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1.
Dr Susan E. Opper MD Eugene E. Fibuch MD Gerald F. Tuohy MD 《Journal of clinical monitoring and computing》1988,4(2):86-90
Transcutaneous oxygen electrodes have been used with success in neonates as indicators of arterial oxygenation, but with less success in adults because of differences in skin thickness and vascularity. In this study a prototype transoral oxygen electrode was evaluated to determine if a heated mucous membrane would yield arterialized values of oxygen tension in adults. Using a miniaturized Clark electrode, we measured transoral oxygen tension (PtoO2) in 29 subjects at steady-state conditions. Simultaneously a sample was anaerobically obtained from a radial artery for measurement of arterial oxygen tension (PaO2). Data were analyzed using linear regression analysis, Student'st test, and analysis of variance. There was no statistically significant difference between non-white and white subjects or male and female subjects. There was a highly significant difference (P<0.001) between the pooled, matched values for PtoO2 versus PaO2, and the regression between the PtoO2 and the PaO2 was linear (slope 0.92, y-intercept ?8.37,r=0.62,P<0.003). The calculated ratio of PtoO2 to PaO2 was 0.83±0.03 (standard error). We concluded that the PtoO2 was linearly related to the PaO2, although its accuracy in reflecting PaO2 was low. This finding correlates with previously published data that suggested that the PtoO2 reflects tissue oxygen tension rather than arterialized oxygen tension. Gender and race appeared not to affect the function of the electrode in our study. 相似文献
2.
Hannu Olavi Soini MD Dr Jukka Takala MD PhD 《Journal of clinical monitoring and computing》1991,7(3):227-231
We compared the 95% response time (95% RT) of two tissue oxygen tonometers under two sets of circumstances. We first evaluated the devices during normoxia, hyperoxia, and anoxia in vitro, using a transcutaneous PO2 electrode (PtcO2) as the reference. The responses to normoxia and to different grades of hyperoxia were examined in vivo in 8 healthy volunteers to assess the relationship between changes in subcutancous PO2 and PtcO2, an estimate of arterial PO2 (PaO2). One subcutaneous method (ScA) used a technique based on a polarographic needle electrode in situ connected to an ammeter; the second method (ScB) was based on a blood gas analyzer system first described by Hunt (Lancet 164;2:1370). ScA and PtcO2 both responded to stepwise changes in ambient oxygen concentration (21–100%) in vitro within 10 seconds; the 95% RT of ScA was 1.39±0.5 to 2.39±0.8 minutes and that of PtcO2 was 0.32±0.1 to 0.49±0.1 minutes. ScB had a lag of 3 minutes, and the 95% RT was 6.75±0.5 to 8.2±0.8 minutes. In contrast to the results in vitro, the response of ScA to changes in FiO2 in vivo was delayed compared with the rapid response of PtcO2, reflecting the physiologic delay of tissue PO2 in response to increased PaO2. The time lag and the long 95% RT of ScB were even more evident in vivo. ScA reacted three to four times faster than ScB, both in vitro and in vivo, to changes in the oxygen environment. The in vitro 95% RT of ScA to changes in ambient oxygen varied from 2 to 3.5 minutes. In contrast, the 95% RT of ScB was 8 to 9 minutes. PtcO2 had the fastest 95% RT, from 0.4 to 0.5 minutes. The results suggest that the subcutaneous needle electrode method (ScA) provides close to real-time assessment of tissue PO2.Supported by the Paulo Foundation and the Orion Foundation of Research.We thank the local distributor of Radiometer, Oriola Oy, for the loan of TINA. 相似文献
3.
