Cerebrovascular Dynamics With Head-of-Bed Elevation in Patients With Mild or Moderate Vasospasm After Aneurysmal Subarachnoid Hemorrhage

• Background In patients with aneurysmal subarachnoid hemorrhage, elevation of the head of the bed during vasospasm has been limited in an attempt to minimize vasospasm or its sequelae or both. Consequently, some patients have remained on bed rest for weeks. • Objectives To determine how elevations of the head of the bed of 20° and 45° affect cerebrovascular dynamics in adult patients with mild or moderate vasospasm after aneurysmal subarachnoid hemorrhage and to describe the response of mild or moderate vasospasm to head-of-bed elevations of 20° and 45° with respect to variables such as grade of subarachnoid hemorrhage and degree of vasospasm. • Methods A within-patient repeated-measures design was used. The head of the bed was positioned in the sequence of 0°-20°-45°-0° in 20 patients with mild or moderate vasospasm between days 3 and 14 after aneurysmal subarachnoid hemorrhage. Continuous transcranial Doppler recordings were obtained for 2 to 5 minutes after allowing approximately 2 minutes for stabilization in each position. • ResultsNo patterns or trends indicated that having the head of the bed elevated increases vasospasm. As a group, there were no significant differences within patients at the different positions of the head of the bed. Utilizing repeated-measures analysis of variance, P values ranged from .34 to .97, well beyond .05. No neurological deterioration occurred. • Conclusions In general, elevation of the head of the bed did not cause harmful changes in cerebral blood flow related to vasospasm.

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Decrease of blood flow velocity in the middle cerebral artery after stellate ganglion block following aneurysmal subarachnoid hemorrhage: a potential vasospasm treatment?

Journal of Neurosurgery ◽

10.3171/2019.5.jns182890 ◽

2020 ◽

Vol 133 (3) ◽

pp. 773-779

Author(s):

Christopher Wendel ◽

Ricardo Scheibe ◽

Sören Wagner ◽

Wiebke Tangemann ◽

Hans Henkes ◽

...

Keyword(s):

Blood Flow ◽

Subarachnoid Hemorrhage ◽

Middle Cerebral Artery ◽

Flow Velocity ◽

Neurological Deficit ◽

Blood Flow Velocity ◽

Aneurysmal Subarachnoid Hemorrhage ◽

Stellate Ganglion ◽

Stellate Ganglion Block ◽

Ganglion Block

OBJECTIVECerebral vasospasm (CV) is a delayed, sustained contraction of the cerebral arteries that tends to occur 3–14 days after aneurysmal subarachnoid hemorrhage (aSAH) from a ruptured aneurysm. Vasospasm potentially leads to delayed cerebral ischemia, and despite medical treatment, 1 of 3 patients suffer a persistent neurological deficit. Bedside transcranial Doppler (TCD) ultrasonography is used to indirectly detect CV through recognition of an increase in cerebral blood flow velocity (CBFV). The present study aimed to use TCD ultrasonography to monitor how CBFV changes on both the ipsi- and contralateral sides of the brain in the first 24 hours after patients have received a stellate ganglion block (SGB) to treat CV that persists despite maximum standard therapy.METHODSThe data were culled from records of patients treated between 2013 and 2017. Patients were included if an SGB was administered following aSAH, whose CBFV was ≥ 120 cm/sec and who had either a focal neurological deficit or reduced consciousness despite having received medical treatment and blood pressure management. The SGB was performed on the side where the highest CBFV had been recorded with 8–10 ml ropivacaine 0.2%. The patient’s CBFV was reassessed after 2 and 24 hours.RESULTSThirty-seven patients (male/female ratio 18:19), age 17–70 years (mean age 49.9 ± 11.1), who harbored 13 clipped and 22 coiled aneurysms (1 patient received both a coil and a clip, and 3 patients had 3 untreated aneurysms) had at least one SGB. Patients received up to 4 SGBs, and thus the study comprised a total of 76 SGBs.After the first SGB, CBFV decreased in 80.5% of patients after 2 hours, from a mean of 160.3 ± 28.2 cm/sec to 127.5 ± 34.3 cm/sec (p < 0.001), and it further decreased in 63.4% after 24 hours to 137.2 ± 38.2 cm/sec (p = 0.007). A similar significant effect was found for the subsequent SGB. Adding clonidine showed no significant effect on either the onset or the duration of the SGB. Contralateral middle cerebral artery (MCA) blood flow was not reduced by the SGB.CONCLUSIONSTo the authors’ knowledge, this is the largest study on the effects of administering an SGB to aSAH patients after aneurysm rupture. The data showed a significant reduction in ipsilateral CBFV (MCA 20.5%) after SGB, lasting in about two-thirds of cases for over 24 hours with no major complications resulting from the SGB.

