BACKGROUND: Continuous monitoring of arterial pressure is important in severely obese patients who are at particular risk for cardiovascular complications. Innovative technologies for continuous noninvasive arterial pressure monitoring are now available. In this study, we compared noninvasive arterial pressure measurements using the vascular unloading technique (Clearsight system; Edwards Lifesciences Corp, Irvine, CA) with invasive arterial pressure measurements (radial arterial catheter) in severely obese patients during laparoscopic bariatric surgery. METHODS: In 35 severely obese patients (median body mass index, 47 kg/m2), we simultaneously recorded noninvasive and invasive arterial pressure measurements over a period of 45 minutes. We compared noninvasive (test method) and invasive (reference method) arterial pressure measurements (sampling rate 1 Hz = 1/s) using Bland-Altman analysis (accounting for multiple measurements per subject), 4-quadrant plot/concordance analysis (2-minute interval, 5 mm Hg exclusion zone), and error grid analysis (calculating the proportions of measurements in risk zones A–E with A indicating no risk, B low risk, C moderate risk, D significant risk, and E dangerous risk for the patient due to the risk of wrong clinical interventions because of measurement errors). RESULTS: We observed a mean of the differences (±SD, 95% limits of agreement) between the noninvasively and invasively assessed arterial pressure values of 1.1 mm Hg (±7.4 mm Hg, −13.5 to 15.6 mm Hg) for mean arterial pressure (MAP), 6.8 mm Hg (±10.3 mm Hg, −14.4 to 27.9 mm Hg) for systolic arterial pressure, and 0.8 mm Hg (±6.9 mm Hg, −12.9 to 14.4 mm Hg) for diastolic arterial pressure. The 4-quadrant plot concordance rate (ie, the proportion of arterial pressure measurement pairs showing concordant changes to all changes) was 93% (CI, 89%–96%) for MAP, 93% (CI, 89%–97%) for systolic arterial pressure, and 88% (CI, 84%–92%) for diastolic arterial pressure. Error grid analysis showed that the proportions of measurements in risk zones A–E were 89.5%, 10.0%, 0.5%, 0%, and 0% for MAP and 93.7%, 6.0%, 0.3%, 0%, and 0% for systolic arterial pressure, respectively. CONCLUSIONS: During laparoscopic bariatric surgery, the accuracy and precision of the vascular unloading technique (Clearsight system) was good for MAP and diastolic arterial pressure, but only moderate for systolic arterial pressure according to Bland-Altman analysis. The system showed good trending capabilities. In the error grid analysis, >99% of vascular unloading technique–derived arterial pressure measurements were categorized in no- or low-risk zones.
Wearable sensors to continuously measure blood pressure and derived cardiovascular variables have the potential to revolutionize patient monitoring. Current wearable methods analyzing time components (e.g., pulse transit time) still lack clinical accuracy, whereas existing technologies for direct blood pressure measurement are too bulky. Here we present an innovative art of continuous noninvasive hemodynamic monitoring (CNAP2GO). It directly measures blood pressure by using a volume control technique and could be used for small wearable sensors integrated in a finger-ring. As a software prototype, CNAP2GO showed excellent blood pressure measurement performance in comparison with invasive reference measurements in 46 patients having surgery. The resulting pulsatile blood pressure signal carries information to derive cardiac output and other hemodynamic variables. We show that CNAP2GO can self-calibrate and be miniaturized for wearable approaches. CNAP2GO potentially constitutes the breakthrough for wearable sensors for blood pressure and flow monitoring in both ambulatory and in-hospital clinical settings.
It remains unclear whether reduced myocardial contractility, venous dilation with decreased venous return, or arterial dilation with reduced systemic vascular resistance contribute most to hypotension after induction of general anesthesia. We sought to assess the relative contribution of various hemodynamic mechanisms to hypotension after induction of general anesthesia with sufentanil, propofol, and rocuronium. In this prospective observational study, we continuously recorded hemodynamic variables during anesthetic induction using a finger-cuff method in 92 non-cardiac surgery patients. After sufentanil administration, there was no clinically important change in arterial pressure, but heart rate increased from baseline by 11 (99.89% confidence interval: 7 to 16) bpm (P < 0.001). After administration of propofol, mean arterial pressure decreased by 23 (17 to 28) mmHg and systemic vascular resistance index decreased by 565 (419 to 712) dyn*s*cm−5*m2 (P values < 0.001). Mean arterial pressure was < 65 mmHg in 27 patients (29%). After propofol administration, heart rate returned to baseline, and stroke volume index and cardiac index remained stable. After tracheal intubation, there were no clinically important differences compared to baseline in heart rate, stroke volume index, and cardiac index, but arterial pressure and systemic vascular resistance index remained markedly decreased. Anesthetic induction with sufentanil, propofol, and rocuronium reduced arterial pressure and systemic vascular resistance index. Heart rate, stroke volume index, and cardiac index remained stable. Post-induction hypotension therefore appears to result from arterial dilation with reduced systemic vascular resistance rather than venous dilation or reduced myocardial contractility.
