Reflectance measurements of hematocrit and oxyhemoglobin saturation

1987 ◽  
Vol 253 (1) ◽  
pp. H147-H153 ◽  
Author(s):  
J. M. Steinke ◽  
A. P. Shepherd
Keyword(s):  
Fiber Optic ◽  
Diffusion Theory ◽  
Animal Experiments ◽  
Mean Difference ◽  
Photon Diffusion ◽  
Oxyhemoglobin Saturation ◽  
Light Emitting ◽  
The Mean ◽  
Light Guides ◽  
Reflectance Measurements

Fiberoptic oximeters measure oxyhemoglobin saturation from the optical reflectance of whole blood, but the calibration of such oximeters is hematocrit dependent. Therefore, using photon-diffusion theory and an empirical approach, we have developed a new reflectance method that determines hematocrit and correspondingly corrects the oxyhemoglobin-saturation measurement. Our method employs four fiber-optic light guides, a photodetector, and three inexpensive light-emitting diodes (one with emissions at 660 nm and two at 813 nm). Hematocrit is determined from the ratio of reflectances from the differently spaced emitting fibers at 813 nm and is used to correct the 813-660 nm measurement of oxyhemoglobin saturation. In red cell suspensions, the mean difference between reflectance measurements of hematocrit and conventional determinations was only 2.09% (r = 0.99), and when compared with conventional gasometric measurements of oxyhemoglobin saturation, the reflectance method yielded the same calibration curve for different hematocrits and gave a mean difference of only 2.67%. Although the technique is demonstrated with a cuvette appropriate for an extracorporeal circulation in animal experiments, it could possibly be further developed for fiber-optic catheter oximeters.

Temporal and spatial characteristics of tonically active neurons of the primate's striatum

1995 ◽  
Vol 73 (3) ◽  
pp. 1234-1252 ◽  
Author(s):  
T. Aosaki ◽  
M. Kimura ◽  
A. M. Graybiel
Keyword(s):  
Light Emitting Diode ◽  
Temporal Analysis ◽  
Tonic Firing ◽  
Light Emitting ◽  
Macaque Monkeys ◽  
Tonically Active Neurons ◽  
The Mean ◽  
Temporal And Spatial Characteristics ◽  
Conditioning Stimuli ◽  
Visual Light

1. Tonically active neurons (TANs) in the primate striatum develop transient responses to sensory conditioning stimuli during behavioral training in classical conditioning tasks. In this study we examined the temporal characteristics of such TAN responses and mapped the sites of TANs responding to auditory and visual conditioned stimuli in the striatum in macaque monkeys. We further mapped the locations of TANs recorded acutely in the squirrel monkey striatum in relation to the neurochemically distinguished striosome and matrix compartments of the striatum, and made quantitative comparisons between the densities and compartmental distributions of TANs and those of four major types of striatal interneuron identified by histochemical and immunohistochemical staining. 2. We made recordings from 858 TANs at different sites in the striatum in two behaving macaque monkeys at different times during training with auditory (click) and visual (light-emitting diode flash) conditioning stimuli. TANs distributed across large parts of the striatum developed responses to the conditioning stimuli. The responses comprised a decrement of tonic firing (pause) followed by a rebound excitation. Measurements were made of the onsets, offsets, and durations of the pauses of individual TANs and of the interspike intervals (ISIs) of the same cells. 3. The mean duration of the pause responses (268.3 ms) was greater than the mean ISI of the same neurons (181 ms), suggesting that the pause represents an active suppression of TAN firing. The coefficient of variation (CV) for the pause responses was 0.28, compared with a CV of 0.63 for the same cells' ISIs. The population CV for the pauses was 0.16, compared with a population CV of 0.20 for the ISIs. These data, together with temporal analysis of the responses and population histograms, suggest that the pauses became temporally aligned across large parts of the striatum after learning. Analyses of variance (ANOVAs) were carried out to determine whether there were differences in the onset and offset latencies of the pause response or in the durations of the pause responses for TANs at different sites. These analyses suggested that, with rare exceptions, there was no difference in the timing of the TAN responses across large (> 10 mm3) parts of the striatum. 4. Comparisons of TAN responses in different regions of the striatum showed that, for responses to a given modality of conditioned stimulus, there were no significant differences in pause offset times for TANs recorded in the caudate nucleus or putamen, or for TANs recorded in more anterior or more posterior parts of these nuclei.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Do we need to improve the reporting of evidence in tendinopathy management? A critical appraisal of systematic reviews with recommendations on strength of evidence assessment

