Urinary Tract Injury in Gynecologic Laparoscopy for Benign Indication: A Systematic Review.

OBJECTIVE: To perform a comprehensive literature review of the incidence, location, etiology, timing, management, and long-term sequelae of urinary tract injury in gynecologic laparoscopy for benign indication. DATA SOURCES: A systematic review of PubMed, EMBASE, Cochrane Library, and ClinicalTrials.gov was conducted. METHODS OF STUDY SELECTION: Four hundred thirty-three studies were screened for inclusion with 136 full-text articles reviewed. Ninety studies published between 1975 and 2015 met inclusion criteria, representing 140,444 surgeries. Articles reporting the incidence of urinary tract injury in gynecologic laparoscopy for benign indication were included. Exclusion criteria comprised malignancy, surgery by urogynecologists, research not in English, and insufficient data. TABULATION, INTEGRATION, AND RESULTS: A total of 458 lower urinary tract injuries were reported with an incidence of 0.33% (95% CI 0.30-0.36). Bladder injury (0.24%, 95% CI 0.22-0.27) was overall three times more frequent than ureteral injury (0.08%, 95% CI 0.07-0.10). Laparoscopic hysterectomy not otherwise specified (1.8%, 95% CI 1.2-2.6) and laparoscopically assisted vaginal hysterectomy (1.0%, 95% CI 0.9-1.2) had the highest rates of injury. Most ureteral injuries resulted from electrosurgery (33.3%, 95% CI 24.3-45.8), whereas most bladder injuries resulted from lysis of adhesions (23.3%, 95% CI 18.7-29.0). Ureteral injuries were most often recognized postoperatively (60%, 95% CI 47-76) and were repaired by open ureteral anastomosis (47.4%, 95% CI 36.3-61.9). In contrast, bladder injuries were most often recognized intraoperatively (85%, 95% CI 75-95) and were repaired by laparoscopic suturing (34.9%, 95% CI 29.2-41.7). CONCLUSION: The incidence of lower urinary tract injury in gynecologic laparoscopy for benign indication remains low at 0.33%. Bladder injury was three times more common than ureteral injury, although ureteral injuries were more often unrecognized intraoperatively and underwent open surgical repair. These risk estimates can assist gynecologic surgeons in effectively counseling their patients preoperatively concerning the risks of lower urinary tract injury.

Correlation of Computed Tomography Measured Presacral Thickness with Body Mass Index.

Sacral colpopexy is often chosen as a reliable approach that effectively resolves vaginal vault prolapse. Advancements in minimally invasive technology, robotic and laparoscopic surgery, have helped facilitate surgical dissection and operation when performing this procedure. An increased presacral thickness can potentially present a surgical challenge when operating in the presacral space. We hypothesize that there is a correlation between body mass index and presacral thickness. Computed Tomography (CT) images of 241 patients were reviewed in this retrospective study. The presacral thickness was measured by taking the cross sectional distance from the sacral promontory to the upper aspect of the iliac arteries. The corresponding demographic information of age, body mass index (BMI), and comorbidities were evaluated using univariate analysis, linear regression, and multiple regression analysis. The mean age was 56.6 years, and BMI was 27.6. The mean presacral thickness measurement based on the CT scan was 21.08 mm. Univariate linear regression models demonstrated a positive correlation between presacral thickness and BMI and a negative correlation with age. When adjusting for both age and BMI on multivariate analysis, a positive correlation with hypertension was found. The surgeon should be aware of this potential change in anatomy when operating in the presacral space.

Correlation of patient age with CT-measured aorta-sacral promontory distance.

