Continuous arterial pressure waveform monitoring in pediatric cardiac transplant, cardiomyopathy and pulmonary hypertension patients

Perioperative management of a child with Klippel–Feil syndrome and severe uncorrected aortic stenosis undergoing cervical spine stabilization

Severe stenotic aortic valve poses serious anesthetic challenges because of the fixed cardiac output and complex hemodynamics. The challenges magnify in the presence of a difficult airway which not only puts the airway at risk but also disturbs the hemodynamics, which can negatively impact the patient outcome. Moreover, prone positioning, intraoperative hemodynamics, recovery, and extubation are equally challenging for management. This case report highlights the perioperative management of a child with severe uncorrected aortic stenosis and Klippel–Feil syndrome posted for cervical spinal stabilization under anesthesia.

Case Report: Anesthetic Management and Electrical Cardiometry as Intensive Hemodynamic Monitoring During Cheiloplasty in an Infant With Enzyme-Replaced Pompe Disease and Preserved Preoperative Cardiac Function

Introduction: Pompe disease is caused by deficiency of the lysosomal enzyme acid α-glucosidase, which results in cardiac and muscular complications that can jeopardize perioperative outcomes. We report a 4-month-old infant with Pompe disease receiving cheiloplasty under general anesthesia with the aid of peripheral nerve blocks and intensive hemodynamic monitoring. Case Description: This case report describes a 4-month-old full-term Taiwanese female infant who presented with left unilateral cleft lip and palate in the prenatal examination. She was diagnosed with infantile-onset Pompe disease after acidic α-glucosidase (GAA) gene sequencing. She also received enzyme replacement therapy (ERT) 15 days after birth and regular ERT every other week. Cheiloplasty was performed under general anesthesia uneventfully, and peripheral nerve blocks were adopted for analgesia. Intensive hemodynamic monitoring using electrical cardiometry technology (ICON^®) and pulse contour analysis (FloTrac system) were applied during the operation. No adverse effects were observed, and the wound healed well. Therefore, the patient was discharged 4 days after surgery. Conclusion: With the availability of ERT, severe organ dysfunction in infantile-onset Pompe disease patients is no longer common. However, moderate cardiac depression can still occur while increasing inspiratory pressure and deepening the anesthesia level despite a normal preoperative echocardiogram report. Therefore, careful, gradual titration is desirable. Furthermore, electrical cardiometry can detect hemodynamic changes more instantaneously and reliably than pulse contour analysis. In addition, we suggest taking advantage of the peripheral nerve block as a part of balanced anesthesia to alleviate the cardiac suppression caused by general anesthesia.

Cardiac output monitoring in paediatric cardiac surgery: a review

The aim of this review is to present the current options for cardiac output (CO) monitoring in children undergoing cardiac surgery. Current technologies for monitoring identified were a range of invasive, minimally invasive, and non-invasive technologies. These include pulmonary artery catheter, transoesophageal echocardiography, pulse contour analysis, electrical cardiography, and thoracic bioreactance. A literature search was conducted using evidence databases which identified two current guidelines; the NHS Greater Glasgow and Clyde guideline and Royal College of Anaesthetics Guideline. These were appraised using the AGREE II tool and the evidence identified was used to create an overview summary of each technological option for CO monitoring. There is limited evidence regarding the accuracy of modalities available for CO monitoring in paediatric patients during cardiac surgery. Each technology has advantages and disadvantages; however, none could be championed as the most beneficial. Furthermore, a gold standard for CO monitoring has not yet been identified for paediatric populations, nor is it apparent whether one modality is preferable based on the available evidence. Additional evidence using a standardised method for comparing CO measurements should be conducted in order to determine the best option for CO monitoring in paediatrics. Furthermore, cost-effectiveness assessment of each modality should be conducted. Only then will it be possible for clear, evidence-based guidance to be written.