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Intraperitoneal Microdialysis as a Monitoring Method in the Intensive Care Unit

International Surgery ◽

10.9738/intsurg-d-13-00139.1 ◽

2014 ◽

Vol 99 (6) ◽

pp. 729-733 ◽

Cited By ~ 4

Author(s):

Tasiopoulos Konstantinos ◽

Komnos Apostolos ◽

Paraforos Georgios ◽

Tepetes Konstantinos

Keyword(s):

Intensive Care Unit ◽

Intensive Care ◽

Glucose Concentration ◽

Repeated Measures ◽

Statistical Significance ◽

Monitoring Method ◽

P Values ◽

Repeated Measures Analysis ◽

Low Glucose ◽

Surgical Condition

Abstract Studies on surgical patients provide some evidence of prompt detection of enteric ischemia with microdialysis. The purpose of the study was to measure intraperitoneal microdialysis values (glucose, glycerol, pyruvate, and lactate) in patients hospitalized in an intensive care unit (ICU) with an underlying abdominal surgical condition and to correlate these values with patients' outcomes. Twenty-one patients, 10 female, were enrolled in the study. The intraperitoneal metabolite values were measured for 3 consecutive days, starting from the first day of ICU hospitalization. Descriptive and inferential statistics were performed. The t-test, repeated measures analysis, Holm's test, and a logistic regression model were applied. Level of statistical significance was set at P = 0.05. Mean age of participants was 68.10 ± 8.02 years old. Survivors exhibited statistically significantly higher glucose values on day 3 (6.61 ± 2.01 against 3.67 ± 1.62; P = 0.002). Mean lactate/ pyruvate (L/P) values were above 20 (35.35 ± 27.11). All non-survivors had a mean three day L/P values greater than 25.94. Low L/P values were related to increased survival possibilities. High microdialysis glucose concentration, high L/P ratio and low glucose concentration were the major findings during the first three ICU hospitalization days in non-survivors. Intraperitoneal microdialysis may serve as a useful tool in understanding enteric ischemia pathophysiology.

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Effects of Vaporized Perfluorocarbon on Pulmonary Blood Flow and Ventilation/Perfusion Distribution in a Model of Acute Respiratory Distress Syndrome

Anesthesiology ◽

10.1097/00000542-200112000-00021 ◽

2001 ◽

Vol 95 (6) ◽

pp. 1414-1421 ◽

Cited By ~ 12

Author(s):

Matthias Hübler ◽

Jennifer E. Souders ◽

Erin D. Shade ◽

Nayak L. Polissar ◽

Carmel Schimmel ◽

...

Keyword(s):

Blood Flow ◽

Oleic Acid ◽

Gas Exchange ◽

Lung Injury ◽

Repeated Measures ◽

Pulmonary Blood Flow ◽

Analysis Of Covariance ◽

Inert Gas ◽

Low Flow ◽

Repeated Measures Analysis

Background Perfluorocarbon (PFC) liquids are known to improve gas exchange and pulmonary function in various models of acute respiratory failure. Vaporization has been recently reported as a new method of delivering PFC to the lung. Our aim was to study the effect of PFC vapor on the ventilation/perfusion (VA/Q) matching and relative pulmonary blood flow (Qrel) distribution. Methods In nine sheep, lung injury was induced using oleic acid. Four sheep were treated with vaporized perfluorohexane (PFX) for 30 min, whereas the remaining sheep served as control animals. Vaporization was achieved using a modified isoflurane vaporizer. The animals were studied for 90 min after vaporization. VA/Q distributions were estimated using the multiple inert gas elimination technique. Change in Qrel distribution was assessed using fluorescent-labeled microspheres. Results Treatment with PFX vapor improved oxygenation significantly and led to significantly lower shunt values (P < 0.05, repeated-measures analysis of covariance). Analysis of the multiple inert gas elimination technique data showed that animals treated with PFX vapor demonstrated a higher VA/Q heterogeneity than the control animals (P < 0.05, repeated-measures analysis of covariance). Microsphere data showed a redistribution of Qrel attributable to oleic acid injury. Qrel shifted from areas that were initially high-flow to areas that were initially low-flow, with no difference in redistribution between the groups. After established injury, Qrel was redistributed to the nondependent lung areas in control animals, whereas Qrel distribution did not change in treatment animals. Conclusion In oleic acid lung injury, treatment with PFX vapor improves gas exchange by increasing VA/Q heterogeneity in the whole lung without a significant change in gravitational gradient.

