Recovery of arterial blood pressure after chest compressions pauses in patients with out-of-hospital cardiac arrest.

BACKGROUND AND AIMS: Chest compressions generating good perfusion during cardiopulmonary resuscitation (CPR) in cardiac arrest patients are critical for positive patient outcomes. Conventional wisdom advises minimizing compression pauses because several compressions are required to recover arterial blood pressure (ABP) back to pre-pause values. Our study examines how compression pauses influence ABP recovery post-pause in out-of-hospital cardiac arrest. METHODS: We analyzed data from a subset of a prospective, randomized LUCAS 2 Active Decompression trial. Patients were treated by an anesthesiologist-staffed rapid response car program in Oslo, Norway (2015-2017) with mechanical chest compressions using the LUCAS device at 102 compressions/min. Patients with an ABP signal during CPR and at least one compression pause >2 sec were included. Arterial cannulation, compression pauses, and ECG during the pause were verified by physician review of patient records and physiological signals. Pauses were excluded if return of spontaneous circulation occurred during the pause (pressure pulses associated with ECG complexes). Compression, mean, and decompression ABP for 10 compressions before/after each pause and the mean ABP during the pause were measured with custom MATLAB code. The relationship between pause duration and ABP recovery was investigated using linear regression. RESULTS: We included 56 patients with a total of 271 pauses (pause duration: median = 11 sec, Q1 = 7 sec, Q3 =18 sec). Mean ABP dropped from 53 ± 10 mmHg for the last pre-pause compression to 33 ± 7 mmHg during the pause. Compression and mean ABP recovered to >90% of pre-pause pressure within 2 compressions, or 1.7 sec. Pause duration did not affect the recovery of ABP post-pause (R2: 0.05, 0.03, 0.01 for compression, mean, and decompression ABP, respectively). CONCLUSIONS: ABP generated by mechanical CPR recovered quickly after pauses. Recovery of ABP after a pause was independent of pause duration.

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

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Diagnostic test accuracy for cessation of circulation during death determination: a systematic review.

PURPOSE: To synthesize the available evidence comparing noninvasive methods of measuring the cessation of circulation in patients who are potential organ donors undergoing death determination by circulatory criteria (DCC) with the current accepted standard of invasive arterial blood pressure (IAP) monitoring. SOURCE: We searched (from inception until 27 April 2021) MEDLINE, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials. We screened citations and manuscripts independently and in duplicate for eligible studies that compared noninvasive methodologies assessing circulation in patients who were monitored around a period of cessation of circulation. We performed risk of bias assessment, data abstraction, and quality assessment using Grading of Recommendations, Assessment, Development, and Evaluation in duplicate and independently. We presented findings narratively. PRINCIPAL FINDINGS: We included 21 eligible studies (N = 1,177 patients). Meta-analysis was not possible because of study heterogeneity. We identified low quality evidence from four indirect studies (n = 89) showing pulse palpation is less sensitive and specific than IAP (reported sensitivity range, 0.76-0.90; specificity, 0.41-0.79). Isoelectric electrocardiogram (ECG) had excellent specificity for death (two studies; 0% [0/510]), but likely increases the average time to death determination (moderate quality evidence). We are uncertain whether point-of-care ultrasound (POCUS) pulse check, cerebral near-infrared spectroscopy (NIRS), or POCUS cardiac motion assessment are accurate tests for the determination of circulatory cessation (very low-quality evidence). CONCLUSION: There is insufficient evidence that ECG, POCUS pulse check, cerebral NIRS, or POCUS cardiac motion assessment are superior or equivalent to IAP for DCC in the setting of organ donation. Isoelectric ECG is specific but can increase the time needed to determine death. Point-of-care ultrasound techniques are emerging therapies with promising initial data but are limited by indirectness and imprecision. STUDY REGISTRATION: PROSPERO (CRD42021258936); first submitted 16 June 2021.

