What is the relationship between free flow and pressure flow studies in women?

Introduction and hypothesis

The relationship between free flow (FFS) and pressure flow (PFS) voiding studies remains uncertain and the effect of a urethral catheter on flow rates has not been determined. The relationship between residuals obtained at FF and PFS has yet to be established.

Methods

This was a prospective cohort study based on 474 consecutive women undergoing cystometry using different sized urethral catheters at different centres. FFS and PFS data were compared for different conditions and the relationship of residuals analysed for FFS and PFS. The null hypothesis was that urethral catheters do not produce an alteration in maximum flow rates for PFS and FF studies.

Results

Urethral catheterisation results in lower flow rates (p?<?0.01) and this finding is confirmed when flows are corrected for voided volume (p?<?0.01). FFS and PFS maximum flow rates are lower in women with DO than USI (p?<?0.01). A 6-F urethral catheter does not have a significantly greater effect than a 4.5-F urethral catheter. A mathematical model can be applied to transform FFS to PFS flow rates and vice versa. There was no significant difference between the mean residuals of the two groups (FFS vs PFS—two-tailed t?=?0.54, p?=?0.59). Positive residuals in FFS showed a good association with positive residuals in the PFS (r?=?0.53, p?<?0.01)

Conclusions

Urethral catheterisation results in lower maximum flow rates. The relationship can be compared mathematically. The null hypothesis can be rejected.     

Critical care and perioperative medicine. How goes the flow?

The specialty of anesthesiology is at a crossroad. Do anesthesiologists stay in the illusionary safe harbor of the operating room and allow critical care anesthesiologists to float alone? How can in-fighting with other medical and nonmedical providers be avoided, while maintaining or expanding the historic and hopefully future roles of anesthesiologists as hospital-based physicians? A different tact is required to redefine the scope of the practice with broadened training to provide increased expertise in the evolving medical marketplace. This approach would include solid training in business, informatics, data management, and critical thinking on outcomes. This paradigm shift may be challenging, and requires redirection, reallocation of assets, re-education, and a new mindset. If successfully applied, however, it presents a means to strengthen the respected position of the specialty and to promote the medical care and practice of perioperative specialists in the rapidly changing landscape of modern medicine. Regarding the question of turf and ownership of the ICU, the authors suggest pursuing the higher ground of an excellent scope of practice, which facilitates the care and activities of surgical and primary care colleagues. These colleagues, administrators, and governmental agencies will have to be re-educated to support training and provide equitable remuneration. Appropriately trained anesthesiologist-intensivists can complement many other care providers, while providing a wide range of services with an economy of care, whether in a semiclosed or closed ICU setting.     

Differences between the data from free flow and intubated flow in women with urinary incontinence. What do they mean?

AIMS: To assess the effects of a urethral catheter on the urodynamic data extracted from uroflow in women, and to interpret the differences from free uroflow using the VBN mathematical micturition model. METHODS: Urodynamic data of 217 consecutive (June 2002 to December 2004) women with urinary incontinence and without neurological disease or more than grade 2 prolapse were reviewed. Inclusion criteria were to perform one free flow (FF) and one intubated flow (IF) (voided volumes of at least 100 ml and continuous flow curves). Voiding parameters: volumes, maximum flow rate, detrusor pressure and flow time, were analyzed as some characteristic ratios. The VBN model was used to make simulations of various pathophysiological hypotheses. RESULTS: Significant increased residual volume and flow time, decreased maximum flow rate were observed during IF. Twenty five patients had a residual volume only during IF; in that group, both decrease of Q(max) and increase of flow time were significant. Simulations showed that the geometrical effect of the catheter was not the only cause and allowed to propose the occurrence of a compression-like effect of the urethra and of a fading of the detrusor excitation after Q(max) to explain the results. CONCLUSION: Significant differences were found between the data from a FF and an IF in women with urinary incontinence. These findings bring to the fore the impact of the transurethral catheter and underline the necessity to obtain at least one FF and one IF during a urodynamic session.     

SPECT/CT-plethysmography – non-invasive quantitation of bone and soft tissue blood flow

Preserved blood flow to bone and soft tissue is essential for their normal function. To date only numerous methods are suitable for direct bone blood flow (BBF) measurement. Here, we introduce a novel quantitative method for bone and soft tissue blood flow (BBF and SBF, respectively) measurement. It involves a combination of SPECT/CT imaging for blood pool localization in a specific region of interest ("soft" and "hard" tissues composing a limb) with veno-occlusive plethysmography. Using it, we measured BBF and SBF in the four limbs of 10 healthy subjects. At steady state blood flow measurements in the four limbs were similar, ranging between 5.5 – 6.5 and 1.87–2.48 ml per 100 ml of tissue per minute for BBF and SBF, respectively. Our results are comparable to those in the literature. We concluded that SPECT/CT-plethysmography appears to be a readily available and easy to use method to measure BBF and SBF, and can be added to the armamentarium of methods for BBF measurements.     

