Radial Arterial Monitoring Research Articles

ClearSight™ finger cuff versus invasive arterial pressure measurement in patients with body mass index above 45 kg/m2

BackgroundMeasuring blood pressure in patients with obesity is challenging. The ClearSight™ finger cuff (FC) uses the vascular unloading technique to provide continuous non-invasive blood pressure measurements. We aimed to test the agreement of the FC with invasive radial arterial monitoring (INV) in patients with obesity.MethodsParticipants had a body mass index (BMI) ≥45 kg/m2 and underwent laparoscopic bariatric surgery. FC and INV measurements were obtained simultaneously every 5 min on each patient, following induction of anesthesia. Agreement over time was assessed using modified Bland-Altman plots and error grid analysis permitted clinical interpretation of the results. Four-quadrant plots allowed assessment of concordance in blood pressure changes.ResultsThe 30 participants had a median (IQR) BMI of 50.2 kg/m2 (IQR 48.3–55.3). The observed bias (SD, 95% limits of agreement) for systolic blood pressure (SBP) was 14.3 mmHg (14.1, -13.4 – 42.0), 5.2 mmHg (10.9, -16.0 – 26.5) for mean arterial pressure (MAP) and 2.6 mmHg (10.8, -18.6 – 23.8) for diastolic blood pressure (DBP). Error grid analysis showed that the proportion of readings in risk zones A-E were 90.8, 6.5, 2.7, 0 and 0% for SBP and 91.4, 4.3, 4.3, 0 and 0% for MAP, respectively. Discordance occurred in ≤8% of pairs for consecutive change in SBP, MAP and DBP.ConclusionsThe vascular unloading technique was not adequately in agreement with radial arterial monitoring. Evaluation in a larger sample is required before recommending this technique for intraoperative monitoring of patients with BMI ≥45 kg/m2.

Non-Invasive Blood Pressure Monitoring Underestimates Exercise-Induced Hypertension in Heart Failure with Preserved Ejection Fraction (HFpEF)

Hypertensive response to exercise (HTR - peak systolic blood pressure (BP) ≥190 mmHg in women; ≥220 mmHg in men during exercise) contributes to the development of HFpEF and subsequent exercise intolerance. This study assesses the reliability of non-invasive (NI) BP monitoring for the diagnosis of HTR in suspected HFpEF patients undergoing exercise right heart catheterisation (ExRHC). Methods: Data from 12 patients with suspected HFpEF undergoing ExRHC were retrospectively analysed. BP was recorded simultaneously from invasive radial arterial monitoring (IBP) and NI cuff measurements. 6 patients met HTR criteria from IBP monitoring, and 6 did not (non-HTR). BP at rest and peak exercise in the HTR and non-HTR subgroups were correlated and also analysed for agreement using the Bland-Altman method and plotted graphically as shown. Results: NIBP monitoring detected HTR in only 2 of 6 (33%) cases. Poor correlation between IBP and NIBP at exercise in HTR is demonstrated from Pearson correlation coefficient analysis: Non-HTR – rest r = 0.88; exercise r = 0.87 – HTR: rest r = 0.81; exercise r = 0.44. Agreement between measurement techniques diverges at peak exercise; with this discrepancy exaggerated in patients with HTR. Conclusion: Invasive BP monitoring may be required to accurately diagnose HTR in this patient cohort, and its use could be considered during ExRHC.

Efficacy of inhalational sevoflurane anesthesia induction on inhibiting the stress response to endotracheal intubation in children with congenital heart disease.