RéSUMé: OBJECTIF: Synthétiser les données probantes disponibles comparant les méthodes non invasives de mesure de l'arrêt de la circulation chez les patients qui sont des donneurs d'organes potentiels soumis à une détermination du décès selon des critères circulatoires (DCC) avec la norme actuellement acceptée de surveillance invasive de la tension artérielle (TA). SOURCES: Nous avons mené des recherches dans les bases de données MEDLINE, EMBASE, Web of Science et le registre Cochrane des essais contrôlés de leur création jusqu'au 27 avril 2021. Nous avons examiné les citations et les manuscrits de manière indépendante et en double pour en tirer les études éligibles qui comparaient des méthodologies non invasives d'évaluation de la circulation chez les patients qui étaient sous surveillance avant, pendant et après une période d'arrêt de la circulation. Nous avons réalisé l'évaluation du risque de biais, l'extraction des données et l'évaluation de la qualité en nous fondant sur la méthodologie GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) en double et de manière indépendante. Nous présentons les résultats de façon narrative. CONSTATATIONS PRINCIPALES: Nous avons inclus 21 études éligibles (N = 1177 patients). Une méta-analyse n'a pas été possible en raison de l'hétérogénéité des études. Nous avons identifié des données de faible qualité issues de quatre études indirectes (n = 89) montrant que la palpation du pouls est moins sensible et spécifique que la mesure invasive de la TA (plage de sensibilité rapportée, 0,76-0,90; spécificité, 0,41-0,79). L'électrocardiogramme (ECG) isoélectrique avait une excellente spécificité pour le décès (deux études; 0 % [0/510]), mais augmente probablement le délai moyen avant la détermination du décès (données probantes de qualité modérée). Nous ne savons pas si la vérification du pouls par échographie ciblée (POCUS), la spectroscopie proche infrarouge (SPIR) cérébrale ou l'évaluation ciblée (POCUS) des mouvements cardiaques sont des examens précis pour la détermination de l'arrêt circulatoire (données probantes de très faible qualité). CONCLUSION: Il n'y a pas suffisamment de données probantes pour affirmer que l'ECG, la vérification ciblée du pouls, la SPIR cérébrale ou l'évaluation ciblée des mouvements cardiaques sont supérieurs ou équivalents à la mesure invasive de la TA pour un DCC dans le cadre du don d'organes. L'ECG isoélectrique est spécifique, mais peut augmenter le délai nécessaire avant de déterminer le décès. Les techniques d'échographie ciblée sont des thérapies émergentes avec des données initiales prometteuses, mais elles sont limitées par leur caractère indirect et l'imprécision de l'examen. ENREGISTREMENT DE L'éTUDE: PROSPERO (CRD42021258936); soumis pour la première fois le 16 juin 2021.

Discussion on the zero-calibration and the zero line in the measurement of central venous pressure and invasive arterial blood pressure / 中华危重病急救医学

Objective: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.Methods: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.Results: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 cmH 2O (1 cmH 2O ≈ 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. Conclusion: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.

Effect of perioperative intravenous amiodarone on cardioversion of atrial fibrillation early after video-assisted thoracoscopic surgical ablation: Study protocol for a double-blind randomized controlled trial.

Introduction: Video-assisted thoracoscopic surgical (VATS) ablation is widely performed in surgical areas to treat atrial fibrillation (AF), which is minimally invasive and highly effective. Amiodarone, known as a class III antiarrhythmic agent, has the greatest potential to maintain sinus rhythm of AF. At present, few studies focused on the efficacy of perioperative intravenous amiodarone in the VATS ablation of AF. Therefore, the trial is designed to investigate the effect of perioperative amiodarone infusion on cardioversion of AF early after VATS ablation. Methods: and analysis: This will be a prospective, randomized, double-blind, controlled trial. The trial is to enroll 182 patients aged 18-70 years who will undergo VATS ablation of AF. All eligible participants will be randomly allocated to either the amiodarone or placebo group by using the block randomization in a 1:1 ratio. The primary endpoint will be freedom from atrial arrhythmias 24 h after the VATS procedure and be assessed using the Kaplan-Meier method. All data will be analyzed in accordance with the intention-to-treat principle. Discussion: The clinical trial has been designed to investigate the efficacy of perioperative intravenous amiodarone on cardioversion of AF early after VATS ablation. We are hoping to demonstrate that perioperative infusion of amiodarone could improve the maintenance of sinus rhythm 24 h after VATS ablation.