Dr Sergio Fanconi MD Hannes Sigrist MD 《Journal of clinical monitoring and computing》1988,4(2):103-106
We evaluated a new combined sensor for monitoring transcutaneous carbon dioxide tension (PtcCO2) and oxygen tension (PtcO2) in 20 critically ill newborn infants. Arterial oxygen tension (PaO2) ranged from 16 to 126 torr and arterial carbon dioxide tension (PaCO2) from 14 to 72 torr. Linear correlation analysis (100 paired values) of PtcO2 versus PaO2 showed anr value of 0.75 with a regression equation of PtcO2=8.59+0.905 (PaO2), while PtcCO2 versus PaCO2 revealed a correlation coefficient ofr=0.89 with an equation of PtcCO2=2.53+1.06 (PaCO2). The bias between PaO2 and PtcO2 was –2.8 with a precision of ±16.0 torr (range, –87 to +48 torr). The bias between PaCO2 and PtcCO2 was –5.1 with a precision of ±7.3 torr (range, –34 to +8 torr). The transcutaneous sensor detected 83% of hypoxia (PaO2 <45 torr), 75% of hyperoxia (PaO2 >90 torr), 45% of hypocapnia (PaCO2 <35 torr), and 96% of hypercapnia (PaCO2 >45 torr). We conclude that the reliability of the combined transcutaneousPo
2 andPCo
2 monitor in sick neonates is good for detecting hypercapnia, fair for hypoxia and hyperoxia, but poor for hypocapnia. It is an improvement in that it spares available skin surface and requires less handling, but it appears to be slightly less accurate than the single electrodes. 相似文献
4.
Stanley Fink Edward Abraham Helene Ehrlich 《Journal of clinical monitoring and computing》1988,5(1):37-43
To define the utility of conjunctival temperature (Tcj) and conjunctival oxygen tension (PcjO2) monitoring during rewarming in the postoperative period, we measured serial Tcj, PcjO2 and PcjO2 index (PcjO2/PaO2) values in 10 patients after cardiac surgery. PcjO2 and PcjO2 index were markedly depressed at the low conjunctival temperatures recorded during the immediate postoperative period. As the patients' core and conjunctival temperatures increased, there was a concomitant, linear increase in PcjO2 and PcjO2 index for Tcj<33.5° C. Two patients showed deviation from this temperature-related rise in PcjO2 and PcjO2 index, and both of these patients demonstrated physiologic deterioration associated with cardiac arrest or hypotension. These results indicate that monitoring of PcjO2 and Tcj can provide a continuous assessment of the adequacy of peripheral perfusion and oxygenation in the postoperative period. 相似文献
5.
Continuous non-invasive monitoring of conjunctival oxygen tension (PcjO2) versus conventional invasive hemodynamic and oxygen transport variables was evaluated in a porcine model of septic shock induced by a continuous i.v. infusion of E.coli endotoxin over 2 hours. Seventeen pigs under ketamine anesthesia and breathing air spontaneously were investigated. PcjO2, which reflects local oxygen tension at tissue level, correlated significantly at baseline and throughout the septic course with mixed venous oxygen saturation and oxygen utilization coefficient. All these correlations were significant at the 1% level. The corresponding correlations between PcjO2 and cardiac output were significant at the 5% level. A finding of great importance was that changes in PcjO2 preceded major changes in the intermittently measured physiological variables such as SvO2 and cardiac output.We conclude that PcjO2 monitoring is a valuable non-invasive method and which can provide a continuous assessment of the hemodynamic and oxygenation status in experimental septic shock. 相似文献
6.
Eastwood G Bellomo R Bailey M Taori G Pilcher D Young P Beasley R 《Intensive care medicine》2012,38(1):91-98
Purpose
Early hyperoxia may be an independent risk factor for mortality in mechanically ventilated intensive care unit (ICU) patients. We examined the relationship between early arterial oxygen tension (PaO2) and in-hospital mortality. 相似文献7.
F Gottrup S Gellett L Kirkegaard E S Hansen G Johannsen 《Critical care medicine》1988,16(12):1229-1234
Subcutaneous, transcutaneous, and conjunctival oxygen tensions (PscO2, PtcO2, and PcjO2, respectively) were measured in anesthetized dogs subjected sequentially to normoxia, hyperoxia, and hypoxia. Intravascular pressure, hemodynamic and oxygen transport variables were measured simultaneously. PtcO2 and PcjO2 closely paralleled PaO2 during normoxia, hyperoxia, and hypoxia over a wide range of arterial oxygen tensions. PtcO2 was reliable over the widest range of PaO2, with a correlation coefficient of .94. The PcjO2/PaO2 index fell at very low PaO2. The PscO2/PaO2 index decreased at both very low and very high PaO2. Only minor changes were found in hemodynamic and oxygen transport variables during hyperoxia. During hypoxia, however, cardiac output and other central hemodynamic measurements increased, while PscO2, PtcO2, and PcjO2 fell. Oxygen delivery and oxygen consumption were maintained or only slightly changed during hypoxia. All three continuous measurements of oxygen tension are reliable indices of PaO2 over a wide range under normovolemic conditions. The instruments for measuring PscO2 and PcjO2 are unheated and therefore may have advantages for human application. 相似文献
8.