Cardiac Output Monitoring in Preterm Infants

Maintaining optimal circulatory status is a key component of preterm neonatal care. Low-cardiac output (CO) in the preterm neonate leads to inadequate perfusion of vital organs and has been linked to a variety of adverse outcomes with heightened acute morbidity and mortality and adverse neurodevelopmental outcomes. Having technology available to monitor CO allows us to detect low-output states and potentially intervene to mitigate the unwanted effects of reduced organ perfusion. There are many technologies available for the monitoring of CO in the preterm neonatal population and while many act as useful adjuncts to aid clinical decision-making no technique is perfect. In this review, we discuss the relative merits and limitations of various common methodologies available for monitoring CO in the preterm neonatal population. We will discuss the ongoing challenges in monitoring CO in the preterm neonate along with current gaps in our knowledge. We conclude by discussing emerging technologies and areas that warrant further study.

Perioperative management of paraganglioma and catecholamine-induced cardiomyopathy in child- a case report and review of the literature

Background

Paragangliomas are catecholamine-secreting tumors of the paraganglia. Perioperative mortality of children with paraganglioma is high, but preoperative therapy and anesthetic management of paraganglioma resection are controversial in children. The literatures on catecholamine-induced cardiomyopathy are limited to several case reports,with few reports of studies on children.

Case presentation

Here we report the anesthetic management of a child with paraganglioma and catecholamine-induced cardiomyopathy, and the possible perioperative anesthesia problems of the paraganglioma resection are discussed.

Conclusion

Preoperative and intraoperative anesthetic management of Pheochromocytomas children should follow the same principles as for adults, The most important aspects are the control of blood pressure liability and maintenance of adequate blood volume. Pheochromocytomas patient may have cardiomoyopathy due to myocardial toxicity of excessive circulating catecholamines level. The perioperative management of catecholamine-induced cardiomyopathy should include lowering sympathetic activation by means of α-and β-adrenergic receptor blocker and diuretics administration in case of volume overload.

Vasoactive Drugs and Hemodynamic Monitoring in Pediatric Cardiac Intensive Care: An Italian Survey

BACKGROUND

Little is known about practitioner preference, the availability of technology, and variability in practice with respect to hemodynamic monitoring and vasoactive drug use after congenital heart surgery. The aim of this study was to characterize current hospital practices related to the management of low cardiac output syndrome (LCOS) across Italy.

METHODS

We issued a 22-item questionnaire to 14 Italian hospitals performing pediatric cardiac surgery.

RESULTS

Electrocardiogram, invasive blood pressure, central venous pressure, pulse oximetry, diuresis, body temperature, arterial lactate, and blood gas analysis were identified as routine in hemodynamic monitoring. With regard to advanced hemodynamic monitoring, pulmonary arterial catheter and transpulmonary thermodilution were available in 43% of the centers, uncalibrated pulse contour methods in 29% of the centers, and transesophageal/transthoracic echocardiograms in all of the centers. Dopamine added to milrinone was the most frequent drug regimen for LCOS prevention after cardiopulmonary bypass. Overall, 86% of centers used milrinone alone as the initial treatment for LCOS with elevated systemic vascular resistances and levosimendan, the second preferred choice. In cases of LCOS with low vascular resistance, epinephrine was the first choice (10 centers), dopamine was the second choice (4 centers), followed by vasopressin and norepinephrine (3 centers). For treatment of LCOS with elevated pulmonary resistances, milrinone was the first choice (eight centers), followed by inhaled nitric oxide (five centers).

CONCLUSIONS

The survey shows that advanced hemodynamic monitoring is rarely performed. The most commonly used vasoactive drugs are milrinone, levosimendan, dopamine, epinephrine, vasopressin, and norepinephrine. Guidelines on the topic are warranted.

Comparison between pressure-recording analytical method (PRAM) and femoral arterial thermodilution method (FATD) cardiac output monitoring in an infant animal model of cardiac arrest

Background

The pressure-recording analytical method is a new semi-invasive method for cardiac output measurement (PRAM). There are no studies comparing this technique with femoral artery thermodilution (FATD) in an infant animal model.

Methods

A prospective study was performed using 25 immature Maryland pigs weighing 9.5 kg. Fifty-eight simultaneous measurements of cardiac index (CI) were made by FATD and PRAM at baseline and after return of spontaneous circulation. Differences, correlation, and concordance between both methods were analyzed. The ability of PRAM to track changes in CI was explored with a polar plot.

