Reduction of pulmonary edema after SAH with a pulmonary artery catheter-guided hemodynamic management protocol

Emergency Medical Management of Aneurysmal Subarachnoid Hemorrhage

Aneurysmal subarachnoid hemorrhage is a medical emergency that necessitates direct transfer to a tertiary referral center specialized in the diagnosis and treatment of this condition. The initial hours after aneurysmal rupture are critical for patients with aneurysmal subarachnoid hemorrhage, both in terms of rebleeding and combating the effect of early brain injury. No good treatment options are available to reduce the risk of rebleeding before aneurysm occlusion. Lowering the blood pressure may reduce the risk of rebleeding but carries a risk of inducing delayed cerebral ischemia or aggravating the consequences of early brain injury. Early brain injury after aneurysmal rupture has an important effect on final clinical outcome. Proper cerebral perfusion is pivotal in these initial hours after aneurysmal rupture but threatened by complications such as neurogenic pulmonary edema and cardiac stunning, or by acute hydrocephalus, which may necessitate early drainage of cerebrospinal fluid.

The Use of Standardized Management Protocols for Critically Ill Patients with Non-traumatic Subarachnoid Hemorrhage: A Systematic Review

The use of standardized management protocols (SMPs) may improve patient outcomes for some critical care diseases. Whether SMPs improve outcomes after subarachnoid hemorrhage (SAH) is currently unknown. We aimed to study the effect of SMPs on 6-month mortality and neurologic outcomes following SAH. A systematic review of randomized control trials (RCTs) and observational studies was performed by searching multiple indexing databases from their inception through January 2019. Studies were limited to adult patients (age ≥ 18) with non-traumatic SAH reporting mortality, neurologic outcomes, delayed cerebral ischemia (DCI) and other important complications. Data on patient and SMP characteristics, outcomes and methodologic quality were extracted into a pre-piloted collection form. Methodologic quality of observational studies was assessed using the Newcastle-Ottawa scale, and RCT quality was reported as per the Cochrane risk of bias tool. A total of 11,260 studies were identified, of which 37 (34 full-length articles and 3 abstracts) met the criteria for inclusion. Two studies were RCTs and 35 were observational. SMPs were divided into four broad domains: management of acute SAH, early brain injury, DCI and general neurocritical care. The most common SMP design was control of DCI, with 22 studies assessing this domain of care. Overall, studies were of low quality; most described single-center case series with small patient sizes. Definitions of key terms and outcome reporting practices varied significantly between studies. DCI and neurologic outcomes in particular were defined inconsistently, leading to significant challenges in their interpretation. Given the substantial heterogeneity in reporting practices between studies, a meta-analysis for 6-month mortality and neurologic outcomes could not be performed, and the effect of SMPs on these measures thus remains inconclusive. Our systematic review highlights the need for large, rigorous RCTs to determine whether providing standardized, best-practice management through the use of a protocol impacts outcomes in critically ill patients with SAH.Trial registration Registration number: CRD42017069173.

Bioreactance-Based Noninvasive Fluid Responsiveness and Cardiac Output Monitoring: A Pilot Study in Patients with Aneurysmal Subarachnoid Hemorrhage and Literature Review

Management of volume status, arterial blood pressure, and cardiac output are core elements in approaching the patients with aneurysmal subarachnoid hemorrhage (SAH). For the prevention and treatment of delayed cerebral ischemia (DCI), euvolemia is advocated and caution is made towards the avoidance of hypervolemia. Induced hypertension and cardiac output augmentation are the mainstays of medical management during active DCI, whereas the older triple-H paradigm has fallen out of favor due to lack of demonstrable physiological or clinical benefits and serious concern for adverse effects such as pulmonary edema and multiorgan system dysfunction. Furthermore, insight into clinical hemodynamics of patients with SAH becomes salient when one considers the frequently associated cardiac and pulmonary manifestations of the disease such as SAH-associated cardiomyopathy and neurogenic pulmonary edema. In terms of fluid and volume targets, less attention has been paid to dynamic markers of fluid responsiveness despite the well-established, in the general critical care literature, superiority of these as compared to traditionally used static markers such as central venous pressure (CVP). Based on this literature and sound pathophysiologic reasoning, reliance on static markers (such as CVP) is unjustified when one attempts to assess strategies augmenting stroke volume (SV), arterial blood pressure, and oxygen delivery. There are several options for continuous bedside cardiorespiratory monitoring and optimization of SAH patients. We, here, review a noninvasive monitoring technique based on thoracic bioreactance and focusing on continuous cardiac output and fluid responsiveness markers.