C. Kees Mahutte MD PhD Catherine S. H. Sassoon MD JesÚs R. Muro MD Douglas R. Hansmann PhD Thomas P. Maxwell BSME William W. Miller PhD Masao Yafuso PhD 《Journal of clinical monitoring and computing》1990,6(2):147-157
In vitro and in vivo animal studies have shown accurate measurements of arterial blood pH (pHa), carbon dioxide tension (PaCO2), and oxygen tension (PaO2) with small intravascular fluorescent probes. Initial human clinical studies showed unexplained intermittent large drops
in sensor oxygen tension (PiO2). Normal volunteers were studied to elucidate this problem. In the first part of this study, the probe and cannula were manipulated
and the probe configuration and its position within the cannula were varied. The decreases in PiO2 were judged to be primarily due to the sensor touching the arterial wall. Retraction of the sensor tip within the cannula
eliminated the problem. In the second part of this study, the accuracy of the retracted probe was evaluated in 4 subjects
who breathed varying fractions of inspired oxygen and carbon dioxide. The arterial ranges achieved were 7.20 to 7.59 for pH,
22 to 70 mm Hg for PaCO2, and 46 to 633 mm Hg for PaO2. Linear regression of 48 paired sensor (i) versus arterial values showed pHi = 0.896 pHa + 0.773 (r = 0.98, SEE = 0.017);
PiCO2 = 1.05 PaCO2-1.33 (r = 0.98, SEE = 2.4 mm Hg); and PiO2 = 1.09 PaO2-20.6 (r = 0.99, SEE = 21.2 mm Hg). Bias (defined as the mean differences between sensor and arterial values) and precision
(SD of differences) were, respectively, -0.003 and 0.02 tor pHi, 0.77 and 2.44 mm Hg for PiCO2, and -2.9 and 25.4 mm Hg for PiO2. The mean in vivo 90% response times for step changes in inspired gas were 2.64, 3.88,
and 2.60 minutes, respectively, for pHi, PiCO2, and PiO2. 相似文献
9.
Cardiorespiratory and conjunctival oxygen tension monitoring during resuscitation from hemorrhage 总被引:1,自引:0,他引:1
Placement of an unheated miniaturized oxygen electrode against the palpebral conjunctiva permits noninvasive measurement of tissue oxygen tension. In this study, the relationship between conjunctival oxygen tension (PcjO2) and standard cardiorespiratory variables was examined during a sequential resuscitation protocol after acute hemorrhage. Anesthetized dogs were rapidly bled to a mean arterial pressure of 40 mm Hg and then retransfused with the shed blood in a stepwise fashion. PcjO2 fell to 2% of control values after hemorrhage and did not return to prehemorrhage values until more than 90% of the shed blood had been reinfused. PcjO2 was among the last set of cardiorespiratory variables to return to control values during resuscitation and was the last noninvasive variable to normalize. The ratio of PcjO2 to arterial oxygen tension decreased from a prehemorrhage value of 0.76 +/- 0.05 (SEM) to 0.02 +/- 0.003 after hemorrhage, and did not increase to values greater than 0.50 until resuscitation was more than 90% complete. Conjunctival oxygen monitoring may play an important role in assessing the adequacy of resuscitation after acute hemorrhage. 相似文献
10.
Dr J. Reddy Kambam MD Bennett F. Horton MD Winston C. V. Parris MD Duncan A. Holaday MD 《Journal of clinical monitoring and computing》1988,4(4):261-263
Fresh samples of heparinized human blood from 10 healthy nonsmoking volunteers were used to study the effect of the inhaled anesthetic sevoflurane on the oxygen half-saturation pressure of hemoglobin (P50) and on polarographic measurements of oxygen tension at low values. Control samples had a baseline P50 of 26.9±0.2 mm Hg. When the blood samples were exposed to 1.75% (1 minimum alveolar concentration, MAC), 2.75%, and 3.5% (2 MAC) of sevoflurane, the P50 values were 27.0±0.5 mm Hg, 27.1±0.4 mm Hg, and 26.9±0.5 mm Hg, respectively. Our present data show that 1 to 2 MAC sevoflurane has no significant effect on P50 (P>0.05). Our data also show that sevoflurane did not interfere with polarographic measurements of oxygen tension (P>0.05). Other inhaled agents—halothane, enflurane, and isoflurane—do interfere with these measurements, and we cannot explain the difference.Presented at the annual meeting of the American Society of Anesthesiologists, Atlanta, GA, October 1987. 相似文献
11.