Results

Mean CI measurements were 4.5 L/min/m² (95 % CI, 4.2–4.8 L/min/m²; coefficient of variation, 27 %) by FATD and 4.0 L/min/m² (95 % CI, 3.6–4.3 L/min/m²; coefficient for variation, 37 %) by PRAM (difference, 0.5 L/min/m²; 95 % CI for the difference, 0.1–1.0 L/min/m²; p = 0.003; n = 58). No correlation between both methods was observed (r = 0.170, p = 0.20). Limits of agreement were −2.9 to 4.0 L/min/m² (−69.9 to 84.9 %). Percentage error was 80.6 %. Only 26.1 % of data points lied within an absolute deviation of ±30° from the polar axis.

Conclusions

No correlation nor concordance between both methods was observed. Limits of agreement and percentage of error were high and clinically not acceptable. No concurrence between both methods in CI changes was observed. PRAM is not a useful method for measurement of the CI in this pediatric model of cardiac arrest.

Usefulness of stroke volume variation to assess blood volume during blood removal for autologous blood transfusion in pediatric patients

BACKGROUND

Dynamic variables based on the heart-lung interaction induced by positive pressure ventilation have not been shown to be useful in assessing cardiac preload in pediatric patients.

OBJECTIVE

To evaluate whether stroke volume variation (SVV) obtained from the FloTrac/Vigileo(TM) monitoring system can reflect a change in blood volume during the blood removal and fluid replacement protocol in acute normovolemic hemodilution (ANH).

METHODS

Sixteen pediatric patients scheduled for elective cranioplasty were recruited. In the ANH protocol, 10 ml · kg(-1) blood removal and fluid replacement were performed. SVV, heart rate, mean blood pressure, and femoral venous pressure were recorded. Differences at four time points (T0: baseline, T1: 5 ml · kg(-1) blood loss, T2: 10 ml · kg(-1) blood loss, and T3: after fluid replacement) during ANH were compared. The blood volume (EBV) was estimated as 70 ml · kg(-1) at T0 and decreased to 60 ml · kg(-1) at T2.

RESULTS

Of the 16 patients, four were excluded and 12 were analyzed. Significant differences in all of the parameters were observed between each time point. The SVV significantly increased after the blood removal and decreased after the fluid replacement (P < 0.01, Bonferroni adjustment). In addition, the increases in SVV during the blood removal, T0-T1 and T0-T2, were 70% ± 40% and 159% ± 91%, respectively. SVV showed a significant correlation with EBV during the blood removal in ANH (rs = -0.68, 95% confidence interval -0.73 to -0.63, P < 0.001).

CONCLUSION

Stroke volume variation obtained from the FloTrac/Vigileo(TM) monitoring system revealed a strong correlation with EBV during ANH without surgical stimulation. The usefulness of this device as an indicator of cardiac preload under hypovolemic or normovolemic conditions in children during surgery remains to be determined.

Accuracy and precision of minimally-invasive cardiac output monitoring in children: a systematic review and meta-analysis

Several minimally-invasive technologies are available for cardiac output (CO) measurement in children, but the accuracy and precision of these devices have not yet been evaluated in a systematic review and meta-analysis. We conducted a comprehensive search of the medical literature in PubMed, Cochrane Library of Clinical Trials, Scopus, and Web of Science from its inception to June 2014 assessing the accuracy and precision of all minimally-invasive CO monitoring systems used in children when compared with CO monitoring reference methods. Pooled mean bias, standard deviation, and mean percentage error of included studies were calculated using a random-effects model. The inter-study heterogeneity was also assessed using an I(2) statistic. A total of 20 studies (624 patients) were included. The overall random-effects pooled bias, and mean percentage error were 0.13 ± 0.44 l min(-1) and 29.1 %, respectively. Significant inter-study heterogeneity was detected (P < 0.0001, I(2) = 98.3 %). In the sub-analysis regarding the device, electrical cardiometry showed the smallest bias (-0.03 l min(-1)) and lowest percentage error (23.6 %). Significant residual heterogeneity remained after conducting sensitivity and subgroup analyses based on the various study characteristics. By meta-regression analysis, we found no independent effects of study characteristics on weighted mean difference between reference and tested methods. Although the pooled bias was small, the mean pooled percentage error was in the gray zone of clinical applicability. In the sub-group analysis, electrical cardiometry was the device that provided the most accurate measurement. However, a high heterogeneity between studies was found, likely due to a wide range of study characteristics.

