Clinical observation of the time course of raised intracranial pressure after subarachnoid hemorrhage

Intracranial Pressure Monitoring and Management in Aneurysmal Subarachnoid Hemorrhage

Aneurysmal subarachnoid hemorrhage is a medical condition that can lead to intracranial hypertension, negatively impacting patients' outcomes. This review article explores the underlying pathophysiology that causes increased intracranial pressure (ICP) during hospitalization. Hydrocephalus, brain swelling, and intracranial hematoma could produce an ICP rise. Although cerebrospinal fluid withdrawal via an external ventricular drain is commonly used, ICP monitoring is not always consistently practiced. Indications for ICP monitoring include neurological deterioration, hydrocephalus, brain swelling, intracranial masses, and the need for cerebrospinal fluid drainage. This review emphasizes the importance of ICP monitoring and presents findings from the Synapse-ICU study, which supports a correlation between ICP monitoring and treatment with better patient outcomes. The review also discusses various therapeutic strategies for managing increased ICP and identifies potential areas for future research.

Oxidative Stress and Intracranial Hypertension after Aneurysmal Subarachnoid Hemorrhage

Intracranial hypertension is a common phenomenon in patients with aneurysmal subarachnoid hemorrhage (aSAH). Elevated intracranial pressure (ICP) plays an important role in early brain injuries and is associated with unfavorable outcomes. Despite advances in the management of aSAH, there is no consensus about the mechanisms involved in ICP increases after aSAH. Recently, a growing body of evidence suggests that oxidative stress (OS) may play a crucial role in physio-pathological changes following aSAH, which may also contribute to increased ICP. Herein, we discuss a potential relation between increased ICP and OS, and resultantly propose antioxidant mechanisms as a potential therapeutic strategy for the treatment of ICP elevation following aSAH.

Intracranial Pressure Monitoring in Poor-Grade Patients with Aneurysmal Subarachnoid Hemorrhage Treated by Coiling

OBJECTIVE

The main objective of the present study was to analyze the intracranial pressure (ICP) and cerebral perfusion pressure (CPP) changes during coiling. We also evaluated the prevalence of rebleeding and outcomes for patients monitored before and after coiling.

METHODS

Ninety-nine consecutive poor-grade patients with aneurysmal subarachnoid hemorrhage (aSAH; World Federation of Neurological Surgeons grade IV and V) were enrolled in our prospective observational study. For 31 patients, ICP and CPP monitoring was started immediately after the diagnosis of aSAH, and the values were recorded every 15 minutes during coiling (early ICP group). For 68 patients, ICP and CPP monitoring began after coiling (late ICP group). The outcomes were evaluated at 90 days using the modified Rankin scale.

RESULTS

At the beginning of coiling, the ICP was >20 mm Hg in 10 patients (35.7%). The median ICP was 18 mm Hg (range, 5-60 mm Hg). The CPP was <60 mm Hg in 6 patients (24%). The median CPP was 70 mm Hg (range, 30-101 mm Hg). Despite medical treatment and/or cerebrospinal fluid drainage, 51.6% of the patients monitored during coiling had at least one episode of intracranial hypertension (defined as ICP >20 mm Hg), and 51.6% had at least one episode of reduced CPP (defined as CPP <60 mm Hg). Early monitoring (before aneurysm repair) was not associated with rebleeding. At 90 days, the functional recovery was better in the early ICP group (P = 0.004).

CONCLUSIONS

During coiling, patients with poor-grade aSAH can experience episodes of intracranial hypertension and reduced CPP. Early and appropriate treatment of elevated ICP was not associated with rebleeding and might have improved the outcomes.

Diagnosis and Treatment of Unruptured Intracranial Aneurysms and Aneurysmal Subarachnoid Hemorrhage