INTRODUCTION AND HYPOTHESIS: Pelvic floor disorders are becoming more prevalent in the elderly population. Since more patients are seeking definitive management for their prolapse, the number of elderly patients undergoing sacral colpopexies will likely increase. During sacral colpopexies, the surgeon must carefully dissect in the presacral space and avoid vital structures. In elderly patients the aorta potentially elongates and the vertebral body height decreases. Consequently, there is a potential for anatomical change of distance from the bifurcation of the aorta to the sacral promontory. This study aimed to correlate the aorta-sacral promontory distance with age. METHODS: From 1 January 2013 to 31 January 2014 computed tomography (CT) images of 241 patients were reviewed in this retrospective study. Radiologists measured the aorta-sacral promontory distance on sagittal acquisition. The corresponding demographic information of age, body mass index, and comorbidities was evaluated using univariate analysis and univariate linear regression. RESULTS: The mean age was 56.6 years, and BMI was 27.6. The mean aorta-sacral promontory measurement based on the CT scan was 63.11 mm. Univariate analysis using a t test and ANOVA demonstrated an inverse correlation with age (p < 0.0001) and hypertension (p = 0.0034) and a positive correlation with BMI categories (p < 0.0017) Under univariate linear regression, the weight of the patient in kilograms demonstrated positive correlation (p = 0.0413). CONCLUSIONS: Based on CT measurements, the aorta-sacral promontory distance is decreased in elderly and hypertensive patients. Heavier patients have an increased aorta-sacral promontory distance. These potential anatomical variants should be considered before operating in the presacral space.

Prior antimicrobial exposure and the risk for bloodstream infection with fluconazole-non-susceptible Candida strains.

Candida species are a common cause of bloodstream infection among hospitalized patients. Increasingly these infections are caused by strains resistant to commonly used antifungal agents. The aim of this study was to assess the association between exposure to specific antimicrobial agents and subsequent bloodstream infection with fluconazole-non-susceptible and fluconazole-susceptible Candida strains. A retrospective case-case-control study was performed. From 2002 to 2006, 50 consecutive patients with hospital-acquired bloodstream infection caused by Candida strains not fully susceptible to fluconazole were identified (case group 1). For comparison, 54 patients with fluconazole-susceptible candidaemia (case group 2) and a control group of 104 patients without candidaemia were studied. Models were adjusted for demographic and clinical risk factors. The risk for candidaemia associated with exposure to specific antimicrobial agents was assessed. Piperacillin/tazobactam (odds ratio (OR) 6.8, 95% confidence interval (CI) 1.4-32.2) and ciprofloxacin (OR 8.0, 95% CI 1.5-42.5), but not fluconazole, were significant risk factors for bloodstream infection with fluconazole-non-susceptible Candida. Only ciprofloxacin (OR 7.8, 95% CI 1.2-50.7) was associated with bloodstream infection with fluconazole-susceptible Candida. Despite adjustment for prior exposure to fluconazole, exposure to specific antibacterial agents was associated with hospital-acquired bloodstream infection with fluconazole-non-susceptible Candida.

Optimizing empirical antimicrobial therapy for infection due to gram-negative pathogens in the intensive care unit: utility of a combination antibiogram.

OBJECTIVE: To determine whether the use of dual antimicrobial therapy based on the results of a combination antibiotic susceptibility report (antibiogram) increases the likelihood of selecting adequate empirical coverage in critically ill patients with infection due to potentially resistant gram-negative pathogens. DESIGN: Retrospective data analysis. SETTING: Urban academic medical center. METHODS: An analysis of culture results and susceptibility data from intensive care unit patients determined by the clinical microbiology laboratory was performed. The proportion of 5 common gram-negative pathogens susceptible to monotherapy with 1 of 3 antipseudomonal antibiotics (piperacillin-tazobactam, ceftazidime, or imipenem) was compared with the proportion susceptible to each of these 3 "backbone" agents plus 1 of 4 additional antimicrobial agents used in combination. RESULTS: More than 5,000 clinical isolates were examined. When all isolates recovered during the entire study period were included, the addition of any of the second antibiotics studied to each of the 3 backbone agents significantly increased the likelihood of covering the causative pathogen (P < .01 for each). The benefit of combination therapy was variable when results for each of the 5 organisms were examined individually. When temporal trends in susceptibility were examined, the decrease in the proportion of organisms susceptible to monotherapy was statistically significant for both imipenem and ceftazidime (P < .01). CONCLUSIONS: Reporting antibiotic susceptibility data in the form of a combination antibiogram may be useful to clinicians who are considering empirical antimicrobial therapy in the intensive care unit.

