Hemodynamic effects of ketamine in children with congenital heart disease and/or pulmonary hypertension

Factors associated with renal oxygen extraction in mechanically ventilated children after the Norwood operation: insights from high fidelity haemodynamic data

BACKGROUND

Maintaining the adequacy of systemic oxygen delivery is of utmost importance, particularly in critically ill children. Renal oxygen extraction can be utilised as metric of the balance between systemic oxygen delivery and oxygen consumption. The primary aim of this study was to determine what clinical factors are associated with renal oxygen extraction in children after Norwood procedure.

METHODS

Mechanically ventilated children who underwent Norwood procedure from 1 September, 2022 to 1 March, 2023 were identified as these patients had data collected and stored with high fidelity by the T3 software. Data regarding haemodynamic values, fluid balance, and airway pressure were collected and analysed using Bayesian regression to determine the association of the individual metrics with renal oxygen extraction.

RESULTS

A total of 27,270 datapoints were included in the final analyses. The resulting top two models explained had nearly 80% probability of being true and explained over 90% of the variance in renal oxygen extraction. The coefficients for each variable retained in the best were -1.70 for milrinone, -19.05 for epinephrine, 0.129 for mean airway pressure, -0.063 for mean arterial pressure, 0.111 for central venous pressure, 0.093 for arterial saturation, 0.006 for heart rate, -0.025 for respiratory rate, 0.366 for systemic vascular resistance, and -0.032 for systemic blood flow.

CONCLUSION

Increased milrinone, epinephrine, mean arterial pressure, and systemic blood flow were associated with decreased (improved) renal oxygen extraction, while increased mean airway pressure, central venous pressure, arterial saturation, and systemic vascular resistance were associated with increased (worsened) renal oxygen extraction.

A single institution anesthetic experience with catheterization of pediatric pulmonary hypertension patients

Cardiac catheterization remains the gold standard for the diagnosis and management of pediatric pulmonary hypertension (PH). There is lack of consensus regarding optimal anesthetic and airway regimen. This retrospective study describes the anesthetic/airway experience of our single center cohort of pediatric PH patients undergoing catheterization, in which obtaining hemodynamic data during spontaneous breathing is preferential. A total of 448 catheterizations were performed in 232 patients. Of the 379 cases that began with a natural airway, 274 (72%) completed the procedure without an invasive airway, 90 (24%) received a planned invasive airway, and 15 (4%) required an unplanned invasive airway. Median age was 3.4 years (interquartile range [IQR] 0.7-9.7); the majority were either Nice Classification Group 1 (48%) or Group 3 (42%). Vasoactive medications and cardiopulmonary resuscitation were required in 14 (3.7%) and eight (2.1%) cases, respectively; there was one death. Characteristics associated with use of an invasive airway included age <1 year, Group 3, congenital heart disease, trisomy 21, prematurity, bronchopulmonary dysplasia, WHO functional class III/IV, no PH therapy at time of case, preoperative respiratory support, and having had an intervention (p < 0.05). A composite predictor of age <1 year, Group 3, prematurity, and any preoperative respiratory support was significantly associated with unplanned airway escalation (26.7% vs. 6.9%, odds ratio: 4.9, confidence interval: 1.4-17.0). This approach appears safe, with serious adverse event rates similar to previous reports despite the predominant use of natural airways. However, research is needed to further investigate the optimal anesthetic regimen and respiratory support for pediatric PH patients undergoing cardiac catheterization.

Ketamine, an Old-New Drug: Uses and Abuses

Ketamine as an old-new drug has a variety of clinical implications. In the last 30 years, ketamine has become popular for acute use in humans. Ketamine in standard doses is principally utilized for the induction and maintenance of surgical procedures. Besides its use in anesthesia and analgesia, recent studies have shown that ketamine has found a place in the treatment of asthma, epilepsy, depression, bipolar affective disorders, alcohol and heroin addiction. Ketamine primarily functions as a noncompetitive antagonist targeting the N-methyl-D-aspartate (NMDA) receptor, but its mechanism of action is complex. It is generally regarded as safe, with low doses and short-term use typically not leading to significant adverse effects. Also, ketamine is known as a powerful psychostimulant. During the past decade, ketamine has been one of the commonly abused drugs.

Factors associated with the need for inotropic support following pulmonary artery banding surgery for CHD

OBJECTIVE

We aimed to identify factors independently associated with the need for inotropic support for low cardiac output or haemodynamic instability after pulmonary artery banding surgery for CHD.