Unruptured intracranial aneurysms (UIAs) are commonly acquired vascular lesions that form an outpouching of the arterial wall due to wall thinning. The prevalence of UIAs in the general population is 3.2%. In contrast, an intracranial aneurysm may be manifested after rupture with classic presentation of a thunderclap headache suggesting aneurysmal subarachnoid hemorrhage (SAH). Previous consensus suggests that although small intracranial aneurysms (<7 mm) are less susceptible to rupture, aneurysms larger than 7 mm should be treated on a case-by-case basis with consideration of additional risk factors of aneurysmal growth and rupture. However, this distinction is outdated. The PHASES score, which comprises data pooled from several prospective studies, provides precise estimates by considering not only the aneurysm size but also other variables, such as the aneurysm location. The International Study of Unruptured Intracranial Aneurysms is the largest observational study on the natural history of UIAs, providing the foundation to the current guidelines for the management of UIAs. Although SAH accounts for only 3% of all stroke subtypes, it is associated with considerable burden of morbidity and mortality. The initial management is focused on stabilizing the patient in the intensive care unit with close hemodynamic and serial neurologic monitoring with endovascular or open surgical aneurysm treatment to prevent rebleeding. Since the results of the International Subarachnoid Aneurysm Trial, treatment of aneurysmal SAH has shifted from surgical clipping to endovascular coiling, which demonstrated higher odds of survival free of disability at 1 year after SAH. Nonetheless, aneurysmal SAH remains a public health hazard and is associated with high rates of disability and death.

Validation of Noninvasive Absolute Intracranial Pressure Measurements in Traumatic Brain Injury and Intracranial Hemorrhage

BACKGROUND

Increased intracranial pressure (ICP) causes secondary damage in traumatic brain injury (TBI), and intracranial hemorrhage (ICH). Current methods of ICP monitoring require surgery and carry risks of complications.

OBJECTIVE

To validate a new instrument for noninvasive ICP measurement by comparing values obtained from noninvasive measurements to those from commercial implantable devices through this pilot study.

METHODS

The ophthalmic artery (OA) served as a natural ICP sensor. ICP measurements obtained using noninvasive, self-calibrating device utilizing Doppler ultrasound to evaluate OA flow were compared to standard implantable ICP measurement probes.

RESULTS

A total of 78 simultaneous, paired, invasive, and noninvasive ICP measurements were obtained in 11 ICU patients over a 17-mo period with the diagnosis of TBI, SAH, or ICH. A total of 24 paired data points were initially excluded because of questions about data independence. Analysis of variance was performed first on the 54 remaining data points and then on the entire set of 78 data points. There was no difference between the 2 groups nor was there any correlation between type of sensor and the patient (F[10, 43] = 1.516, P = .167), or the accuracy and precision of noninvasive ICP measurements (F[1, 43] = 0.511, P = .479). Accuracy was [-1.130; 0.539] mm Hg (CL = 95%). Patient-specific calibration was not needed. Standard deviation (precision) was [1.632; 2.396] mm Hg (CL = 95%). No adverse events were encountered.

CONCLUSION

This pilot study revealed no significant differences between invasive and noninvasive ICP measurements (P < .05), suggesting that noninvasive ICP measurements obtained by this method are comparable and reliable.

[Reasonability and efficacy of decompressive craniectomy in patients with subarachnoid hemorrhage after microsurgical aneurysm exclusion]

In recent years, the so-called primary or preventive decompressive craniectomy (DC) has been increasingly used in patients with aneurysmal subarachnoid hemorrhage (SAH). The main goal of the technique is prevention of refractory intracranial hypertension (ICH) and its consequences.

PURPOSE

The study purpose was to define the CT criteria for reasonability and efficacy of DC as well as clarification of the indications for preventive DC in patients with SAH after microsurgical aneurysm exclusion.

MATERIAL AND METHODS

The study included 46 patients who underwent microsurgical clipping of aneurysms and DC in the period between 2010 and 2016. All patients underwent surgery in the period of 1 to 12 days after SAH. Preventive DC (imultaneously with clipping of aneurysms) was performed in 38 patients. Secondary (delayed) DC was performed in 8 patients.

RESULTS

Mortality in a group of all patients with DC was 15.2%. Preventive DC was considered as 'reasonable' when the patient had signs of cerebral edema in the postoperative period. The X-ray criteria of reasonable DC included a more than 5 mm brain prolapse into the trephination defect or a lateral dislocation of more than 5 mm. If the patient had no prolapse and dislocation in the postoperative period, DC was considered 'unreasonable'. Among patients with ICH in the postoperative period, including 20 patients with reasonable preventive DC and 8 patients with delayed DC, mortality was 25%. The CT signs of efficient DC were found to be a more than 5 mm brain prolapse into the trephination defect in combination with a decrease in the lateral dislocation less than 5 mm. All seven patients with inefficient DC in our group died. To clarify the indications for preventive DC, we analyzed various preoperative factors in patients with reasonable and unreasonable DC.