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

INTRODUCTION: Blood 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. METHODS: This 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. RESULTS: We 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. CONCLUSIONS: ABPM was frequently higher than CBPM, resulting in 34% of changes of management, most commonly increasing anti-hypertensive infusion rates.

The Effect of Data Length on the Assessment of Dynamic Cerebral Autoregulation with Transfer Function Analysis in Neurological ICU Patients.

BACKGROUND: Cerebral autoregulation plays an important role in safeguarding adequate cerebral perfusion and reducing the risk of secondary brain injury, which is highly important for patients in the neurological intensive care unit (neuro-ICU). Although the consensus white paper suggests that a minimum of 5 min of data are needed for assessing dynamic cerebral autoregulation with transfer function analysis (TFA), it remains unknown if the length of these data is valid for patients in the neuro-ICU, of whom are notably different than the general populations. We aimed to investigate the effect of data length using transcranial Doppler ultrasound combined with invasive blood pressure measurement for the assessment of dynamic cerebral autoregulation in patients in the neuro-ICU. METHODS: Twenty patients with various clinical conditions (severe acute encephalitis, ischemic stroke, subarachnoid hemorrhage, brain injury, cerebrovascular intervention operation, cerebral hemorrhage, intracranial space-occupying lesion, and toxic encephalopathy) were recruited for this study. Continuous invasive blood pressure, with a pressure catheter placed at the radial artery, and bilateral continuous cerebral blood flow velocity with transcranial Doppler ultrasound were simultaneously recorded for a length of 10 min for each patient. TFA was applied to derive phase shift, gain, and coherence function at all frequency bands from the first 2, 3, 4, 5, 6, 7, 8, 9, and 10 min of the 10-min recordings in each patient on both hemispheres. The variability in the autoregulatory parameters in each hemisphere was investigated by repeated measures analysis of variance. RESULTS: Forty-one recordings (82 hemispheres) were included in the study. According to the critical values of coherence provided by the Cerebral Autoregulation Research Network white paper, acceptable rates for the data were 100% with a length ≥ 7 min. The final analysis included 68 hemispheres. The effects of data length on trends in phase shift in the very low frequency (VLF) band (F1.801,120.669 = 6.321, P = 0.003), in the LF band (F1.274,85.343 = 4.290, P = 0.032), and in the HF band (F1.391,93.189 = 3.868, P = 0.039) were significant for 3-7 min, for 4-7 min, and for 5-8 min, respectively. Effects were also significant on the gain in the VLF band (F1.927,129.134 = 3.215, P = 0.045) for 2-8 min and on the coherence function in all frequency bands (VLF F2.846,190.671 = 90.247, P < 0.001, LF F2.515,168.492 = 55.770, P < 0.001, HF F2.411, 161.542 = 33.833, P < 0.001) for 2-10 min. CONCLUSIONS: Considering the acceptable rates for the data and the variation in the TFA variables (phase shift and gain), we recommend recording data for a minimum length of 7 min for TFA in patients in the neuro-ICU.

Mechanical active compression-decompression versus standard mechanical cardiopulmonary resuscitation: A randomised haemodynamic out-of-hospital cardiac arrest study.