METHODS

We performed a retrospective chart review of all neonates and infants who underwent pulmonary banding between January 2016 and June 2019 at our institution. Bivariate and multivariable analyses were performed to identify factors independently associated with the use of post-operative inotropic support, defined as the initiation of inotropic infusion(s) for depressed myocardial function, hypotension, or compromised perfusion within 24 hours of pulmonary artery banding.

RESULTS

We reviewed 61 patients. Median age at surgery was 10 days (25%,75%:7,30). Cardiac anatomy was biventricular in 38 patients (62%), hypoplastic right ventricle in 14 patients (23%), and hypoplastic left ventricle in 9 patients (15%). Inotropic support was implemented in 30 patients (49%). Baseline characteristics of patients who received inotropic support, including ventricular anatomy and pre-operative ventricular function, were not statistically different from the rest of the cohort. Patients who received inotropic support, however, were exposed to larger cumulative doses of ketamine intraoperatively - median 4.0 mg/kg (25%,75%:2.8,5.9) versus 1.8 mg/kg (25%,75%:0.9,4.5), p < 0.001. In a multivariable model, cumulative ketamine dose greater than 2.5mg/kg was associated with post-operative inotropic support (odds ratio 5.5; 95% confidence interval: 1.7,17.8), independent of total surgery time.

CONCLUSIONS

Inotropic support was administered in approximately half of patients who underwent pulmonary artery banding and more commonly occurred in patients who received higher cumulative doses of ketamine intraoperatively, independent of the duration of surgery.

Procedural Sedation in Congenital Heart Disease

Procedural sedation in patients with congenital heart disease (CHD) is associated with significant morbidity and mortality. It is vital for the practitioner to fully understand the complexity of lesions, their hemodynamics, and the impact of medications commonly used for procedural sedation on the stability of systemic vascular resistance and pulmonary flow. According to the literature, we explain the interaction of the systemic vascular resistance and pulmonary flow in such lesions and divide them into five categories outlined in this article: (1) CHDs with left-to-right shunt with normal pulmonary arterial pressure and resistance, (2) CHD with left-to-right shunt and moderate to severe elevation of pulmonary arterial pressure with near-normal pulmonary vascular resistance, (3) CHD with pulmonary flow dependent on systemic vascular resistance, (4) patients with congenital coronary stenosis and coronary anomalies, and 5) aortic obstructive lesions.

Intensive care management of right ventricular failure and pulmonary hypertension crises

Pulmonary hypertension (PH), an often unrelenting disease that carries with it significant morbidity and mortality, affects not only the pulmonary vasculature but, in turn, the right ventricle as well. The survival of patients with PH is closely related to the right ventricular function. Therefore, having an understanding of how to manage right ventricular failure (RVF) and acute pulmonary hypertensive crises is imperative for clinicians who encounter these patients. This review addresses the management of these patients in detail, addressing: (a) the pathophysiology of RVF, (b) intensive care monitoring of these patients in the intensive care unit, (c) imaging of the right ventricle, (d) intubation and mechanical ventilation, (e) inotrope and vasopressor selection, (f) pulmonary vasodilator use, (g) interventional and surgical procedures for the acutely failing right ventricle, and (h) mechanical support for RVF.

Perioperative management of patients with pulmonary hypertension undergoing non-cardiothoracic, non-obstetric surgery: a systematic review and expert consensus statement

BACKGROUND

The risk of complications, including death, is substantially increased in patients with pulmonary hypertension (PH) undergoing anaesthesia for surgical procedures, especially in those with pulmonary arterial hypertension (PAH) and chronic thromboembolic PH (CTEPH). Sedation also poses a risk to patients with PH. Physiological changes including tachycardia, hypotension, fluid shifts, and an increase in pulmonary vascular resistance (PH crisis) can precipitate acute right ventricular decompensation and death.

METHODS

A systematic literature review was performed of studies in patients with PH undergoing non-cardiac and non-obstetric surgery. The management of patients with PH requiring sedation for endoscopy was also reviewed. Using a framework of relevant clinical questions, we review the available evidence guiding operative risk, risk assessment, preoperative optimisation, and perioperative management, and identifying areas for future research.

RESULTS

Reported 30 day mortality after non-cardiac and non-obstetric surgery ranges between 2% and 18% in patients with PH undergoing elective procedures, and increases to 15-50% for emergency surgery, with complications and death usually relating to acute right ventricular failure. Risk factors for mortality include procedure-specific and patient-related factors, especially markers of PH severity (e.g. pulmonary haemodynamics, poor exercise performance, and right ventricular dysfunction). Most studies highlight the importance of individualised preoperative risk assessment and optimisation and advanced perioperative planning.

