Invasive Arterial Blood Pressure Monitoring Research Articles

Continuous non-invasive vs. invasive arterial blood pressure monitoring during neuroradiological procedure: a comparative, prospective, monocentric, observational study

BackgroundIn the perioperative setting, the most accurate way to continuously measure arterial blood pressure (ABP) is using an arterial catheter. Surrogate methods such as finger cuff have been developed to allow non-invasive measurements and are increasingly used, but need further evaluation. The aim of this study is to evaluate the accuracy and clinical concordance between two devices for the measurement of ABP during neuroradiological procedure.MethodsThis is a prospective, monocentric, observational study. All consecutive patients undergoing a neuroradiological procedure were eligible. Patients who needed arterial catheter for blood pressure measurement were included. During neuroradiological procedure, ABP (systolic, mean and diatolic blood pressure) was measured with two different technologies: radial artery catheter and Nexfin. Bland-Altman and error grid analyses were performed to evaluate the accuracy and clinical concordance between devices.ResultsFrom March 2022 to November 2022, we included 50 patients, mostly ASA 3 (60%) and required a cerebral embolization (94%) under general anaesthesia (96%). Error grid analysis showed that 99% of non-invasive ABP measures obtained with the Nexfin were located in the risk zone A or B. However, 65.7% of hypertension events and 41% of hypotensive events were respectively not detected by Nexfin. Compared to the artery catheter, a significant relationship was found for SAP (r2 = 0.78) and MAP (r2 = 0.80) with the Nexfin (p < 0.001). Bias and limits of agreement (LOA) were respectively 9.6 mmHg (− 15.6 to 34.8 mmHg) and − 0.8 mmHg (− 17.2 to 15.6 mmHg), for SAP and MAP.ConclusionsNexfin is not strictly interchangeable with artery catheter for ABP measuring. Further studies are needed to define its clinical use during neuroradiological procedure.Trial registrationClinicaltrials.gov, registration number: NCT05283824.

Association of Postarrest Hypotension Burden With Unfavorable Neurologic Outcome After Pediatric Cardiac Arrest.

Quantify hypotension burden using high-resolution continuous arterial blood pressure (ABP) data and determine its association with outcome after pediatric cardiac arrest. Retrospective observational study. Academic PICU. Children 18 years old or younger admitted with in-of-hospital or out-of-hospital cardiac arrest who had invasive ABP monitoring during postcardiac arrest care. None. High-resolution continuous ABP was analyzed up to 24 hours after the return of circulation (ROC). Hypotension burden was the time-normalized integral area between mean arterial pressure (MAP) and fifth percentile MAP for age. The primary outcome was unfavorable neurologic status (pediatric cerebral performance category ≥ 3 with change from baseline) at hospital discharge. Mann-Whitney U tests compared hypotension burden, duration, and magnitude between favorable and unfavorable patients. Multivariable logistic regression determined the association of unfavorable outcomes with hypotension burden, duration, and magnitude at various percentile thresholds from the 5th through 50th percentile for age. Of 140 patients (median age 53 [interquartile range 11-146] mo, 61% male); 63% had unfavorable outcomes. Monitoring duration was 21 (7-24) hours. Using a MAP threshold at the fifth percentile for age, the median hypotension burden was 0.01 (0-0.11) mm Hg-hours per hour, greater for patients with unfavorable compared with favorable outcomes (0 [0-0.02] vs. 0.02 [0-0.27] mm Hg-hr per hour, p < 0.001). Hypotension duration and magnitude were greater for unfavorable compared with favorable patients (0.03 [0-0.77] vs. 0.71 [0-5.01]%, p = 0.003; and 0.16 [0-1.99] vs. 2 [0-4.02] mm Hg, p = 0.001). On logistic regression, a 1-point increase in hypotension burden below the fifth percentile for age (equivalent to 1 mm Hg-hr of burden per hour of recording) was associated with increased odds of unfavorable outcome (adjusted odds ratio [aOR] 14.8; 95% CI, 1.1-200; p = 0.040). At MAP thresholds of 10th-50th percentiles for age, MAP burden below the threshold was greater in unfavorable compared with favorable patients in a dose-dependent manner. High-resolution continuous ABP data can be used to quantify hypotension burden after pediatric cardiac arrest. The burden, duration, and magnitude of hypotension are associated with unfavorable neurologic outcomes.

Invasive arterial blood pressure delineator for cardiopulmonary resuscitation patients during pauses of chest compressions

