The influence of spinal venous blood pressure on cerebrospinal fluid pressure

In Alligator mississippiensis the spinal dura is surrounded by a venous sinus; pressure waves can propagate in the spinal venous blood, and these spinal venous pressures can be transmitted to the spinal cerebrospinal fluid (CSF). This study was designed to explore pressure transfer between the spinal venous blood and the spinal CSF. At rest the cardiac-related CSF pulsations are attenuated and delayed, while the ventilatory-related pulsations are amplified as they move from the spinal venous blood to the spinal CSF. Orthostatic gradients resulted in significant alterations of both cardiac- and ventilatory-related CSF pulsations. Manual lateral oscillations of the alligator's tail created pressure waves in the spinal CSF that propagated, with slight attenuation but no delay, to the cranial CSF. Oscillatory pressure pulsations in the spinal CSF and venous blood had little influence on the underlying ventilatory pulsations, though the same oscillatory pulsations reduced the ventilatory- and increased the cardiac-related pulsations in the cranial CSF. In Alligator the spinal venous anatomy creates a more complex pressure relationship between the venous and CSF systems than has been described in humans.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Who's challenging who training for staff empathy towards adults with challenging behaviour: cluster randomised controlled trial

BACKGROUND

One in five adults with intellectual disabilities (ID) known to services display challenging behaviours (CBs), and these individuals are at risk for restrictive practices and poor care. Staff attitudes may contribute to the development and/or maintenance of CBs. We investigated the effectiveness of co-produced Who's Challenging Who? training delivered by people with ID to staff.

METHOD

This study involved a cluster randomised controlled trial (RCT) of Who's Challenging Who? training with follow-up at six and 20 weeks post-randomisation.

PARTICIPANTS

two staff from each of 118 residential care settings for adults with ID at least one of whom displayed aggressive CB.

PRIMARY OUTCOME

Self-reported Staff Empathy for people with Challenging Behaviour Questionnaire.

ANALYSIS

intention to treat of all randomised settings. ISCRTN registration: ISRCTN53763600.

RESULTS

118 residential settings (including 236 staff) were randomised to either receive training (59 settings) or to receive training after a delay (59 settings). The primary analysis included data from 121 staff in 76 settings (51% of staff, 64% of settings). The adjusted mean difference on the transformed (cubed) Staff Empathy for people with Challenging Behaviour Questionnaire score at the primary end point was 1073.2 (95% CI: -938.1 to 3084.5, P = 0.296) in favour of the intervention group (effect size Cohen's d = .19).

CONCLUSIONS

This is the first large-scale RCT of a co-produced training course delivered by people with ID. Findings indicated a small positive (but statistically non-significant) effect on increased staff empathy at 20 weeks, and small to moderate effects for staff reported secondary outcomes in favour of the intervention group.

An examination of the elastic properties of tissue-mimicking phantoms using vibro-acoustography and a muscle motor system

Tissue hardness, often quantified in terms of elasticity, is an important differentiating criterion for pathological identity and is extensively used by surgeons for tumor localization. Delineation of malignant regions from benign regions is typically performed by visual inspection and palpation. Although practical, this method is highly subjective and does not provide quantitative metrics. We have previously reported on Vibro-Acoustography (VA) for tumor delineation. VA is unique in that it uses the specific, non-linear properties of tumor tissue in response to an amplitude modulated ultrasound beam to generate spatially resolved, high contrast maps of tissue. Although the lateral and axial resolutions (sub-millimeter and sub-centimeter, respectively) of VA have been extensively characterized, the relationship between static stiffness assessment (palpation) and dynamic stiffness characterization (VA) has not been explicitly established. Here we perform a correlative exploration of the static and dynamic properties of tissue-mimicking phantoms, specifically elasticity, using VA and a muscle motor system. Muscle motor systems, commonly used to probe the mechanical properties of materials, provide absolute, quantitative point measurements of the elastic modulus, analogous to Young's modulus, of a target. For phantoms of varying percent-by-weight concentrations, parallel VA and muscle motor studies conducted on 18 phantoms reveal a negative correlation (p < - 0.85) between mean signal amplitude levels observed with VA and calculated elastic modulus values from force vs. indentation depth curves. Comparison of these elasticity measurements may provide additional information to improve tissue modeling, system characterization, as well as offer valuable insights for in vivo applications, specifically surgical extirpation of tumors.