2021 ◽  
Vol 7 (1) ◽  
pp. e000920
Author(s):  
Dimitris Challoumas ◽  
Neal L Millar
Keyword(s):  
Systematic Reviews ◽  
Assessment Tool ◽  
Data Extraction ◽  
Cochrane Collaboration ◽  
Mean Difference ◽  
Strength Of Evidence ◽  
The Mean ◽  
Randomised Controlled ◽  
Meta Analyses ◽  
The Cochrane Collaboration

ObjectiveTo critically appraise the quality of published systematic reviews (SRs) of randomised controlled trials (RCTs) in tendinopathy with regard to handling and reporting of results with special emphasis on strength of evidence assessment.Data sourcesMedline from inception to June 2020.Study eligibilityAll SRs of RCTs assessing the effectiveness of any intervention(s) on any location of tendinopathy.Data extraction and synthesisIncluded SRs were appraised with the use of a 12-item tool devised by the authors arising from the Preferred Reporting Items in Systematic Reviews and Meta-Analyses statement and other relevant guidance. Subgroup analyses were performed based on impact factor (IF) of publishing journals and date of publication.ResultsA total of 57 SRs were included published in 38 journals between 2006 and 2020. The most commonly used risk-of-bias (RoB) assessment tool and strength of evidence assessment tool were the Cochrane Collaboration RoB tool and the Cochrane Collaboration Back Review Group tool, respectively. The mean score on the appraisal tool was 46.5% (range 0%–100%). SRs published in higher IF journals (>4.7) were associated with a higher mean score than those in lower IF journals (mean difference 26.4%±8.8%, p=0.004). The mean score of the 10 most recently published SRs was similar to that of the first 10 published SRs (mean difference 8.3%±13.7%, p=0.54). Only 23 SRs (40%) used the results of their RoB assessment in data synthesis and more than half (n=30; 50%) did not assess the strength of evidence of their results. Only 12 SRs (21%) assessed their strength of evidence appropriately.ConclusionsIn light of the poor presentation of evidence identified by our review, we provide recommendations to increase transparency and reproducibility in future SRs.

scholarly journals The Sankara Nethralaya Tamil Nadu Essilor Myopia (STEM) Study—Defining a Threshold for Non-Cycloplegic Myopia Prevalence in Children

2021 ◽  
Vol 10 (6) ◽  
pp. 1215
Author(s):  
Aparna Gopalakrishnan ◽  
Jameel Rizwana Hussaindeen ◽  
Viswanathan Sivaraman ◽  
Meenakshi Swaminathan ◽  
Yee Ling Wong ◽  
...  
Keyword(s):  
Open Field ◽  
Tamil Nadu ◽  
Mean Difference ◽  
School Vision ◽  
Elite School ◽  
Prevalence Estimates ◽  
The Mean ◽  
Clinically Significant ◽  
Set Up ◽  
Definition Of

The aim of this study was to investigate the agreement between cycloplegic and non-cycloplegic autorefraction with an open-field auto refractor in a school vision screening set up, and to define a threshold for myopia that agrees with the standard cycloplegic refraction threshold. The study was conducted as part of the Sankara Nethralaya Tamil Nadu Essilor Myopia (STEM) study, which investigated the prevalence, incidence, and risk factors for myopia among children in South India. Children from two schools aged 5 to 15 years, with no ocular abnormalities and whose parents gave informed consent for cycloplegic refraction were included in the study. All the children underwent visual acuity assessment (Pocket Vision Screener, Elite school of Optometry, India), followed by non-cycloplegic and cycloplegic (1% tropicamide) open-field autorefraction (Grand Seiko, WAM-5500). A total of 387 children were included in the study, of whom 201 were boys. The mean (SD) age of the children was 12.2 (±2.1) years. Overall, the mean difference between cycloplegic and non-cycloplegic spherical equivalent (SE) open-field autorefraction measures was 0.34 D (limits of agreement (LOA), 1.06 D to −0.38 D). For myopes, the mean difference between cycloplegic and non-cycloplegic SE was 0.13 D (LOA, 0.63D to −0.36D). The prevalence of myopia was 12% (95% CI, 8% to 15%) using the threshold of cycloplegic SE ≤ −0.50 D, and was 14% (95% CI, 11% to 17%) with SE ≤ −0.50 D using non-cycloplegic refraction. When myopia was defined as SE of ≤−0.75 D under non-cycloplegic conditions, there was no difference between cycloplegic and non-cycloplegic open-field autorefraction prevalence estimates (12%; 95% CI, 8% to 15%; p = 1.00). Overall, non-cycloplegic refraction underestimates hyperopia and overestimates myopia; but for subjects with myopia, this difference is minimal and not clinically significant. A threshold of SE ≤ −0.75 D agrees well for the estimation of myopia prevalence among children when using non-cycloplegic refraction and is comparable with the standard definition of cycloplegic myopic refraction of SE ≤ −0.50 D.