BACKGROUND: Active compression-decompression cardiopulmonary resuscitation (ACD-CPR) utilises a suction cup to lift the chest-wall actively during the decompression phase (AD). We hypothesised that mechanical ACD-CPR (Intervention), with AD up to 30 mm above the sternal resting position, would generate better haemodynamic results than standard mechanical CPR (Control). METHODS: This out-of-hospital adult non-traumatic cardiac arrest trial was prospective, block-randomised and non-blinded. We included intubated patients with capnography recorded during mechanical CPR. Exclusion criteria were pregnancy, prisoners, and prior chest surgery. The primary endpoint was maximum tidal carbon dioxide partial pressure (pMTCO2) and secondary endpoints were oxygen saturation of cerebral tissue (SctO2), invasive arterial blood pressures and CPR-related injuries. Intervention device lifting force performance was categorised as Complete AD (≥30 Newtons) or Incomplete AD (≤10 Newtons). Haemodynamic data, analysed as one measurement for each parameter per ventilation (Observation Unit, OU) with non-linear regression statistics are reported as mean (standard deviation). A two-sided p-value < 0.05 was considered as statistically significant. RESULTS: Of 221 enrolled patients, 210 were deemed eligible (Control 109, Intervention 101). The Control vs. Intervention results showed no significant differences for pMTCO2: 29(17) vs 29(18) mmHg (p = 0.86), blood pressures during compressions: 111(45) vs. 101(68) mmHg (p = 0.93) and decompressions: 21(20) vs. 18(18) mmHg (p = 0.93) or for SctO2%: 55(36) vs. 57(9) (p = 0.42). The 48 patients who received Complete AD in > 50% of their OUs had higher SctO2 than Control patients: 58(11) vs. 55(36)% (p < 0.001). CONCLUSIONS: Mechanical ACD-CPR provided similar haemodynamic results to standard mechanical CPR. The Intervention device did not consistently provide Complete AD. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov identifier (NCT number): NCT02479152. The Haemodynamic Effects of Mechanical Standard and Active Chest Compression-decompression During Out-of-hospital CPR.

The consistency of invasive and non-invasive arterial blood pressure for the assessment of dynamic cerebral autoregulation in NICU patients.

Background: Studies of the clinical application of dynamic cerebral autoregulation show considerable variations, and differences in blood pressure devices may be one of the reasons for this variation. Few studies have examined the consistency of invasive and non-invasive arterial blood pressure for evaluating cerebral autoregulation. We attempted to investigate the agreement between invasive and non-invasive blood pressure methods in the assessment of dynamic cerebral autoregulation with transfer function analysis. Methods: Continuous cerebral blood flow velocity and continuous invasive and non-invasive arterial blood pressure were simultaneously recorded for 15 min. Transfer function analysis was applied to derive the phase shift, gain and coherence function at all frequency bands from the first 5, 10, and 15 min of the 15-min recordings. The consistency was assessed with Bland-Altman analysis and intraclass correlation coefficient. Results: The consistency of invasive and noninvasive blood pressure methods for the assessment of dynamic cerebral autoregulation was poor at 5 min, slightly improved at 10 min, and good at 15 min. The values of the phase shift at the low-frequency band measured by the non-invasive device were higher than those measured with invasive equipment. The coherence function values measured by the invasive technique were higher than the values derived from the non-invasive method. Conclusion: Both invasive and non-invasive arterial blood pressure methods have good agreement in evaluating dynamic cerebral autoregulation when the recording duration reaches 15 min. The phase shift values measured with non-invasive techniques are higher than those measured with invasive devices. We recommend selecting the most appropriate blood pressure device to measure cerebral autoregulation based on the disease, purpose, and design.

Invasive arterial blood pressure monitoring improves the prognosis of patients with sepsis / 中华急诊医学杂志