Prescribing competence of junior doctors: does it add up?

BACKGROUND

Prescribing errors complicate a significant number of paediatric admissions. Ongoing training and monitoring of prescribing competency in junior doctors has occurred in Cardiff since 2001, alongside national measures aimed at improving training and competency.

AIM

Ongoing monitoring of junior doctors' prescribing competency to assess the effect of these national and local initiatives.

METHODS

Junior doctors receive training and subsequent assessment on prescribing competency at induction. A 1 h bleep-free session concerning paediatric prescribing precedes completion of four prescribing tasks. British National Formulary for children and calculators are provided. Those scoring 0 or 1 are retrained before prescribing is permitted. Our previously published data of doctors between 2001 and 2004 was compared with assessment in 2007.

RESULTS

30 junior doctors were assessed in 2007 (32 in 2001-2004). All four questions were answered correctly by 22/30, compared to 10/32 (31%) in 2001-2004. The mean score in 2007 was 93.3% compared to 57.8% previously (see table 1). Comparison of means with previous results demonstrated statistically significant improvement with a mean difference of 36% (95% CI 24 to 47). In 2007, eight (27%) doctors got just one question wrong and no doctor answered all questions incorrectly. In 2001-2004, 22/32 (67%) made at least one error during previous assessment, and one doctor answered all questions incorrectly. Table 1Prescribing assessment scores in 2001-2004 and 2007 Answer scores2001-2004 (n=32)2007 (n=30)All questions correct10 (31%)22 (73%)One incorrect08 (27%)Two incorrect13 (41%)0Three incorrect8 (25%)0All questions incorrect1 (3%)0

CONCLUSION

Ongoing monitoring of junior doctors' prescribing ability has demonstrated improvements which may be due to local and national training initiatives.

A simplified gentamicin dosing chart is quicker and more accurate for nurse verification than the BNFc

BACKGROUND

At least 5% of paediatric admissions are complicated by medication error. Nurses can prevent some errors by correctly verifying prescriptions before administering drugs, which requires adequate drug calculation skills and familiarity with the BNFc. We wished to explore whether a newly devised chart would improve nurses' dose calculation ability and thus potentially reduce doctors' prescription errors.

AIMS

To explore nurses' ability to calculate doses of gentamicin for neonates and children using a new simple dosing chart compared with the BNFc.

METHODS

Two gentamicin dosing charts (paediatric and neonatal) devised by a multidisciplinary group to simplify dose calculation and selection of frequency were compared with the BNFc using four questions (two neonatal, two paediatric) asking ward nurses to calculate gentamicin doses. Answers were scored for both the correct dosage and correct frequency.

RESULTS

51 nurses participated. 11 nurses (22%) answered all four questions correctly. A higher proportion correctly answered both the dosage and frequency questions simultaneously when using the chart compared with the BNFc: paediatric questions 100% (51/51 chart) versus 80% (41/51 BNFc) (OR 0.20) and neonatal questions 55% (28/51 chart) versus 35% (18/51 BNFc) (OR 0.2). Errors when using the BNFc were due to selection of the incorrect regimen (23%), wrong frequency (17%) and one 10-fold dosing error. When using the chart, there were no dosing errors, only frequency errors for the neonatal regimen.

CONCLUSION

The chart was more reliable, quicker and may be useful for patient safety. Revising the format of the BNFc may be beneficial for nurses.