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Temporal and Spatial Changes in Cerebral Blood Flow during Management for Preventing Delayed Cerebral Ischemia after Aneurysmal Subarachnoid Hemorrhage: Serial Semiquantitative Analysis

Journal of Stroke and Cerebrovascular Diseases ◽

10.1016/j.jstrokecerebrovasdis.2017.06.006 ◽

2017 ◽

Vol 26 (9) ◽

pp. 2027-2037 ◽

Cited By ~ 3

Author(s):

Kenichi Sato ◽

Hiroaki Shimizu ◽

Takashi Inoue ◽

Miki Fujimura ◽

Hidenori Endo ◽

...

Keyword(s):

Blood Flow ◽

Cerebral Blood Flow ◽

Subarachnoid Hemorrhage ◽

Cerebral Ischemia ◽

Aneurysmal Subarachnoid Hemorrhage ◽

Delayed Cerebral Ischemia ◽

Semiquantitative Analysis ◽

Spatial Changes ◽

Temporal And Spatial

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Physiological Rationale and Current Evidence for Therapeutic Positioning of Critically Ill Patients

AACN Advanced Critical Care ◽

10.4037/15597768-2009-3005 ◽

2009 ◽

Vol 20 (3) ◽

pp. 228-240

Author(s):

Karen L. Johnson ◽

Tim Meyenburg

Keyword(s):

Critically Ill ◽

Patient Outcomes ◽

Critically Ill Patients ◽

Bed Rest ◽

Current Evidence ◽

Kinetic Therapy ◽

Bed Elevation ◽

Continuous Lateral Rotation ◽

Head Of Bed Elevation ◽

Improve Patient

Prolonged bed rest is common in critically ill patients, and therapeutic positioning is important to prevent further complications and to improve patient outcomes. Nurses use therapeutic positioning to prevent complications of immobility. This article reviews therapeutic positions including stationary positions (supine, semirecumbent with head of bed elevation, lateral, and prone) and active repositioning (manual, continuous lateral rotation, and kinetic therapy). The physiological rationale and current evidence for each position are described. Applicable evidence-based practice guidelines are summarized. Special considerations for therapeutic positioning of critically ill obese and elderly patients are also discussed.

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Regional cerebral blood flow and oxygen metabolism in aneurysmal subarachnoid hemorrhage: positron emission tomography evaluation of clipping versus coiling

Cerebral Hemorrhage - Acta Neurochirurgica Supplementum ◽

10.1007/978-3-211-09469-3_40 ◽

2009 ◽

pp. 211-215 ◽

Cited By ~ 1

Author(s):

N. Kawai ◽

T. Nakamura ◽

T. Tamiya ◽

S. Nagao

Keyword(s):

Positron Emission Tomography ◽

Blood Flow ◽

Cerebral Blood Flow ◽

Subarachnoid Hemorrhage ◽

Regional Cerebral Blood Flow ◽

Aneurysmal Subarachnoid Hemorrhage ◽

Oxygen Metabolism ◽

Emission Tomography ◽

Regional Cerebral Blood ◽

Positron Emission

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Vocal Function and Upper Airway Thermoregulation in Five Different Environmental Conditions

Journal of Speech Language and Hearing Research ◽

10.1044/1092-4388(2013/13-0015 ◽

2014 ◽

Vol 57 (1) ◽

pp. 16-25 ◽

Cited By ~ 14

Author(s):

Mary J. Sandage ◽

Nadine P. Connor ◽

David D. Pascoe

Keyword(s):

Relative Humidity ◽

Repeated Measures ◽

Upper Airway ◽

Threshold Pressure ◽

Vocal Function ◽

Repeated Measures Design ◽

Repeated Measures Analysis ◽

C 23 ◽

Phonation Threshold Pressure ◽

Perceived Phonatory Effort

Purpose Phonation threshold pressure and perceived phonatory effort were hypothesized to increase and upper airway temperature to decrease following exposure to cold and/or dry air. Greater changes were expected with mouth versus nose breathing. Method In a within-participant repeated measures design, 15 consented participants (7 men, 8 women) completed 20-min duration trials to allow for adequate thermal equilibration for both nose and mouth breathing in 5 different environments: 3 temperatures (°C) matched for relative humidity (% RH), cold (15 °C, 40% RH), thermally neutral (25 °C, 40% RH), and hot (35 °C, 40% RH); and 2 temperatures with variable relative humidity to match vapor pressure for the neutral environment (25 °C, 40% RH), cold (15 °C, 74% RH) and hot (35 °C, 23% RH). Following each equilibration trial, measures were taken in this order: upper airway temperature (transnasal thermistor probe), phonation threshold pressure, and perceived phonatory effort. Results Data were analyzed using repeated measures analysis of variance, and no significant differences were established. Conclusions The study hypotheses were not supported. Findings suggest that the upper airway is tightly regulated for temperature when challenged by a realistic range of temperature and relative humidity environments. This is the first study of its kind to include measurement of upper airway temperature in conjunction with measures of vocal function.

