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Transcutaneous CO2在急性医疗环境中,测量不是可靠的动脉血液采样的替代方法http://ow.ly/kOll30ntSP1
To the Editor:
测量动脉二氧化碳张力(PaCO2)是至关重要的在各种各样的急性临床洞穴ings and it is often necessary to monitor changes inPaCO2over time rather than just a one-off measurement. The current gold standard of measuringPaCO2is arterial blood gas (ABG) sampling but the collection of arterial blood is invasive and associated with complications [1]。为了避免频繁的动脉刺,有时会放置动脉线,但是这些导致对2级护理的要求,并与显着风险相关[2,3]。Transcutaneous carbon dioxide tension (PTCCO2) has been used in the field of sleep medicine and nocturnal monitoring of carbon dioxide using the transcutaneous method is widely recognised. The technique is noninvasive, low-risk, requires minimal training and is well tolerated [4,5]。但是,不知道是否PTCCO2can be used as a reliable measure ofPaCO2在急性环境中,迄今为止支持其使用的证据是矛盾的,并且来自选定患者群体的小型研究[6–8], who were often medically stable [9]。接受无创通气治疗(NIV)的患者通常是那些需要最频繁的ABG监测以及最近对英国对患者结果和NIV护理死亡审查的国家机密调查的患者[10]强调需要仔细,及时审查PaCO2in these patients. An arterial line can help avoid distress to the patient but increased pressure on resources and level 2 beds means that this is not always available, and patients may therefore have to be subjected to repeated arterial stabs. Therefore, we hypothesised thatPTCCO2would be reliable, easy to use and preferred by patients as a means of measuring carbon dioxide in the acute, unselected medical setting.
Medical patients admitted to hospital acutely unwell who required at least one ABG test were eligible to participate. Patients were identified and approached consecutively from acute medical admissions patient lists. Ethical approval for the study was obtained (Regional Ethics Committee 17/LO/1137: IRAS 228887). Written consent, demographic and clinical data were collected. Patients completed a questionnaire about their experience of both techniques.
The procedure for ABG sampling (both arterial stab and collection of blood from arterial lines) was carried out in the standard way either by the researcher or by the clinical team. ABGs were only taken at a time that was clinically indicated as determined by the clinical team. A Resmed SenTec monitor (SenTec AG, Therwil, Switzerland) was used to measure thePTCCO2。可以在www.sentec.ch.tv。In brief, the technique involves the machine being used in its “spot check” mode and placement of an electrode sensor on the forehead of the patient. The sensor takes ∼15 min to equilibrate before it will give aPTCCO2reading. The arterial blood was sampled at the point at which the machine delivered the equilibrated reading.
Bland–Altman analysis calculating the actual differenceversus平均用来比较PaCO2andPTCCO2(Prism 6; GraphPad,La Jolla,CA,美国);95%的协议限制以0.25 kPa的预定值为可接受的差异计算。然后将测量值之间的差异与临床参数相关(Pearson的相关性),以确定任何潜在影响因素。在测量二氧化碳的两种技术之间比较了同一患者之间两个连续的配对测量结果之间的变化方向(i.e.在不同时间点从同一患者采集多个配对样品的地方,该问题被问到“每种技术测量时二氧化碳是否在相同方向上变化?”)。定性分析患者经验。
50 participants (23 males; median age 68 years, range 17–90 years) were recruited and consented to the study (72 screened; five patients did not require further ABG and 17 were unwilling or unable to consent). 45 patients completed the questionnaire; the five remaining were unable to partake in this element of the study due to their medical condition. Patients were admitted to hospital for a range of diagnoses: respiratory problems were most common (27 out of 50,) followed by nonrespiratory sepsis (seven out of 50), then cardiovascular (five out of 50) and the remaining 11 were admitted with other medical diagnosis (including neurological, diabetic and general medical issues). 74 paired samples (PTCCO2andPaCO2) were collected; no one participant had more than four pairs of samples. The following clinical data were collected at the time of the carbon dioxide measurements: median (range) temperature 36.7°C (35.7–38.4°C), oxygen saturations 93% (83–100%), heart rate 88 beats per min (60–100 beats per min) and mean arterial blood pressure 86 mmHg (53–109 mmHg). The ABG measurements showed a medianPaCO2of 6.45 kPa (3.4–13.4 kPa) and thePTCCO2measurements 6.36 kPa (3.1–12.6 kPa) (n=74 for both).