Kevin K. Tremper MD PhD Steven J. Barker MD PhD David H. Blatt MD Ronald H. Wender MD 《Journal of clinical monitoring and computing》1986,2(4):234-236
Both halothane and nitrous oxide can be reduced at the cathode of a polarographic oxygen electrode, causing the electrode
current to drift upward and report falsely high oxygen tension. Because transcutaneous oxygen tension is measured by a heated
oxygen electrode, there is a potential for significant upward drift of these values. To examine the clinical significance
of this drift, the following study was performed. Transcutaneous oxygen tension sensors were calibrated at oxygen tensions
of 0 mm Hg and 157 mm Hg (room air) just before clinical use during anesthesia. This calibration was rechecked immediately
upon removal of the sensor from the patient at the end of the anesthesia. The predominant anesthetic agent used and the duration
of monitoring were noted from the record. Data were collected from 208 patients representing a total of 463.6 hours of anesthesia.
The patients were divided into five groups based on anesthetic administered: halothane, enflurane, isoflurane, nitrous oxide-narcotic,
and local/regional. The mean zero point recalibration value was 0.4 mm Hg or less for all agents except halothane, for which
it was 1.8 ± 3.2 mm Hg. This halothane drift was significantly greater than that for the other agents (P<0.01). Room air recalibration
was not significantly different in any of the five groups, varying from 160 ± 4.9 mm Hg for halothane to 157 ± 4.9 mm Hg for
enflurane. All these drift values are within the manufacturer’s specifications. We conclude that the drift of the transcutaneous
oxygen tension sensor due to anesthetic agents is not clinically significant. However, caution should be exercised when halothane
is used during an extremely long period of anesthesia. 相似文献
12.
Pekka Jakkula Matti Reinikainen Johanna Hästbacka Pekka Loisa Marjaana Tiainen Ville Pettilä Jussi Toppila Marika Lähde Minna Bäcklund Marjatta Okkonen Stepani Bendel Thomas Birkelund Anni Pulkkinen Jonna Heinonen Tuukka Tikka Markus B. Skrifvars COMACARE study group 《Intensive care medicine》2018,44(12):2112-2121
Purpose
We assessed the effects of targeting low-normal or high-normal arterial carbon dioxide tension (PaCO2) and normoxia or moderate hyperoxia after out-of-hospital cardiac arrest (OHCA) on markers of cerebral and cardiac injury.Methods
Using a 23 factorial design, we randomly assigned 123 patients resuscitated from OHCA to low-normal (4.5–4.7 kPa) or high-normal (5.8–6.0 kPa) PaCO2 and to normoxia (arterial oxygen tension [PaO2] 10–15 kPa) or moderate hyperoxia (PaO2 20–25 kPa) and to low-normal or high-normal mean arterial pressure during the first 36 h in the intensive care unit. Here we report the results of the low-normal vs. high-normal PaCO2 and normoxia vs. moderate hyperoxia comparisons. The primary endpoint was the serum concentration of neuron-specific enolase (NSE) 48 h after cardiac arrest. Secondary endpoints included S100B protein and cardiac troponin concentrations, continuous electroencephalography (EEG) and near-infrared spectroscopy (NIRS) results and neurologic outcome at 6 months.Results
In total 120 patients were included in the analyses. There was a clear separation in PaCO2 (p?<?0.001) and PaO2 (p?<?0.001) between the groups. The median (interquartile range) NSE concentration at 48 h was 18.8 µg/l (13.9–28.3 µg/l) in the low-normal PaCO2 group and 22.5 µg/l (14.2–34.9 µg/l) in the high-normal PaCO2 group, p?=?0.400; and 22.3 µg/l (14.8–27.8 µg/l) in the normoxia group and 20.6 µg/l (14.2–34.9 µg/l) in the moderate hyperoxia group, p?=?0.594). High-normal PaCO2 and moderate hyperoxia increased NIRS values. There were no differences in other secondary outcomes.Conclusions
Both high-normal PaCO2 and moderate hyperoxia increased NIRS values, but the NSE concentration was unaffected.Registration
ClinicalTrials.gov, NCT02698917. Registered on January 26, 2016.13.