Objective:To evaluate the effect of invasive arterial blood pressure (IBP) monitoring on the prognosis of patients with sepsis.Methods:Patients with sepsis from the MIMIC-Ⅳ database were collected and divided into IBP and non-invasive blood pressure monitoring (NIBP) groups according to whether IBP monitoring was performed. Baseline variables that were considered clinically relevant or showed a univariate relationship with the outcome were entered into a multivariate logistic regression model as covariates.Propensity score matching(PSM) and inverse probability of treatment weighing(IPTW) were used to adjust confounders to ensure the robustness of findings.Subgroup analysis were conducted to evaluate the effect of differences in IBP onset and duration on outcome.Results:The 28-day mortality is lower in IBP group compared with NIBP group( OR=0.54, 95% CI 0.46-0.62, P<0.001), the conclusion maintain robust after PSM and IPTW.Then we conducted a series of logistic regression regarding to different initial IBP time(<24 h,24 h-48 h,>48 h) and the initial IBP time within 24 h showed the same results compared to primary outcoms( OR=0.42, 95% CI: 0.36-0.49, P<0.001). IBP duration varied (≤1day, ≤2days, ≤3days, ≤4days, >4days) all showed a statistically significant association with decreased 28-day mortality in the IBP group. Conclusions:IBP is associated with decreased 28-day mortality in patients with sepsis, and the optimal time of IBP is within 24 hours.

Arterial or cuff pressure: Clinical predictors among patients in shock in a critical care resuscitation unit.

OBJECTIVES: Blood pressure (BP) measurement is essential for managing patients with hypotension. There are differences between invasive arterial blood pressure (IABP) and noninvasive blood pressure (NIBP) measurements. However, the clinical applicability of these differences in patients with shock [need for vasopressor or serum lactate ≥ 4 millimole per liter (mmol/L)] has not been reported. This study investigated differences in IABP and NIBP as well as changes in clinical management in critically ill patients with shock. METHODS: This was a retrospective study involving adult patients admitted to the Critical Care Resuscitation Unit (CCRU). Adult patients who received IABP upon admission between 01/01/2017-12/31/2017 with non-hypertensive diseases were eligible. The primary outcome, clinically relevant difference (CRD), was defined as difference of 10 mm of mercury (mmHg) between IABP and NIBP and change of blood pressure management according to goal mean arterial pressure (MAP) ≥ 65 mmHg. We performed forward stepwise multivariable logistic regression to measure associations. RESULTS: Sample size calculation recommended 200 patients, and we analyzed 263. 121 (46%) patients had shock, 23 (9%) patients had CRD. Each mmol/L increase in serum lactate was associated with 11% higher likelihood of having CRD (OR 1.11, 95%CI 1.002-1.2). Peripheral artery disease and any kidney disease was significantly associated with higher likelihood of MAP difference ≥ 10 mmHg. CONCLUSION: Approximately 9% of patients with shock had clinically-relevant MAP difference. Higher serum lactate was associated with higher likelihood of CRD. Until further studies are available, clinicians should consider using IABP in patients with shock.

Error grid analysis for risk management in the difference between invasive and noninvasive blood pressure measurements.

PURPOSE: Invasive arterial blood pressure (IAP) and noninvasive blood pressure (NIBP) measurements are both common methods. Recently, a new method of error grid analysis was proposed to compare blood pressure obtained using two measurement methods. This study aimed to compare IAP and NIBP measurements using the error grid analysis and investigate potential confounding factors affecting the discrepancies between IAP and NIBP. METHODS: Adult patients who underwent general anesthesia in the supine position with both IAP and NIBP measurements were retrospectively investigated. The error grid analyses were performed to compare IAP and NIBP. In the error grid analysis, the clinical relevance of the discrepancies between IAP and NIBP was evaluated and classified into five zones from no risk (A) to dangerous risk (E). RESULTS: Overall, data of 1934 IAP/NIBP measurement pairs from 100 patients were collected. The error grid analysis revealed that the proportions of zones A-E for systolic blood pressure were 96.4%, 3.5%, 0.05%, 0%, and 0%, respectively. In contrast, the proportions for mean blood pressure were 82.5%, 16.7%, 0.8%, 0%, and 0%, respectively. The multiple regression analysis revealed that continuous phenylephrine administration (p = 0.016) and age (p = 0.044) were the significant factors of an increased clinical risk of the differences in mean blood pressure. CONCLUSIONS: The error grid analysis indicated that the differences between IAP and NIBP for mean blood pressure were not clinically acceptable and had the risk of leading to unnecessary treatments. Continuous phenylephrine administration and age were the significant factors of an increased clinical risk of the discrepancies between IAP and NIBP.