Invasive arterial blood pressure (IBP) monitoring is important to assess patient’s cardiovascular competence and guide clinical treatment. Besides, international resuscitation guidelines in force suggest its use during Cardiopulmonary Resuscitation (CPR), but current automated algorithms for IBP variables computation were not designed for cardiac arrest patients. A lack of knowledge is detected in the automated processing of IBP signal during CPR.The aim of this study was to design algorithms for heartbeat detection and for IBP physiological variable computation during CPR, and compare to state-of-the-art (SoA) proposals. The dataset used consists of 81 out-of-hospital-cardiac-arrest (OHCA) patients and two additional public datasets with hemodynamically stable patients. A set of 377 IBP segments, total duration of 1127 min, were extracted from the OHCA dataset during the pauses of chest compressions. The method includes artifact removing from the in IBP using Stationary Wavelet Decomposition and heartbeat detection in the first difference signal. A multicomponent evaluation and two adaptive thresholds were applied to compute IBP physiological variables.Pulsatile segments with heartbeats were discriminated from pulseless segments with mean (standard deviation) sensitivity(Se)/specificity and positive (PPV)/negative predictive values of 98.8(6.9)/91.6(20.2)% and 97.4(9.7)/98.7(6.1)%, respectively. The heartbeat detection showed 96.1(8.3)% of Se, 96.1(7.6)% of PPV and 95.7(6.4)% of F1-score , with absolute errors of 0.55(2.91)/0.39(4.87)/0.78(6.08)mmHg in systolic, diastolic and pulse pressure values, respectively. The proposed algorithms outperformed SoA solutions with both OHCA and stable patients.

Sex differences in in-hospital management in patients with sepsis and septic shock: a prospective multicenter observational study

Sex differences in the in-hospital management of sepsis exist. Previous studies either included patients with sepsis that was defined using previous definitions of sepsis or evaluated the 3-h bundle therapy. Therefore, this study sought to assess sex differences in 1-h bundle therapy and in-hospital management among patients with sepsis and septic shock, defined according to the Sepsis-3 definitions. This observational study used data from Korean Shock Society (KoSS) registry, a prospective multicenter sepsis registry. Adult patients with sepsis between June 2018 and December 2021 were included in this study. The primary outcome was adherence to 1-h bundle therapy. Propensity score matching (PSM) and multivariable logistic regression analyses were performed. Among 3264 patients with sepsis, 3129 were analyzed. PSM yielded 2380 matched patients (1190 men and 1190 women). After PSM, 1-h bundle therapy was performed less frequently in women than in men (13.0% vs. 19.2%; p < 0.001). Among the bundle therapy components, broad-spectrum antibiotics were administered less frequently in women than in men (25.4% vs. 31.6%, p < 0.001), whereas adequate fluid resuscitation was performed more frequently in women than in men (96.8% vs. 95.0%, p = 0.029). In multivariable logistic regression analysis, 1-h bundle therapy was performed less frequently in women than in men [adjusted odds ratio (aOR) 1.559; 95% confidence interval (CI) 1.245–1.951; p < 0.001] after adjustment. Among the bundle therapy components, broad-spectrum antibiotics were administered less frequently to women than men (aOR 1.339, 95% CI 1.118–1.605; p = 0.002), whereas adequate fluid resuscitation was performed more frequently for women than for men (aOR 0.629, 95% CI 0.413–0.959; p = 0.031). Invasive arterial blood pressure monitoring was performed less frequently in women than in men. Resuscitation fluid, vasopressor, steroid, central-line insertion, ICU admission, length of stay in the emergency department, mechanical ventilator use, and renal replacement therapy use were comparable for both the sexes. Among patients with sepsis and septic shock, 1-h bundle therapy was performed less frequently in women than in men. Continuous efforts are required to increase adherence to the 1-h bundle therapy and to decrease sex differences in the in-hospital management of patients with sepsis and septic shock.

Accuracy of Noninvasive Blood Pressure Monitoring in Critically Ill Adults.

Background: Blood pressure (BP) is routinely invasively monitored by an arterial catheter in the intensive care unit (ICU). However, the available data comparing the accuracy of noninvasive methods to arterial catheters for measuring BP in the ICU are limited by small numbers and diverse methodologies. Purpose: To determine agreement between invasive arterial blood pressure monitoring (IABP) and noninvasive blood pressure (NIBP) in critically ill patients. Methods: This was a single center, observational study of critical ill adults in a tertiary care facility evaluating agreement (≤10% difference) between simultaneously measured IABP and NIBP. We measured clinical features at time of BP measurement inclusive of patient demographics, laboratory data, severity of illness, specific interventions (mechanical ventilation and dialysis), and vasopressor dose to identify particular clinical scenarios in which measurement agreement is more or less likely. Results: Of the 1852 critically ill adults with simultaneous IABP and NIBP readings, there was a median difference of 6 mm Hg in mean arterial pressure (MAP), interquartile range (1-12), P < .01. A logistic regression analysis identified 5 independent predictors of measurement discrepancy: increasing doses of norepinephrine (adjusted odds ratio [aOR] 1.10 [95% confidence interval, CI 1.08-1.12] P = .03 for every change in 5 µg/min), lower MAP value (aOR 0.98 [0.98-0.99] P < .01 for every change in 1 mm Hg), higher body mass index (aOR 1.04 [1.01-1.09] P = .01 for an increase in 1), increased patient age (aOR 1.31 [1.30-1.37] P < .01 for every 10 years), and radial arterial line location (aOR 1.74 [1.16-2.47] P = .04). Conclusions: There was broad agreement between IABP and NIBP in critically ill patients over a range of BPs and severity of illness. Several variables are associated with measurement discrepancy; however, their predictive capacity is modest. This may guide future study into which patients may specifically benefit from an arterial catheter.