H-Wave® effects on blood flow and angiogenesis in longitudinal studies in rats

Effects of repeated H-Wave? device stimulation (HWDS) on blood flow and angiogenesis in the rat hind limb were studied. The hypothesis tested was that HWDS acutely increases hind limb blood flow, and that repeated HWDS would elicit angiogenesis. Animals were HWDS-conditioned (``Conditioned') or sham-stimulated (``Sham') (n = 5/group) daily for 3 weeks. The contralateral limb in both groups served as the control. Each animal was injected with bromodeoxyuridine (BrDU). After 3 weeks, rats were anesthetized and iliac artery blood flow was measured bilaterally before, during, and after acute HWDS. HWDS of the Conditioned limbs elicited a 247% increase in blood flow above resting conditions compared to a 200% increase in control legs. Sham animals did not demonstrate between-leg differences in flow. Hindlimb musculature staining for BrDU revealed angiogenesis in Conditioned versus Sham groups. Flow changes accompanying HWDS corroborated earlier microvascular findings demonstrating a significant striated muscle arteriolar dilation with HWDS.     

HLA-B27 detection – comparison of genetic sequence-based method and flow cytometry assay

Objectives

The presence of human leukocyte antigen B27 (HLA-B27) is strongly associated with ankylosing spondylitis. HLA-B27 testing is routinely applied in the diagnosis of this disease. The aim of the present study was to compare two methods of HLA-B27 detection – a genetic sequence-based method and a flow cytometry assay.

Material and methods

Peripheral blood was obtained from 300 individuals with suspected spondyloarthropathy. Expression of HLA-B27 on the T cell surface was analysed by flow cytometry assay using GS145.2 monoclonal antibody specific for HLA-B27. DNA was isolated from the whole blood. Genes coding for HLA-B27, -B40 and -B47:01 were detected by polymerase chain reaction using the MW02/MW09 primer pair. Then, positive samples were sequenced in order to discriminate allelic variations of the HLA-B27 gene. Results of sequencing were analysed using Chromas LITE 2.1.1 software, BLAST software and the IMGT/HLA database. Ambiguous samples were additionally analysed by polymerase chain reaction using E91 and E136 primers amplifying a 135-bp fragment of the human HLA-B27 gene.

Results

Among 300 samples, 76 were HLA-B27-positive on the basis of flow cytometry analysis. Genetic sequence analysis confirmed positivity of 73 from among 76 samples. Two hundred twenty six samples were HLA-B27-negative, whereas the result of one sample analysis was ambiguous. Fifty-three samples were identified as allelic variation 27:05, 19 samples as allelic variation 27:02, and one sample as allelic variation 27:07.

Conclusions

This study shows that the genetic sequence-based method and the flow cytometry assay give consistent results in 99% of cases. The performed genetic analysis proves that the majority of HLA-B27-positive samples belong to the 27:05 allelic variation, which is strongly associated with high risk of ankylosing spondylitis.     

Absorptiometry and “osteoporosis”: problems

connecting the dots between diverse clinical and other matters and an updated bone physiology reveals relationships that could modify some ideas about the roles and uses of absorptiometry in osteoporosis work. Herein, absorptiometry means that part of clinical densitometry that depends on X-ray absorption by bone and other tissues, thus excluding ultrasound methods and magnetic resonance imaging. The modifications concern, in part, some limitations of bone mineral density data, the kinds of physiological information that absorptiometry can and cannot provide, the relative importance of bone mass and whole-bone strength, how to define and study bone health and osteoporosis, and two kinds of osteoporotic fractures. As those modifications concern important national health care issues, they deserve answers based on hard evidence. Identifying those modifications might help others to evaluate them.     

“Physiological osteoporosis” and “osteoblast insufficiency” in old age

Summary To investigate the expectation of general insufficiency of osteoblasts with increasing age, we studied autotopsy material from 105 deceased persons of both sexes who had died between 16 and 91 years and in whom clinically manifest diseases of the bone had been excluded. Quantitative morphometric examination of the structure of the spongy bone of the 3rd–5th lumbar vertebral bodies (LVBs) and of the 5th–7th cervical vertebral bodies (CVBs) was carried out in frontal and saggital planes, the parameters analysed being volumetric density (V_v), surface density (S_v) and specific surface area (S/V), and the results were subjected to statistical evaluation. The results showed that in the three LVBs, V_v, S_v and S/V behave in a similar manner, V_v and S_v decreasing after the age of 50 years by more than one-third while S/V remains constant throughout life. The three lower CVBs had higher values than the LVBs for all three structural parameters. In the 7th CVB somewhat lower V_v and S_v values and higher S/V values were found than in the 5th and 6th. The age-related changes, by contrast, were very small. This differing behavior of the spongy bone in the two regions of the spinal column is an expression of the different characteristic loading forces in each regions: LVB loading is predominantly static, CVB loading mainly dynamic. Thus, from the functional point of view, what is known as physiological osteoporosis due to ageing is nothing more than adaptation by an ageing bone to physical activity, reflecting —like the bone of the young adult — the current loading of the cancellous bone by the actions of the musculoskeletal system. Since such physical activity is often age-related, the performance of the osteoblasts does not depend upon age per se, but merely on the remaining functional adaptive capacities of the ageing organism as whole.Dedicated to Prof. Dr. Heinz Wagner on the occasion of his 60th birthday     

