Coupling of Central Venous Pressure and Intracranial Pressure in a 6-Year-Old Patient With Fontan Circulation and Intracranial Hemorrhage

Risk Factors for Thromboembolic and Bleeding Events in Patients After the Fontan Operation (Insights from the National Database of Health Insurance Claims of Japan)

Risk stratification of thromboembolic events (TEs) and bleeding events is important for the appropriate selection of thromboprophylaxis in patients after the Fontan operation. Therefore, we clarified the risk factors for TEs and bleeding events in patients after the Fontan operation using the National Database of Health Insurance Claims and Specific Health Checkups of Japan. We conducted a retrospective cohort study including 2,515 patients who underwent the Fontan operation between June 2011 and September 2019. The end points were TEs and bleeding events within 1 year of the Fontan operation analysis. We analyzed the risk factors for these end points using a multivariate analysis. In total, 1,903 patients were included in the analysis. The median age at the time of the Fontan operation was 3 (1 to 22) years, and 1,067 patients (56%) were male. The incidence rates of TEs and bleeding events were 12% and 11%, respectively. Age (odds ratio [OR] 1.1 per 1 year older, p <0.05) was an independent risk factor for TEs. Thromboprophylaxis with aspirin after the Fontan operation significantly reduced TEs (OR 0.3, p <0.05). A history of postoperative hemorrhage (OR 1.5, p <0.05) and the use of a potassium channel blocker (OR 2.1, p <0.05) were independent risk factors for bleeding events. In conclusion, aspirin was found to reduce the risk of TEs within 1 year of the Fontan operation. The results of this study will be useful in selecting effective and safe thromboprophylaxis in patients after the Fontan operation.

Effect of increased positive end-expiratory pressure on intracranial pressure and cerebral oxygenation: impact of respiratory mechanics and hypovolemia

BACKGROUND

To evaluate the impact of positive end-expiratory pressure (PEEP) on intracranial pressure (ICP) in animals with different respiratory mechanics, baseline ICP and volume status.

METHODS

A total of 50 male adult Bama miniature pigs were involved in four different protocols (n = 20, 12, 12, and 6, respectively). Under the monitoring of ICP, brain tissue oxygen tension and hemodynamical parameters, PEEP was applied in increments of 5 cm H₂O from 5 to 25 cm H₂O. Measurements were taken in pigs with normal ICP and normovolemia (Series I), or with intracranial hypertension (via inflating intracranial balloon catheter) and normovolemia (Series II), or with intracranial hypertension and hypovolemia (via exsanguination) (Series III). Pigs randomized to the control group received only hydrochloride instillation while the intervention group received additional chest wall strapping. Common carotid arterial blood flow before and after exsanguination at each PEEP level was measured in pigs with intracranial hypertension and chest wall strapping (Series IV).

RESULTS

ICP was elevated by increased PEEP in both normal ICP and intracranial hypertension conditions in animals with normal blood volume, while resulted in decreased ICP with PEEP increments in animals with hypovolemia. Increasing PEEP resulted in a decrease in brain tissue oxygen tension in both normovolemic and hypovolemic conditions. The impacts of PEEP on hemodynamical parameters, ICP and brain tissue oxygen tension became more evident with increased chest wall elastance. Compare to normovolemic condition, common carotid arterial blood flow was further lowered when PEEP was raised in the condition of hypovolemia.

CONCLUSIONS

The impacts of PEEP on ICP and cerebral oxygenation are determined by both volume status and respiratory mechanics. Potential conditions that may increase chest wall elastance should also be ruled out to avoid the deleterious effects of PEEP.

Characteristics of Patients With Congenital Heart Disease Requiring ICU Admission From Japanese Emergency Departments

OBJECTIVES

To evaluate the characteristics of patients with congenital heart disease requiring ICU admission from emergency departments and determine the associations between the reasons for emergency department visits and specific congenital heart disease types or cardiac procedures.

DESIGN

Retrospective observational study using data from a Japanese multicenter database.

SETTING

Twelve PICUs and 11 general ICUs in Japan.

PATIENTS

All patients requiring ICU admission from an emergency department during 2013-2018, divided into two groups: with congenital heart disease and without congenital heart disease groups.