High Early Fluid Input After Aneurysmal Subarachnoid Hemorrhage: Combined Report of Association With Delayed Cerebral Ischemia and Feasibility of Cardiac Output-Guided Fluid Restriction

BACKGROUND

Guidelines on the management of aneurysmal subarachnoid hemorrhage (aSAH) recommend euvolemia, whereas hypervolemia may cause harm. We investigated whether high early fluid input is associated with delayed cerebral ischemia (DCI), and if fluid input can be safely decreased using transpulmonary thermodilution (TPT).

METHODS

We retrospectively included aSAH patients treated at an academic intensive care unit (2007-2011; cohort 1) or managed with TPT (2011-2013; cohort 2). Local guidelines recommended fluid input of 3 L daily. More fluids were administered when daily fluid balance fell below +500 mL. In cohort 2, fluid input in high-risk patients was guided by cardiac output measured by TPT per a strict protocol. Associations of fluid input and balance with DCI were analyzed with multivariable logistic regression (cohort 1), and changes in hemodynamic indices after institution of TPT assessed with linear mixed models (cohort 2).

RESULTS

Cumulative fluid input 0 to 72 hours after admission was associated with DCI in cohort 1 (n=223; odds ratio [OR] 1.19/L; 95% confidence interval 1.07-1.32), whereas cumulative fluid balance was not. In cohort 2 (23 patients), using TPT fluid input could be decreased from 6.0 ± 1.0 L before to 3.4 ± 0.3 L; P = .012), while preload parameters and consciousness remained stable.

CONCLUSION

High early fluid input was associated with DCI. Invasive hemodynamic monitoring was feasible to reduce fluid input while maintaining preload. These results indicate that fluid loading beyond a normal preload occurs, may increase DCI risk, and can be minimized with TPT.

High Early Fluid Input After Aneurysmal Subarachnoid Hemorrhage: Combined Report of Association With Delayed Cerebral Ischemia and Feasibility of Cardiac Output-Guided Fluid Restriction

BACKGROUND

Guidelines on the management of aneurysmal subarachnoid hemorrhage (aSAH) recommend euvolemia, whereas hypervolemia may cause harm. We investigated whether high early fluid input is associated with delayed cerebral ischemia (DCI), and if fluid input can be safely decreased using transpulmonary thermodilution (TPT).

METHODS

We retrospectively included aSAH patients treated at an academic intensive care unit (2007-2011; cohort 1) or managed with TPT (2011-2013; cohort 2). Local guidelines recommended fluid input of 3 L daily. More fluids were administered when daily fluid balance fell below +500 mL. In cohort 2, fluid input in high-risk patients was guided by cardiac output measured by TPT per a strict protocol. Associations of fluid input and balance with DCI were analyzed with multivariable logistic regression (cohort 1), and changes in hemodynamic indices after institution of TPT assessed with linear mixed models (cohort 2).

RESULTS

Cumulative fluid input 0 to 72 hours after admission was associated with DCI in cohort 1 (n=223; odds ratio [OR] 1.19/L; 95% confidence interval 1.07-1.32), whereas cumulative fluid balance was not. In cohort 2 (23 patients), using TPT fluid input could be decreased from 6.0 ± 1.0 L before to 3.4 ± 0.3 L; P = .012), while preload parameters and consciousness remained stable.

CONCLUSION

High early fluid input was associated with DCI. Invasive hemodynamic monitoring was feasible to reduce fluid input while maintaining preload. These results indicate that fluid loading beyond a normal preload occurs, may increase DCI risk, and can be minimized with TPT.

Advanced monitoring of systemic hemodynamics in critically ill patients with acute brain injury

Hemodynamic monitoring is widely used in critical care; however, the impact of such intervention in patients with acute brain injury (ABI) remains unclear. Using PubMed, a systematic review was performed (1966-August 2013), and 118 studies were included. Data were extracted using the PICO approach. The evidence was classified, and recommendations were developed according to the GRADE system. Electrocardiography and invasive monitoring of arterial blood pressure should be the minimal hemodynamic monitoring required in unstable or at-risk patients in the intensive care unit. Advanced hemodynamic monitoring (i.e., assessment of preload, afterload, cardiac output, and global systemic perfusion) could help establish goals that take into account cerebral blood flow and oxygenation, which vary depending on diagnosis and disease stage. Choice of techniques for assessing preload, afterload, cardiac output, and global systemic perfusion should be guided by specific evidence and local expertise. Hemodynamic monitoring is important and has specific indications among ABI patients. Further data are necessary to understand its potential for therapeutic interventions and prognostication.