To investigate the efficacy of inhalational sevoflurane anesthesia induction on inhibiting the stress response to endotracheal intubation in pediatric patients with congenital heart disease (CHD). Forty ASA physical status I/II pediatric patients scheduled for interventricular septal defect repair or interatrial septal defect repair, were randomly divided into two groups (20 each): intravenous induction group (Group C) and inhalational sevoflurane anesthesia induction group (Group D). In group C, anesthesia was induced with midazolam, pipecuronium bromide and fentanyl, and the children were examined by radial artery monitoring after the consciousness extinction. Also, they were endotracheally intubated after muscle relaxation. In group D, anesthesia was induced with inhalation of 8% sevoflurane and 6 L/min oxygen, and the children were examined by radial artery monitoring after the consciousness extinction and were endotracheally intubated 4 min later. Before anesthesia induction (T0), consciousness extinction (T1), endotracheal intubation (T2), endotracheal intubation (T3), and after endotracheal intubation (T4), 1 and 3 min after intratracheal intubation (T5,6), HR and bispectral index (BIS) were monitored. The MAP of T2-T6 points was recorded. Ulnar vein blood samples were taken for determination of Endothelin (ET) and Thromboxane A2(TXA2) in the points of consciousness extinction, and 5 and 10 min after endotracheal. All the children were well examined by endotracheal intubation. Compared with the baseline value at T0, there was no significant difference of HR in group D, but the HR of group C was decreased at T2, T3, T4 and T6. The BIS of the two groups were decreased at T1-T6 (p<0.05). Compared with the values at T2, they were increased at T5 and T6 in group C, and increased at T6 in group D (p<0.05). Compared with group C, the MAP of group D was decreased at T5, and the BIS of the two groups was decreased at T2-T6 (p<0.05). There were no significant differences of ET and TXA2 between groups. It is well inhibited the endotracheal intubation stress response in children with congenital heart diseases using sevoflurane inhalational anesthesia induction.

The Hemodynamic and Respiratory Effects of Continuous Negative and Control-Mode Cuirass Ventilation in Recently Extubated Cardiac Surgery Patients: Part 2

Negative-pressure ventilation (NPV) by external cuirass (RTX; Deminax Medical Instruments Limited, London, UK) in intubated patients after cardiac surgery improves hemodynamics measured by pulmonary artery catheter (PAC)-based methods with increased cardiac output (CO) and stroke volume (SV) without changing the heart rate (HR). The less-invasive pressure recording analytical method (PRAM) (MostCare; Vytech Health srl, Padova, Italy) allows radial artery monitoring of CO, SV, SV variation, and cardiac cycle efficiency (CCE). The authors investigated the hypothesis that NPV improves PRAM-based hemodynamics and arterial blood gas analysis in extubated cardiac surgery patients. A clinical investigation. A teaching hospital. Twenty recently extubated cardiac surgery patients. Five consecutive experimental ventilation modalities lasted 5 minutes: (1) baseline (no cuirass ventilation), (2) mode 1 (cuirass ventilation with a continuous negative pressure of -20 cmH(2)O), (3) rest 1 (no cuirass ventilation), (4) mode 2 (cuirass ventilation in the control mode of 12 breaths/min at -20 cmH(2)O, and (5) rest 2. PRAM parameters were analyzed throughout the final minute of each experimental modality, concluding with arterial blood gas sampling. NPV was well tolerated. HR was unchanged. Mode 2 SV was higher than baseline and rest 2. Mode 2 CO was higher than rest 2. Rest 2 systolic blood pressure was lower than rest 1 and mode 2. Increased CCE with NPV was not significant (p = 0.0696). Oxygenation and PCO(2) were unchanged although mode 2 pH increased. Extubated sedated cardiac surgery patients comfortably tolerated NPV with unchanged HR. SV and pH increased.

Cardiac Output Measured with Both Esophageal Doppler Device and Vigileo-FloTrac Device