背景:课题组以往研究证实,氧浓度过低乃至处于低氧时(体积分数2%O2),破骨前体细胞的增殖及破骨细胞的分化和功能都受到抑制,但体外培养的破骨细胞在不同氧环境下的基因表达未见有相关报道。目的:实验拟观察不同氧环境下破骨细胞各特异性基因的表达规律,探寻氧环境改变影响破骨细胞分化的表达机制。方法:将破骨前体细胞株经质量浓度均为10μg/L的核因子κB受体活化因子配体和巨噬细胞集落刺激因子联合诱导成为成熟的破骨细胞,然后分别置于常氧、组织氧、低氧(体积分数20%,7%,2%)条件下培养,用抗酒石酸酸性磷酸酶染色检测破骨细胞形成的变化,并分别在培养第1-7天收集细胞,通过定量PCR方法检测核因子κB受体活化因子,肿瘤坏死因子受体相关因子6,抗酒石酸酸性磷酸酶,组织蛋白酶K基因mRNA的表达。结果与结论:低氧条件下抗酒石酸酸性磷酸酶阳性的破骨细胞数显著低于组织氧和常氧培养时形成的抗酒石酸酸性磷酸酶阳性细胞数(P〈0.05)。不同氧环境下,破骨细胞中核因子κB受体活化因子mRNA的表达无明显改变,组织氧和常氧培养下肿瘤坏死因子受体相关因子6 mRNA的表达在培养第5天最高(P〈0.05)。随着氧浓度的降低,抗酒石酸酸性磷酸酶和组织蛋白酶K mRNA表达时间延后,组织氧培养条件下此2者的表达可以保持在最高水平。结果证实,与常氧和低氧条件相比,破骨细胞在组织氧培养条件下培养时更易促进其分化,从而维持其活性和功能。 相似文献
14.
Dr Anne Viitanen MD Markku Salmenperä MD Jussi Heinonen MD Jussi Heinonen MD 《Journal of clinical monitoring and computing》1987,3(2):90-95
Oxygenation was monitored concomitantly by measurement of transcutaneous oxygen tension and by pulse oximetry, and the data were compared with arterial blood oxygen tension and saturation values in 10 patients who became hypoxemic when undergoing thoracotomy and one-lung ventilation. A steep decrease in arterial blood oxygen tension was obvious immediately after the institution of one-lung ventilation, reaching the lowest mean value of 63 ± 2 mm Hg (± SEM) at 12 minutes. Despite significant correlation between transcutaneous oxygen tension and arterial blood oxygen tension during one-lung ventilation (r = 0.75;P < 0.001), the delay in the transcutaneous oxygen tension response resulted in underestimation of the severity of hypoxemia at the beginning of one-lung ventilation. In contrast, the decrease in arterial blood oxygen saturation from 97.9 ± 0.3% to 92.2 ± 0.8% as measured by CO-Oximeter was accurately followed by pulse oximetry with almost beat-to-beat response, bringing about a highly significant linear correlation between the two methods (r = 0.93;P < 0.001). We conclude that pulse oximetry is a simpler and more rapidly responding method than measurement of transcutaneous oxygen tension for detection of hypoxemia during one-lung ventilation in adults. 相似文献
15.