Predictors of clinically relevant differences between noninvasive versus arterial blood pressure.

OBJECTIVE: Blood pressure (BP) measurements are important for managing patients with hypertensive emergencies (HE). Previous studies showed that there was significant difference between IABP and NIBP but no information whether these differences changed management. Our study investigated the factors associated with the differences affecting BP management of patients with HE. METHODS: This was a retrospective study involving adult patients admitted to a resuscitation unit. We screened all patients who received IABP upon admission between 06/01/2017 and 12/31/2017 as sample size calculation recommended 64 patients. Primary outcome was the clinical relevance of the difference of IABP vs. NIBP, which was defined as having both: a) difference of 10 mm of mercury (mmHg), and b) resulting in possible change of blood pressure managements according to treatment guidelines. We performed backward stepwise multivariable logistic regression to measure associations. RESULTS: We analyzed 147 patients whose mean age was 69 (±16) years and included 69 (47%) patients with spontaneous intracerebral hemorrhage (sICH). Mean difference between IABP and NIBP was 21 (±16) mmHg while 41 (28%) patients who had difference affecting managements. In multivariable regression, sICH (Odd Ratios 13.5, 95%CI 2.3-79.5, p-value < 0.001) was significantly associated with clinically relevant difference between the two modalities of BP monitoring. CONCLUSIONS: There was a large difference between IABP and NIBP among patients with hypertensive emergencies. Up to 30% of patients had clinically relevant differences. Patients with sICH were more likely to have differences affecting BP management. Further studies are needed to confirm our observation.

Measurement of non-invasive blood pressure in lateral decubitus position under general anaesthesia - Which arm gives more accurate BP in relation to invasive BP - dependent or non-dependent arm?

BACKGROUND AND AIMS: Non-invasive blood pressure (NiBP) varies with the arm and body position. In the lateral decubitus position (LDP), the non-dependent arm reads lower, and the dependent arm reads higher pressure. We aimed to study the correlation between the NiBP and invasive arterial blood pressure (ABP) as anaesthesia progressed and its correlation in different BP ranges. METHODS: American Society of Anesthesiologists (ASA I-III) patients, between 18-70 years undergoing neurosurgical procedures in the LDP were studied. All were anaesthetised using a standard protocol, positioned in the LDP. NiBP was measured every 15 min in both dependent and non-dependent arms and correlated with the ABP. RESULTS: Intra-class correlation (ICC) done between the dependent arm NiBP and ABP showed good correlation for mean and systolic BP and moderate correlation for diastolic BP. ICC was 0.800, 0.846 and 0.818 for mean and 0.771, 0.782, 0.792 for systolic BP at 15 min, 1 h, and 2 h, respectively. The ICC between the non-dependent arm NiBP and the invasive ABP showed poor correlation for all BP (systolic, diastolic and mean). As anaesthesia progressed, the mean difference between the NiBP and the ABP decreased in the dependent arm and increased in the non-dependent arm. The strength of agreement between the NiBP and the ABP in various BP ranges showed moderate correlation for the dependent arm NiBP (0.45-0.54) and poor correlation (0.21-0.38) for the non-dependent arm. CONCLUSION: The NiBP of the dependent arm correlated well with ABP in LDP under general anaesthesia (GA). It is better to defer measuring NiBP in the non-dependent arm as the correlation with ABP is poor.

Pulsatile arterial blood pressure mimicking aortic valve opening during continuous-flow LVAD support: a case report.