Current options for the management of aneurysmal subarachnoid hemorrhage-induced cerebral vasospasm: a comprehensive review of the literature

OBJECTIVES

Cerebral vasospasm is one of the leading causes of morbi-mortality following aneurysmal subarachnoid hemorrhage. The aim of this article is to discuss the current status of vasospasm therapy with emphasis on endovascular treatment.

METHODS

A comprehensive review of the literature obtained by a PubMed search. The most relevant articles related to medical, endovascular and alternative therapies were selected for discussion.

RESULTS

Current accepted medical options include the oral nimodipine and 'triple-H' therapy (hypertension, hypervolemia and hemodilution). Nimodipine remains the only modality proven to reduce the incidence of infarction. Although widely used, 'triple-H' therapy has not been demonstrated to significantly change overall outcome after cerebral vasospasm. Indeed, both induced hypervolemia and hemodilution may have deleterious effects, and more recent physiologic data favor normovolemia with induced hypertension or optimization of cardiac output. Endovascular options include percutaneous transluminal balloon angioplasty (PTA) and intra-arterial (IA) infusion of vasodilators. Multiple case reports and case series have been encountered in the literature using different drug regimens with diverse mechanisms of action. Compared with PTA, IA drug infusion has the advantages of distal penetration and a better safety profile. Its main disadvantages are the more frequent need for repeat treatments and its systemic hemodynamic repercussions. Alternative options using intraventricular/cisternal drug therapy and flow augmentation strategies have also shown possible benefits; however, their use is not yet as well established.

CONCLUSION

Blood pressure or cardiac output optimization should be the mainstay of hyperdynamic therapy. Endovascular treatment appears to have a positive impact on neurological outcome compared with the natural history of the disease. The role of intraventricular therapy and flow augmentation strategies in association with medical and endovascular treatment may, in the future, play a growing role in the management of patients with severe refractory vasospasm.

Risk Factors, Incidence, and Effect of Cardiac Failure and Myocardial Infarction in Aneurysmal Subarachnoid Hemorrhage Patients

BACKGROUND:

Cardiac dysfunction is a well-known complication of aneurysmal subarachnoid hemorrhage (aSAH). However, the clinical significance of cardiac complications is largely unknown.

OBJECTIVE:

To determine whether cardiac complications are independently related to outcomes and to identify potential predictors associated with these complications.

METHODS:

We extracted all hospitalizations for aSAH from the National Inpatient Sample database for years 2002 to 2009. We used generalized estimating equations to determine whether cardiac complications were associated with the patient outcomes and to evaluate potential predictors of cardiac complications.

RESULTS:

Among 53 713 cases of aSAH, there were 3609 (6.72%) and 151 (0.28%) incidences of cardiac failure (CF) and myocardial infarction (MI), respectively. The overall in-hospital mortality rate was 24.8%, whereas the mortality rate for patients with CF was 34.4% and the mortality rate for patients with MI was 29.8%. Patients who experienced CF were significantly more likely than other patients to die in the hospital (odds ratio: 1.6, 95% confidence interval: 1.47-1.68; P < .001). The difference in mortality rates between MI patients and other patients, however, was not statistically significant. The generalized estimating equation model identified 7 factors that were predictive of CF: age, sex, race, primary payer, diabetes, smoker, and cardiac disease. For MI, the model identified age, race, and primary payer as significant predictors of MI.

CONCLUSION:

Our results suggest that an important association exists between cardiac complications and mortality/morbidity in aSAH patients. aSAH patients with CF appear to have a higher mortality rate, longer hospital length of stay, and higher hospitalization costs compared with those without CF.

Patterns in neurosurgical adverse events: open cerebrovascular neurosurgery

OBJECT

As part of a project to devise evidence-based safety interventions for specialty surgery, we sought to review current evidence concerning the frequency of adverse events in open cerebrovascular neurosurgery and the state of knowledge regarding methods for their reduction. This review represents part of a series of papers written to consolidate information about these events and preventive measures as part of an ongoing effort to ascertain the utility of devising system-wide policies and safety tools to improve neurosurgical practice.

METHODS

The authors performed a PubMed search using search terms "cerebral aneurysm", "cerebral arteriovenous malformation", "intracerebral hemorrhage", "intracranial hemorrhage", "subarachnoid hemorrhage", and "complications" or "adverse events." Only papers that specifically discussed the relevant complication rates were included. Papers were chosen to be included to maximize the range of rates of occurrence for the reported adverse events.