To the Editor We disagree with Meng et al.'s1 conclusions in their comparison of cardiac output (CO) measurements using both the third-generation Vigileo-FloTrac device (COFT) (Edwards Lifesciences, Irvine, CA) and the esophageal Doppler device (COED). The authors were wrong to assume that the COED was a valid reference. Furthermore, the significant disconcordance between COED and COFT measurements with phenylephrine boluses was predictable. Knapp et al.2 demonstrated that stroke volume initially increases during the first 4 minutes after initiating a phenylephrine infusion, peaks at 19.3 minutes, after which the stroke volume decreases. Schwinn and Reves3 showed that the time course and hemodynamic effects of bolus phenylephrine administration in anesthetized patients ranges from 40 seconds to 55 seconds depending on the dose administered. The patient's underlying volume status,4,5,6 relative density and activation of α- and β-adrenergic receptors, the underlying catecholamine state and cardiac function, and chronic medication use all influence hemodynamic responses to these study interventions. There is interindividual variability in response to anesthetic and a 20% decrease in mean arterial blood pressure after induction hardly guarantees equivalent volume status (especially considering the variable size of the splanchnic reservoir). The χ (Ķ) factor accounting for arterial compliance in the Vigileo-FloTrac (FT) algorithm is updated every minute in the third-generation FT software. Thus, the FT device was using an “unupdated” correction factor because it was trying to make sense of the acutely increased pulse pressure with a phenylephrine bolus. In other words, Meng et al. were testing the FT in a situation for which it had not been intended to perform. Therefore, we could have anticipated study findings given the lack of synchrony between the time course of phenylephrine bolus effects (well below 60 seconds) and the updating interval for the arterial compliance correction factor on the third-generation FT algorithm (60 seconds). Preload-augmenting effects of phenylephrine are generally predominant5–9 and these effects are largely related to splanchnic and abdominal visceral venous constriction5 (in response to α-agonist effects of phenylephrine) resulting in the displacement of blood from a previously nonstressed compartment into the central circulation.5,9,10 Although stroke volume may increase, CO may decrease secondary to an overall negative effect of phenylephrine on the heart rate. Global CO was not directly measured by Meng et al. The implicit assumption with COED-based monitoring is that the proportion of bloodflow in the ascending and descending aorta remains fixed (at a constant 30:70 ratio), despite fluctuations in various hemodynamic variables. Effects of changes in posture have not been formally examined using the esophageal Doppler device.11 Situations altering the proportion of upper lower body bloodflow will affect Doppler-derived values.11 The physiologic effects of an acute bolus of phenylephrine are not dissimilar to those associated with aortic cross-clamping; acute simultaneous increases in preload and afterload. We contend that the esophageal Doppler device assumed ratio of ascending to descending aortic flow (the relative distribution of global cardiac output) will not hold true after a phenylephrine bolus. With an acute phenylephrine bolus, global bloodflow is redirected away from the lower body (splanchnic viscera) toward the vital organs in the upper body (heart and brain). Therefore, when a phenylephrine bolus is used to treat hypotension occurring after the induction of general anesthesia we would expect the COED to decrease (because it is measuring only descending aortic flow) and the COFT to increase (because it is using an “unupdated” arterial compliance correction factor based off a radial arterial monitoring site). In essence, both the devices (esophageal Doppler device and FT) were not accurately measuring the effects of a phenylephrine bolus on global bloodflow. Karthik Raghunathan, MD, MPH Department of Anesthesiology Baystate Medical Center Tufts University School of Medicine Springfield, Massachusetts [email protected] Joshua A. Bloomstone, MD Department of Anesthesiology and Perioperative Medicine Banner Thunderbird Medical Center Glendale, Arizona Valley Anesthesiology Consultants, Ltd Phoenix, Arizona William T. McGee, MD, MHA Division of Critical Care Department of Internal Medicine Baystate Medical Center Tufts University School of Medicine Springfield, Massachusetts

Transcutaneous Ultrasound Measurements of Carotid Flow to Monitor for Cerebral Malperfusion During Type-A Aortic Dissection Repair

HE REPAIR OF TYPE-A aortic dissection often requires alternative sites for arterial cannulation for cardiopulmonary bypass (CPB). The risks of cannulation of the femoral artery for the institution of CPB are well known and include retrograde perfusion of the false lumen with potential worsening of the dissection with compromise of organ perfusion, and retrograde embolization. Some techniques, including axillary artery, 1 transapical aortic, 2 and central aorta cannulation, have been described to minimize this complication.3 Some of these techniques require more time and may not be appropriate for all patients. Monitoring the adequacy of cerebral perfusion is of vital importance in all aortic surgical cases and even more whenever the femoral artery is used for CPB. Different methods have been described, including bilateral radial arterial monitoring in addition to transesophageal echocardiographic (TEE) imaging of the descending aorta, 4 right radial artery with left femoral artery monitoring, 5 cerebral oximetric monitoring using nearinfrared spectroscopy, 6,7 transcranial Doppler ultrasonography, 8 ophthalmic artery Doppler ultrasonography, 9 and color-flow Doppler transcutaneous carotid artery ultrasound imaging.10 The authors describe a case of chronic type-A dissection requiring surgical repair in which axillary artery cannulation for the institution of CPB was impossible, requiring femoral artery cannulation. They illustrate a method to quantify carotid artery flow velocity and monitor for intraoperative cerebral malperfusion using transcutaneous Doppler ultrasound of the carotid arteries.