Dr Klaus Erdmann Dr med Jan-Peter A. H. Jantzen Dr med Christopher Etz Wolfgang F. Dick 《Journal of clinical monitoring and computing》1986,2(2):105-113
Monitoring of inspired oxygen concentration during anesthesia with nitrous oxide is becoming accepted as essential. This type of monitoring demands accurate monitors that respond rapidly. We evaluated two such devices for their response patterns to rapid changes in oxygen concentration, a galvanic or “fuel cell” unit and a polarographic device. Data were stored after analog-to-digital conversion. The response patterns to stepwise changes in nitrous oxide and oxygen mixtures were recorded at flow rates ranging from 2 to 10 L/min. Both units responded accurately to all changes in the absolute oxygen concentration; the polarographic unit was, on average, twice as fast. Responsiveness to nitrous oxide was low (<0.4% at 100% nitrous oxide), and the stability of the signals was good. The 90% response time (T90) was consistent for any stepwise increase or decrease in oxygen concentration between 0, 21, 33, 50, and 100%. After a step change from 0 to 100% oxygen at a gas flow rate of 10 L/min, the T90 was 5.8 seconds in the polarographic device and 11.4 seconds in the galvanic device (p<0.01). After a decrease from 100 to 0% oxygen, the T90 was 0.6 second longer in both monitors. Comparing flow rates of 2 L/min with 10 L/min, the T90 was delayed by 1.1 and 2.3 seconds for an increase, and by 1.4 and 2.9 seconds for a decrease in oxygen concentration. Experimental data suggest that both sensors respond adequately during routine clinical use. The faster response of the polarographic device is probably of limited clinical relevance, but it may aid in calibration. 相似文献
16.
Supplemental oxygen is administered in the vast majority of patients in the perioperative setting and in the intensive care unit to prevent the potentially deleterious effects of hypoxia. On the other hand, the administration of high concentrations of oxygen may induce hyperoxia that may also be associated with significant complications. Oxygen therapy should therefore be precisely titrated and accurately monitored. Although pulse oximetry has become an indispensable monitoring technology to detect hypoxemia, its value in assessing the oxygenation status beyond the range of maximal arterial oxygen saturation (SpO2 ≥97%) is very limited. In this hyperoxic range, we need to rely on blood gas analysis, which is intermittent, invasive and sometimes delayed. The oxygen reserve index (ORI) is a new continuous non-invasive variable that is provided by the new generation of pulse oximeters that use multi-wavelength pulse co-oximetry. The ORI is a dimensionless index that reflects oxygenation in the moderate hyperoxic range (PaO2 100–200 mmHg). The ORI may provide an early alarm when oxygenation deteriorates well before any changes in SpO2 occur, may reflect the response to oxygen administration (e.g., pre-oxygenation), and may facilitate oxygen titration and prevent unintended hyperoxia. In this review we describe this new variable, summarize available data and preliminary experience, and discuss its potential clinical utilities in the perioperative and intensive care settings. 相似文献
17.
Steven J. Barker MD PhD Kevin K. Tremper MD PhD John Hyatt BS June Zaccari BS Harold A. Heitzmann PhD Brian M. Holman BS Kelly Pike BS Lawrence S. Ring BS Maria Teope BS Thierry B. Thaure BSE 《Journal of clinical monitoring and computing》1987,3(1):48-52
An experimental study using a new fiberoptic sensor for the continuous intraarterial measurement of oxygen tension is described. This optode sensor uses the phenomenon of fluorescence quenching to determine the oxygen tension of the surrounding medium. To assess the accuracy of this device, we anesthetized 4 dogs and monitored them continuously with arterial catheters and an intraarterial optode probe, and intermittently with arterial blood gas analysis. The inspired oxygen fraction was varied from 1.0 to 0.1, and arterial blood gases were measured for comparison with the optode reading. Two hundred ninety data sets yielded a correlation coefficient of 0.96, with a linear regression slope of 0.98 and intercept of 5.1 mm Hg. In the 72 data sets from the last dog, the bias and precision of the optode arterial oxygen tension values were –10.3 mm Hg and 20.0 mm Hg, respectively. The optode probe was easily inserted through a 20-gauge catheter and did not interfere with continuous arterial pressure measurement or blood sampling. This study suggests that the optode has great potential as a continuous, real-time monitor of arterial oxygen tension. 相似文献
18.
