Respiratory pattern disturbances in ischemic cerebral vascular disease

Derivation and validation of a screening tool for stroke-associated sepsis

BACKGROUND

Post-stroke infections may cause sepsis, which is associated with poor clinical outcome. Sepsis is defined by life-threatening organ dysfunction that can be identified using the Sequential Organ Failure Assessment (SOFA) score. The applicability of the SOFA score for patients not treated on an intensive care unit (ICU) is limited. The aim of this study was to develop and validate an easier-to-use modification of the SOFA score for stroke patients.

METHODS

Using a registry-based cohort of 212 patients with large vessel occlusion stroke and infection, potential predictors of a poor outcome indicating sepsis were assessed by logistic regression. The derived score was validated on a separate cohort of 391 patients with ischemic stroke and infection admitted to our hospital over a period of 1.5 years.

RESULTS

The derived Stroke-SOFA (S-SOFA) score included the following predictors: National Institutes of Health stroke scale ≥ 14, peripheral oxygen saturation < 90%, mean arterial pressure < 70 mmHg, thrombocyte count < 150 10⁹/l and creatinine ≥ 1.2 mg/dl. The area under the receiver operating curve for the prediction of a poor outcome indicating sepsis was 0.713 [95% confidence interval: 0.665-0.762] for the S-SOFA score, which was comparable to the standard SOFA score (0.750 [0.703-0.798]), but the prespecified criteria for non-inferiority were not met (p = 0.115). However, the S-SOFA score was non-inferior compared to the SOFA score in non-ICU patients (p = 0.013).

CONCLUSIONS

The derived S-SOFA score may be useful to identify non-ICU patients with stroke-associated sepsis who have a high risk of a poor outcome.

Sepsis in Patients With Large Vessel Occlusion Stroke–Clinical Characteristics and Outcome

Background

Infections are an important complication after stroke and negatively affect clinical outcome. While pneumonia and urinary tract infections are well recognized after stroke, the incidence and consequences of sepsis remain unclear. The aim of this study was to evaluate the frequency and characteristics of sepsis in patients undergoing endovascular therapy for large vessel occlusion stroke, and its association with clinical outcome.

Methods

We analyzed a cohort of patients who underwent endovascular therapy at a single center between 2016 and 2020. The diagnosis and timing of infections and Sequential Organ Failure Assessment scores were evaluated retrospectively to identify patients with sepsis. Patients with sepsis were compared to controls regarding clinical characteristics and outcome.

Results

Fifty-four of 406 patients (13.3%) were found to have sepsis. The median onset of sepsis was 2 days after admission. The majority of cases (85.2%) was caused by pneumonia. At 3 months, 72.5% of patients with sepsis were bedridden or dead compared to 25.7 and 42.7% of controls and patients with an infection without sepsis, respectively. The adjusted odds ratio (95% confidence interval) for a poor outcome was 5.4 (1.6–17.6) for patients with sepsis vs. controls, and 2.0 (0.8–5.2) for patients with sepsis vs. patients with an infection without sepsis.

Conclusions

Sepsis is a frequent complication after large vessel occlusion stroke, and may be associated with a poor clinical outcome. More studies are needed to determine specific risk factors and measures to early recognize and reduce the possibly negative impact of sepsis on outcome after stroke.

Respiratory disorders during sleep in patients with acute ischemic stroke

Introduction

Sleep breathing disorders (SBD) especially obstructive hypopnea apnea syndrome (OSA) in patients with stroke are common and can complicate their evolution. The objective was analyzing the different sleep breathing disorders in patients with stroke.

Methods

Descriptive, cross-sectional and retrospective study of acute ischemic stroke patients, using nightly polysomnography with oximetry (PSG).

Results

It was a descriptive, cross-sectional, retrospective study during 19 months; 53 patients with stroke were included, with a men age of 67 ±12 years and 62% were men. SBD was evaluated by nocturnal polysomnography with oximetry within 10 days of installing the stroke. The Apnea hypopnea index (AHI) was 24.5±20, of mild grade in 21%, moderate in 31%, severe grade in 34%. The average oxygen saturation time less than 90% was 38 ±51 minutes. The minimum oxygen saturation was marked in infratentorial lesions.

Conclusion

We found a high percentage of OSA, which was associated with older patients and a higher body mass index. There was a marked decrease in the minimum oxygen saturation and greater tendency to present central apneas in infratentorial lesion. Early diagnosis and treatment could minimize neuronal damage and improve prognosis.