Micro- and macrocirculatory effects of norepinephrine on anaesthesia-induced hypotension: a prospective preliminary study

BackgroundIntraoperative arterial hypotension (IOH) leads to increased postoperative morbidity. Norepinephrine is often use to treat IOH. The question regarding the mode of administration in either a bolus or continuous infusion remains unanswered. The aim of the present study was to describe and compare the effects on macrocirculation and microcirculation of a bolus and a continuous infusion of norepinephrine to treat IOH.MethodsWe conducted a prospective observational study with adult patients who underwent neurosurgery. Patients with invasive arterial blood pressure and cardiac output (CO) monitoring were screened for inclusion. All patients underwent microcirculation monitoring by video-capillaroscopy, laser doppler, near-infrared spectroscopy technology, and tissular CO2. In case of IOH, the patient could receive either a bolus of 10 µg or a continuous infusion of 200 µg/h of norepinephrine. Time analysis for comparison between bolus and continuous infusion were at peak of MAP. The primary outcome was MFI by videocapillaroscopy.ResultsThirty-five patients were included, with 41 boluses and 33 continuous infusion.Bolus and continuous infusion induced an maximal increase in mean arterial pressure of +30[20-45] and +23[12-34] %, respectively (P=0,07). For macrocirculatory parameters, continuous infusion was associated with a smaller decrease in CO and stroke volume (p<0.05).For microcirculatory parameters, microvascular flow index (-0,1 vs. + 0,3, p=0,03), perfusion index (-12 vs. +12%, p=0,008), total vessel density (-0,2 vs. +2,3 mm2/mm2, p=0,002), showed significant opposite variations with bolus and continuous infusion, respectively.ConclusionsThese results on macro and microcirculation enlighten the potential benefits of a continuous infusion of norepinephrine rather than a bolus to treat anaesthesia-induced hypotension.Trial registration(NOR-PHARM: 1-17-42 Clinical Trials: NCT03454204), 05/03/2018

The effect of intraoperative cerebral oxygen desaturations on postoperative cerebral oxygen metabolism in neonates and infants a pilot study.

Cerebral oxygen desaturation during pediatric surgery has been associated with adverse perioperative outcomes. The aim of this pilot study was to analyze the frequency and severity of intraoperative cerebral oxygen desaturations and their impact on postoperative cerebral oxygen metabolism in neonates and infants undergoing pediatric surgery. In a prospective pilot study, intra- and postoperative regional cerebral oxygen saturation and blood flow were measured noninvasively using a device combining laser Doppler flowmetry and white-light-spectrometry. Thirty-seven consecutive neonates and infants undergoing noncardiac surgery under general anesthesia for more than 30 min and necessity for invasive arterial blood pressure monitoring were included. Patients with pre-known congenital structural heart disease or cerebral disease were excluded. Continuously brain monitor recording was started in sedated patients before induction of anesthesia (preoperative baseline) and was completed 1 h postoperatively in the PICU in sedated, intubated, and mechanically ventilated states at the PICU (postoperative state). Baseline and postoperative state for cerebral fractional tissue oxygen extraction and approximated cerebral metabolic rate of oxygen were calculated. Seventeen (46%) of the 37 studied neonates and infants suffered from intraoperative periods of regional cerebral oxygen desaturation below 20% of the baseline (event group). Severity of cerebral desaturations was median 4.0%min/h [range 0.1-58.7; interquartile range [IQR] 0.99-21.29]. In the event group, the duration of surgery was significantly longer (median 135 min [range 11-260; IQR 113.5-167.0] vs median 46.5 min [range 11-180; IQR 30.5-159.3]; difference of -62.94; 95% confidence interval [CI] -105.17 to -20.71; p = .021). In the event group, cerebral fractional tissue oxygen extraction (median 0.41 [range 0.20-0.55; IQR 0.26-0.44] vs. median 0.27 [range 0.11-0.41; IQR 0.20-0.31]; difference of -0.11; 95% CI -0.17 to -0.05; p = .001) and approximated cerebral metabolic rate of oxygen (median 6.15 arbitrary unit [range 2.69-12.07; IQR 5.12-7.21] vs. median 4.14 arbitrary unit [range 1.78-7.86; IQR 3.82-6.31]; difference of -1.76; 95% CI -3.03 to -0.49; p = .009) were significantly higher and the cerebral regional oxygen saturation (median 58.99% [range 44.87-79.1; IQR 54.26-72.61] vs median 70.94% [range 57.9-86.13; IQR 67.07-76.59]; difference of 10.01; 95% CI 4.13-15.90; p = .002) significantly lower after surgery compared to the nonevent group. The increase of approximated cerebral metabolic rate of oxygen could indicate an elevated oxidative energy metabolism in the "stressed" brain, due to repair processes. The increased cerebral fractional tissue oxygen extraction fits with the decreased NIRS cerebral oxygenation. Our data suggest that an increase in cerebral oxygen metabolism was the cause. Cerebral oxygen desaturation during major surgery in neonates and infants is associated with early postoperative increased cerebral oxygen extraction and possibly increased cerebral oxygen metabolism.