Prevalence of antimicrobial-resistant bacteria isolated from older versus younger hospitalized adults: results of a two-centre study.

OBJECTIVES: To compare the proportion of antimicrobial-resistant strains among bacterial isolates from younger and older hospital patients and to quantify changes in the proportion of antimicrobial-resistant strains in both groups over time. PATIENTS AND METHODS: A retrospective analysis of microbiology data from two centres in Maryland and Chicago was performed. Adult hospital inpatients with positive clinical cultures for specific antimicrobial-resistant bacterial pathogens between 1999 and 2005 (55 427 isolates) were included. The proportions of isolates not susceptible to specific antimicrobial agents were compared between patients > or =65 and <65 years. Additional analyses examined temporal trends in the frequency of resistance and the frequency of resistance among the oldest patients (> or =80 years), in bacteria isolated from blood cultures and in bacteria obtained from intensive care unit patients. RESULTS: Heterogeneity was observed in the frequency of resistance among different bacteria between older and younger patients, between the two centres and over the study period. Staphylococcus aureus isolates were more likely to be resistant to methicillin when obtained from older patients at Chicago (50.9% versus 40.9%; P < 0.001). In contrast, younger patients yielded a greater proportion of enterococci resistant to vancomycin at Maryland (19.4% versus 16.5%; P = 0.009). Results were variable when resistance to fluoroquinolones, cephalosporins and imipenem were compared for Pseudomonas aeruginosa, Escherichia coli and Klebsiella spp. CONCLUSIONS: Overall, advanced patient age was not uniformly associated with a greater likelihood of antimicrobial resistance among all bacterial pathogens. Moreover, the frequency of resistance in older and younger patients varied considerably at the two sites over the study period. Variability in the frequency of resistance precludes simplistic conclusions regarding the relationship between age and resistance.

Effect of country or continent of treatment on outcome after aneurysmal subarachnoid hemorrhage. Clinical article.

OBJECT: Prognostic factors for outcome after aneurysmal subarachnoid hemorrhage (SAH) include the clinical and pathological characteristics of the patient and hemorrhage as well as some aspects of treatment. Because treatment can vary between countries and continents, the authors used a large database of patients with SAH to determine the effect of the geographic location of treatment on outcome. METHODS: Data obtained in 3567 patients who were entered into randomized trials of tirilazad between 1991 and 1997 were analyzed. Patients underwent treatment in 162 neurosurgical centers in 21 countries in North America, Europe, Africa, and Australia. The dependent variable was clinical outcome assessed 3 months after SAH with the Glasgow Outcome Scale, which was analyzed as a 5-point variable and dichotomized into favorable (good recovery or moderate disability) and unfavorable (severe disability, vegetative state, or death) outcomes. The effect of country or continent of treatment on outcome was assessed using univariate and multivariate logistic regression and proportional odds modeling before and after adjusting for numerous other factors significantly associated with outcome. RESULTS: The authors constructed several multivariate analysis models and demonstrated that for almost every model, country was not a significant predictor of outcome (p>0.05). There was variation in outcome between countries, but this was mostly due to differences in other admission characteristics that influence outcome such as age, clinical grade, and subarachnoid clot thickness. Because the number of patients entered from some countries was small, countries were grouped, and the data were analyzed by continent. This grouping gave more stable estimates and created an appropriate model for both logistic and proportional odds models and again showed that continent had no significant effect on outcome. CONCLUSIONS: Despite the variations in treatment that undoubtedly exist between countries and continents, the location of treatment had minimal effect on outcome. Outcome was influenced mostly by clinical characteristics on admission such as neurological grade, patient age, and amount of SAH.

