the various definitions for oxygen quantities. Furthermore, the possible influences of dyshaemoglobins and fetal haemoglobin on the accuracy of pulse ...

We have designed a quality control tool for haemoximetry using the principle that standard p50, calculated from blood gas and haemoximetry measurements using the Siggaard-Andersen algorithm, remains unchanged when a specimen of venous blood is oxygenated progressively to 97% saturation of haemoglobin. If the haemoximeter is inaccurate, progressively larger deviations ...

Tissue oxygenation depends on the volume of oxygen consumed by the tissue and the volume of oxygen supply. This is particularly important in the liver after ischaemia and reperfusion, due to the relatively low oxygen saturation of the portal blood flow, the main source of oxygen to the liver. In ...

OBJECTIVE: To assess the usefulness of differences in oxygen content between mixed venous blood and cerebral venous blood for predicting neurological outcome after cardiac arrest. DESIGN: Observational study. SETTING: Medical-surgical intensive care unit (IUC) in a university hospital. PATIENTS AND PARTICIPANTS: 34 acutely comatose patients who had been admitted to ...

In vitro monitoring is inherently invasive with discrete measurements on blood samples and the results are often delayed an hour or more when the analyses are performed in the central laboratory. The delay may be greatly reduced if the analyses are performed near the patient. In vivo monitoring may be ...

Mixed venous oxygen content (commonly measured as oxygen saturation) is a highly relevant parameter in the monitoring of critically ill patients; unfortunately, its measurement requires catheterization of the pulmonary artery. Though less invasive, the central venous oxygen saturation is an unsatisfactory substitute, due to fluctuations in perfusion distribution and regional ...

Conventional near infrared spectroscopy (NIRS), introduced by Jöbsis in 1977, can be considered as a reliable trend monitor for cerebral oxygenation. Quantisation, however, is complex and cumbersome. Recently a relatively simple system for cerebral oximetry (INVOS 3100, Somanetics Corporation, USA) was developed, measuring the regional oxygen saturation (rSO2) in the ...

Patent Blue V (PBV) is a blue dye solution which is used to visualize lymphatic vessels for surgical procedures. There has been some conflicting reports about the influence of this dye solution on pulse oximetry and haemoximetry, why we decided to: 1) produce a spectrum of PBV in plasma, 2) ...

Four venous hemoglobin oxygen saturation monitors, two of which provide hemoglobin monitoring, were evaluated and compared to a performance standard (control) during cardiopulmonary bypass (CPB). The CDI 100 Hematocrit/Saturation Monitor, CDI 400, Cobe Hematocrit/Saturation Monitor, and the Baxter Bentley OxySat values were compared to the Radiometer Copenhagen OSM3 Hemoximeter and ...

Near-infrared (NIR) spectroscopy is a noninvasive technique that uses the differential absorption properties of hemoglobin to evaluate skeletal muscle oxygenation. Oxygenated and deoxygenated hemoglobin absorb light equally at 800 nm, whereas at 760 nm absorption is primarily from deoxygenated hemoglobin. Therefore, monitoring these two wavelengths provides an index of deoxygenation. ...

The authors report a new method of monitoring tissue oxygen saturation and haemoglobin concentration simultaneously and continuously using a three-wavelength spectrophotometry. Light emitting diodes were used as light source which made the recording probe small and flexible enough to be placed on the brain surface tightly. Stable and reliable recording ...

Two in-line oxygen saturation monitors, the CDI 100 and OxySat II, were evaluated in the clinical setting. Eighty-seven venous blood samples were drawn during 20 elective cardiopulmonary bypass procedures. Monitor readings were compared to OSM III co-oximeter values. The results revealed that saturation (%) determination was biased, -3.16 +/- 2.21 ...

Inadequate cerebral oxygenation during cardiopulmonary bypass may lead to postoperative cognitive dysfunction in patients undergoing cardiac operations. A psychological test battery was administered to 255 patients before cardiac operation and just before hospital discharge. Postoperative impairment was defined as a decline of more than one standard deviation in 20% of ...

Near-infrared spectroscopy was used to measure global cerebral blood flow and volume in 10 healthy adult volunteers. High- and low-cerebral blood flow compartments were detected with mean flows for all 10 subjects of 59 +/- 21 (SD) and 11 +/- 4 ml.100 g-1.min-1, respectively. The mean cerebral blood volume of ...

Techniques for determining intraoperative compromise in colonic blood flow during aortic reconstruction are inadequate. We investigated the use of transanally recorded oxygen saturation in a porcine model. A Nellcor RS-10 reflectance pulse oximeter probe was attached to the balloon of a Foley catheter and passed transanally to record the oxygen ...

OBJECTIVE: To test the hypothesis that the mean cerebral oxygen saturation measured by near-infrared spectroscopy shortly before delivery correlates with fetal acid-base status in umbilical cord blood. METHODS: A specially designed optical probe was inserted through the dilated cervix and placed against the fetal head during labor in 41 women. ...