Noninvasive continuous arterial pressure monitoring shortens atrial fibrillation ablation procedural duration

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Transcatheter atrial fibrillation (AF) ablation is in most centres commonly carried out with continuous invasive radial arterial blood pressure (BP) monitoring. Novel devices enable continuous non-invasive BP monitoring, with acceptable agreement and optimal safety profile when compared to standard of care invasive BP monitoring, leading to improved patient comfort in the electrophysiology lab. Purpose Aim of the study was to assess in terms of procedural efficiency continuous non-invasive BP monitoring during transcatheter atrial fibrillation ablation. Methods We prospectively enrolled 42 consecutive patients (age 61±9 years, 80% male) undergoing transcatheter AF ablation (60% paroxysmal, 40% persistent) at our centre undergoing AF ablation with continuous BP measurement using a non-invasive finger volume clamp device. We then compared them with an historical cohort of 42 consecutive patients undergoing AF ablation (62% paroxysmal, 38% persistent) with standard of care invasive BP monitoring with a radial cannula. We compared the two groups in terms of total procedural duration (in and out from the EP lab). Results Mean total procedural duration was 165,29±54,95 minutes in the non-invasive group and 196,55±46,67 minutes in the invasive group (P=0,006). Conclusion In patients undergoing AF ablation, non-invasive finger volume-clamp continuous BP monitoring allowed for a significant reduction of total procedural duration when compared to standard of care invasive BP monitoring. Larger studies are needed to confirm these results.

Feasibility and Accuracy of Noninvasive Continuous Arterial Pressure Monitoring during Transcatheter Atrial Fibrillation Ablation

Transcatheter atrial fibrillation (AF) ablation is still carried out with continuous invasive radial arterial blood pressure (IBP) monitoring in many centers. Continuous noninvasive blood pressure (CNBP) measurement using the volume-clamp method is a noninvasive alternative method used in ICU. No data on CNBP reliability are available in the electrophysiology lab during AF ablation, where rhythm variations are common. The objective of the present study was to compare continuous noninvasive arterial pressure measured with the ClearSight device (Edwards Lifesciences, Irvine, CA, USA) with invasive radial artery pressure used as the reference method during AF ablation. We prospectively enrolled 55 consecutive patients (age 62 ± 11 years, 80% male) undergoing transcatheter AF ablation (62% paroxysmal, 38% persistent) at our center. Standard of care IBP monitoring via a radial cannula and a contralateral noninvasive finger volume-clamp CNBP measurement device were positioned simultaneously in all patients for the entire procedure. Bland-Altman analysis was used to analyze the agreement between the two techniques. A total of 1219 paired measurements for systolic, diastolic, and mean arterial pressure were obtained in 55 subjects, with a mean (SD) of 22 (9) measurements per patient. The mean bias (SD) was -12.97 (13.89) mmHg for systolic pressure (level of agreement -14.24-40.20; correlation coefficient 0.84), -1.85 (8.52) mmHg for diastolic pressure (level of agreement -18.54-14.84; correlation coefficient 0.77) and 2.31 (8.75) mmHg for mean pressure (level of agreement -14.84-19.46; correlation coefficient 0.85). In patients undergoing AF ablation, CNBP monitoring with the ClearSight device showed acceptable agreement with IBP monitoring. Larger studies are needed to confirm the potential clinical implications of continuous noninvasive BP monitoring during AF ablation.

Critical Closing Pressure and Cerebrovascular Resistance Responses to Intracranial Pressure Variations in Neurocritical Patients

BackgroundCritical closing pressure (CrCP) and resistance-area product (RAP) have been conceived as compasses to optimize cerebral perfusion pressure (CPP) and monitor cerebrovascular resistance, respectively. However, for patients with acute brain injury (ABI), the impact of intracranial pressure (ICP) variability on these variables is poorly understood. The present study evaluates the effects of a controlled ICP variation on CrCP and RAP among patients with ABI.MethodsConsecutive neurocritical patients with ICP monitoring were included along with transcranial Doppler and invasive arterial blood pressure monitoring. Internal jugular veins compression was performed for 60 s for the elevation of intracranial blood volume and ICP. Patients were separated in groups according to previous intracranial hypertension severity, with either no skull opening (Sk1), neurosurgical mass lesions evacuation, or decompressive craniectomy (DC) (patients with DC [Sk3]).ResultsAmong 98 included patients, the correlation between change (Δ) in ICP and the corresponding ΔCrCP was strong (group Sk1 r = 0.643 [p = 0.0007], group with neurosurgical mass lesions evacuation r = 0.732 [p < 0.0001], and group Sk3 r = 0.580 [p = 0.003], respectively). Patients from group Sk3 presented a significantly higher ΔRAP (p = 0.005); however, for this group, a higher response in mean arterial pressure (change in mean arterial pressure p = 0.034) was observed. Exclusively, group Sk1 disclosed reduction in ICP before internal jugular veins compression withholding.ConclusionsThis study elucidates that CrCP reliably changes in accordance with ICP, being useful to indicate ideal CPP in neurocritical settings. In the early days after DC, cerebrovascular resistance seems to remain elevated, despite exacerbated arterial blood pressure responses in efforts to maintain CPP stable. Patients with ABI with no need of surgical procedures appear to remain with more effective ICP compensatory mechanisms when compared with those who underwent neurosurgical interventions.