Fat and neurosurgery: does obesity affect outcome after intracranial surgery?

OBJECTIVE: Obesity has been linked to increased morbidity and mortality after some surgical procedures. The purpose of this study was to determine whether obesity affects outcome after general neurosurgery and subarachnoid hemorrhage (SAH). METHODS: Three data sets were analyzed, including a retrospective review of 404 patients undergoing cranial and spinal neurosurgical procedures, a prospective collection of 100 patients with aneurysmal SAH, and data from 3567 patients with aneurysmal SAH who were entered into randomized clinical trials of tirilazad. For each data set, outcome was assessed by mortality, postoperative morbidity, and Glasgow Outcome Scale score. Prognostic factors, including body weight and body mass index, were tested for their effect on these outcomes using multivariable logistic regression. RESULTS: For patients undergoing general cranial and spinal neurosurgery, independent predictors of morbidity and mortality were age, American Society of Anesthesia class, disseminated malignancy, emergency surgery, and increased duration of surgery. For patients with SAH, score on the Glasgow Outcome Scale was associated with age and admission Glasgow Coma Scale score. In the tirilazad data set, multiple factors were associated with score on the Glasgow Outcome Scale, but, as with the other 2 data sets, body weight had no relationship to outcome. CONCLUSION: Obesity may have less effect on the outcome of patients with mainly cranial neurosurgical disease and aneurysmal SAH than it does on patients undergoing other types of surgery.

Epidemiology of vancomycin-resistant enterococci among patients on an adult stem cell transplant unit: observations from an active surveillance program.

OBJECTIVE: To use the findings of an active surveillance program to delineate the unique epidemiology of vancomycin-resistant enterococci (VRE) in a mixed population of transplant and nontransplant patients hospitalized on a single patient care unit. DESIGN: Surveillance survey and case-control analysis. SETTING: A 19-bed adult bone marrow and stem cell transplant unit at a referral and primary-care center. PATIENTS: The study included patients undergoing transplantation, patients who had previously received bone marrow or stem cell transplants, and patients with other malignancies and hematological disorders who were admitted to the study unit. METHODS: Patients not previously identified as colonized with VRE had perirectal swab specimens collected at admission and once weekly while hospitalized on the unit. The prevalence of VRE colonization at admission and the incidence throughout the hospital stay, genotypes of VRE specimens as determined by pulsed field gel electrophoresis, and risk factors related to colonization were analyzed. RESULTS: There was no significant difference in the prevalence or incidence of new colonization between nontransplant patients and prior or current transplant recipients, although overall prevalence at admission was significantly higher in the prior transplant group. Preliminary genotypic analysis of VRE isolates from transplant patients suggests that a proportion of cases of newly detected VRE carriage may represent prior colonization not detected at admission, with different risk factors suggestive of a potential epidemiological distinction. CONCLUSION: Examination of epidemiological and microbiological data collected by an active surveillance program provides useful information about the epidemiology of VRE that can be applied to inform rational infection control strategies.

Predictive factors for the development of central line-associated bloodstream infection due to gram-negative bacteria in intensive care unit patients after surgery.