scholarly journals Estimates of the mean difference in orthopaedic randomized trials: obligatory yet obscure

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Lauri Raittio ◽  
Antti Launonen ◽  
Ville M. Mattila ◽  
Aleksi Reito
Keyword(s):  
Primary Outcome ◽  
Outcome Measure ◽  
Patient Reported Outcome ◽  
Ceiling Effect ◽  
Mean Difference ◽  
Discussion Section ◽  
Power Calculations ◽  
Randomized Controlled ◽  
Patient Reported ◽  
The Mean

Abstract Background Randomized controlled trials in orthopaedics are powered to mainly find large effect sizes. A possible discrepancy between the estimated and the real mean difference is a challenge for statistical inference based on p-values. We explored the justifications of the mean difference estimates used in power calculations. The assessment of distribution of observations in the primary outcome and the possibility of ceiling effects were also assessed. Methods Systematic review of the randomized controlled trials with power calculations in eight clinical orthopaedic journals published between 2016 and 2019. Trials with one continuous primary outcome and 1:1 allocation were eligible. Rationales and references for the mean difference estimate were recorded from the Methods sections. The possibility of ceiling effect was addressed by the assessment of the weighted mean and standard deviation of the primary outcome and its elaboration in the Discussion section of each RCT where available. Results 264 trials were included in this study. Of these, 108 (41 %) trials provided some rationale or reference for the mean difference estimate. The most common rationales or references for the estimate of mean difference were minimal clinical important difference (16 %), observational studies on the same subject (8 %) and the ‘clinical relevance’ of the authors (6 %). In a third of the trials, the weighted mean plus 1 standard deviation of the primary outcome reached over the best value in the patient-reported outcome measure scale, indicating the possibility of ceiling effect in the outcome. Conclusions The chosen mean difference estimates in power calculations are rarely properly justified in orthopaedic trials. In general, trials with a patient-reported outcome measure as the primary outcome do not assess or report the possibility of the ceiling effect in the primary outcome or elaborate further in the Discussion section.

scholarly journals Corneal Biomechanical Parameters and Central Corneal Thickness in Glaucoma Patients, Glaucoma Suspects, and a Healthy Population

2021 ◽  
Vol 10 (12) ◽  
pp. 2637
Author(s):  
Mª. Ángeles del Buey-Sayas ◽  
Elena Lanchares-Sancho ◽  
Pilar Campins-Falcó ◽  
María Dolores Pinazo-Durán ◽  
Cristina Peris-Martínez
Keyword(s):  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Mean Difference ◽  
The Other ◽  
Control Group ◽  
Healthy Population ◽  
Diagnostic Categories ◽  
Significant Difference ◽  
Biomechanical Parameters ◽  
The Mean