重症くも膜下出血の管理．根治術施行までの問題点

We evaluated the management of patients with subarachnoid hemorrhage (SAH) after arrival for surgical intervention in the ultra-acute stage. Immediately after brief neurological and systemic examination, patients were deeply sedated to prevent aneurysmal rerupture. Principally they were intubated with intensive control of systolic blood pressure below 120 mmHg by radial arterial monitoring. Buprenorphine, midazolam, and vecuronium were rontinely intravenously administered; and propofol, barbiturate, nicardipine, or prostaglandin was added to lower blood pressure if necessary. A total of 163 consecutive patients with SAH (59 men and 104 women, mean age of 61.1 years) arrived between 2003 and 2005 were enrolled. The majority of patients were in poor grade: 26 with Grade IV, 54 with Grade V by grading scale of the World Federation of Neurological Society, and 32 with cardiopulmonary arrest. Eighty-seven patients (53%) arrived within 1 hour after onset of SAH and 127 patients (78%) arrived within 3 hours. Most of the poor-grade patients were intubated before initial brain CT scan. Mean systolic blood pressure was around 170 mmHg at the time of arrival, which was controlled around 120 mmHg or less during resuscitation and angiography. A total of 117 patients had DSA, 111 of them (68%) within 3 hours, and 111 patients underwent surgery, 81 of them (85%) within 6 hours. Despite intensive resuscitation, 36 episodes of rebleeding were detected in 32 patients, 24 before and 12 after arrival. Extravasation of contrast media was seen in 6 patients during cerebral angiography. Favorable outcome (good recovery and moderate disability) was obtained in 69% of Grade IV and 24% of the Grade V patients. The risk of ultra-early rebleeding is highest for patients with poor grades. Deep sedation and strict blood pressure control followed by urgent obliteration of the ruptured aneurysm have a strong rationale to prevent rerupture and to achieve better overall outcome.

An Accuracy Evaluation of the T-Line® Tensymeter (Continuous Noninvasive Blood Pressure Management Device) versus Conventional Invasive Radial Artery Monitoring in Surgical Patients

Continuous beat-to-beat arterial blood pressure (BP) monitoring with a simultaneous arterial waveform display is typically achieved with an invasive arterial catheter. We evaluated a noninvasive device, the T-Line Tensymeter, that provides a calibrated arterial pressure waveform from which continuous BP measurements and heart rate may be computed by either a bedside host monitor or the tensymeter device itself. In 25 patients given general anesthesia, we measured systolic, mean, and diastolic BPs via the tensymeter and compared these measurements with those obtained from the contralateral radial artery catheter. Data were analyzed using the Bland Altman test to determine agreement between the two systems. The mean +/- sd bias and precision (mm Hg) were as follows: 1.7 +/- 7.0 and 5.7 +/- 4.4 for systolic BP; 2.3 +/- 6.9 and 5.7 +/- 4.5 for diastolic BP; and 1.7 +/- 5.3 and 4.0 +/- 4.8 for mean BP. Noninvasive pressures from the tensymeter-produced arterial waveform agreed with simultaneous contralateral BPs measured from arterial catheters within an acceptable clinical range for a limited population of surgical patients studied over a systolic arterial BP range from 41 to 189 mm Hg without significant temporal performance degradation. The tensymeter may enable physicians to circumvent arterial cannulation in certain circumstances (such as with low- or intermediate-risk procedures) on patients when beat-to-beat BP measurement is desirable.