RESULTS

The review revealed hemorrhage-related hyperglycemia (incidence rates ranging from 27% to 71%) and cerebral salt-wasting syndromes (34%-57%) to be the most common perioperative adverse events related to subarachnoid hemorrhage (SAH). Next in terms of frequency was new cerebral infarction associated with SAH, with a rate estimated at 40%. Many techniques are advocated for use during surgery to minimize risk of this development, including intraoperative neurophysiological monitoring, but are not universally used due to surgeon preference and variable availability of appropriate staffing and equipment. The comparative effectiveness of using or omitting monitoring technologies has not been evaluated. The incidence of perioperative seizure related to vascular neurosurgery is unknown, but reported seizure rates from observational studies range from 4% to 42%. There are no standard guidelines for the use of seizure prophylaxis in these patients, and there remains a need for prospective studies to support such guidelines. Intraoperative rupture occurs at a rate of 7% to 35% and depends on aneurysm location and morphology, history of rupture, surgical technique, and surgeon experience. Preventive strategies include temporary vascular clipping. Technical adverse events directly involving application of the aneurysm clip include incomplete aneurysm obliteration and parent vessel occlusion. The rates of these events range from 5% to 18% for incomplete obliteration and 3% to 12% for major vessel occlusion. Intraoperative angiography is widely used to confirm clip placement; adjuncts include indocyanine green video angiography and microvascular Doppler ultrasonography. Use of these technologies varies by institution.

DISCUSSION

A significant proportion of these complications may be avoidable through development and testing of standardized protocols to incorporate monitoring technologies and specific technical practices, teamwork and communication, and concentrated volume and specialization. Collaborative monitoring and evaluation of such protocols are likely necessary for the advancement of open cerebrovascular neurosurgical quality.

[Cardiac complications of acute brain injury]

The clinical importance of cardiovascular consequences resulting from cerebral injury has long been recognized. However, interactions between the brain and the cardiovascular system remain poorly defined and their importance for the management of patients suffering from acute brain injury is largely underestimated. This should have profound consequences on treatment strategies during anaesthesia and intensive cares of these patients, taking into account not only brain perfusion, but also cardiovascular optimisation. This report summarizes the main data available regarding the cardiovascular consequences of brain death, traumatic brain injury, stroke and epilepsy.

Perioperative hypothermia (33 degrees C) does not increase the occurrence of cardiovascular events in patients undergoing cerebral aneurysm surgery: findings from the Intraoperative Hypothermia for Aneurysm Surgery Trial

BACKGROUND

Perioperative hypothermia has been reported to increase the occurrence of cardiovascular complications. By increasing the activity of sympathetic nervous system, perioperative hypothermia also has the potential to increase cardiac injury and dysfunction associated with subarachnoid hemorrhage.

METHODS

The Intraoperative Hypothermia for Aneurysm Surgery Trial randomized patients undergoing cerebral aneurysm surgery to intraoperative hypothermia (n = 499, 33.3 degrees +/- 0.8 degrees C) or normothermia (n = 501, 36.7 degrees +/- 0.5 degrees C). Cardiovascular events (hypotension, arrhythmias, vasopressor use, myocardial infarction, and others) were prospectively followed until 3-month follow-up and were compared in hypothermic and normothermic patients. A subset of 62 patients (hypothermia, n = 33; normothermia, n = 29) also had preoperative and postoperative (within 24 h) measurement of cardiac troponin-I and echocardiography to explore the association between perioperative hypothermia and subarachnoid hemorrhage-associated myocardial injury and left ventricular function.

RESULTS

There was no difference between hypothermic and normothermic patients in the occurrence of any single cardiovascular event or in composite cardiovascular events. There was no difference in mortality (6%) between groups, and there was only a single primary cardiovascular death (normothermia). There was no difference between hypothermic and normothermic patients in postoperative versus preoperative left ventricular regional wall motion or ejection fraction. Compared with preoperative values, hypothermic patients had no postoperative increase in cardiac troponin-I (median change 0.00 microg/l), whereas normothermic patients had a small postoperative increase (median change + 0.01 microg/l, P = 0.038).

CONCLUSION

In patients undergoing cerebral aneurysm surgery, perioperative hypothermia was not associated with an increased occurrence of cardiovascular events.

Medical complications after subarachnoid hemorrhage

The prevention and management of medical complications are important for improving outcomes after subarachnoid hemorrhage (SAH). Fever, anemia requiring transfusion, hyperglycemia, hyponatremia, pneumonia, hypertension, and neurogenic cardiopulmonary dysfunction occur frequently after SAH. There is increasing evidence that acute hypoxia and extremes of blood pressure can exacerbate brain injury during the acute phase of bleeding. There are promising strategies to minimize these complications. Randomized controlled trials are needed to evaluate the risks and benefits of these and other medical management strategies after SAH.