OBJECTIVES: To examine the relative proportions of central line-associated bloodstream infection (BSI) due to gram-negative bacteria and due to gram-positive bacteria among patients who had undergone surgery and patients who had not. The study also evaluated clinical predictive factors and unadjusted outcomes associated with central line-associated BSI caused by gram-negative bacteria in the postoperative period. DESIGN: Observational, case-control study based on a retrospective review of medical records. SETTING: University of Chicago Medical Center, a 500-bed tertiary care center located on Chicago's south side. PATIENTS: Adult intensive care unit (ICU) patients who developed central line-associated BSI. RESULTS: There were a total of 142 adult patients who met the Centers for Disease Control and Prevention National Nosocomial Infection Surveillance System definition for central line-associated BSI. Of those, 66 patients (46.5%) had infections due to gram-positive bacteria, 49 patients (34.5%) had infections due to gram-negative bacteria, 23 patients (16.2%) had infections due to yeast, and 4 patients (2.8%) had mixed infections. Patients who underwent surgery were more likely to develop central line-associated BSI due to gram-negative bacteria within 28 days of the surgery, compared with patients who had not had surgery recently (57.6% vs 27.3%; P= .002). On multivariable logistic regression analysis, diabetes mellitus (adjusted odds ratio [OR], 4.6 [95% CI, 1.2-18.1]; P= .03) and the presence of hypotension at the time of the first blood culture positive for a pathogen (adjusted OR, 9.8 [95% CI, 2.5-39.1]; P= .001) were found to be independently predictive of central line-associated BSI caused by gram-negative bacteria. Unadjusted outcomes were not different in the group with BSI due to gram-negative pathogens, compared to the group with BSI due to gram-positive pathogens. CONCLUSIONS: Clinicians caring for critically ill patients after surgery should be especially concerned about the possibility of central line-associated BSI caused by gram-negative pathogens. The presence of diabetes and hypotension appear to be significant associated factors.

Acoustic neuromas following childhood radiation treatment for benign conditions of the head and neck.

Childhood radiation exposure has been associated with an increased risk for developing several neoplasms, particularly benign and malignant thyroid tumors, but little is known about the risk of developing acoustic neuromas. The aim of this study was to confirm whether there is a risk for acoustic neuromas and, if so, to determine its magnitude and duration. We investigated the time trend and dose-response relationships for acoustic neuroma incidence in a cohort of 3,112 individuals who were irradiated as children between 1939 and 1962. Most of the patients were treated to reduce the size of their tonsils and adenoids and received substantial radiation exposure to the cerebellopontine angle, the site of acoustic neuromas. Forty-three patients developed benign acoustic neuromas, forty of them surgically resected, far in excess of what might be expected from data derived from brain tumor registries. The mean dose (+/-SD) to the cerebellopontine angle was 4.6 +/- 1.9 Gy. The relative risk per Gy was 1.14 (95% confidence interval 1.0-1.3). The earliest case occurred 20.4 years after exposure and the latest 55 years after exposure (mean 38.3 +/- 10.1 years). Our study provides support for an association between acoustic neuromas and childhood radiation exposure. Although acoustic neuromas are usually benign and often asymptomatic, many cause significant morbidity. Following childhood radiation exposure, they appear after a long latency and continue to occur many decades afterward. Any symptoms of an acoustic neuroma in a patient with a history of radiation to the head and neck area should be investigated carefully, and the threshold for employing imaging should be lowered.

Outcome in patients with subarachnoid hemorrhage treated with antiepileptic drugs.

OBJECT: Prophylactic use of antiepileptic drugs (AEDs) in patients admitted with aneurysmal subarachnoid hemorrhage (SAH) is common practice; however, the impact of this treatment strategy on in-hospital complications and outcome has not been systematically studied. The goal in this study was twofold: first, to describe the prescribing pattern for AEDs in an international study population; and second, to delineate the impact of AEDs on in-hospital complications and outcome in patients with SAH. METHODS: The authors examined data collected in 3552 patients with SAH who were entered into four prospective, randomized, double-blind, placebo-controlled trials conducted in 162 neurosurgical centers and 21 countries between 1991 and 1997. The prevalence of AED use was assessed by study country and center. The impact of AEDs on in-hospital complications and outcome was evaluated using conditional logistic regressions comparing treated and untreated patients within the same study center. RESULTS: Antiepileptic drugs were used in 65.1% of patients and the prescribing pattern was mainly dependent on the treating physicians: the prevalence of AED use varied dramatically across study country and center (intraclass correlation coefficients 0.22 and 0.66, respectively [p < 0.001]). Other predictors included younger age, worse neurological grade, and lower systolic blood pressure on admission. After adjustment, patients treated with AEDs had odds ratios of 1.56 (95% confidence interval [CI] 1.16-2.10; p = 0.003) for worse outcome based on the Glasgow Outcome Scale; 1.87 (95% CI 1.43-2.44; p < 0.001) for cerebral vasospasm; 1.61 (95% CI 1.25-2.06; p < 0.001) for neurological deterioration; 1.33 (95% CI 1.01-1.74; p = 0.04) for cerebral infarction; and 1.36 (95% CI 1.03-1.80; p = 0.03) for elevated temperature during hospitalization. CONCLUSIONS: Prophylactic AED treatment in patients with aneurysmal SAH is common, follows an arbitrary prescribing pattern, and is associated with increased in-hospital complications and worse outcome.

