CNAP文献的摘要翻译.doc

A comparison of a continuous noninvasive arterial pressure (CNAP™) monitor with an invasive arterial blood pressure monitor in the cardiac surgical ICU

AM Jagadeesh, Naveen G Singh, Subramanyam Mahankali
Department of Cardiac Anaesthesiology, Sri Jayadeva Institute of Cardiovascular Sciences and Research, Jayanagar, Bangalore, India
Abstract
Accurate measurement and display of arterial blood pressure is essential for rational management of adult cardiac surgical patients. Because of the lower risk of complications, noninvasive monitoring methods gain importance. A newly developed continuous noninvasive arterial blood pressure (CNAP™) monitor is available and has been validated perioperatively. In a prospective study we compared the CNAP™ monitoring device with invasive arterial blood pressure (IAP) measurement in 30 patients in a cardiac surgical Intensive Care Unit (ICU). Patients were either mechanically ventilated or spontaneously breathing, with or without inotropes. CNAP™ was applied on two fingers of the hand contralateral to the IAP monitoring catheter. Systolic, diastolic and mean pressure data were recorded every minute for 2 h simultaneously for both IAP and CNAP™. Statistical analysis included construction of mountain plot and Bland Altman plots for assessing limits of agreement and bias (accuracy) calculation. Three thousand and six hundred pairs of data were analyzed. The CNAP™ systolic arterial pressure bias was 10.415 mmHg and the CNAP™ diastolic arterial pressure bias was −5.3386 mmHg; the mean arterial pressure (MAP) of CNAP™ was close to the MAP of IAP, with a bias of 0.03944 mmHg. The Bland Altman plot showed a uniform distribution and a good agreement of all arterial blood pressure values between CNAP™ and IAP. Percentage within limits of agreement was 94.5%, 95.1% and 99.4% for systolic, diastolic and MAP. Calculated limits of agreement were −4.60 to 25.43, −13.38 to 2.70 and −5.95 to 6.03 mmHg for systolic, diastolic and mean BP, respectively. The mountain plot showed similar results as the Bland Altman plots. We conclude CNAP™ is a reliable, noninvasive, continuous blood pressure monitor that provides real-time estimates of arterial pressure comparable to those generated by an invasive arterial catheter system. CNAP™ can be used as an alternative to IAP.
Keywords: Arterial blood pressure, Continuous noninvasive arterial pressure, Monitoring

Comput Biol Med. 2013 Oct 1;43(10):1583-9. doi: 10.1016/pbiomed.2013.07.020. Epub 2013 Jul 23.
Evaluation of a novel automated non-invasive pulse pressure variation algorithm.
Schmid M, Prettenthaler H, Weger C, Smolle KH.
Author information
Abstract
In mechanically ventilated patients, Pulse Pressure Variation (PPV) has been shown to be a useful parameter to guide fluid management. We evaluated a real-time automated PPV-algorithm by comparing it to manually calculated PPV-values. In 10 critically ill patients, blood pressure was measured invasively (IBP) and non-invasively (CNAP(®) Monitor, CNSystems Medizintechnik, Austria). PPV was determined manually and compared to automated PPV values: PPVmanIBP vs. PPVautoIBP was -0.19 ± 1.65% (mean bias ± standard deviation), PPVmanCNAP vs. PPVautoCNAP was -1.02 ± 2.03% and PPVautoCNAP vs. PPVmanIBP was -2.10 ± 3.14%, suggesting that the automated CNAP(®) PPV-algorithm works well on both blood pressure waveforms but needs further clinical evaluation.
© 2013 Elsevier Ltd. All rights reserved.
KEYWORDS:
CNAP(®) Monitor 500, Continuous non-invasive arterial blood pressure monitoring, Fluid management, Mechanical ventilation, Pulse pressure variation, Vascular unloading