BACKGROUND: Left ventricular assist devices (LVAD) have become a common treatment option in advanced heart failure. Lack of aortic valve opening during left ventricular unloading is a common complication and associated with a worse outcome. Maintaining a minimum pulse pressure is an important goal during the early postoperative period after LVAD implantation since it is commonly seen as secure sign of aortic valve opening. AIMS/OBJECTIVE: We report a case of an LVAD-supported patient with early permanent closure of the aortic valve despite a pulse pressure > 15 mmHg at all times following LVAD implantation. We demonstrate how careful assessment of the invasive arterial blood pressure curve can indicate aortic valve closure irrespective of pulsatile blood flow. METHOD: A 69-year old male patient with terminal ischemic cardiomyopathy was referred for long-term mechanical circulatory support. Due to mild aortic regurgitation both an aortic bioprosthesis and a continuous-flow left ventricular assist device were implanted. Postoperative echocardiography documented a patent aortic bioprosthesis and an acceptable residual systolic left ventricular contractility. During invasive arterial blood pressure monitoring repetitive transient slight blood pressure decreases followed by slight blood pressure increases coincided with programmed LVAD flushing cycles. Permanent pulsatile flow with a pulse pressure of ≥15 mmHg conveyed systolic opening of the aortic valve. Echocardiography, however, proved early permanent aortic valve closure. In retrospect, transformation of the automated LVAD flushing cycles into visible changes of the arterial blood pressure curve during invasive blood pressure monitoring is indicative of ejection of the complete cardiac output through LVAD itself, and therefore an early clinical sign of aortic valve closure. DISCUSSION/CONCLUSION: We present this interesting didactic case to highlight caveats during the early postoperative period after LVAD implantation. Moreover, this case demonstrates that careful and differentiated observation of the arterial blood pressure waveform provides crucial information in this unique and growing patient population of continuous-flow LVAD support.

Oscillometric and intra-arterial blood pressure in children post-kidney transplantation: Is invasive blood pressure measurement always needed?

OBJECTIVE: Blood pressure (BP) monitoring in children immediately after kidney transplantation is ideally performed with an arterial line. Accurate measurement of BP is necessary for optimal management. However, during the first days postoperative, the arterial line is removed and BP measurement is switched to a non-invasive device. The aim of this study was to determine the accuracy and reliability of the automated oscillometric device compared to invasive arterial BP (IBP) monitoring in patients after renal transplantation in pediatric intensive care unit (PICU). METHOD: We analyzed all simultaneously measured BPs in children with a kidney transplant in the Amalia Children's Hospital Radboud University Medical Center between January 1, 2012, and January 1, 2016. BP measurements were performed according to the hospital protocol. Agreement between invasive and non-invasive methods was assessed using Bland-Altman plots. RESULTS: A total of 29 patients were included in this retrospective study. The majority of children were male (59%), and median age was 11 years (range 1-17 years). Totally, 80 BP measurements were recorded during the first days post-kidney transplantation. The correlation coefficients (R) of systolic, diastolic, and MAP of non-invasive (NIBP) and IBP measurements were 0.84, 0.76, and 0.77, respectively (P < 0.01). Overall, the average MAP (7.5 ± 1.2 mm Hg; P < 0.05) NIBP values were lower compared to IBP. In hypertensive patients, MAP (10.4 ± 10.0 mm Hg; P < 0.05) BP values were significantly lower using the NIBP device. Clinically relevant difference of >10 mm Hg was found in 51% (41/80) of measurements and mainly observed in hypertensive measurements. CONCLUSIONS: IBP measurement is considered the golden standard for monitoring BP in patients immediately after kidney transplantation. NIBP values showed a good agreement with invasive reading, but the variability of NIBP mainly in hypertensive patients is high as it is the number of clinically relevant differences to IBP. We conclude that IBP remains the golden standard to monitor BP in children directly postoperatively.

Correlation of Noninvasive Blood Pressure and Invasive Intra-arterial Blood Pressure in Patients Treated with Vasoactive Medications in a Neurocritical Care Unit.