INTERVENTIONS

None for this analysis.

MEASUREMENTS AND MAIN RESULTS

Of the 297 patients with congenital heart disease (9.2% of a total of 3,240 patients), more than half had moderate-to-high complexity congenital heart disease; most of them were pediatric patients who had visited specialized congenital heart disease centers. All the patients' clinical outcomes were similar. Regarding the reasons for emergency department admission, seizure was significantly associated with a single ventricle anatomy (odds ratio, 3.3; 95% CI, 1.1-10.0), post-Glenn shunt placement (odds ratio, 5.6; 95% CI, 1.1-29.4), and a Fontan-type operation status (odds ratio, 6.3; 95% CI, 1.5-25.5). Sepsis and gastrointestinal bleeding were associated with asplenia (odds ratio, 21.1; 95% CI, 4.3-104 and odds ratio, 21.0; 95% CI, 3.1-141, respectively); gastrointestinal bleeding was also associated with systemic-to-pulmonary artery shunt placement (odds ratio, 18.8; 95% CI, 2.8-125) and a Fontan-type operation status (odds ratio, 17.0; 95% CI, 2.6-112). Arrhythmia was associated with a single ventricle anatomy (odds ratio, 21.0; 95% CI, 3.1-141), systemic-to-pulmonary artery shunt placement (odds ratio, 18.8; 95% CI, 2.8-125), and a Fontan-type operation status (odds ratio, 17.0; 95% CI, 2.6-112).

CONCLUSIONS

Classification of the reasons for emergency department admission by congenital heart disease type and surgical stage may guide clinicians in the selection of appropriate treatments in such settings.

Monitoring of central venous pressure and stroke volume variation in a case with a ruptured brain arteriovenous malformation and Fontan circulation

Background

Patients with complex congenital heart disease increasingly undergo noncardiac surgeries because of advancements in surgical techniques and medical management. In Fontan circulation, maintaining an adequate transpulmonary gradient is essential for preserving both pulmonary blood flow and cardiac output. However, intraoperative circulatory monitoring of Fontan patients has not been established.

Case presentation

A 17-year-old girl required an emergency craniotomy for ruptured arteriovenous malformation. She had a surgical history of bidirectional Glenn operation and Fontan palliation for her congenital hypoplastic left heart syndrome and double outlet right ventricle. We performed general anesthesia with continuous monitoring of central venous pressure (CVP) and stroke volume variation (SVV). Transesophageal echocardiography was not conducted because of difficulty in manipulating the probe due to the patient's position and surgical setting. After incision of the dura, approximately 1700 ml of rapid blood loss from the arteriovenous malformation was observed in 30 min. In this period, CVP decreased from 15 to 5 mmHg or less. In contrast, there was only a slight rise in SVV from 5 to 8%. We rapidly administered fluid and then transfused blood, and CVP gradually recovered to 10-15 mmHg. During the surgery, circulatory collapse was not observed. The patient was transferred to the intensive care unit under sedation and controlled ventilation.

Conclusions

CVP decreased sharply, whereas SVV rose only slightly during acute bleeding in the present case. CVP monitoring may have been useful for the management of an acute bleeding case with a Fontan circulation but SVV may not have been reliable. As more patients with a Fontan circulation undergo noncardiac surgeries, appropriate circulatory monitoring in these patients should be further investigated.

Fluid management of the neurological patient: a concise review

Maintenance fluids in critically ill brain-injured patients are part of routine critical care. Both the amounts of fluid volumes infused and the type and tonicity of maintenance fluids are relevant in understanding the impact of fluids on the pathophysiology of secondary brain injuries in these patients. In this narrative review, current evidence on routine fluid management of critically ill brain-injured patients and use of haemodynamic monitoring is summarized. Pertinent guidelines and consensus statements on fluid management for brain-injured patients are highlighted. In general, existing guidelines indicate that fluid management in these neurocritical care patients should be targeted at euvolemia using isotonic fluids. A critical appraisal is made of the available literature regarding the appropriate amount of fluids, haemodynamic monitoring and which types of fluids should be administered or avoided and a practical approach to fluid management is elaborated. Although hypovolemia is bound to contribute to secondary brain injury, some more recent data have emerged indicating the potential risks of fluid overload. However, it is acknowledged that many factors govern the relationship between fluid management and cerebral blood flow and oxygenation and more research seems warranted to optimise fluid management and improve outcomes.