Patient anxiety and experiences associated with an outpatient “one-stop” “see and treat” hysteroscopy clinic

Background One-stop outpatient hysteroscopy clinics have become well established for the investigation and treatment of women with abnormal uterine bleeding. However, the advantages of these clinics may be offset by patient factors such as anxiety, pain, and dissatisfaction. This study aimed to establish patients views and experiences of outpatient service delivery in the context of a one-stop diagnostic and therapeutic hysteroscopy clinic, to determine the amount of anxiety experienced by these women and compare this with other settings, and to determine any predictors for patient preferences.Methods The 20-item State–Trait Anxiety Inventory was given to 240 women attending a one-stop hysteroscopy clinic: to 73 consecutive women before their appointment in a general gynecology clinic and to 36 consecutive women attending a chronic pelvic pain clinic. The results were compared with published data for the normal female population, for women awaiting major surgery, and for women awaiting a colposcopy clinic appointment. In addition, a questionnaire designed to ascertain patients views and experiences was used. Logistic regression analysis was used to delineate the predictive values of diagnostic or therapeutic hysteroscopy, and to determine their effect on the preference of patients to have the procedure performed under general anesthesia in the future.Results Women attending the hysteroscopy clinic in this study reported significantly higher levels of anxiety than those attending the general gynecology clinic (median, 45 vs 39; p = 0.004), but the levels of anxiety were comparable with those of women attending the chronic pelvic pain clinic (median, 45 vs 46; p = 0.8). As compared with the data from the normal female population (mean, 35.7) and those reported for women awaiting major surgery (mean, 41.2), the levels of anxiety experienced before outpatient hysteroscopy clinic treatment were found to be higher (mean, 45.7). Only women awaiting colposcopy (6-item mean score, 51.1 ± 13.3) experienced significantly higher anxiety scores than the women awaiting outpatient hysteroscopy (6-item mean score, 47.3 ± 13.9; p = 0.002). Despite their anxiety, most women are satisfied with the outpatient hysteroscopy see and treat service. High levels of anxiety, particularly concerning pain but not operative intervention, were significant predictors of patients desiring a future procedure to be performed under general anesthesia.Conclusions Outpatient hysteroscopy is associated with significant anxiety, which increases the likelihood of intolerance for the outpatient procedure. However, among those undergoing operative therapeutic procedures, dissatisfaction was not associated with the outpatient setting.     

Bilateral severe carotid artery stenosis or occlusion – cerebral autoregulation dynamics and collateral flow patterns

Summary ¶Background. Bilateral severe obstruction of the internal carotid artery is a hemodynamically critical state. We aimed to (1) analyze dynamic cerebral autoregulation (DCA) in affected patients, and (2) to correlate DCA data with different collateral flow patterns. Methods. DCA was assessed noninvasively by transfer function analysis (phase shift) of respiratory-induced oscillations at 0.1Hz of arterial blood pressure (Finapres method) and cerebral blood flow velocity (transcranial Doppler) in 30 patients with severe bilateral carotid stenosis (75%) or occlusion. CO₂-reactivity was measured via inhalation of 7% CO₂. 30 patients with unilateral stenosis were recruited as controls. Results. Patients with bilateral 75–89% stenosis had a virtually preserved phase shift. A pronounced reduction was found in bilateral critical stenosis or obstruction (90–100%). Patients with ipsilateral 90–100% and contralateral 75–89% stenosis had a significantly less severe reduction of phase shift on the ipsilateral side. CO₂-reactivity showed a less marked reduction in patients with bilateral critical stenosis or occlusion. Phase shift was best if Willisian collaterals were present. Significantly reduced values were found if only secondary collaterals (ophthalmic artery, leptomeningeal flow) were detected. Poorest values occured with recruitment of functionally stenosed Willisian collaterals. CO₂-reactivity showed poor values with sole recruitment of secondary collaterals, whereas functionally stenosed primary collaterals did not show values as poor as for phase shift. Clinically symptomatic patients had significantly lower phase shift and CO₂-reactivity values. Conclusions. DCA is severely impaired in bilateral critical carotid stenosis or occlusion. Sole recruitment of secondary collaterals and signs of a functional stenosis in primary (Willisian) collaterals reflect insufficient collateral supply with a poor hemodynamic status. CO₂-reactivity assessing the vasodilatory reserve and DCA represent different information for characterizing cerebral hemodynamic impairment. Determining transfer function phase might be a physiologically well supported approach for analysis of cerebral hemodynamic compromise.