Subject-specific non-linear biomechanical model of needle insertion into brain

The previous models for predicting the forces acting on a needle during insertion into very soft organs (such as, e.g. brain) relied on oversimplifying assumptions of linear elasticity and specific experimentally derived functions for determining needle-tissue interactions. In this contribution, we propose a more general approach in which the needle forces are determined directly from the equations of continuum mechanics using fully non-linear finite element procedures that account for large deformations (geometric non-linearity) and non-linear stress-strain relationship (material non-linearity) of soft tissues. We applied these procedures to model needle insertion into a swine brain using the constitutive properties determined from the experiments on tissue samples obtained from the same brain (i.e. the subject-specific constitutive properties were used). We focused on the insertion phase preceding puncture of the brain meninges and obtained a very accurate prediction of the needle force. This demonstrates the utility of non-linear finite element procedures in patient-specific modelling of needle insertion into soft organs such as, e.g. brain.

Factors associated with identifying tuberculosis contacts

SETTING

Little is known about why some tuberculosis (TB) patients identify few or even no contacts.

OBJECTIVES

To describe patient perceptions of the contact investigation interview and determine potential factors associated with identifying TB contacts.

DESIGN

A total of 13 focus groups were conducted: 10 groups with previously smear-positive pulmonary TB patients born in the United States or Mexico, and three with program staff to discuss attitudes toward and perceptions of the contact investigation interview. Patients were recruited into separate groups by country of birth and number of contacts identified.

RESULTS

The data indicated that patients-even those who identified few contacts-overwhelmingly reported identifying contacts easily and willingly. Understanding the purpose of the contact investigation and seriousness of TB facilitated naming contacts, while miscommunication and misconceptions about TB hindered the process. Patients felt strongly about informing their contacts before the health department contacted them. Staff respondents reported that education and effective communication were critical during contact investigation interviewing.

CONCLUSION

Data indicated that patients, including those identifying few contacts, reported wanting to name their contacts. However, misconceptions may affect their understanding of who their contacts are, and hence the quantity and quality of the contacts identified. These findings underscore the need for effective communication and education.

Prevalence of zoonotic important parasites in the red fox (Vulpes vulpes) in Great Britain

A national necropsy survey of red foxes was carried out across Great Britain to record Echinococcus, Trichinella and Toxoplasma. The survey did not record directly, or indirectly using coproantigen/PCR tests, evidence for the presence of Echinococcus multilocularis in 588 animals, although E. granulosus was suspected in six animals. Parasitological evidence for Trichinella spp. could not be found in 587 fox muscle digests, and a specific PCR test also failed to detect Toxoplasma in a sub-set of 61 random fox tongue biopsies. The upper 95% confidence interval for the above parasites was 0.60% (E. multilocularis), 0.60% (Trichinella spp.) and 5.6% (Toxoplasma). The commonest gut parasites were the hookworm Uncinaria stenocephala (41.3%) and the ascarid Toxocara canis (61.6%). This study also reports the second occurrence of Trichuris vulpis in Great Britain.

Tuberculosis contact investigations: outcomes in selected areas of the United States, 1999

SETTING

Twenty-nine United States jurisdictions.

OBJECTIVE

To determine yields of tuberculosis (TB) contact investigations.

METHODS

Health departments within the jurisdictions reported counts and outcomes from routine contact investigations for cases reported in 1999.

RESULTS

The 29 jurisdictions reported 9199 TB cases, 51.9% of the US and Puerto Rico 1999 total, and listed 67585 contacts. While 571 (10.6%) of 5405 pulmonary cases confirmed by sputum bacteriology had no contacts listed, 13904 contacts were listed for other cases that were unlikely to be contagious. Diagnostic evaluation was completed for 56100 contacts (83.0%), with 561 TB cases found. Of 13083 contacts found to have latent TB infection, 5746 (44.5%) completed treatment to prevent TB. Loss to follow-up and self-discontinuation of treatment accounted for 70% of reasons why treatment was not completed.

CONCLUSION

Contact investigations capture substantial numbers of TB cases and latent TB infections, but the impact on prevention is limited by the poor treatment rates for infected contacts. Contacts should be sought for each potentially contagious TB case; why so many contacts are sought for cases who are unlikely to be contagious needs to be determined.