Anesth Analg. 2013 Jul;117(1):76-82. doi: 10.1213/ANE.0b013e3182910df5. Epub 2013 May 17.
The accuracy and responsiveness of continuous noninvasive arterial pressure during rapid ventricular pacing for transcatheter aortic valve replacement
Schramm C, Huber A, Plaschke K.
Author information
Abstract
BACKGROUND:
The accuracy of measurement of the continuous noninvasive arterial blood pressure (CNAP) technique is unknown during sudden cardiocirculatory arrest.
METHODS:
In 33 patients undergoing elective transfemoral aortic valve implantation procedures under analgesic sedation, invasive arterial blood pressure (IAP) was compared with a CNAP device during episodes of severe hypotension (functional cardiocirculatory arrests by rapid pacing) and the remaining time without severe hypotension. Systolic, diastolic, and mean pairs of blood pressure measurements were extracted for both groups and were analyzed by Bland-Altman plots. The responsiveness of the CNAP technique was assessed in the various phases of severe hypotension concerning time and amplitude of changes.
RESULTS:
Overall CNAP accuracy (bias), calculated by subtracting IAP from CNAP, was -6.3 ± 18.9, 7.4 ± 10.5, and 4.0 ± 11.3 mm Hg (mean ± SD, systolic, diastolic, and mean). Bias increased during episodes of severe hypotension to 11.8 ± 14.5, 13.8 ± 12.4, and 12.9 ± 12.4 mm Hg. The percentage of agreements (95% confidence interval) between the blood pressure pairs with a difference ≤15 mm Hg was 58.5% (57.9-58.6), 75.8% (75.5-76.0), 82.2% (81.9-82.4; systolic, diastolic, mean) for all data and 56.4% (54.2-58.9; P = 0.71), 53.2%* (51.1-56.0), and 57.4%* (56.3-59.1; *P < 0.001) during rapid pacing. The responsiveness of mean CNAP and mean IAP did not differ significantly during the various phases of rapid pacing.
CONCLUSIONS:
The stand-alone CNAP monitor (model 500at, software V3.5) accurately and rapidly measures the changes of blood pressure that occur during sudden development of cardiocirculatory arrest and recovery to baseline blood pressures. CNAP monitors the duration of the arrest.

J Clin Anesth. 2013 Jun;25(4):309-13. doi: 10.1016/j.jclinane.2013.01.010. Epub 2013 May 17.
Accuracy of the CNAP monitor, a noninvasive continuous blood pressure device, in providing beat-to-beat blood pressure readings in the prone position
Dewhirst E, Corridore M, Klamar J, Beebe A, Rice J, Barry N, Tobias JD.
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Abstract
STUDY OBJECTIVE:
To assess the accuracy of a noninvasive continuous arterial pressure (CNAP) monitor in patients who are positioned prone in the operating room.
DESIGN:
Prospective study.
SETTING:
Operating room at a children's hospital.
PATIENTS:
20 pediatric patients, aged 13.8 ± 2 years, and weight 63.7 ± 18.8 kg, scheduled for surgery in the prone position, and for which arterial catheter placement was planned.
INTERVENTIONS:
Measurements were recorded with an arterial line (AL) and a new noninvasive continuous blood pressure (BP) monitor.
MEASUREMENTS:
Systolic (SBP), diastolic (DBP), and mean arterial (MAP) pressure readings were captured from an arterial cannula and theCNAP device every minute during anesthesia.
MAIN RESULTS:
The study cohort consisted of analysis of 4104 pairs of SBP, DBP, and MAP values, which showed an absolute difference between the AL and CNAP device readings of 7.9 ± 6.3 mmHg for SBP, 5.3 ± 4.3 mmHg for DBP, and 4.6 ± 3.9 mmHg for MAP. Bland-Altman analysis of MAP values showed a bias of 0.26 mmHg, with upper and lower limits of agreement of 12.18 mmHg and -11.67 mmHg, respectively. CNAP readings deviated from arterial values by ≤ 5 mmHg in 67% of MAP values, 59% of DBP values, and 43% of SBP readings. The difference was ≤ 10 mmHg for 94% of MAP readings, 90% of DBP values, and 73% of SBP readings.
CONCLUSIONS:
During prone positioning, the CNAP monitor provided clinically acceptable accuracy for MAP values, similar to those reported in adults in the supine position.
Copyright © 2013 Elsevier Inc. All rights reserved.
KEYWORDS:
Anesthesia, Blood pressure monitoring devices, Hemodynamics, Hypotension, Pediatric, Pediatrics, intraoperative