CONCLUSIONS

With an increasing number of patients requiring surgery in specialist and non-specialist PH centres, a systematic, evidence-based, multidisciplinary approach is required to minimise complications. Adequate risk stratification and a tailored-individualised perioperative plan is paramount.

Changes in ET-1, Plasma Neuropeptide Y, and CGRP in Child Patients With Congenital Heart Disease Complicated With Pulmonary Hypertension Before and After Operation

This study aims to explore the changes in endothelin-1 (ET-1), plasma neuropeptide Y, and calcitonin gene-related peptide (CGRP) in child patients before and after operation. A total of 80 child patients with congenital heart disease (CHD) complicated with pulmonary hypertension (PH) were enrolled and divided into control group (n = 40, conservative treatment for various reasons) and observation group (n = 40, active preoperative preparation and timely operative intervention) according to different treatments. There were positive correlations between systolic pulmonary arterial pressure (sPAP) and ET-1, plasma neuropeptide Y, while negative correlation between sPAP and CGRP. In conclusion, our data demonstrate that the levels of ET-1, plasma neuropeptide Y, and CGRP in PH-CHD were significantly changed after interventions, which provides new leads as alternative biomarkers to assess the efficacy of treatments against PH-CHD.

Perioperative Complications and Clinical Outcomes in Patients with Congenital Cyanotic Heart Disease Undergoing Surgery for Brain Abscess

Background  Brain abscess is a rare neurological complication in patients with congenital cyanotic heart disease (CCHD). Perioperative complications are high in patients with CCHD. We evaluated incidence of and risk factors for perioperative complications and their impact on clinical outcomes in patients with CCHD undergoing brain abscess surgery with monitored anesthesia care (MAC) or general anesthesia (GA).

Methods  In this single-center retrospective cohort study, data were collected from consecutive patients with CCHD who presented with brain abscess and underwent surgery from January 2006 to December 2018. Data regarding demographics, type of CCHD, signs and symptoms of brain abscess and CCHD, type and duration of surgery, details of anesthesia, perioperative complications, and clinical outcomes were collected. Chi-square test was used to analyze nonparametric data and student t -test for parametric data.

Results  Of the 402 patients with brain abscess, data of 34 patients with CCHD who underwent brain abscess surgery were analyzed. The mean age at presentation of brain abscess was 15.8 ± 10.8 years and duration of symptoms was 17.3 ± 15.5 days. The incidence of perioperative complications was 82.4% (28/34 patients). Seven patients (20.6%) developed perioperative cyanotic spells which led to cardiac arrest in 5 patients (14.7%) and death in 2 patients (5.9%). Patients on cardiac medications and with high heart rate had higher incidence of cyanotic spells and mortality. Technique of anesthesia did not affect cardiac and neurological outcome.

Conclusions  Perioperative complications are high after brain abscess surgery in patients with CCHD. Perioperative characteristics and outcomes were similar with MAC and GA techniques.

Factors Affecting Cardiovascular Physiology in Cardiothoracic Surgery: Implications for Lumped-Parameter Modeling

Cardiothoracic surgeries are complex procedures during which the patient cardiovascular physiology is constantly changing due to various factors. Physiological changes begin with the induction of anesthesia, whose effects remain active into the postoperative period. Depending on the surgery, patients may require the use of cardiopulmonary bypass and cardioplegia, both of which affect postoperative physiology such as cardiac index and vascular resistance. Complications may arise due to adverse reactions to the surgery, causing hemodynamic instability. In response, fluid resuscitation and/or vasoactive agents with varying effects may be used in the intraoperative or postoperative periods to improve patient hemodynamics. These factors have important implications for lumped-parameter computational models which aim to assist surgical planning and medical device evaluation. Patient-specific models are typically tuned based on patient clinical data which may be asynchronously acquired through invasive techniques such as catheterization, during which the patient may be under the effects of drugs such as anesthesia. Due to the limited clinical data available and the inability to foresee short-term physiological regulation, models often retain preoperative parameters for postoperative predictions; however, without accounting for the physiologic changes that may occur during surgical procedures, the accuracy of these predictive models remains limited. Understanding and incorporating the effects of these factors in cardiovascular models will improve the model fidelity and predictive capabilities.