Outcomes of contact investigations of infectious tuberculosis patients

The objective of this study was to describe outcomes of tuberculosis (TB) contact investigations, factors correlated with those outcomes, and current successes and ways to improve TB contact investigations. We abstracted clinic records of a representative U.S. urban sample of 1,080 pulmonary, sputum-smear(+) TB patients reported to CDC July 1996 through June 1997 and the cohort of their 6,225 close contacts. We found a median of four close contacts per patient. Fewer contacts were identified for homeless patients. A visit to the patient's residence resulted in two additional (especially child) contacts identified. Eighty-eight percent of eligible contacts received tuberculin skin tests (TSTs). Recording the last exposure date to the infectious patient facilitated follow-up TST provision. Thirty-six percent of contacts were TST(+). Household contacts and contacts to highly smear(+) or cavitary TB patients were most likely to be TST(+). Seventy-four percent of TST(+) contacts started treatment for latent TB infection (LTBI), of whom 56% completed. Sites using public health nurses (PHNs) started more high-risk TST(-) contacts on presumptive treatment for LTBI. Using directly observed treatment (DOT) increased the likelihood of treatment completion. We documented outcomes of contact investigation efforts by urban TB programs. We identified several successful practices, as well as suggestions for improvements, that will help TB programs target policies and procedures to enhance contact investigation effectiveness.

Causes and costs of hospitalization of tuberculosis patients in the United States

OBJECTIVE

To examine the costs, lengths of stay and patient characteristics associated with tuberculosis (TB) hospitalizations.

METHODS

A prospective cohort study of 1493 TB patients followed from diagnosis to completion of therapy at 10 public health programs and area hospitals in the US. The main outcome measures were the following: 1) occurrence, 2) cost, and 3) length of stay of TB-related hospitalizations.

RESULTS

There were 821 TB-related hospitalizations among the study participants; 678 (83%) were initial hospitalizations and 143 (17%) were hospitalizations during the treatment of TB. Patients infected with human immunodeficiency virus (HIV) (OR 1.8, 95% CI 1.2-2.6), and homeless patients (OR, 1.7 95% CI 1.1-2.8) were at increased risk of being hospitalized at diagnosis. Homeless patients (RR 2.5, 95%CI 1.5-4.3), patients who used alcohol excessively (RR 1.9, 95% CI 1.2-3.0), and patients with multidrug-resistant TB (RR 5.7, 95% CI 2.7-11.8) were at increased risk of hospitalization during treatment. The median length of stay varied from 9 to 17 days, and median costs per hospitalization varied from $6441 to $12968 among the sites.

CONCLUSION

Important social factors, HIV infection, and local hospitalization practice patterns contribute significantly to the high cost of TB-related hospitalizations. Efforts to address these specific factors are needed to reduce the cost of preventable hospitalizations.

Hospitalization of homeless persons with tuberculosis in the United States

OBJECTIVES

This study assessed whether homeless patients are hospitalized for tuberculosis (TB) more frequently and longer than other patients and possible reasons for this.

METHODS

We prospectively studied hospitalizations of a cohort of TB patients.

RESULTS

HIV-infected homeless patients were hospitalized more frequently than other patients, while homeless patients who had no insurance or whose insurance status was unknown were hospitalized longer. Hospitalization cost $2000 more per homeless patient than for other patients. The public sector paid nearly all costs.

CONCLUSIONS

Homeless people may be hospitalized less if given access to medical care that provides early detection and treatment of TB infection and disease and HIV infection. Providing housing and social services may also reduce hospital utilization and increase therapy completion rates.

Contribution of the assisted reproductive technologies to fertility in males suffering spinal cord injury

This study reviews 19 couples referred between 1990 and 1997 for fertility treatment for anejaculatory infertility in the male partner following spinal injury. Using sperm obtained by assisted ejaculation procedures, 14 of the 19 patients (74%) achieved at least 1 pregnancy. Pregnancy rates per treatment cycle were 12.0% for timed intrauterine insemination, 38.9% for gamete intra-Fallopian transfer and 19.2% for intracytoplasmic sperm injection followed by uterine embryo transfer. Choice of the appropriate assisted reproduction treatment to match the available semen quality results in a high level of success in such patients.