Purpose: To evaluate and compare corneal hysteresis (CH), corneal resistance factor (CRF), and central corneal thickness (CCT), measurements were taken between a healthy population (controls), patients diagnosed with glaucoma (DG), and glaucoma suspect patients due to ocular hypertension (OHT), family history of glaucoma (FHG), or glaucoma-like optic discs (GLD). Additionally, Goldmann-correlated intraocular pressure (IOPg) and corneal-compensated IOP (IOPcc) were compared between the different groups of patients. Methods: In this prospective analytical-observational study, a total of 1065 patients (one eye of each) were recruited to undergo Ocular Response Analyzer (ORA) testing, ultrasound pachymetry, and clinical examination. Corneal biomechanical parameters (CH, CRF), CCT, IOPg, and IOPcc were measured in the control group (n = 574) and the other groups: DG (n = 147), FHG (n = 78), GLD (n = 90), and OHT (n = 176). We performed a variance analysis (ANOVA) for all the dependent variables according to the different diagnostic categories with multiple comparisons to identify the differences between the diagnostic categories, deeming p < 0.05 as statistically significant. Results: The mean CH in the DG group (9.69 mmHg) was significantly lower compared to controls (10.75 mmHg; mean difference 1.05, p < 0.001), FHG (10.70 mmHg; mean difference 1.00, p < 0.05), GLD (10.63 mmHg; mean difference 0.93, p < 0.05) and OHT (10.54 mmHg; mean difference 0.84, p < 0.05). No glaucoma suspects (FHG, GLD, OHT groups) presented significant differences between themselves and the control group (p = 1.00). No statistically significant differences were found in the mean CRF between DG (11.18 mmHg) and the control group (10.75 mmHg; mean difference 0.42, p = 0.40). The FHG and OHT groups showed significantly higher mean CRF values (12.32 and 12.41 mmHg, respectively) than the DG group (11.18 mmHg), with mean differences of 1.13 (p < 0.05) and 1.22 (p < 0.001), respectively. No statistically significant differences were found in CCT in the analysis between DG (562 μ) and the other groups (control = 556 μ, FHG = 576 μ, GLD = 569 μ, OHT = 570 μ). The means of IOPg and IOPcc values were higher in the DG patient and suspect groups than in the control group, with statistically significant differences in all groups (p < 0.001). Conclusion: This study presents corneal biomechanical values (CH, CRF), CCT, IOPg, and IOPcc for diagnosed glaucoma patients, three suspected glaucoma groups, and a healthy population, using the ORA. Mean CH values were markedly lower in the DG group (diagnosed with glaucoma damage) compared to the other groups. No significant difference was found in CCT between the DG and control groups. Unexpectedly, CRF showed higher values in all groups than in the control group, but the difference was only statistically significant in the suspect groups (FHG, GLD, and OHT), not in the DG group.

A New Equal Area Method to Calculate and Represent Physiologic, Anatomical, and Alveolar Dead Spaces

2006 ◽  
Vol 104 (4) ◽  
pp. 696-700 ◽  
Author(s):  
Yongquan Tang ◽  
Martin J. Turner ◽  
A Barry Baker
Keyword(s):  
Carbon Dioxide ◽  
Dead Space ◽  
Graphical Method ◽  
Mean Difference ◽  
Equal Area ◽  
Area Method ◽  
Physiologic Dead Space ◽  
Anatomical Dead Space ◽  
The Mean ◽  
The Difference

Background Physiologic dead space is usually estimated by the Bohr-Enghoff equation or the Fletcher method. Alveolar dead space is calculated as the difference between anatomical dead space estimated by the Fowler equal area method and physiologic dead space. This study introduces a graphical method that uses similar principles for measuring and displaying anatomical, physiologic, and alveolar dead spaces. Methods A new graphical equal area method for estimating physiologic dead space is derived. Physiologic dead spaces of 1,200 carbon dioxide expirograms obtained from 10 ventilated patients were calculated by the Bohr-Enghoff equation, the Fletcher area method, and the new graphical equal area method and were compared by Bland-Altman analysis. Dead space was varied by varying tidal volume, end-expiratory pressure, inspiratory-to-expiratory ratio, and inspiratory hold in each patient. Results The new graphical equal area method for calculating physiologic dead space is shown analytically to be identical to the Bohr-Enghoff calculation. The mean difference (limits of agreement) between the physiologic dead spaces calculated by the new equal area method and Bohr-Enghoff equation was -0.07 ml (-1.27 to 1.13 ml). The mean difference between new equal area method and the Fletcher area method was -0.09 ml (-1.52 to 1.34 ml). Conclusions The authors' equal area method for calculating, displaying, and visualizing physiologic dead space is easy to understand and yields the same results as the classic Bohr-Enghoff equation and Fletcher area method. All three dead spaces--physiologic, anatomical, and alveolar--together with their relations to expired volume, can be displayed conveniently on the x-axis of a carbon dioxide expirogram.

scholarly journals Longitudinal Raman Spectroscopic Observation of Skin Biochemical Changes due to Chemotherapeutic Treatment for Breast Cancer in Small Animal Model

2017 ◽  
Vol 2017 ◽  
pp. 1-9
Author(s):  
Myeongsu Seong ◽  
NoSoung Myoung ◽  
Songhyun Lee ◽  
Hyeryun Jeong ◽  
Sang-Youp Yim ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Animal Model ◽  
Raman Spectra ◽  
Fiber Optic ◽  
Animal Experiments ◽  
Small Animal ◽  
Fiber Optic Probe ◽  
Small Animal Model ◽  
Biochemical Compositions ◽  
Optic Probe