Paediatr Anaesth. 2013 Nov;23(11):989-93. doi: 10.1111/pan.12173. Epub 2013 Apr 9.
Accuracy of the CNAP™ monitor, a noninvasive continuous blood pressure device, in providing beat-to-beat blood pressure readings in pediatric patients weighing 20-40 kilograms.
Kako H, Corridore M, Rice J, Tobias JD.
Author information
Abstract
BACKGROUND:
During perioperative care, the continuous measurement of blood pressure (BP) provides superior physiologic monitoring to intermittent techniques. However, such monitoring requires placement of an intraarterial catheter, which may be time-consuming or associated with adverse events and technical difficulty. A noninvasive, continuous BP monitoring device has been studied in the adult population. This study prospectively assesses its accuracy in pediatric patients, weighing 20-40 kg.
METHODS:
The technology evaluated is the CNAP™ Monitor 500, developed by CNSystems AG (Graz, Austria). The study cohort included pediatric patients weighing between 20 and 40 kg, scheduled for surgery for which arterial line (AL) placement was planned. Systolic (sBP), diastolic (dBP), and mean arterial (MAP) blood pressure readings were captured from the AL and the CNAP™ device every minute during anesthetic care.
RESULTS:
The study cohort consisted of 20 patients (11 weighing between 30 and 40 kg and 9 weighing between 20 and 29.9 kg) with a mean age of 9.8 ± 3.4 years (range, 6-16 years) and weight of 29.8 ± 6.1 kg (range, 20.9-38.7 kg). There were a total of 1076 pairs each of sBP, dBP, and MAP values in the 20-29.9 kg group. The absolute difference between the sBP, dBP, and MAP was 9.8 ± 8.5, 6.8 ± 5.3, and 6.7 ± 6.2 mmHg, respectively. The correlation coefficient between the AL and the CNAP™ device was 0.48, 0.60, and 0.64 for the sBP, dBP, and MAP, respectively. The CNAP™ values (sBP, dBP, MAP) were ≤5 mmHg from the AL values in 38.6%, 48.5%, and 55.0% of the values, respectively. In the 30-40 kg group, there were a total of 2737 pairs of sBP, dBP, and MAP values. The absolute difference between the sBP, dBP, and MAP was 11.5 ± 9.3, 7.5 ± 5.3, and 7.9 ± 6.6 mmHg, respectively. The correlation coefficient between the arterial cannula and the CNAP™ device was 0.48, 0.45, and 0.51 for the sBP, dBP, and MAP, respectively. CNAP™ readings were ≤5 mmHg from the AL values (sBP, dBP, MAP) in 29.0%, 41.9%, and 40.5% of the values, respectively.
CONCLUSION:
Although some variation in its accuracy was noted, the CNAP™ device provides a noninvasive and continuous blood pressure reading which appears to be within clinically useful limits. It may be that modification of the finger cuffs is needed to improve its absolute accuracy as our clinical experience demonstrated that achieving an effective fit with the cuffs was at times difficult.
© 2013 John Wiley & Sons Ltd.
KEYWORDS:
arterial blood pressure, blood pressure monitors, pediatrics