Clinical Evaluation of the Hemodynamic Effects of the High-Flow Nasal Cannula Therapy on the Fontan Circulation

High-flow nasal cannula (HFNC) therapy supports respiratory effort with a minimal elevation in airway pressure. We examined hemodynamic effects of HFNC therapy in a 10-year-old girl with Fontan circulation, in which positive airway pressure has deleterious hemodynamic effects. The HFNC therapy at 30 L/min improved oxygenation without an increase in central venous pressure. It also reduced heart rate, and systemic and pulmonary vascular resistance, and increased cardiac output. In addition, the HFNC therapy improved the cerebral circulation measured by near-infrared spectroscopy. Thus, HFNC therapy may be a potentially useful noninvasive ventilation modality, particularly for patients with Fontan circulation.

Aldosterone-cortisol imbalance immediately after fontan operation with implications for abnormal fluid homeostasis

Abnormal water metabolism is frequently observed after Fontan surgery. We hypothesized that patients' adrenal hormones show unique responses immediately after Fontan operation and that such a hormonal profile is related to postoperative hemodynamics and water imbalance. Twenty-eight patients who underwent a Fontan operation (n = 16) or a non-Fontan type operation (n = 12; controls) under cardiopulmonary bypass were studied. Postoperative urine cortisol and aldosterone levels were measured daily to minimize the influence of circadian rhythms and temporal hemodynamic variations. Cortisol excretion was markedly elevated on postoperative day (POD) 0 in controls, consistent with a stress-induced cortisol response. Cortisol excretion was not high on POD 0 in Fontan patients and was markedly lower than that in the controls (444 ± 150 vs 34 ± 6 μg/m(2)/day, p <0.05), indicating an adrenal insufficiency status. Conversely, aldosterone levels were significantly higher in Fontan patients than in controls immediately after surgery and remained so thereafter. The cortisol-to-aldosterone ratio was significantly lower in Fontan patients on POD 0 (p <0.05 vs controls); low cortisol-to-aldosterone ratios were associated with a longer pleural drainage duration and intensive care unit stay. Daily cortisol and aldosterone levels were significantly associated with postoperative hemodynamics; low cortisol levels correlated with low cardiac and urine outputs, whereas high aldosterone levels correlated with low cardiac output and increased blood pressure and central venous pressure. Thus, aldosterone-to-cortisol imbalance occurred specifically after the Fontan operation. This unique hormonal profile significantly affected patients' postoperative water balance and hemodynamics. Modulation of the adrenal hormone could be useful for reducing postoperative complications after the Fontan operation.

Pseudotumor cerebri associated with modified Fontan anatomy

Surgical treatment of functional single-ventricle heart disease with a modified Fontan procedure results in elevated central venous pressure. The case report describes a 19-year-old boy with hypoplastic left heart syndrome and Fontan palliation that resulted in frequent debilitating headaches after transcatheter closure of systemic venous-to-pulmonary venous collaterals. Measured increased intracranial pressure and prompt relief of the headaches with lumbar puncture favored a diagnosis of pseudotumor cerebri. After implantation of a lumboperitoneal shunt, the patient's headaches improved dramatically. Headaches are frequent in patients with Fontan circulation. The current literature supports a pivotal role of elevated dural venous sinus pressure in the pathogenesis of pseudotumor cerebri. The high superior and inferior vena caval pressures characteristic of modified Fontan anatomy may account for headaches in some of these patients.

Postoperative acute anisocoria and old traumatic brain injury

Anisocoria is an uncommon entity in general postoperative intensive care. We present a case of a 45-year-old man suffering from severe acute pancreatitis with a past history of traumatic brain injury (TBI), who developed hypertension, bradycardia and anisocoria soon after re-exploration surgery under general anaesthesia. Computed tomography showed no new lesion. Measures directed towards reducing intracranial pressure resulted in amelioration in about 12h. The possible role of old TBI in the causation of anisocoria during general anaesthesia and resuscitation has been explored in this report.