Chih-Hung Wang Wei-Tien Chang Chien-Hua Huang Min-Shan Tsai Ping-Hsun Yu An-Yi Wang Nai-Chuan Chen Wen-Jone Chen 《Resuscitation》2014
Objective
Studies have shown the detrimental effect of hyperoxia in animals with return of spontaneous circulation (ROSC) after cardiac arrest. To maximize the value of existing clinical studies, we performed the systemic review and meta-analysis of human observational studies to examine the effect of hyperoxia on outcomes of post-ROSC patients.Methods
We searched PubMed and Embase from the inception to October 2013. We selected adult observational studies that compared different levels of partial pressure of arterial oxygen (PaO2) in post-ROSC patients with mortality or neurological status at hospital discharge as outcome. Studies comparing hypoxia with normoxia only were excluded.Results
Fourteen studies were identified from 2982 references. Odds ratio (OR) was used as effect estimate. OR was reconstructed if not provided in original articles. Hyperoxia was defined as a PaO2 >300 mmHg. Meta-analysis indicated that hyperoxia appeared to be correlated with increased in-hospital mortality (OR, 1.40; 95% CI, 1.02–1.93; I2, 69.27%; 8 studies) but not worsened neurological outcome (OR, 1.62; 95% CI, 0.87–3.02; I2, 55.61%; 2 studies). However, the results were inconsistent in subgroup and sensitivity analyses.Conclusions
Hyperoxia appears to be correlated with increased in-hospital mortality of post-ROSC patients. This result should be interpreted cautiously because of the significant heterogeneity and limited number of studies analyzed. However, because exposure to hyperoxia had no obvious benefits, clinicians should monitor PaO2 closely and titrate oxygen administration cautiously. 相似文献19.
《The American journal of emergency medicine》2020,38(10):2125-2129
ObjectiveHyperoxia, the delivery of high levels of supplemental oxygen (sO2) despite normoxia, may increase cerebral oxygenation to penumbral tissue and improve stroke outcomes. However, it may also alter peripheral hemodynamic profiles with potential negative effects on cerebral blood flow (CBF). This study examines the hemodynamic consequences of prehospital sO2 in stroke.MethodsA retrospective analysis of adult acute stroke patients (aged ≥18 years) presenting via EMS to an academic Comprehensive Stroke Center between January 1, 2013 and December 31, 2017 was conducted using demographic and clinical characteristics obtained from Get with the Guidelines-Stroke registry and subjects' medical records. Outcomes were compared across three groups based on prehospital oxygen saturation and sO2 administration. Chi-square, ANOVA, and multivariable linear regression were used to determine if sO2 was associated with differences in peripheral hemodynamic profiles.ResultsAll subjects had similar initial EMS vitals except for oxygen saturation. However, both univariate and multivariable analysis revealed that hyperoxia subjects had slightly lower average ED mean arterial pressures (MAP) compared to normoxia (Cohen's d = 0.313).ConclusionsPrehospital-initiated hyperoxia for acute stroke is associated with a small, but significant decrease in average ED MAP, without changes in heart rate, compared to normoxia. While limited by the inability to link changes in peripheral hemodynamical profiles directly to changes in CBF, this study suggests that hyperoxia may result in a relative hypotension. Further studies are needed to determine if this small change in peripheral vascular resistance translates into a clinically significant reduced CBF. 相似文献
20.
Hypoxic ventilatory response in subjects with normal and high oxygen affinity hemoglobins. 总被引:1,自引:1,他引:0
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It has still not been shown unequivocally whether a decrement of arterial oxygen content or tension governs the ventilatory response to hypoxia. In an attempt to discriminate between the two possibilities, we have measured the ventilatory response to isocapnic progressive hypoxia in two healthy children with a high oxygen affinity hemoglobin (Hb Andrew-Minneapolis) and in their age- and sex-matched normal siblings. Hypoxic ventilatory response was identical in all subjects, there being no difference in minute ventilation at PAo2 = 40 mm Hg or in k (decrement of PO2 required to increase ventilation by a factor of 2.718). In contrast, at PAo2 = 40 mm Hg, hemoglobin oxygen saturation decreased markedly in controls but only slightly in high affinity subjects. Furthermore the increase in heart rate at PAo2 = 40 mm Hg was significantly less in high affinity subjects, suggesting a concomitant difference in oxygen delivery. Thus, with identical decrements in PAo2 but widely divergent changes in arterial oxygen content and oxygen delivery, controls and high affinity subjects showed virtually identical ventilatory response to hypoxia. We conclude that decrements of oxygen tension are the major stimulus for hypoxic ventilatory response. 相似文献