Assessing the impact of Medicaid managed care on TB activities in local health departments

Three in-depth case studies were conducted to explore the impact of Medicaid managed care on local health department prevention activities. Tuberculosis (TB) was selected as a sentinel issue because TB includes both clinical treatment and population-based public health considerations (such as surveillance and contact tracing). Overall, study results indicated that there has been a minimal impact on TB prevention and control services, primarily because few TB patients are served by managed care. However, the sites offer many suggestions for areas to monitor, possible collaborative opportunities, and mechanisms to assure continued TB prevention and control.

Assessment of reproductive disorders and birth defects in communities near hazardous chemical sites. II. Female reproductive disorders

Members of the workgroup on female reproductive disorders discussed methods to evaluate five principal functions: menstrual dysfunction, infertility, pregnancy loss, lactation disorders, and pregnancy complications. To test each function, a nested strategy was considered, based on progressive levels of effort available to conduct field investigations. This strategy was analogous to the three-tier classification of biomarkers used by other workshops. The lowest level of effort, corresponding to Tier 1, consists only of questionnaires, diaries, and reviews of maternal and infant medical records. The medium level of effort (Tier 2) collects data from questionnaires and diaries, and some biologic specimens. Suggested laboratory analyses included measurement of progesterone in saliva and several glycoprotein hormones in urine that evaluate menstrual dysfunction, infertility, and pregnancy loss. The highest level of effort (Tier 3) involves prospective collection of diary information and simultaneous collection of biological specimens.

Access to heart and liver transplantation in the late 1980s

Because of a shortage of usable organs, many who require heart or liver transplants for survival will not have access to them. Access to care may reflect demographic factors and ability to pay, as well as medical considerations. Receipt of an organ may be influenced by expected survival with and without a transplant, age, gender, race, ability to pay, and distance to a transplant center. Discharge abstract data from a national sample of over 500 hospitals in 1986 and 1987 were used to select heart and liver recipients and others with end-stage diseases who did not receive a transplant. Multivariate logistic regression analyses were then used to estimate how receipt of a transplant was influenced by expected years of survival after transplantation (YAT), expected ability to pay, age, sex, race, and distance to a transplant center. Controlling for differences in expected YAT, age, sex, race, and distance to the transplant center, those expected to have the most ability to pay were more likely to receive heart and liver transplants, compared to those expected to have medium ability to pay. Third-party coverage was particularly important in receipt of a transplant for those with absolute contraindications. Expected YAT and age were significant, with some evidence of a tradeoff between urgency and expected YAT in the case of hearts. Men were more likely to obtain heart transplants and women were more likely to get liver transplants. The effects of distance were small. Existing regulatory incentives and biological, medical, and cultural reasons may justify the age-, sex-, race-, and prognosis-related differences in the odds of receiving a transplant. The importance of ability to pay may not have been adequately observed in previous studies restricted to the patients screened at major transplant centers. Hospital discharge records with personal identifiers, linkage to official waiting lists, and better patient level socioeconomic information would permit more definitive analysis.

Mortality and reoperation following prostatectomy: outcomes in a Medicare population

Data from a series of pilot projects undertaken by the Health Care Financing Administration and seven peer review organizations were used to evaluate the outcomes of prostatectomy. Outcomes in both the original random sample of 3,641 patients and subsample of 2,617 patients that had a diagnosis of benign prostatic hyperplasia and did not have a diagnosis of prostatic carcinoma were examined. Patients undergoing a transurethral resection had increased probabilities of reoperation and mortality. However, the increased risk associated with having a transurethral resection was not statistically significant after controlling for other variables associated with mortality.

Brain injured patients: comorbidities and ancillary medical requirements

Traumatic brain injuries are medically and economically devastating conditions. Rehabilitation may be affected by premorbid factors such as substance abuse and violence. Successful rehabilitation is an ongoing process.