Respiratory disorders during sleep in patients with acute ischemic stroke

Introduction

Sleep breathing disorders (SBD) especially obstructive hypopnea apnea syndrome (OSA) in patients with stroke are common and can complicate their evolution. The objective was analyzing the different sleep breathing disorders in patients with stroke.

Methods

Descriptive, cross-sectional and retrospective study of acute ischemic stroke patients, using nightly polysomnography with oximetry (PSG).

Results

It was a descriptive, cross-sectional, retrospective study during 19 months; 53 patients with stroke were included, with a men age of 67 ±12 years and 62% were men. SBD was evaluated by nocturnal polysomnography with oximetry within 10 days of installing the stroke. The Apnea hypopnea index (AHI) was 24.5±20, of mild grade in 21%, moderate in 31%, severe grade in 34%. The average oxygen saturation time less than 90% was 38 ±51 minutes. The minimum oxygen saturation was marked in infratentorial lesions.

Conclusion

We found a high percentage of OSA, which was associated with older patients and a higher body mass index. There was a marked decrease in the minimum oxygen saturation and greater tendency to present central apneas in infratentorial lesion. Early diagnosis and treatment could minimize neuronal damage and improve prognosis.

Severe Respiratory Alkalosis in Acute Ischemic Stroke: A Rare Presentation

Respiratory alkalosis is a rare but severe complication of acute ischemic stroke (AIS). In ischemic stroke, respiratory alkalosis results from hyperventilation due to the effect of stroke on the respiratory center. We report a case of a young male who presented with acute encephalopathy. Work-up revealed ischemic infarcts in the bilateral cerebellar and left posterior cerebral artery territory. Arterial blood gas (ABG) showed severe respiratory alkalosis with a pH of 7.72. Alkalosis resolved with mechanical ventilation. Such a high pH associated with AIS has not been reported in the medical literature so far. The index case highlights the severity of respiratory alkalosis that can be caused by an AIS. We conclude that early diagnosis and management of severe respiratory alkalosis is crucial for survival and recovery.

Factors Associated with Cheyne-Stokes Respiration in Acute Ischemic Stroke

Background and Purpose

Cheyne-Stokes respiration (CSR) is frequently observed in patients with acute stroke. There have been conflicting opinions about the associations of CSR with the location and size of the lesion. We aimed to better define the clinical relevance and pathogenesis of CSR in acute stroke.

Methods

We investigated patients who had been admitted with acute ischemic stroke and received an overnight sleep apnea test. We collected data on demographics, risk factors, etiologic subtypes, initial vital signs, clinical course of the stroke, and parameters associated with respiratory events during the sleep apnea test. We performed a multivariate logistic regression analysis to determine the factors associated with CSR.

Results

Among 182 patients, 35 patients showed CSR in sleep apnea testing. Large-artery atherosclerosis or cardioembolism, bilateral hemispheric involvement, atrial fibrillation, low left-ventricle ejection fraction (LVEF), and left atrium (LA) enlargement were all associated with the presence of CSR. Multivariate analysis revealed that the previous modified Rankin Scale (mRS) score, bilateral hemispheric involvement, low LVEF, and LA enlargement were significantly associated with CSR. Subgroup analysis with large-artery atherosclerosis without cardiac disease revealed that the previous mRS score is the only independent factor associated with CSR.

Conclusions

CSR frequently occurs in strokes involving large arteries or due to cardioembolism, regardless of the location and severity of the stroke. Predisposing conditions such as preexisting neurologic disability, low LVEF, and LA enlargement are associated with CSR in acute stroke.

The Association Between Spontaneous Hyperventilation, Delayed Cerebral Ischemia, and Poor Neurological Outcome in Patients with Subarachnoid Hemorrhage

BACKGROUND

The frequency and associations of spontaneous hyperventilation in subarachnoid hemorrhage (SAH) are unknown. Because hyperventilation decreases cerebral blood flow, it may exacerbate delayed cerebral ischemia (DCI) and worsen neurological outcome.

METHODS

This is a retrospective analysis of data from a prospectively collected cohort of SAH patients at an academic medical center. Spontaneous hyperventilation was defined by PaCO2 <35 mmHg and pH >7.45 and subdivided into moderate and severe groups. Clinical and demographic characteristics of patients with and without spontaneous hyperventilation were compared using χ (2) or t tests. Bivariate and multivariable logistic regression analyses were conducted to examine the association of moderate and severe hyperventilation with DCI and discharge neurological outcome.