Prognostic factors for outcome in patients with aneurysmal subarachnoid hemorrhage.

BACKGROUND AND PURPOSE: The purpose of this study was to describe prognostic factors for outcome in a large series of patients undergoing neurosurgical clipping of aneurysms after subarachnoid hemorrhage (SAH). METHODS: Data were analyzed from 3567 patients with aneurysmal SAH enrolled in 4 randomized clinical trials between 1991 and 1997. The primary outcome measure was the Glasgow outcome scale 3 months after SAH. Multivariable logistic regression with backwards selection and Cox proportional hazards regression models were derived to define independent predictors of unfavorable outcome. RESULTS: In multivariable analysis, unfavorable outcome was associated with increasing age, worsening neurological grade, ruptured posterior circulation aneurysm, larger aneurysm size, more SAH on admission computed tomography, intracerebral hematoma or intraventricular hemorrhage, elevated systolic blood pressure on admission, and previous diagnosis of hypertension, myocardial infarction, liver disease, or SAH. Variables present during hospitalization associated with poor outcome were temperature >38 degrees C 8 days after SAH, use of anticonvulsants, symptomatic vasospasm, and cerebral infarction. Use of prophylactic or therapeutic hypervolemia or prophylactic-induced hypertension were associated with a lower risk of unfavorable outcome. Time from admission to surgery was significant in some models. Factors that contributed most to variation in outcome, in descending order of importance, were cerebral infarction, neurological grade, age, temperature on day 8, intraventricular hemorrhage, vasospasm, SAH, intracerebral hematoma, and history of hypertension. CONCLUSIONS: Although most prognostic factors for outcome after SAH are present on admission and are not modifiable, a substantial contribution to outcome is made by factors developing after admission and which may be more easily influenced by treatment.

Subarachnoid clot volume correlates with age, neurological grade, and blood pressure.

OBJECTIVE: Cerebral vasospasm after aneurysmal subarachnoid hemorrhage (SAH) is associated with the volume and location of subarachnoid blood clots. Factors that influence the volume of SAH have seldom been studied. METHODS: Two independent sets of data were analyzed. Data from 3028 patients with SAH enrolled in four clinical trials of the drug tirilazad were analyzed in addition to data from 74 patients with SAH who underwent digital volumetric analysis of admission computed tomographic scans to determine the subarachnoid clot volume. In the smaller sample of 74 patients, aneurysm width, length, neck size, aspect ratio, and volume were measured on diagnostic cerebral angiograms. Statistical inference bearing on the question of what factors are associated with clot volume was derived by univariate methods, including analysis of variance, chi and t tests, and polytomous logistic regression. RESULTS: Of 22 clinical parameters examined by univariate analysis of the tirilazad dataset, age, World Federation of Neurological Surgeons (WFNS) clinical grade, time from SAH to admission, history of hypertension or diabetes mellitus, aneurysm location, and admission diastolic and systolic blood pressure were correlated with the subarachnoid clot volume (P < 0.05). Polytomous logistic regression found that only age, WFNS grade, time to admission, admission systolic blood pressure, and history of hypertension were higher in patients with larger subarachnoid clots (P < 0.05). Analysis of 74 patients with quantitative subarachnoid clot volumes also found that age and WFNS grade were higher in patients with larger subarachnoid clots (P < 0.05). No aneurysm location or measurement of aneurysm size showed a statistically significant relationship to clot volume in either dataset. CONCLUSION: SAH volume is correlated with clinical characteristics, including age, history of hypertension, admission systolic blood pressure, and WFNS grade. Anatomic aneurysm characteristics such as size and location do not reliably predict clot volume.