Performance of bedside transpulmonary thermodilution monitoring for goal-directed hemodynamic management after subarachnoid hemorrhage

BACKGROUND AND PURPOSE

Early goal-directed hemodynamic therapy is of particular importance for adequate cerebral circulation of patients with vasospasm after subarachnoid hemorrhage but is often precluded by the invasiveness of established cardiac output determination using a pulmonary artery catheter. This study was undertaken to validate the usefulness of less invasive goal-directed hemodynamic monitoring by transpulmonary thermodilution technique in patients after subarachnoid hemorrhage.

METHODS

One hundred sixteen patients with subarachnoid hemorrhage who underwent surgical clipping within 24 hours of ictus were investigated. Validation of transpulmonary thermodilution-derived intermittent/continuous cardiac output and cardiac preload (global end diastolic volume) were compared with pulmonary artery catheter-derived reference cardiac output and pulmonary capillary wedge pressure or central venous pressure in 16 patients diagnosed with vasospasm. In a subsequent trial of 100 consecutive cases, clinical results between the new and standard management paradigms were compared.

RESULTS

Transpulmonary thermodilution-derived intermittent cardiac output and transpulmonary thermodilution-derived continuous cardiac output showed close agreement to catheter-derived reference cardiac output with high correlation (r=0.85 and 0.77) and low percentage error (13.5% and 18.0%). Fluid responsiveness to defined volume loading was predicted better with global end diastolic volume than with pulmonary capillary wedge pressure and central venous pressure for larger receiver operating characteristic curve area. Patients receiving early goal-directed management by transpulmonary thermodilution experienced reduced frequencies of vasospasm and cardiopulmonary complications compared with those managed with standard therapy (P<0.05), whereas their functional outcomes at 3 months were not different (P=0.06).

CONCLUSIONS

Goal-directed hemodynamic management guided by transpulmonary thermodilution appears to have a therapeutic advantage for optimizing the prognosis of patients with subarachnoid hemorrhage with vasospasm over conventional methods.

Death from cardiac failure in a child with ruptured cerebral arteriovenous malformation

We present the case of a 13-year-old boy with a ruptured cerebral arteriovenous malformation who had rapidly progressive cardiac failure leading to death. Serial electrocardiograms, cardiac enzymes, echocardiograms, and pulmonary artery catheter data confirmed severe ventricular dysfunction related to myocardial ischemia and infarction. Cardiac dysfunction after cerebral insult is commonly described in adults with aneurysmal subarachnoid hemorrhage and has been termed "neurogenic stunned myocardium" because of its transient nature in most of patients. In children, cardiovascular dysfunction has been described in a few reports and only after traumatic brain injury. No deaths have been reported. This case report illustrates the potentially lethal consequences of cardiovascular dysfunction in children after ruptured cerebral arteriovenous malformation with subarachnoid hemorrhage. Compromised cardiac function should be considered during the early evaluation and management of these patients and supportive care instituted to limit secondary brain injury from poor perfusion.

Medical complications after subarachnoid hemorrhage: new strategies for prevention and management

PURPOSE OF REVIEW

To summarize new concepts regarding the occurrence, prevention, and management of medical complications following subarachnoid hemorrhage.

RECENT FINDINGS

Data regarding the impact of common medical complications after subarachnoid hemorrhage on delayed cerebral ischemia and neurological outcome after subarachnoid hemorrhage are available from recent outcomes studies. Fever, anemia requiring transfusion, hyperglycemia, electrolyte abnormalities, pneumonia, hypertension, and neurogenic stunned myocardium and pulmonary edema occur frequently after subarachnoid hemorrhage. Fever, anemia, hyperglycemia, and acute hypoxia and hypotension related to neurogenic stunned myocardium have the greatest impact on mortality and functional outcome after subarachnoid hemorrhage. Potential treatment interventions for these complications include the development of acute resuscitation strategies to optimize cerebral perfusion in poor-grade patients, maintaining normothermia with systemic cooling devices, administration of erythropoietin to prevent severe anemia, preserving normoglycemia with continuous insulin infusions, and goal-directed hemodynamic support guided by brain tissue oxygenation.

SUMMARY

Clinical trials to investigate interventions targeted at preventing or treating common medical complications after subarachnoid hemorrhage are needed.