Discussion on the zero-calibration and the zero line in the measurement of central venous pressure and invasive arterial blood pressure

To figure out the timing of zeroing and the location of the zero line in the central venous pressure (CVP) monitoring and invasive arterial blood pressure (IBP) monitoring, and to provide scientific and accurate data for patients management. The liquid vessel models were used to simulate the pressure measurement process of the continuous pressure monitoring system. Based on the theory of fluid mechanics and the knowledge of blood pressure physiology and cardiovascular anatomy, the composition and influencing factors of the pressure in the fluid-filled catheter system during the zeroing and placing the transducer in the zero line of CVP and IBP, were analyzed. The pressure in the liquid-filled catheter system was composed of atmospheric pressure, the pressure of pumping bag, the gravity of the water column (the vertical distance between the liquid level of Murphy's dropper and pressure transducer, ΔH), and the resistance of tube wall. This pressure value is set as a pressure of 0 mmHg (1 mmHg ≈ 0.133 kPa). In the process of pressure measurement, when the pressure transducer was placed at a horizontal position of 10 cm below the highest liquid level of the vessel, the pressure measured at different catheter tip positions was all 10 cmH2O (1 cmH2O ≈ 0.098 kPa); When the pressure transducer was placed at the horizontal position of the highest liquid level of the vessel, the measured pressure is 0 mmHg. Zeroing should repeatedly be performed only when one or more conditions (atmospheric pressure, pressure of pumping bag, gravity of ΔH water column and resistance of tube wall) are changed. In the measurement process, the pressure transducer should be placed at the zero line position at any time to eliminate the influence of hydrostatic pressure and to ensure the objective and accurate value.

Experience with clinical cerebral autoregulation testing in children hospitalized with traumatic brain injury: Translating research to bedside.

To report our institutional experience with implementing a clinical cerebral autoregulation testing order set with protocol in children hospitalized with traumatic brain injury (TBI). After IRB approval, we examined clinical use, patient characteristics, feasibility, and safety of cerebral autoregulation testing in children aged <18 years between 2014 and 2021. A clinical order set with a protocol for cerebral autoregulation testing was introduced in 2018. 25 (24 severe TBI and 1 mild TBI) children, median age 13 years [IQR 4.5; 15] and median admission GCS 3[IQR 3; 3.5]) underwent 61 cerebral autoregulation tests during the first 16 days after admission [IQR1.5; 7; range 0-16]. Testing was more common after implementation of the order set (n = 16, 64% after the order set vs. n = 9, 36% before the order set) and initiated during the first 2 days. During testing, patients were mechanically ventilated (n = 60, 98.4%), had invasive arterial blood pressure monitoring (n = 60, 98.4%), had intracranial pressure monitoring (n = 56, 90.3%), brain-tissue oxygenation monitoring (n = 56, 90.3%), and external ventricular drain (n = 13, 25.5%). Most patients received sedation and analgesia for intracranial pressure control (n = 52; 83.8%) and vasoactive support (n = 55, 90.2%) during testing. Cerebral autoregulation testing was completed in 82% (n = 50 tests); 11 tests were not completed [high intracranial pressure (n = 5), high blood pressure (n = 2), bradycardia (n = 2), low cerebral perfusion pressure (n = 1), or intolerance to blood pressure cuff inflation (n = 1)]. Impaired cerebral autoregulation on first assessment resulted in repeat testing (80% impaired vs. 23% intact, RR 2.93, 95% CI 1.06:8.08, p = 0.03). Seven out of 50 tests (14%) resulted in a change in cerebral hemodynamic targets. Findings from this series of children with TBI indicate that: (1) Availability of clinical order set with protocol facilitated clinical cerebral autoregulation testing, (2) Clinicians ordered cerebral autoregulation tests in children with severe TBI receiving high therapeutic intensity and repeatedly with impaired status on the first test, (3) Clinical cerebral autoregulation testing is feasible and safe, and (4) Testing results led to change in hemodynamic targets in some patients.

Anomalous origin of the left main coronary artery from the right pulmonary artery: a case report