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Cerebral blood flow and vasoresponsivity within and around cerebral contusions

Journal of Neurosurgery ◽

10.3171/jns.1996.85.5.0871 ◽

1996 ◽

Vol 85 (5) ◽

pp. 871-876 ◽

Cited By ~ 115

Author(s):

Mark R. McLaughlin ◽

Donald W. Marion

Keyword(s):

Blood Flow ◽

Cerebral Blood Flow ◽

Repeated Measures ◽

Closed Head Injury ◽

Ct Scanning ◽

Brain Parenchyma ◽

Secondary Brain Injury ◽

Content Type ◽

Repeated Measures Analysis ◽

Surrounding Parenchyma

✓ There is increasing evidence that regional ischemia plays a major role in secondary brain injury. Although the cortex underlying subdural hematomas seems particularly vulnerable to ischemia, little is known about the adequacy of cerebral blood flow (CBF) or the vasoresponsivity within the vascular bed of contusions. The authors used the xenon-enhanced computerized tomography (CT) CBF technique to define the CBF and vasoresponsivity of contusions, pericontusional parenchyma, and the remainder of the brain 24 to 48 hours after severe closed head injury in 10 patients: six patients with one contusion and four with two contusions, defined as mixed or high-density lesions on CT scanning. The CBF within the contusions (29.3 ± 16.4 ml/100 g/minute, mean ± standard deviation) was significantly lower than both that found in the adjacent 1-cm perimeter of normal-appearing tissue (42.5 ± 15.8 ml/100 g/minute) and the mean global CBF (52.5 ± 17.5 ml/100 g/minute) (p < 0.004, repeated-measures analysis of variance). A subset of seven patients (10 contusions) also underwent a second Xe-CT CBF study during mild hyperventilation (a PaCO of 24–32 mm Hg). In only two of these 10 contusions was vasoresponsivity less than 1% (range 0%–7.6%); in the rim of normal-appearing pericontusional tissue, it was 0.4% to 9.1%. The authors conclude that CBF within intracerebral contusions is highly variable and is often above 18 ml/100 g/minute, the reported threshold for irreversible ischemia. Intracontusional CBF is significantly reduced relative to surrounding brain parenchyma, and CO2 vasoresponsivity is usually present. In the contusion and the surrounding parenchyma, vasoresponsivity may be nearly three times normal, suggesting hypersensitivity to hyperventilation therapy. Given this possible hypersensitivity and relative hypoperfusion within and around cerebral contusions, these lesions are particularly vulnerable to secondary injury such as that which may be caused by hypotension or aggressive hyperventilation.

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Effect of Positioning on Oxygenation in Single-Lung Transplant Recipients

American Journal of Critical Care ◽

10.4037/ajcc2002.11.1.66 ◽

2002 ◽

Vol 11 (1) ◽

pp. 66-75 ◽

Cited By ~ 5

Author(s):

Elisabeth L. George ◽

Leslie A. Hoffman ◽

Arthur Boujoukos ◽

Thomas G. Zullo

Keyword(s):

Blood Flow ◽

Postoperative Period ◽

Repeated Measures ◽

Lung Transplant ◽

Transplant Recipients ◽

Repeated Measures Design ◽

Native Lung ◽

Single Lung Transplant ◽

Quasi Experimental ◽

Lung Transplant Recipients

• Background Many benefits and adverse effects of positioning are related to changes in ventilation and perfusion. A number of unique factors related to the allograft make the effects of positioning difficult to determine in single-lung transplant recipients.• Objectives To determine the effect of 3 body positions (supine, lateral with allograft lung down, and lateral with native lung down) on oxygenation and blood flow in single-lung transplant recipients in the 24 hours immediately after surgery.• Methods A quasi-experimental repeated-measures design with stratified assignment to 1 of 3 different sequencing patterns for turning group was used to study 15 transplant recipients, 9 with emphysema and 6 with fibrosis. Oxygenation, ventilation, and blood flow measures (heart rate, blood pressure) were assessed after each turn. The effect of ischemic reperfusion injury was also explored.• Results The oxygenation, ventilation, and blood flow variables did not differ significantly across group, diagnosis, or time. Oxygenation variables measured when the allograft lung was dependent did not differ significantly from such measurements obtained when the native lung was dependent.• Conclusions No single position maximizes oxygenation in the immediate postoperative period in single-lung transplant recipients. Although a single standard protocol for positioning cannot be supported, the study does support the idea that transplant recipients can be safely turned in the immediate postoperative period without compromising oxygenation or hemodynamic status.

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