RESULTS

Of 207 patients, 113 (55 %) had spontaneous hyperventilation. Spontaneously hyperventilating patients had greater illness severity as measured by the Hunt-Hess, World Federation of Neurosurgical Societies (WFNS), and SAH sum scores. They were also more likely to develop the following complications: pneumonia, neurogenic myocardial injury, systemic inflammatory response syndrome (SIRS), radiographic vasospasm, DCI, and poor neurological outcome. In a multivariable logistic regression model including age, gender, WFNS, SAH sum score, pneumonia, neurogenic myocardial injury, etiology, and SIRS, only moderate [odds ratio (OR) 2.49, 95 % confidence interval (CI) 1.10-5.62] and severe (OR 3.12, 95 % CI 1.30-7.49) spontaneous hyperventilation were associated with DCI. Severe spontaneous hyperventilation (OR 4.52, 95 % CI 1.37-14.89) was also significantly associated with poor discharge outcome in multivariable logistic regression analysis.

CONCLUSION

Spontaneous hyperventilation is common in SAH and is associated with DCI and poor neurological outcome.

Neurologic Causes of Acute Respiratory Dysfunction

Many neurologic diseases can cause acute respiratory decompensation, therefore a familiarity with these diseases is critical for any clinician managing patients with respiratory dysfunction. In this article, we review the anatomy of the respiratory system, focusing on the neurologic control of respiration. We discuss general mechanisms by which diseases of the peripheral and central nervous systems can cause acute respiratory dysfunction, and review the neurologic diseases which can adversely affect respiration. Lastly, we discuss the diagnosis and general management of acute respiratory impairment due to neurologic disease.

Heart rate variability and functional outcome in ischemic stroke: a multiparameter approach

BACKGROUND AND PURPOSE

Heart rate variability (HRV) as a measure of autonomic function might provide prognostic information in ischemic stroke. However, numerous difficulties are associated with HRV parameters assessment and interpretation, especially in short-term ECG recordings. For better understanding of derived HRV data and to avoid methodological bias we simultaneously recorded and analyzed heart rate, blood pressure and respiratory rate.

METHODS

Seventy-five ischemic stroke patients underwent short-term ECG recordings. Linear and nonlinear parameters of HRV as well as beat-to-beat blood pressure and respiratory rate were assessed and compared in patients with different functional neurological outcomes at 7th and 90th days.

RESULTS

Values of Approximate, Sample and Fuzzy Entropy were significantly lower in patients with poor early neurological outcome. Patients with poor 90-day outcome had higher percentage of high frequency spectrum and normalized high frequency power, lower normalized low frequency power and lower low frequency/high frequency ratio. Low frequency/high frequency ratio correlated negatively with scores in the National Institutes of Health Stroke Scale and modified Rankin Scale (mRS) at the 7th and mRS at the 90th days. Mean RR interval, values of blood pressure as well as blood pressure variability did not differ between groups with good and poor outcomes. Respiratory frequency was significantly correlated with the functional neurological outcome at 7th and 90th days.

CONCLUSION

While HRV assessed by linear methods seems to have long-term prognostic value, complexity measures of HRV reflect the impact of the neurological state on distinct, temporary properties of heart rate dynamic. Respiratory rate during the first days of the stroke is associated with early and long-term neurological outcome and should be further investigated as a potential risk factor.

Strokes and their relationship with sleep and sleep disorders

INTRODUCTION

In the current population, strokes are one of the most important causes of morbidity and mortality, to which new risk factors are increasingly being attributed. Of late, there is increased interest in the relationship between sleep disorders and strokes as regards risk and prognosis.

DEVELOPMENT

This article presents the changes in sleep architecture and brain activity in stroke patients, as well as the interaction between stroke and sleep disorders, including those which may also influence the outcome and recovery from strokes. The different treatments discussed in the literature are also reviewed, as correct treatment of such sleep disorders may not only improve quality of life and reduce after-effects, but can also increase life expectancy.

CONCLUSIONS

Sleep disorders are becoming increasingly associated with stroke. In addition to being a risk factor, they can also interfere in the outcome and recovery of stroke patients. This article aims to present an exhaustive and current review on strokes and their relationship with sleep alterations and sleep disorders.

