A Noninvasive Miniaturized Transcutaneous Oxygen Monitor

Author(s):  
Ian Costanzo ◽  
Devdip Sen ◽  
Joseph Adegite ◽  
Pratap Rao ◽  
Ulkuhan Guler
1980 ◽  
Vol 26 (5) ◽  
pp. 629-633 ◽  
Author(s):  
G Graham ◽  
M A Kenny

Abstract We evaluated the performance of the Radiometer TCM-1 Transcutaneous Oxygen Monitor in a Class III neonatal-intensive-care unit during an 11-month clinical trial (in excess of 4000 h) in which we monitored 115 infants ranging in gestational age from 25 to 43 weeks and in birthweight from 595 to 4220 g. In vitro transcutaneous partial pressure of oxygen (ptcO2) measurements were accurate within 1% of the theoretical value and precise (1.4% CV at 156 mmHg) at 44 degrees C. Determinations at other temperature were less accurate except in rare instances when specific patient-associated ptcO2/paO2 bias was identified. In vitro comparison of ptcO2 (y) and arterial partial pressure of oxygen (paO2) (x) measurements agreed well (y = 0.90x + 6.9, r = 0.94) except when infants were less than 24 h old. In this latter group the ptcO2/paO2 ratio usually exceeded 1.0 and fluctuated unpredictably. ptcO2 measurements on infants less than 24 h old had to be interpreted cautiously. In general, the ptcO2 and paO2 measurements agreed sufficiently well for the physicians to use them as the basis for directing patient care.


1980 ◽  
Vol 26 (5) ◽  
pp. 629-633
Author(s):  
G Graham ◽  
M A Kenny

Abstract We evaluated the performance of the Radiometer TCM-1 Transcutaneous Oxygen Monitor in a Class III neonatal-intensive-care unit during an 11-month clinical trial (in excess of 4000 h) in which we monitored 115 infants ranging in gestational age from 25 to 43 weeks and in birthweight from 595 to 4220 g. In vitro transcutaneous partial pressure of oxygen (ptcO2) measurements were accurate within 1% of the theoretical value and precise (1.4% CV at 156 mmHg) at 44 degrees C. Determinations at other temperature were less accurate except in rare instances when specific patient-associated ptcO2/paO2 bias was identified. In vitro comparison of ptcO2 (y) and arterial partial pressure of oxygen (paO2) (x) measurements agreed well (y = 0.90x + 6.9, r = 0.94) except when infants were less than 24 h old. In this latter group the ptcO2/paO2 ratio usually exceeded 1.0 and fluctuated unpredictably. ptcO2 measurements on infants less than 24 h old had to be interpreted cautiously. In general, the ptcO2 and paO2 measurements agreed sufficiently well for the physicians to use them as the basis for directing patient care.


VASA ◽  
2015 ◽  
Vol 44 (3) ◽  
pp. 0220-0228 ◽  
Author(s):  
Marion Vircoulon ◽  
Carine Boulon ◽  
Ileana Desormais ◽  
Philippe Lacroix ◽  
Victor Aboyans ◽  
...  

Background: We compared one-year amputation and survival rates in patients fulfilling 1991 European consensus critical limb ischaemia (CLI) definition to those clas, sified as CLI by TASC II but not European consensus (EC) definition. Patients and methods: Patients were selected from the COPART cohort of hospitalized patients with peripheral occlusive arterial disease suffering from lower extremity rest pain or ulcer and who completed one-year follow-up. Ankle and toe systolic pressures and transcutaneous oxygen pressure were measured. The patients were classified into two groups: those who could benefit from revascularization and those who could not (medical group). Within these groups, patients were separated into those who had CLI according to the European consensus definition (EC + TASC II: group A if revascularization, group C if medical treatment) and those who had no CLI by the European definition but who had CLI according to the TASC II definition (TASC: group B if revascularization and D if medical treatment). Results: 471 patients were included in the study (236 in the surgical group, 235 in the medical group). There was no difference according to the CLI definition for survival or cardiovascular event-free survival. However, major amputations were more frequent in group A than in group B (25 vs 12 %, p = 0.046) and in group C than in group D (38 vs 20 %, p = 0.004). Conclusions: Major amputation is twice as frequent in patients with CLI according to the historical European consensus definition than in those classified to the TASC II definition but not the EC. Caution is required when comparing results of recent series to historical controls. The TASC II definition of CLI is too wide to compare patients from clinical trials so we suggest separating these patients into two different stages: permanent (TASC II but not EC definition) and critical ischaemia (TASC II and EC definition).


VASA ◽  
2015 ◽  
Vol 44 (5) ◽  
pp. 355-362 ◽  
Author(s):  
Marie Urban ◽  
Alban Fouasson-Chailloux ◽  
Isabelle Signolet ◽  
Christophe Colas Ribas ◽  
Mathieu Feuilloy ◽  
...  

Abstract. Summary: Background: We aimed at estimating the agreement between the Medicap® (photo-optical) and Radiometer® (electro-chemical) sensors during exercise transcutaneous oxygen pressure (tcpO2) tests. Our hypothesis was that although absolute starting values (tcpO2rest: mean over 2 minutes) might be different, tcpO2-changes over time and the minimal value of the decrease from rest of oxygen pressure (DROPmin) results at exercise shall be concordant between the two systems. Patients and methods: Forty seven patients with arterial claudication (65 + / - 7 years) performed a treadmill test with 5 probes each of the electro-chemical and photo-optical devices simultaneously, one of each system on the chest, on each buttock and on each calf. Results: Seventeen Medicap® probes disconnected during the tests. tcpO2rest and DROPmin values were higher with Medicap® than with Radiometer®, by 13.7 + / - 17.1 mm Hg and 3.4 + / - 11.7 mm Hg, respectively. Despite the differences in absolute starting values, changes over time were similar between the two systems. The concordance between the two systems was approximately 70 % for classification of test results from DROPmin. Conclusions: Photo-optical sensors are promising alternatives to electro-chemical sensors for exercise oximetry, provided that miniaturisation and weight reduction of the new sensors are possible.


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