Anomalous origin of the left coronary from the right pulmonary artery (AOLCARPA) is an extremely rare anomaly, which has been reported in only a few patients worldwide [1] An 8-month-old male patient weighing 5.7 kg came to our hospital with chief complaints of tachypnea while feeding and failure to thrive. ECG of the patient showed sinus tachycardia. The patient had a heart rate of 140/min and saturation of 99% on room air. Chest radiograph showed cardiomegaly. Transthoracic echocardiography showed moderate mitral regurgitation, dilated left atrium and ventricle, severe left ventricular (LV) dysfunction, global LV hypokinesia with an LV ejection fraction of 15–20%. Flow pattern in the left anterior descending artery and the left circumflex artery was reversed and the right coronary artery (RCA) was dilated. The left main coronary artery (LMCA) origin was not clear. As the diagnosis was unclear, computed tomography coronary angiography (CTCA) was done to delineate the coronary anatomy, which showed an anomalous origin of LMCA from the right pulmonary artery (RPA) (Figs. 1 and 2Figs 1, 2). Blood investigations including complete blood count, and liver and kidney function tests were normal. Preoperative medication of the patient included digoxin, spironolactone, furosemide, and milrinone infusion. The patient was posted for corrective repair of anomalous origin of the left coronary artery from the RPA.Figure 1: Computed tomography coronary angiography showing left main coronary artery (LMCA) arising from the right pulmonary artery (RPA). PROX LAD, proximal left anterior descending artery.Figure 2: (a) Midesophageal (ME) ascending aortic short-axis (SAX) view showing retrograde flow from left main coronary artery (LMCA) to right pulmonary artery (RPA). (b) Midesophageal (ME) four-chamber view showing dilated left ventricle (LV) and mitral regurgitation jet. (c) Origin of LMCA from RPA. LPA, left pulmonary artery; Asc Aorta, ascending aorta.On the day of surgery, the patient was taken to the operating room. Preoperative inotropic support of intravenous infusion of milrinone 0.5 µg/kg/min was continued. After attaching a multiparameter monitor with a five-lead ECG, noninvasive blood pressure monitor, and a pulse oximeter, general anesthesia was induced with intravenous fentanyl 2 µg/kg, midazolam 0.1 mg/kg, vecuronium 0.1 mg/kg, and endotracheal intubation was done. Femoral artery was cannulated for invasive arterial blood pressure monitoring, and central venous catheter was inserted in the right internal jugular vein. Anesthesia was maintained with isoflurane and intermittent boluses of fentanyl and vecuronium. Intraoperative ventilation was instituted with the goals of avoiding hypocarbia, hyperoxia, and alkalosis. An FiO2 of 0.35 was kept with PaO2 targets of 80–100 mm Hg to maintain pulmonary vascular resistance End-tidal carbon dioxide (EtCO2) was maintained between 40 and 42 mm Hg. Pre-bypass transesophageal echocardiography (TOE) examination was carried out with a pediatric 9T probe (Vivid I, GE; Vingmed Ultrasound, Horten, Norway). ME ascending aorta short-axis view showed the origin of LMCA from RPA (Fig. 2a). Midesophageal four-chamber view showed dilated LV and moderate mitral regurgitation (Fig. 2b). Heparin 400 IU/kg was given, and cardiopulmonary bypass was instituted. Cardiopulmonary bypass was established using aortobicaval cannulation with looping of both pulmonary artery branches. Myocardial preservation was obtained with antegrade cold blood potassium cardioplegia into the aorta and main pulmonary artery. Under low pump flows, LMCA origin was identified originating from the RPA (Fig. 2c). Medial trap door was made in the aorta and LMCA was anastomosed to the aorta (coronary translocation). Posterior annuloplasty of the mitral valve was performed through the trans-septal approach. Weaning from the cardiopulmonary bypass was uneventful with minimal inotropic support (milrinone 0.5 µg/kg/min; Epinephrine 0.04 µg/kg/min). The chest was kept open with a sterile membrane cover electively and the patient was shifted to the pediatric ICU with stable hemodynamics. AOLCARPA is an extremely rare congenital coronary anomaly. Only 10–20% of neonates survive till adulthood, and it depends on the adequacy of LV perfusion through collaterals to LCA from RCA and the proportion of coronary steal from the LCA to pulmonary artery [2] Coronary angiogram is usually done to delineate the anatomy and for the diagnosis. In this case, the origin of LMCA could not be visualized on transthoracic echocardiography (TTE) leading to inconclusive diagnosis. CTCA delineated the exact anatomy and showed its origin from RPA. Intraoperative TOE examination also revealed it as a case of AOLCARPA. Anesthetic management of patients presenting with ALOCARPA includes rapid and smooth intubation, while avoiding swings in blood pressure and heart rate. A decrease in pulmonary vascular resistance is avoided by preventing hyperventilation, hyperoxia and hypocarbia [3] The aim is to maintain a PaO2 of 80–100 mm Hg and an EtCO2 of 40–45 mm Hg. Both reduction and increase in afterload can hamper RCA perfusion and stroke volume, respectively. An optimum preload is required to ensure adequate cardiac output. CTCA and TOE examinations are useful modalities for delineating the coronary anatomy and help in planning the perioperative surgical and anesthetic management of the patient.

Most patients with non-hypertensive diseases at a critical care resuscitation unit require arterial pressure monitoring: a prospective observational study.

Blood pressure (BP) monitoring is essential for patient care. Invasive arterial BP (IABP) is more accurate than non-invasive BP (NIBP), although the clinical significance of this difference is unknown. We hypothesized that IABP would result in a change of management (COM) among patients with non-hypertensive diseases in the acute phase of resuscitation. This prospective study included adults admitted to the Critical Care Resuscitation Unit (CCRU) with non-hypertensive disease from February 1, 2019, to May 31, 2021. Management plans to maintain a mean arterial pressure >65 mmHg (1 mmHg=0.133 kPa) were recorded in real time for both NIBP and IABP measurements. A COM was defined as a discrepancy between IABP and NIBP that resulted in an increase/decrease or addition/discontinuation of a medication/infusion. Classification and regression tree analysis identified significant variables associated with a COM and assigned relative variable importance (RVI) values. Among the 206 patients analyzed, a COM occurred in 94 (45.6% [94/206]) patients. The most common COM was an increase in current infusion dosages (40 patients, 19.4%). Patients receiving norepinephrine at arterial cannulation were more likely to have a COM compared with those without (45 [47.9%] vs. 32 [28.6%], P=0.004). Receiving norepinephrine (relative variable importance [RVI] 100%) was the most significant factor associated with a COM. No complications were identified with IABP use. A COM occurred in 94 (45.6%) non-hypertensive patients in the CCRU. Receiving vasopressors was the greatest factor associated with COM. Clinicians should consider IABP monitoring more often in non-hypertensive patients requiring norepinephrine in the acute resuscitation phase. Further studies are necessary to confirm the risk-to-benefit ratios of IABP among these high-risk patients.