The cancer field effect (CFE) has been highlighted as one of indirect indications for tissue variations that are insensitive to conventional diagnostic techniques. In this research, we had a hypothesis that chemotherapy for breast cancer would affect skin biochemical compositions that would be reflected by Raman spectral changes. We used a fiber-optic probe-based Raman spectroscopy to perform preliminary animal experiments to validate the hypothesis. Firstly, we verified the probing depth of the fiber-optic probe (~800 μm) using a simple intravenous fat emulsion-filled phantom having a silicon wafer at the bottom inside a cuvette. Then, we obtained Raman spectra during breast cancer treatment by chemotherapy from a small animal model in longitudinal manner. Our results showed that the treatment causes variations of biochemical compositions in the skin. For further validation, the Raman spectra will have to be collected from more populations and spectra will need to be compared with immunohistochemistry of the breast tissue.

scholarly journals Effect of Hope-oriented group counseling on mental health of infertile women with failed IVF cycles: a randomized controlled trial

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Roya Rahimi ◽  
Shirin Hasanpour ◽  
Mojgan. Mirghafourvand ◽  
Khalil Esmaeilpour
Keyword(s):  
Mental Health ◽  
Confidence Interval ◽  
Group Counseling ◽  
Controlled Trial ◽  
Intervention Group ◽  
Mean Difference ◽  
Control Group ◽  
The Mean ◽  
And Control

Abstract Background Considering the prevalence of infertility in the community and the consequences of failure of infertility treatments on women’s mental health, interventions that can control stress, anxiety and depression in infertile women with a history of IVF failure will be very helpful. This study aimed to determine the effects of hope-oriented group counseling on mental health (primary outcome) and quality of life (QoL) (secondary outcome) of women with failed IVF cycles. Method This randomized controlled trial was conducted on 60 women with failed IVF cycles visiting Infertility Clinic at Al-Zahra Teaching Hospital of Tabriz- Iran. Participants were allocated to the intervention group (n = 30) and control group (n = 30) based on a randomized block design. Hope-oriented group counseling was provided to the intervention group in six 45–60 min sessions (once a week). The control group only received routine care to undergo another IVF cycle. The Depression Anxiety Stress Scale-21 (DASS-21) and the SF-12 Quality of Life Scale were filled out by interviewing the participants before the intervention and one week and one month after the intervention. After intervention 26 participants in each group were included in the analysis. Results There was no significant difference between the intervention and control groups in the socio-demographic profile of participants (P > 0.05). The post-intervention mean score of stress (adjusted mean difference = − 1.7, 95% confidence interval: − 3.2 to − 0.3, P = 0.018) and depression (adjusted mean difference = − 1.3, 95% confidence interval: − 4.7 to − 1.5, P < 0.001) was significantly lower in the intervention group compared to the control. Although the mean anxiety score was lower in the intervention group compared to the control, the difference between them was not statistically significant (adjusted mean difference = − 1.1, 95% confidence interval: − 2.6 to 0.4, P = 0.153). The mean score of QoL was significantly higher in the intervention group than that of the control group (adjusted mean difference = 6.9, 95% confidence interval: 5.1 to 8.8, P < 0.001). Conclusion Hope-oriented group counseling was effective in reducing stress and depression and improving QoL in women with failed IVF cycles. It is recommended to use this counseling approach, along with other methods, to improve the mental health of women with failed IVF cycles. Trial registration TCT Registration Number: TCTR 20191017003, registered on October 17, 2019.

TO COMPARE THE EFFECTIVENESS OF NEBULISATION WITH ADRENALINE, 3% HYPERTONIC SALINE AND NORMAL SALINE IN BRONCHIOLITIS IN CHILDREN OF 2 TO 24 MONTHS OF AGE BASED ON CLINICAL SEVERITY SCORE AND NEBULISATION FREQUENCY.