Giant pseudoaneurysm after proximal aortic surgery treated by means of redo axillary artery cannulation and use of an Endoclamp device

Giant pseudoaneurysm after proximal aortic surgery treated by means of redo axillary artery cannulation and use of an Endoclamp device

Radial to femoral arterial blood pressure differences during liver transplantation

This observational study compared femoral and radial arterial blood pressure in 72 patients undergoing liver transplant surgery. Simultaneous femoral and radial arterial blood pressures, cardiac index, core temperature and vasoconstrictor therapy were recorded at seven time points during the operation. No significant differences between radial and femoral pressures were found at the start of surgery. Femoral and radial systolic arterial blood pressures were statistically significantly different during liver reperfusion (mean (SD) arterial pressure = 92 (22) mmHg vs. 76 (22) mmHg, p < 0.01). Mean arterial blood pressures showed no statistically significant differences throughout the study. Vasoconstrictor drug administration was associated with a larger systolic pressure difference between femoral and radial arteries (28 (24) mmHg in patients being given vasoconstrictor drugs vs. 9 (19) mmHg in patients not needing vasoconstrictors during reperfusion, p < 0.001). In conclusion, differences in systolic arterial blood pressure occur between femoral and radial arterial monitoring sites during liver reperfusion, and in particular in patients being given vasoconstrictor therapy. Thus, if femoral arterial monitoring is not available, clinicians should rely on mean rather than systolic arterial pressure measurements from a radial artery catheter during liver transplantation.

Asystole During Endovascular Embolization of a Dural Arterio-Venous Fistula in the Brain

Asystole During Endovascular Embolization of a Dural Arterio-Venous Fistula in the Brain

Ischaemia of the Hand after Radial Artery Monitoring

Percutaneous radial artery cannulation is commonly used for continuous monitoring of blood pressure and estimation of arterial blood gases. The purpose of this study is to define the incidence of radial artery thrombosis and associated hand ischaemia after cannulation. A prospective study of 40 patients who underwent radial artery cannulation was carried out with patients examined before and after cannulation for radial and ulnar pulses. Doppler waveforms, and Anger/brachial and finger/wrist pressure indices were obtained. After cannulation 27.5% of patients developed abnormal radial artery flows with 10% having absent pulses and none having any symptoms of hand ischaemia. Radial artery cannulation is a safe procedure when performed properly and is associated with a very low incidence of hand ischaemia, despite a 27.5% incidence of abnormal radial artery flow after cannulation.

Ischaemia of the hand after radial artery monitoring

Percutaneous radial artery cannulation is commonly used for continuous monitoring of blood pressure and estimation of arterial blood gases. The purpose of this study is to define the incidence of radial artery thrombosis and associated hand ischaemia after cannulation. A prospective study of 40 patients who underwent radial artery cannulation was carried out with patients examined before and after cannulation for radial and ulnar pulses. Doppler waveforms, and finger/brachial and finger/wrist pressure indices were obtained. After cannulation 27.5% of patients developed abnormal radial artery flows with 10% having absent pulses and none having any symptoms of hand ischaemia. Radial artery cannulation is a safe procedure when performed properly and is associated with a very low incidence of hand ischaemia, despite a 27.5% incidence of abnormal radial artery flow after cannulation. Copyright © 1996 The International Society for Cardiovascular Surgery.

Continuous Blood Pressure Monitorings during Cardiovascular Opertions in Takayasu's Syndrome

We had examined the invasive blood pressure monitoring of superficial temporal, radial and femoral artery in two eases of Takayasus syndrome with mitral regurgitation and acute renal artery infarction. Mitral valve replacement and aorto-renal bypass graft were done by using cardiopulmonary bypass and one-lung ventilation respectively, The results are ; 1) Superficial temporal artery monitoring was more reliable and less fluctuant than femoral and radial artery monitoring in blood pressure. But we dont know the relationship of adequate cerebral perfusion pressure and superficial temporal artery pressure. 2) The femoral artery pressure monitoring was not adequate when the patients had a problem with ascending and descending aorta patency. 3) We had good results in the patient management by the monitoring of superficial temporal artery pressure.

Bacterial infection from intravascular monitoring devices.

During the past decade intravascular monitoring has become commonplace in hospital critical care areas. Early reports, such as that of Gardner et al, reassured us that these devices were safe. In fact, Gardner and associates noted not a single local or systemic infection that could be definitely related to radial artery monitoring catheters in 531 patients. Results of a more recent study by Band and Maki are more sobering. They found a 4% incidence of septicemia and an 18% incidence of local infection when they prospectively studied 130 arterial catheters in 95 patients. There were many differences between these two studies, but perhaps the two most important factors leading to the higher incidence of infection in the later study were increased duration of catheter placement and placement of the catheter by surgical cutdown or in a femoral artery.