Central Versus Peripheral Invasive Arterial Blood Pressure Monitoring in Liver Transplant Surgery.

Introduction Invasive blood pressure monitoring is essential in liver transplant surgery due to expected major hemodynamic shifts.The use of central versusperipheral arterial access, however, is institution-dependent, which can affect clinical decisions regarding vasopressor therapy.Although there are studies that demonstrate inconsistencies based on arterial cannulation sites, few studies have compared femoral and radial artery blood pressures in patients undergoing liver transplant surgery.To our knowledge, there are no studies investigating the differences between continuous minute-to-minute femoral and radial artery measurements during all three phases of liver transplant surgery. Objective The main objective of this study was to evaluate for any differences between central and peripheral blood pressure measurements in liver transplant surgeryand to assess for any correlation between vasopressor infusion dose and femoral-arterial pressure differences. Methods In this retrospective study, we reviewed and studied the data of 61 patientswith American Society of Anesthesiologists (ASA) grade 4who underwent liver transplant surgery at Loma Linda University Medical Center between January and December of 2019.All patients had both femoral and radial arterial lines placed for liver transplant surgery.Femoral and radial arterial blood pressure values were obtained continuously over 60 minutes in the pre-anhepatic phase, 45 minutes during the anhepatic phase, and 60 minutes into the neo-hepatic phase. Vasopressor infusion doses were also recorded for each patient during these time frames. Results This pilot study found statistically significant differences between the mean femoral and radial systolic blood pressure (SBP; p < 0.0001), diastolic blood pressure (DBP; p < 0.0001), and mean arterial pressure (MAP; p < 0.0001)during all phases of liver transplantation.The meanSBP and MAP differences between femoral and radial arteries were highest (femoral blood pressure reading higher than radial blood pressure measurements) in the late anhepatic and early neo-hepatic phases with SBP differences of 20.8 ± 0.8 mmHg and 22.8 ± 0.8 mmHg, respectively, and MAP differences of 10.0 ± 0.4 mmHg and 9.8 ± 0.4 mmHg, respectively. Higher vasopressor infusion doses were strongly associated with greater differences in femoral-radial SBP and MAP measurements (r = 0.69 for vasopressin, 0.68 for norepinephrine, and 0.68 for epinephrine; p < 0.0001) during the anhepatic phase. Conclusions Peripheral invasive blood pressure monitoring may result in underestimation of the central blood pressure, as was seen in all phases of liver transplantation. This may lead to excessive vasopressor use with potentially adverse effects. Although the cause for the difference between femoral and radial artery measurements is unclear, increasing vasopressor infusion dosages appears to contribute. Femoral artery blood pressure monitoring allows clinicians to interpret hemodynamic status and administer appropriate vasopressors more accurately.

58: HYPOTENSION MAGNITUDE VIA HIGH-RESOLUTION ABP IS ASSOCIATED WITH OUTCOME AFTER PEDIATRIC ARREST

Introduction: Early post-arrest hypotension may impact outcomes after pediatric cardiac arrest. Our aim was to utilize high-resolution continuous arterial blood pressure (ABP) data to quantify hypotension burden and determine its association with outcome after pediatric cardiac arrest. We hypothesized that a greater calculated hypotension burden would be associated with unfavorable outcome. Methods: This is a single-center retrospective observational study of patients who suffered cardiac arrest and had invasive ABP monitoring during post-arrest care. We collected high-resolution (100Hz) continuous ABP waveforms in the first 24 hours after return of spontaneous circulation (ROSC). ABP was percentile adjusted for age, and the lower quartile of mean arterial pressure (MAP) was set as threshold. Outcome was unfavorable neurologic status at hospital discharge (Pediatric Cerebral Performance Score, PCPC, of ≥3 with change ≥1 from pre-arrest baseline). We determined the association of outcome with magnitude and duration of MAP below threshold, and with below-threshold burden (area between MAP and threshold MAP) normalized by monitoring duration. Data reported as median and IQR. Mann-Whitney tests compared favorable and unfavorable outcome. Results: Of the 102 patients (age 4.8 [1.3,12.4] years, 64% male, 47% in-hospital cardiac arrest) analyzed, 66% had unfavorable outcome. Time from ROSC to ABP monitoring was 91 [58,157] minutes. Monitoring duration was 21 [7,24] hours. MAP percentile for age was 64th [46th,86th]. Threshold was set at 40th percentile. Magnitude of MAP below threshold was greater for unfavorable vs. favorable patients, (5.61 [2.91,9.00] vs. 3.99 [2.00,5.96] mmHg, p=0.048). Neither percent duration nor burden below threshold MAP differed between unfavorable and favorable patients, respectively (26 [4,50] vs 25 [3,48] percent, p=0.90; 1.51 [0.16,4.56] vs 0.92 [0.13,2.98] mmHg, p=0.32). Conclusions: High-resolution continuous ABP data can be utilized to quantify hypotension burden after pediatric cardiac arrest. Magnitude of MAP below the 40th percentile for age, but not duration or burden, was associated with unfavorable outcome in the first 24 hours after ROSC.