Prophylactic milrinone for the prevention of low cardiac output syndrome and mortality in children undergoing surgery for congenital heart disease

BACKGROUND

Children with congenital heart disease often undergo heart surgery at a young age. They are at risk for postoperative low cardiac output syndrome (LCOS) or death. Milrinone may be used to provide inotropic and vasodilatory support during the immediate postoperative period.

OBJECTIVES

This review examines the effectiveness of prophylactic postoperative use of milrinone to prevent LCOS or death in children having undergone surgery for congenital heart disease.

SEARCH METHODS

Electronic and manual literature searches were performed to identify randomised controlled trials. We searched CENTRAL, MEDLINE, EMBASE and Web of Science in February 2014 and conducted a top-up search in September 2014 as well as clinical trial registries and reference lists of published studies. We did not apply any language restrictions.

SELECTION CRITERIA

Only randomised controlled trials were selected for analysis. We considered studies with newborn infants, infants, toddlers, and children up to 12 years of age.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data according to a pre-defined protocol. We obtained additional information from all study authors.

MAIN RESULTS

Three of the five included studies compared milrinone versus levosimendan, one study compared milrinone with placebo, and one compared milrinone verus dobutamine, with 101, 242, and 50 participants, respectively. Three trials were at low risk of bias while two were at higher risk of bias. The number and definitions of outcomes were non-uniform as well. In one study comparing two doses of milrinone and placebo, there was some evidence in an overall comparison of milrinone versus placebo that milrinone lowered risk for LCOS (risk ratio (RR) 0.52, 95% confidence interval (CI) 0.28 to 0.96; 227 participants). The results from two small studies do not provide enough information to determine whether milrinone increases the risk of LCOS when compared to levosimendan (RR 1.22, 95% CI 0.32 to 4.65; 59 participants). Mortality rates in the studies were low, and there was insufficient evidence to draw conclusions on the effect of milrinone compared to placebo or levosimendan or dobutamine regarding mortality, the duration of intensive care stay, hospital stay, mechanical ventilation, or maximum inotrope score (where available). Numbers of patients requiring mechanical cardiac support were also low and did not allow a comparison between studies, and none of the participants of any study received a heart transplantation up to the end of the respective follow-up period. Time to death within three months was not reported in any of the included studies. A number of adverse events was examined, but differences between the treatment groups could not be proven for hypotension, intraventricular haemorrhage, hypokalaemia, bronchospasm, elevated serum levels of liver enzymes, or a reduced left ventricular ejection fraction < 50% or reduced left ventricular fraction of shortening < 28%. Our analysis did not prove an increased risk of arrhythmias in patients treated prophylactically with milrinone compared with placebo (RR 3.59, 95% CI 0.83 to 15.42; 238 participants), a decreased risk of pleural effusions (RR 1.78, 95% CI 0.92 to 3.42; 231 participants), or a difference in risk of thrombocytopenia on milrinone compared with placebo (RR 0.86, 95% CI 0.39 to 1.88; 238 participants). Comparisons of milrinone with levosimendan or with dobutamine, respectively, did not clarify the risk of arrhythmia and were not possible for pleural effusions or thrombocytopenia.

AUTHORS' CONCLUSIONS

There is insufficient evidence of the effectiveness of prophylactic milrinone in preventing death or low cardiac output syndrome in children undergoing surgery for congenital heart disease, compared to placebo. So far, no differences have been shown between milrinone and other inodilators, such as levosimendan or dobutamine, in the immediate postoperative period, in reducing the risk of LCOS or death. The existing data on the prophylactic use of milrinone has to be viewed cautiously due to the small number of small trials and their risk of bias.

All this monitoring…what's necessary, what's not?