BACKGROUND: The correlation between noninvasive (oscillometric) blood pressure (NBP) and intra-arterial blood pressure (IAP) in critically ill patients receiving vasoactive medications in a Neurocritical Care Unit has not been systematically studied. The purpose of this study is to examine the relationship between simultaneously measured NBP and IAP recordings in these patients. METHODS: Prospective observational study of patients (N = 70) admitted to a neurocritical care unit receiving continuous vasopressor or antihypertensive infusions. Paired NBP/IAP observations along with covariate and demographic data were abstracted via chart audit. Analysis was performed using SAS v9.4. RESULTS: A total of 2177 paired NBP/IAP observations from 70 subjects (49% male, 63% white, mean age 59 years) receiving vasopressors (n = 21) or antihypertensive agents (n = 49) were collected. Paired t test analysis showed significant differences between NBP versus IAP readings: ([systolic blood pressure (SBP): mean = 136 vs. 140 mmHg; p < 0.0001], [diastolic blood pressure (DBP): mean = 70 vs. 68 mmHg, p < 0.0001], [mean arterial blood pressure (MAP): mean = 86 vs. 90 mmHg, p < 0.0001]). Bland-Altman plots for MAP, SBP, and DBP demonstrate good inter-method agreement between paired measures (excluding outliers) and demonstrate NBP-IAP SBP differences at extremes of blood pressures. Pearson correlation coefficients show strong positive correlations for paired MAP (r = 0.82), SBP (r = 0.84), and DBP (r = 0.73) recordings. An absolute NBP-IAP SBP difference of > 20 mmHg was seen in ~ 20% of observations of nicardipine, ~ 25% of observations of norepinephrine, and ~ 35% of observations of phenylephrine. For MAP, the corresponding numbers were ~ 10, 15, and 25% for nicardipine, norepinephrine, and phenylephrine, respectively. CONCLUSION: Despite overall strong positive correlations between paired NBP and IAP readings of MAP and SBP, clinically relevant differences in blood pressure are frequent. When treating with vasoactive infusions targeted to a specific BP goal, it is important to keep in mind that NBP and IAP values are not interchangeable.

Feasibility study on monitoring blood pressure of the superficial temporal artery in neonates / 中华护理杂志

Objective To explore the feasibility of monitoring blood pressure via superficial temporal artery catheterization in neonates,which may provide more ways to monitor arterial blood pressure of neonates.Methods By lottery method,64 neonates from NICU who met inclusion criteria and needed arterial blood pressure monitoring were randomly divided into two groups.Thirty-two cases in the experimental group were treated with superficial temporal artery catheterization,while 32 cases in the control group were treated with radial artery catheterization.The success rate of one-time catheterization,indwelling time of catheter,blood pressure and the rate of complications were compared between two groups.Results There were no significant differences between two groups in the success rate of one-time catheterization,indwelling time of catheter,systolic blood pressure and the rate of complications (P＞0.05).Results showed there was significant difference in diastolic blood pressure between two groups(P＜ 0.05).Conclusion Compared with radial artery blood catheterization,neonatal superficial temporal artery catheterization showed equivalent effect,which made it more convenient for observing condition of neonates.

Feasibility study on monitoring blood pressure of the superficial temporal artery in neonates / 中华护理杂志

Objective To explore the feasibility of monitoring blood pressure via superficial temporal artery catheterization in neonates,which may provide more ways to monitor arterial blood pressure of neonates.Methods By lottery method,64 neonates from NICU who met inclusion criteria and needed arterial blood pressure monitoring were randomly divided into two groups.Thirty-two cases in the experimental group were treated with superficial temporal artery catheterization,while 32 cases in the control group were treated with radial artery catheterization.The success rate of one-time catheterization,indwelling time of catheter,blood pressure and the rate of complications were compared between two groups.Results There were no significant differences between two groups in the success rate of one-time catheterization,indwelling time of catheter,systolic blood pressure and the rate of complications (P＞0.05).Results showed there was significant difference in diastolic blood pressure between two groups(P＜ 0.05).Conclusion Compared with radial artery blood catheterization,neonatal superficial temporal artery catheterization showed equivalent effect,which made it more convenient for observing condition of neonates.

Evaluation of a novel automated non-invasive pulse pressure variation algorithm.

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.