CONCLUSION

In most cases, preventive DC in microsurgical aneurysm exclusion is indicated for patients in an extremely grave condition (Hunt-Hess Grade V), a lateral displacement of the mline structures of more than 5 mm, an intracranial hematoma of over 30 mL, and symptoms of acute cerebral ischemia (pronounced cerebral vasospasm and emerging ischemic foci).

The change of plasma pituitary adenylate cyclase-activating polypeptide levels after aneurysmal subarachnoid hemorrhage

OBJECTIVE

Elevated circulating pituitary adenylate cyclase-activating polypeptide (PACAP) levels have been demonstrated to be associated with clinical outcomes of severe traumatic brain injury. The current study aimed to confirm whether elevated plasma PACAP levels are predictive of clinical outcomes of aneurysmal subarachnoid hemorrhage (aSAH).

MATERIALS AND METHODS

One hundred and eighteen aSAH patients and 118 controls were recruited. Plasma PACAP concentrations were determined using enzyme-linked immunosorbent assay. Patients were followed up until death or completion of 6 months after aSAH. An unfavorable outcome was defined as Glasgow Outcome Scale score of 1-3.

RESULTS

The admission PACAP levels were significantly elevated in all patients (296.6 ± 119.7 pg/ml) compared with controls (77.1 ± 17.9 pg/ml, P < 0.001). Plasma PACAP levels were independently associated with clinical severity indicated by World Federation of Neurological Surgeons (WFNS) score (t = 4.745, P < 0.001) and Fisher score (t = 4.239, P < 0.001) using a multivariate linear regression. PACAP was identified as an independent predictor for 6-month mortality [odds ratio (OR), 1.014; 95% confidence interval (CI), 1.005-1.030; P < 0.001] and 6-month unfavorable outcome (OR, 1.012; 95% CI, 1.006-1.028; P < 0.001) and 6-month overall survival (hazard ratio, 1.016; 95% CI, 1.008-1.023; P < 0.001) using a binary logistic regression analysis and a Cox's proportional hazard analysis, respectively. PACAP had similar predictive values compared with WFNS score and Fisher score according to the receiver operating characteristic curve analysis.

CONCLUSIONS

Higher plasma PACAP levels are associated with clinical severity and long-term prognosis of aSAH patients, and PACAP has potential to be a good prognostic biomarker of aSAH.

High-Resolution Intracranial Pressure Burden and Outcome in Subarachnoid Hemorrhage

Background and Purpose—

Intracranial pressure (ICP) control is a therapeutic target in patients with aneurysmal subarachnoid hemorrhage, although only a limited number of studies assessed its course and effect on outcome. Pressure–time dose (PTD ICP ) is a method to quantify the burden and the time spent above a defined threshold of ICP. PTD ICP or its relationship with outcome has never been evaluated in aneurysmal subarachnoid hemorrhage.

Methods—

Analysis of data prospectively collected from aneurysmal subarachnoid hemorrhage patients admitted to Neurointensive Care Unit. Monitored data, including intraparenchymal ICP, were digitally recorded minute-by-minute in the first 7 days. PTD ICP (mm Hg h) was computed using 4 predefined thresholds (15, 20, 25, and 30 mm Hg). Outcome was assessed through Extended Glasgow Outcome Scale at hospital discharge and at 6 months.

Results—

Fifty-five patients were enrolled. Forty-two patients (76%) presented with a poor clinical grade. Overall, mortality was 17% at hospital discharge and 34% at 6 months. Half of patients required extensive therapy to control high ICP during day 1. Median ICP was 10 mm Hg (4–75), whereas median PTD ICP15 , PTD ICP20 , PTD ICP25 , PTD ICP30 were, respectively, 13, 4, 2, and 1 mm Hg h. We observed an association between mortality at hospital discharge and higher level of PTD ICP using 20, 25, and 30 mm Hg as thresholds and between exposure to a moderate-level PTD ICP30 and unfavorable long-term outcome.

Conclusions—

PTD ICP may better define one of the insults that the brain suffers after aneurysmal rupture, and exposure to moderate PTD ICP30 was significant prognostic factor of 6-month unfavorable outcome.