Bland–Altman analysis suggested that the bias of thePTCCO2tended to be 0.16 kPa (95% CI ±1.54 kPa) lower than thePaCO2with 95% limits of agreement −1.67–1.35 kPa (figure 1a). The difference between the two measurements was compared to the mean arterial blood pressure, heart rate, temperature and oxygen saturations; none of these parameters was found to affect how much thePTCCO2measurement differed from thePaCO2(数据未显示)。连续收集24个样品;但是,在通过两种技术测量时,只有54%的病例(24例中的13个)二氧化碳在相同方向上发生了变化(figure 1b).
患者绝大多数发现PTCCO2measurement more tolerable than the arterial stab. No patients reported any pain, and the only other comments were three patients out of 45 reporting a feeling of “warmth on the skin” during thePTCCO2测量和一项抱怨探针粘在皮肤上的轻微沉重。据报道,动脉刺是疼痛和不愉快的(八名患者有动脉线,因此没有对动脉刺发表评论; 33例报告明显的疼痛,其余四个报告了轻微疼痛或刮擦。)患者报告了可怕的动脉刺伤,其中100%为100%(45分中有45个)说他们会PTCCO2measurements in the future.
PTCCO2is an attractive option for the measurement of carbon dioxide; it is noninvasive, allows the patient to be managed in a low-acuity area and requires little skill to carry out. Other studies have variably shown thatPTCCO2may [6,7]或可能不会[8] be a reliable alternative to the gold standard ABGPaCO2。This larger, real-world study, recruiting unselected acutely unwell patients with a range of diagnoses, demonstrates thatPTCCO2should not be used as an alternative to the ABG to monitor carbon dioxide levels. The limitations to the study include the fact only a Resmed SenTec monitor was tested and only the forehead position was used for placement of the sensor; other devices or sensors in other positions may show other results. However, in this study the limits of agreement for the two techniques of measuringPTCCO2不仅宽,而且显着地躺在可能的差异±0.25 kPa之外。这与以前的工作一致[11]。Furthermore, thePTCCO2could not be reliably used to suggest a trend or direction of change in carbon dioxide level. This is disappointing both for staff and patients, as our qualitative patient analysis clearly demonstrated thatPTCCO2is a much more tolerable technique than ABG sampling. The study did not test whether either method of measuring carbon dioxide tension can be used to predict clinical outcomes or direct clinical decisions; the study question was limited only to whether the two methods of measuring carbon dioxide have comparable and clinically reliable results, so further research would be needed to answer this question. In conclusion, the results of this study suggest thatPTCCO2通过这种方法测量不应在急性临床环境中使用PaCO2measured by ABG sampling. Health economic pressures and patient experience considerations continue to call for more work to be done to find an alternative to the ABG.
Acknowledgements
T. Woodcock reviewed the statistical analysis.
脚注
Conflict of interest: V. Mummery reports grants from CLAHRC NWL during the conduct of the study and that the SenTecPTCCO2在研究期间,Monitor是从Resmed借来的。
Conflict of interest: E. Rogers has nothing to disclose.
Conflict of interest: V. Padmanaban reports conference sponsorship from Chiesi outside the submitted work.
Conflict of interest: D. Matthew has nothing to disclose.
Conflict of interest: T. Woodcock has nothing to disclose.
Conflict of interest: S. Bloch reports that the SenTecPTCCO2在研究期间,Monitor是从Resmed借来的。
支持声明:这项工作是通过用于应用健康研究和护理领导力的合作(CLAHRC)研究驱动的QI项目赠款资助的。V. Mummery由这笔赠款资助。本文介绍了由国家卫生研究所(NIHR)在伦敦西北伦敦的CLAHRC计划下资助的独立研究。本出版物中表达的观点是作者的观点,不一定是NHS,NIHR或卫生和社会护理部的观点。这项工作得到了借用Sentec机器的Resmed的支持。本文的资金信息已存入CrossRef资助人注册表。
- 衰退ivedSeptember 10, 2018.
- AcceptedDecember 23, 2018.
- 复制right ©ERS 2019