OBJECTIVES: This study examined the effects of the pulmonary (QP)/systemic (QS) blood flow ratio (QP/QS) on systemic oxygen availability in neonates with hypoplastic left heart syndrome. BACKGROUND: The management of neonates with hypoplastic left heart syndrome is complex and controversial. Both before and after surgical palliation and before heart transplantation, ...

Oxicom oximeters are widely used in cardiac catheterization laboratories. To calibrate the Oxicom oximeter, samples of oxygenated and deoxygenated whole blood are first analyzed on a CO-Oximeter, and then the Oxicom is adjusted to agree with the CO-Oximeter's readings. Subsequently, the Oxicom's calibration is confirmed at frequent intervals by taking ...

Many commercially available pulse oximeters have a variable pitch blood oxygen saturation indicator, which emits a 'beep' between 175 Hz and 675 Hz with each heart beat. The frequency of this beep is dependent on the blood oxygenation measured by the oximeter, higher frequencies corresponding to higher blood saturation percentages. ...

We report a case of a 15-yr-old North American Indian female with haemoglobin Hammersmith, scheduled for elective tonsillectomy, whose arterial oxygen saturation could not be reliably monitored perioperatively because of technical limitations of conventional dual wavelength pulse oximetry. The patient was chronically icteric. She had an atrial septal defect with ...

We studied a 7.5 French Opticat fiberoptic catheter/Oximetrix computer system as a tool for continuous monitoring of oxygen saturation of jugular venous blood. Eight healthy volunteers had a catheter placed with the tip in the bulb of the right internal jugular vein. During baseline condition, hyperventilation, and rebreathing, jugular venous ...

We have studied the effects of extracranial ischaemia and intracranial hypoxia on measurement of cerebral oxygenation using near-infrared, reflectance-mode, cerebral oximetry (Invos 3100 cerebral oximeter) in healthy adult subjects. Under stable systemic conditions, scalp ischaemia induced by a pneumatic tourniquet caused an apparent reduction in mean regional cerebral oxygenation (rSO2) ...

9 pulse oximeters (BIOX-III, Nellcor 250, Jaeger CNS, Micro2), Pulsox-8, Oxycount, PulsOXImeter, PalcoLabs and Pulsox-7) were studied in 90 COPD patients. The transcutaneus oxygen saturation (SaO2%) was compared with arterial oxygen saturation calculated simultaneously with drawn blood samples (AVL-995). The measurement of error distribution and the cumulative distribution function (CDF) ...

A novel instrument using reflected near-infra-red light spectroscopy to measure cerebral oxygen saturation non-invasively was evaluated during carotid endarterectomy; cerebral perfusion was compared with jugular bulb venous oxygen saturation and transcranial Doppler ultrasonographic measurements. Initially, oximetry sensors with light source-detector separation distances of 10 and 27 mm were positioned over ...

Near infrared spectroscopy is a relatively new technique for monitoring intracerebral oxygen saturation. Using the technique, three episodes of cerebral hypoxia were detected during elective carotid endarterectomy which were not reliably recorded by more standard monitoring of cerebral perfusion. In one case, cerebral hypoxia was related to slippage of the ...

Measurements of carboxyhemoglobin (COHb) for clinical purposes are routinely made with CO-oximeters. However, fetal hemoglobin (HbF) interferes with this spectrophotometric method. The manufacturer (Ciba Corning Diagnostics) of a new CO-oximeter (CCD 270) claims that COHb measurements with this instrument are insignificantly affected by HbF. We examined this claim through CO-oximeter ...

Extracorporeal circulation of blood during cardiopulmonary bypass surgery exposes cells to non-physiological surfaces and shear stress which can activate several regulatory cascades, and neutrophils to release superoxide and hydrogen peroxide. Shear stresses generated by pumps and suction systems cause lysis of red blood cells and the release of haemoglobin. Together ...

Transcranial Doppler ultrasonography (TCD) of the middle cerebral artery (MCA), light-reflective cerebral oximetry and measurement of internal carotid artery stump pressure were compared as methods of monitoring cerebral perfusion during carotid surgery in 33 patients. Median cerebral oxygen saturation was 70 (range 62-85) per cent and TCD-measured mean blood velocity ...

Cyanide poisoning is an uncommon emergency department problem. It has a high mortality, and specific antidotal therapy can be lifesaving. We describe a 23-year-old man who ingested potassium cyanide and survived without antidotal therapy. His blood cyanide concentration was 4.65 mg/L, which is within the lethal range. The arterial venous ...

BACKGROUND: Measurement of mixed venous hemoglobin oxygen saturation via catheters employing reflectance spectrophotometry has been available for more than 10 yr. Despite numerous clinical reports that have presented data showing the poor accuracy of these devices when used clinically, they are still widely used in clinical care. The reason for ...