Central periodic breathing during sleep in 74 patients with acute ischemic stroke - neurogenic and cardiogenic factors

OBJECTIVES

The aims of our study were 1) to better characterize central periodic breathing during sleep (CPBS) and its clinical relevance in acute stroke, 2) to better define the role of brain damage in its pathogenesis.

METHODS

We included 74 consecutive patients admitted within 96 hours after stroke onset. Stroke severity at admission, stroke outcome at discharge and stroke topography were assessed. ECG and transesophageal echocardiography were performed. Nocturnal breathing was assessed with an ambulatory device the first night after admission. CPBS severity was represented as absolute time and percentage of recording time.

RESULTS

Age was 63 +/- 13 (25-82), 49 (66 %) were male. Thirty (41 %) patients showed CPBS during >or= 10 % and 7 (9 %) during >or= 50 % of recording time. CPBS severity was associated with age (p = 0.017), stroke severity (p = 0.008), ECG abnormalities (p = 0.005) and lower left ventricular ejection fraction (p < 0.0001). CPBS severity was higher in patients with extensive hemispheric strokes (n = 6, p < 0.0001), and lower in patients with partial strokes involving the left insula (n = 5, p < 0.0001) and the mesencephalon (n = 5, p = 0.002).

CONCLUSIONS

CPBS is frequent in acute ischemic stroke and is associated with older age, stroke severity/extension, and lower left ventricular function. The lower occurrence of CPBS in left insular and mesencephalic stroke suggests a major role of distinct brain areas in the modulation of respiratory phenomena accompanying acute stroke.

Abnormal breathing patterns in stroke: relationship with location of acute stroke lesion and prior cerebrovascular disease

OBJECTIVE

To determine whether central periodic breathing (CPB) is associated with acute involvement of any particular part of the brain, or the extent of total damage in patients with acute stroke.

METHODS

CPB was identified using portable monitoring equipment in patients with stroke on admission. A neuroradiologist classified acute stroke lesions and prior cerebrovascular disease on brain images.

RESULTS

Among 134 patients with acute stroke, those with CPB were more likely to have a large acute stroke lesion in a cerebral hemisphere (p = 0.01) and more mass effect (p = 0.03). There was no association between CPB and severe prior cerebrovascular disease on imaging (p = 0.76).

CONCLUSION

CPB is related to the acute (not old) lesions, particularly large acute cerebral hemispheric lesions with mass effect. A relationship between lesions in any discrete brain location (unilateral or bilateral) and CPB could not be shown.

Instability of spontaneous breathing patterns in patients with persistent vegetative state

We investigated the breathing patterns of 27 patients in a persistent vegetative state (PVS) and 15 normal control volunteers. During the baseline period breathing air, 15 patients (the PVS-IB) exhibited irregular breathing (IB), whereas the other 12 (the PVS-OB) displayed oscillatory breathing (OB). Both groups maintained an average value for tidal volume (V(T)), total breath duration (T(TOT)), minute ventilation (V (E)), oxygen saturation (SpO2) similar to the control, but the PVS-OB displayed significantly lower end-tidal CO2 tension (P(ET)CO2) than the control. The V(T), T(TOT), V (E) and P(ET)CO2 of the PVS-OB showed cyclic changes. The coefficients of variation of V(T), T(TOT) and V (I) were: PVS-OB>PVS-IB>control. Inhalation of 100% O2 significantly reduced the respiratory variability and prevented OB of the PVS-OB. We concluded that PVS patients display respiratory instability and that brain damage, hypocapnia, and/or increased loop gain of arterial chemoreceptors may contribute to the pathogenesis of OB, whereas brain damage presumably may be the cause of IB.

Cheyne-Stokes respiration in stroke: relationship to hypocapnia and occult cardiac dysfunction

BACKGROUND

Central sleep apnea (CSA) and Cheyne-Stokes respiration have been reported in association with stroke, but their pathophysiologic correlates have not been well described.

OBJECTIVE

To test the hypotheses that (1) CSA in patients with stroke is associated with nocturnal hypocapnia and (2) in those stroke patients with CSA and with left ventricular (LV) systolic dysfunction, periodic breathing (PB) will have a Cheyne-Stokes respiration pattern in which cycle duration is greater than in those without LV systolic dysfunction.