Acta Anaesthesiol Scand. 2013 Apr;57(4):468-73. doi: 10.1111/aas.12028. Epub 2012 Nov 27.
CNAP(®) does not reliably detect minimal or maximal arterial blood pressures during induction of anaesthesia and tracheal intubation.
Gayat E, Mongardon N, Tuil O, Sievert K, Chazot T, Liu N, Fischler M.
Author information
Abstract
BACKGROUND:
CNAP(®) provides continuous non-invasive arterial pressure (AP) monitoring. We assessed its ability to detect minimal and maximal APs during induction of general anaesthesia and tracheal intubation.
METHODS:
Fifty-two patients undergoing surgery under general anaesthesia were enrolled. Invasive pressure monitoring was established at the radial artery, and CNAP monitoring using a finger sensor recording was begun before induction. Statistical analysis was conducted with the Bland-Altman method for comparison of repeated measures and intraclass correlation coefficient (ICC).
RESULTS:
Patients' median age was 67 years [interquartile range (59-76)], median American Society of Anesthesiologists score was 3 [interquartile range (2-3)]. Bias was 5 and -7 mmHg for peak and nadir systolic AP (SAP), with upper and lower limits of agreement of (42:-32) and (27;-42), respectively. The corresponding ICC values were 0.74 [95% confidence interval (CI) = 0.57-0.84] and 0.60 (95% CI = 0.44-0.73). Time lags to reach these values were 7.5 s (95% CI = -10.0 to 60.0) for the highest SAP and 10 s (95% CI = -12.5 to 72.5) for the lowest SAP. Bias, lower and upper limits of agreement for diastolic, and mean AP were -14 (-36 to 9) and -12 (-37 to 13) for the nadir value and -7 (-29 to 15) and -2 (-28 to 25) for the peak value.
CONCLUSIONS:
The CNAP monitor could detect acute change in AP within a reasonable time lag. Precision of its measurements is not satisfactory, and therefore, it could only serve as a clue to the occurrence of changes in AP.
© 2012 The Acta Anaesthesiologica Scandinavica Foundation.

Br J Anaesth. 2012 Sep;109(3):413-9. doi: 10.1093/bja/aes224. Epub 2012 Jul 12.
Detection of hypotension during Caesarean section with continuous non-invasive arterial pressure device or intermittent oscillometric arterial pressure measurement.
Ilies C, Kiskalt H, Siedenhans D, Meybohm P, Steinfath M, Bein B, Hanss R.
Author information
Abstract
BACKGROUND:
The intensified use of spinal anaesthesia (SPA) for Caesarean section significantly contributed to a decreased maternal mortality and morbidity. Nevertheless, one of the major side-effects is hypotension after SPA with potential negative effects on the fetus. Owing to discontinuous oscillometric measurements (non-invasive arterial pressure, NIAP), hypotensive episodes may be missed. Recently, a continuous NIAP measurement device (CNAP) with acceptable agreement with the mean invasive AP was introduced. We hypothesized that CNAP detects hypotensive episodes more reliably compared with NIAP measurements.
METHODS:
A total of 65 women undergoing Caesarean section under SPA were included in the study analysis. A total of 888 NIAP measurements obtained at 3 min cycles, starting from before SPA and continued until delivery, were analysed.
RESULTS:
When averaged over all cycles, the lowest systolic AP identified by CNAP in each cycle [105 mm Hg, (24.4)] was significantly lower (P<0.001) than the average of the individual corresponding single NIAP measurements [126 mm Hg (22.1)] and highest CNAP average [126 mm Hg (24.5)]. Hypotension (systolic AP <100 mm Hg) was detected in 39% of all cycles with CNAP and in 9% with NIAP. Hypotension was detected in 91% of the patients based on CNAP and in 55% based on NIAP. Fetal acidosis defined by an umbilical vein pH under 7.25 did not occur when the lowest systolic AP measured by CNAP was above 100 mm Hg.
CONCLUSIONS:
The CNAP device detected more hypotensive episodes after SPA and significantly lower AP compared with NIAP. AP monitoring based on CNAP may improve haemodynamic management in this patient population with potential benefit for the fetus.

Ann Card Anaesth. 2012 Jul-Sep;15(3):180-4. doi: 10.4103/0971-9784.97973.
A comparison of a continuous noninvasive arterial pressure (CNAP™) monitor with an invasive arterial blood pressure monitor in the cardiac su