2021 ◽  
Vol 5 (2) ◽  
Author(s):  
Priyanka Jain ◽  
Rakesh Jain
Keyword(s):  
Hypertonic Saline ◽  
Normal Saline ◽  
Mean Difference ◽  
Clinical Severity ◽  
Research Centre ◽  
P Value ◽  
College Hospital ◽  
Mean Values ◽  
Significant Difference ◽  
The Mean

Background & Method: We conducted a double blinded study at Index Medical College Hospital & Research Centre, Indore. The sample size was determined to be minimum of 120 cases as based upon previous years admission due to acute bronchiolitis. Initially, 146 cases were included in the study out of which 23 cases dropped out of the study after giving consent by guardian for participation in the study as they left against medical advice from the hospital. Result: The mean difference of CSS between 0 minutes to 60 minutes of nebulisation between groups in all cases was 0.4 ± 0.6, between 60 minutes and 4 hours was 0.8 ± 0.6, between 4 to 8 hours was 0.7 ± 0.6, between 8-12 hours was 0.6 ± 0.4, between 12-24 hours was 1.6 ± 0.9 and between 24-48 hours was 1.9 ± 0.9.The mean values and resultant p-value of ANOVA of various nebulising agents used for improvement in CSS shows significant association between various nebulising agents used along with improvement in CSS at the end of assessment at 48 hours of treatment. Conclusion: This study was conducted to establish the efficacy of each nebulisation agent (i.e.  adrenaline, 3% hypertonic saline and normal saline) currently used and compare the outcomes as there is not enough evidence amongst Indian population on level of efficacy of each drug in causing improvement in symptoms and signs in various severities of bronchiolitis in early childhood. Comparison of significant improvement in mean difference in CSS at various intervals in all cases compared between groups by post hoc test revealed non-significant difference (p-value 0.700) between 3% hypertonic saline and normal saline. Keywords: nebulisation, adrenaline, bronchiolitis & clinical.

Volumetric quantification of aneurysmal subarachnoid hemorrhage independently predicts hydrocephalus and seizures

2021 ◽  
pp. 1-9
Author(s):  
Badih J. Daou ◽  
Siri Sahib S. Khalsa ◽  
Sharath Kumar Anand ◽  
Craig A. Williamson ◽  
Noah S. Cutler ◽  
...  
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Aneurysmal Subarachnoid Hemorrhage ◽  
Characteristic Curve ◽  
Volumetric Analysis ◽  
Aneurysm Rupture ◽  
Mean Difference ◽  
Analysis Tool ◽  
Volume Data ◽  
Hemorrhage Volume ◽  
The Mean

OBJECTIVEHydrocephalus and seizures greatly impact outcomes of patients with aneurysmal subarachnoid hemorrhage (aSAH); however, reliable tools to predict these outcomes are lacking. The authors used a volumetric quantitative analysis tool to evaluate the association of total aSAH volume with the outcomes of shunt-dependent hydrocephalus and seizures.METHODSTotal hemorrhage volume following aneurysm rupture was retrospectively analyzed on presentation CT imaging using a custom semiautomated computer program developed in MATLAB that employs intensity-based k-means clustering to automatically separate blood voxels from other tissues. Volume data were added to a prospectively maintained aSAH database. The association of hemorrhage volume with shunted hydrocephalus and seizures was evaluated through logistic regression analysis and the diagnostic accuracy through analysis of the area under the receiver operating characteristic curve (AUC).RESULTSThe study population comprised 288 consecutive patients with aSAH. The mean total hemorrhage volume was 74.9 ml. Thirty-eight patients (13.2%) developed seizures. The mean hemorrhage volume in patients who developed seizures was significantly higher than that in patients with no seizures (mean difference 17.3 ml, p = 0.01). In multivariate analysis, larger hemorrhage volume on initial CT scan and hemorrhage volume > 50 ml (OR 2.81, p = 0.047, 95% CI 1.03–7.80) were predictive of seizures. Forty-eight patients (17%) developed shunt-dependent hydrocephalus. The mean hemorrhage volume in patients who developed shunt-dependent hydrocephalus was significantly higher than that in patients who did not (mean difference 17.2 ml, p = 0.006). Larger hemorrhage volume and hemorrhage volume > 50 ml (OR 2.45, p = 0.03, 95% CI 1.08–5.54) were predictive of shunt-dependent hydrocephalus. Hemorrhage volume had adequate discrimination for the development of seizures (AUC 0.635) and shunted hydrocephalus (AUC 0.629).CONCLUSIONSHemorrhage volume is an independent predictor of seizures and shunt-dependent hydrocephalus in patients with aSAH. Further evaluation of aSAH quantitative volumetric analysis may complement existing scales used in clinical practice and assist in patient prognostication and management.

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