METHODS

We prospectively performed polysomnography and echocardiography in 93 patients with stroke. CSA was defined as central apneas and hypopneas occurring at a rate of 10 or more per hour of sleep. In patients with CSA, we compared PB cycle duration between those with normal and impaired LV systolic function (LV ejection fraction [LVEF] > 40% and < or = 40%, respectively).

RESULTS

CSA was found in 19% of subjects who had lower nocturnal transcutaneous PCO2 (39.3 +/- 0.9 vs. 42.8 +/- 0.8 mmHg, p = 0.015) and a higher prevalence of LVEF of 40% or less (22 vs. 5%, p = 0.043) than stroke patients without CSA. There was no significant difference in stroke location or type between the two groups. In patients with CSA, those with LVEF of 40% or less had a longer PB cycle than those with an LVEF of more than 40% (66.6 +/- 5.6 vs. 46.6 +/- 2.9 seconds, p = 0.006), but had no symptoms of heart failure.

CONCLUSION

In patients with stroke, CSA is associated with hypocapnia and occult LV systolic dysfunction but is not related to the location or type of stroke. The presence of LV systolic dysfunction is associated with a Cheyne-Stokes pattern of hyperpnea.

Association of obstructive sleep apnea and stenotic artery disease in ischemic stroke patients

BACKGROUND AND PURPOSE

Obstructive sleep apnea (OSA) is suspected to be an independent risk factor for atherosclerotic artery disease. The aim of this hospital-based case-control study was to assess the association between OSA and extracranial artery disease (EAD) as well as peripheral artery disease (PAD) in stroke survivors adjusting for potential confounders.

METHODS

Out of 395 stroke survivors in reconvalescent phase, 235 (male 165, female 70, mean age 64.3 years, standard deviation 10.8 years) were retrospectively examined for the presence of OSA as well as EAD. Statistical analyses were then performed to detect correlations between the presence of medium to high degree artery disease (extracranial stenosis equal or higher than 50%: n=67) and the presence of severe OSA (n=58). Adjustments were made for sex, age, Barthel index and concomitant risk factors as well as body mass index and presence of dysarthria or dysphagia. Additionally, the presence of PAD (Fontaine IIa and higher: n=20) was retrospectively examined in 240 out of 395 patients.

RESULTS

Severe OSA was associated independently with EAD (OR=2.0, 95%CI 1.0-4.1) and with PAD (OR=6.7, 95%CI 2.1-21.0). EAD additionally showed a stronger association with hypertension and hyperlipidemia. PAD additionally showed a strong association with smoking.

CONCLUSION

Our results support the hypothesis that OSA is associated with atherosclerosis and may contribute to ischemic stroke and PAD.

Causes and outcome of mechanical ventilation in patients with hemispheric ischemic stroke

OBJECTIVE

To attempt to determine factors that influence outcome in mechanically ventilated patients with ischemic hemispheric stroke.

MATERIAL AND METHODS

We reviewed data on 24 mechanically ventilated patients with an ischemic stroke in the territory of the middle cerebral artery, who had been admitted to a medical, neurologic, or neurosurgical intensive-care unit during the period between 1976 and 1994.

RESULTS

The circumstances surrounding mechanical ventilation were generalized tonic-clonic seizures or status epilepticus (N = 6), progression to stupor and inability to protect the airway from brain swelling (N = 8), or--most commonly--bilateral pulmonary edema from congestive heart failure (N = 10). Of the 24 patients, 17 patients died (12 of neurologic causes and 5 of cardiac arrest or cardiac arrhythmias). Of the seven surviving patients, however, four with seizures and one with pulmonary edema were functionally independent.

CONCLUSION

Three clinical scenarios generally underlie mechanical ventilation in patients with ischemic hemispheric stroke (generalized tonic-clonic seizures, brain swelling, and bilateral pulmonary edema). The outcome in patients with an ischemic hemispheric stroke and a subsequent need for mechanical ventilation is poor; however, survival and independent function are possible if seizures or pulmonary edema prompt ventilatory support.

Respiration in tetraplegia and in hemiplegia: a review

Impairment of respiratory function is one of the most serious complications of both complete cervical cord injury and stroke with hemiplegia. This review updates the information first gathered 15 years ago. The overall improvement in prognosis is documented and the methods of treatment, including diaphragmatic pacing and physiotherapy are discussed.