Evaluation of a novel optical smartphone blood pressure application: a method comparison study against invasive arterial blood pressure monitoring in intensive care unit patients

BackgroundArterial hypertension is a worldwide public health problem. While it is currently diagnosed and monitored non-invasively using the oscillometric method, having the ability to measure blood pressure (BP) using a smartphone application could provide more widespread access to hypertension screening and monitoring. In this observational study in intensive care unit patients, we compared blood pressure values obtained using a new optical smartphone application (OptiBP™; test method) with arterial BP values obtained using a radial artery catheter (reference method) in order to help validate the technology.MethodsWe simultaneously measured three BP values every hour for five consecutive hours on two consecutive days using both the smartphone and arterial methods. Bland–Altman and error grid analyses were used for agreement analysis between both approaches. The performance of the smartphone application was investigated using the Association for the Advancement of Medical Instrumentation (AAMI) and the International Organization for Standardization (ISO) definitions, which require the bias ± SD between two technologies to be below 5 ± 8 mmHg.ResultsAmong the 30 recruited patients, 22 patients had adequate OptiBP™ values and were thus analyzed. In the other 8 patients, no BP could be measured due to inadequate signals. The Bland–Altman analysis revealed a mean of the differences ± SD between both methods of 0.9 ± 7 mmHg for mean arterial pressure (MAP), 0.2 ± 14 mmHg for systolic arterial pressure (SAP), and 1.1 ± 6 mmHg for diastolic arterial pressure (DAP). Error grid analysis demonstrated that the proportions of measurement pairs in risk zones A to E were 88.8% (no risk), 10% (low risk), 1% (moderate risk), 0% (significant risk), and 0% (dangerous risk) for MAP and 88.4%, 8.6%, 3%, 0%, 0%, respectively, for SAP.ConclusionsThis method comparison study revealed good agreement between BP values obtained using the OptiBP™ and those done invasively. The OptiBP™ fulfills the AAMI/ISO universal standards for MAP and DAP (but not SAP). Error grid showed that the most measurements (≥ 97%) were in risk zones A and B.Trial registrationClinicalTrials.gov registration: NCT04728477

Application of Invasive Arterial Blood Pressure Monitoring in ICU Critical Patients and Analysis of Its Nursing Methods

Application of Invasive Arterial Blood Pressure Monitoring in ICU Critical Patients and Analysis of Its Nursing Methods

Invasive arterial blood pressure monitoring may aid in the medical management of hypertensive patients with acute aortic disease

IntroductionBlood pressure (BP) monitoring and management is essential in the treatment of acute aortic disease (AoD). Previous studies had shown differences between invasive arterial BP monitoring (ABPM) and non-invasive cuff BP monitoring (CBPM), but not whether ABPM would result in patients' change of clinical management. We hypothesized that ABPM would change BP management in AoD patients. MethodsThis was a prospective observational study of adult patients with AoD admitted to the Critical Care Resuscitation Unit from January 2019 to February 2021. Patients with AoD and both ABPM and CBPM measurements were included. Clinician's BP management goals were assessed in real time before and after arterial catheter placement according to current guidelines. We defined change of management as change of current antihypertensive infusion rate or adding a new agent. We used multivariable logistic and ordinal regressions to determine relevant predictors. ResultsWe analyzed 117 patients, and 56 (47%) had type A dissection. ABPM was frequently ≥10 mmHg higher than CBPM values. Among 40 (34%) patients with changes in management, 58% (23/40) had [ABPM-CBPM] differences ≥20 mmHg. ABPM prompted increasing current antihypertensive infusion in 68% (27/40) of patients. Peripheral artery disease (OR 13, 95% CI 1.18–50+) was associated with changes in clinical management, and ordinal regression showed hypertension and serum lactate to be associated with differences between ABPM and CBPM. ConclusionsABPM was frequently higher than CBPM, resulting in 34% of changes of management, most commonly increasing anti-hypertensive infusion rates.

A simple technique to assess postoperative epidural functionality.

To describe an alternative method of measuring the Epidural Waveform Analysis (EWA), a technique through which anesthesiologists can confirm the position of a needle and/or catheter tip in the epidural space. EWA consists of epidural catheter transduction with a pressure system typically used for invasive arterial blood pressure monitoring which generates a characteristic oscillatory waveform (provided the catheter tip is within the epidural space) in synchrony with the pulsatile epidural circulation. The technique requires a double-male connector, a 3-way stopcock and an arterial pressure extension tubing along with the patient's existing arterial line setup while ensuring a meticulously sterile technique to mitigate the risks of neuraxial infection. The technique described herein has been successfully and routinely applied within our institution to measure EWA with the advantage of being potentially less wasteful. EWA allows anesthesiologists to confirm the correct position of an epidural needle/catheter. We describe a method of successfully measuring EWA while reducing wastefulness.