In the setting of laparoscopic bariatric surgery, continuous noninvasive AP monitoring with the CNAP system showed good trending capabilities compared with continuous invasive AP measurements obtained with a radial arterial catheter. However, absolute CNAP- and arterial catheter-derived AP values were not interchangeable.
BACKGROUND Invasive pulse wave analysis is used in peri-operative settings to estimate cardiac output (CO). The ‘pressure recording analytical method’ (PRAM) implemented in the MostCareUp CO monitor is an invasive pulse wave analysis method using high-frequency sampling and analysis of the pulse wave to directly estimate the arterial impedance as a key variable of the proprietary CO estimation algorithm. OBJECTIVE To compare CO estimated by PRAM (PRAM-CO; test method) with CO measured by pulmonary artery thermodilution (PATD-CO; reference method). DESIGN Prospective observational method comparison study. PRAM-CO and PATD-CO were assessed simultaneously at five time points with at least 20 min between measurements. Arterial pressure waveforms were carefully checked for damping artefacts and a proprietary electronic filter of the MostCareUp CO monitor was used to optimise waveform quality. SETTING ICU of a German university hospital from August 2018 until April 2019. PATIENTS We included adult patients admitted to the ICU after elective off-pump coronary artery bypass surgery who were monitored with a radial arterial catheter and a pulmonary artery catheter. Patients with severe heart valve insufficiency or persistent arrhythmia were excluded. MAIN OUTCOME MEASURES AND ANALYSIS PATD-CO and PRAM-CO were compared using Bland-Altman analysis accounting for repeated measurements, the percentage error and trending analysis (four-quadrant plot, concordance rate). RESULTS We analysed 195 paired CO values of 41 patients. Mean PATD-CO and PRAM-CO were 4.99 ± 1.02 and 4.92 ± 1.05 l min−1, respectively. PATD-CO and PRAM-CO ranged from 3.04 to 8.74 and 2.79 to 8.01 l min−1, respectively. The mean of the differences between PATD-CO and PRAM-CO was −0.08 ± 0.74 l min−1 with 95% limits of agreement of −1.55 to +1.40 l min−1. The percentage error was 29.8%. The concordance rate in four-quadrant plot analysis was 92%. CONCLUSION Using the system's electronic waveform filter PRAM-CO shows good agreement and trending ability compared with PATD-CO in adults after off-pump coronary artery bypass surgery.
Wearable sensors to continuously measure blood pressure (BP) and derived cardiovascular variables have the potential to revolutionize patient monitoring. Current wearable methods analyzing time components (e.g., pulse transit time) still lack clinical accuracy, whereas existing technologies for direct BP measurement are too bulky. Here we present a new art of continuous non-invasive arterial blood pressure monitoring (CNAP2GO). It directly measures BP by using a new "volume control technique" and could be used for small wearable sensors integrated in a finger ring. As a software prototype, CNAP2GO showed excellent BP measurement performance in comparison with invasive BP in 46 patients having surgery. The resulting pulsatile BP signal carries information to derive cardiac output and other hemodynamic variables. We show that CNAP2GO can be miniaturized for wearable approaches. CNAP2GO potentially constitutes the breakthrough for wearable sensors for blood pressure and flow monitoring in both ambulatory and in-hospital clinical settings.
Therapy and prognosis of the slipped capital femoral epiphysis are discussed in connection with the results obtained in the authors' own patients. Reduction of a dislocated femoral head is always desirable. If closed reduction fails, it will be necessary to reduce in full view. In smaller children, fixation is effected by means of several Kirschner wires, in older ones via screw osteosynthesis. Bone pegging or osteotomy are not suited for treatment of an acute or subacute slipped capital epiphysis.
Die robotergestützte Ösophagusresektion gehört zu den Hochrisiko-Operationen und bedarf einer aufwendigen Planung und operativ-anästhesiologischen Abstimmung. Aufgrund der Positionierung der Patienten mit intraoperativer Umlagerung ist der Zugang zu den Atemwegen erschwert, was jegliche Manipulation an einem Doppellumentubus limitiert. Ein videogestützter Doppellumentubus kann bei der Abstimmung im interdisziplinären Team sehr hilfreich sein.
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