Prior antimicrobial therapy and risk for hospital-acquired Candida glabrata and Candida krusei fungemia: a case-case-control study.

The incidence of infections caused by Candida glabrata and Candida krusei, which are generally more resistant to fluconazole than Candida albicans, is increasing in hospitalized patients. However, the extent to which prior exposure to specific antimicrobial agents increases the risk of subsequent C. glabrata or C. krusei candidemia has not been closely studied. A retrospective case-case-control study was performed at a university hospital. From 1998 to 2003, 60 patients were identified with hospital-acquired non-C. albicans candidemia (C. glabrata or C. krusei; case group 1). For comparison, 68 patients with C. albicans candidemia (case group 2) and a common control group of 121 patients without candidemia were studied. Models were adjusted for demographic and clinical risk factors, and the risk for candidemia associated with exposure to specific antimicrobial agents was assessed. After adjusting for both nonantimicrobial risk factors and receipt of other antimicrobial agents, piperacillin-tazobactam (odds ratio [OR], 4.15; 95% confidence interval [CI], 1.04 to 16.50) and vancomycin (OR, 6.48; CI, 2.20 to 19.13) were significant risk factors for C. glabrata or C. krusei candidemia. For C. albicans candidemia, no specific antibiotics remained a significant risk after adjusted analysis. Prior fluconazole use was not significantly associated with either C. albicans or non-C. albicans (C. glabrata or C. krusei) candidemia. In this single-center study, exposure to antibacterial agents, specifically vancomycin or piperacillin-tazobactam, but not fluconazole, was associated with subsequent hospital-acquired C. glabrata or C. krusei candidemia. Further studies are needed to prospectively analyze specific antimicrobial risks for nosocomial candidemia across multiple hospital centers.

Clot volume and clearance rate as independent predictors of vasospasm after aneurysmal subarachnoid hemorrhage.

OBJECT: This study was conducted for two purposes. The first was to determine whether a combination of measurements of subarachnoid clot volume, clearance rate, and density could improve prediction of which patients experience vasospasm. The second was to determine if each of these three measures could be used independently to predict vasospasm. METHODS: Digital files of the cranial computerized tomography (CT) scans obtained in 75 consecutive patients admitted within 24 hours of subarachnoid hemorrhage (SAH) were analyzed in a blinded fashion by an observer who used quantitative imaging software to measure the volume of SAH and its density. Clot clearance rates were measured by quantifying SAH volume on subsequent CT scans. Vasospasm was defined as new onset of a focal neurological deficit or altered consciousness 5 to 12 days after SAH in the absence of other causes of deterioration, diagnosed with the aid of or exclusively by confirmatory transcranial Doppler ultrasonography and/or cerebral angiography. Univariate analysis showed that vasospasm was significantly associated with the SAH grade as classified on the Fisher scale, the initial clot volume, initial clot density, and percentage of clot cleared per day (p < 0.05). In multivariate analysis, initial clot volume and percentage of clot cleared per day were significant predictors of vasospasm (p < 0.05), whereas Fisher grade and initial clot density were not. CONCLUSIONS: Quantitative analysis of subarachnoid clot shows that vasospasm is best predicted by initial subarachnoid clot volume and the percentage of clot cleared per day.