The goal of perioperative monitoring is to aid the clinician in optimizing care to achieve the best possible survival with the lowest possible morbidity. Ideally, we would like to have monitoring that can rapidly and accurately identify perturbations in circulatory well-being that would permit timely intervention and allow for restoration before the patient is damaged. The evidence to support the use of our standard monitoring strategies (continuous electrocardiography, blood pressure, central venous pressure, oxygen saturation and capnography) is based on expert opinion, case series, or at best observational studies. While these monitoring parameters will identify life-threatening events, they provide no direct information concerning the oxygen economy of the patient. Nevertheless, they are mandated by professional societies representing specialists in cardiac disease, critical care, and anesthesiology. Additional non-routine monitoring strategies that provide data concerning the body's oxygen economy, such as venous saturation monitoring and near infrared spectroscopy, have shown promise in prospective observational studies in managing these complex groups of patients. Ideally, high-level evidence would be required before adopting these newer strategies, but in the absence of new funding sources and the challenges of the wide variation in practice patterns between centers, this seems unlikely. The evidence supporting the current standard perioperative monitoring strategies will be reviewed. In addition, evidence supporting non-routine monitoring strategies will be reviewed and their potential for added benefit assessed.

Systematic review of uncalibrated arterial pressure waveform analysis to determine cardiac output and stroke volume variation

The FloTrac/Vigileo™, introduced in 2005, uses arterial pressure waveform analysis to calculate cardiac output (CO) and stroke volume variation (SVV) without external calibration. The aim of this systematic review is to evaluate the performance of the system. Sixty-five full manuscripts on validation of CO measurements in humans, published in English, were retrieved; these included 2234 patients and 44,592 observations.

RESULTS

have been analysed according to underlying patient conditions, that is, general critical illness and surgery as normodynamic conditions, cardiac and (post)cardiac surgery as hypodynamic conditions, and liver surgery and sepsis as hyperdynamic conditions, and subsequently released software versions. Eight studies compared SVV with other dynamic indices. CO, bias, precision, %error, correlation, and concordance differed among underlying conditions, subsequent software versions, and their interactions, suggesting increasing accuracy and precision, particularly in hypo- and normodynamic conditions. The bias and the trending capacity remain dependent on (changes in) vascular tone with most recent software. The SVV only moderately agreed with other dynamic indices, although it was helpful in predicting fluid responsiveness in 85% of studies addressing this. Since its introduction, the performance of uncalibrated FloTrac/Vigileo™ has improved particularly in hypo- and normodynamic conditions. A %error at or below 30% with most recent software allows sufficiently accurate and precise CO measurements and trending for routine clinical use in normo- and hypodynamic conditions, in the absence of large changes in vascular tone. The SVV may usefully supplement these measurements.

Goal-directed therapy in intraoperative fluid and hemodynamic management

Intraoperative fluid management is pivotal to the outcome and success of surgery, especially in high-risk procedures. Empirical formula and invasive static monitoring have been traditionally used to guide intraoperative fluid management and assess volume status. With the awareness of the potential complications of invasive procedures and the poor reliability of these methods as indicators of volume status, we present a case scenario of a patient who underwent major abdominal surgery as an example to discuss how the use of minimally invasive dynamic monitoring may guide intraoperative fluid therapy.

New technologies in pediatric anesthesia

This article reviews potential pediatric applications of 3 new technologies. (1) Pulse oximetry-based hemoglobin determination: Hemoglobin determination using spectrophotometric methods recently has been introduced in adults with varied success. This non-invasive and continuous technology may avoid venipuncture and unnecessary transfusion in children undergoing surgery with major blood loss, premature infants undergoing unexpected and complicated emergency surgery, and children with chronic illness. (2) Continuous cardiac output monitoring: In adults, advanced hemodynamic monitoring such as continuous cardiac output monitoring has been associated with better surgical outcomes. Although it remains unknown whether similar results are applicable to children, current technology enables the monitoring of cardiac output non-invasively and continuously in pediatric patients. It may be important to integrate the data about cardiac output with other information to facilitate therapeutic interventions. (3) Anesthesia information management systems: Although perioperative electronic anesthesia information management systems are gaining popularity in operating rooms, their potential functions may not be fully appreciated. With advances in information technology, anesthesia information management systems may facilitate bedside clinical decisions, administrative needs, and research in the perioperative setting.