Understanding medication safety involving patient transfer from intensive care to hospital ward: a qualitative sociotechnical factor study

OBJECTIVE

To understand the sociotechnical factors affecting medication safety when intensive care patients are transferred to a hospital ward. Consideration of these medication safety factors would provide a theoretical basis, on which future interventions can be developed and evaluated to improve patient care.

DESIGN

Qualitative study using semistructured interviews of intensive care and hospital ward-based healthcare professionals. Transcripts were anonymised prior to thematic analysis using the London Protocol and Systems Engineering in Patient Safety V.3.0 model frameworks.

SETTING

Four north of England National Health Service hospitals. All hospitals used electronic prescribing in intensive care and hospital ward settings.

PARTICIPANTS

Intensive care and hospital ward healthcare professionals (intensive care medical staff, advanced practitioners, pharmacists and outreach team members; ward-based medical staff and clinical pharmacists).

RESULTS

Twenty-two healthcare professionals were interviewed. We identified 13 factors within five broad themes, describing the interactions that most strongly influenced the performance of the intensive care to hospital ward system interface. The themes were: Complexity of process performance and interactions; Time pressures and considerations; Communication processes and challenges; Technology and systems and Beliefs about consequences for the patient and organisation.

CONCLUSIONS

The complexity of the interactions on the system performance and time dependency was clear. We make several recommendations for policy change and further research based on improving: availability of hospital-wide integrated and functional electronic prescribing systems, patient flow systems, sufficient multiprofessional critical care staffing, knowledge and skills of staff, team performance, communication and collaboration and patient and family engagement.

Respiratory viral infections during the 2009-2010 winter season in Central England, UK: incidence and patterns of multiple virus co-infections

Acute viral respiratory infections are the most common infections in humans. Co-infection with different respiratory viruses is well documented but not necessarily well understood. The aim of this study was to utilise laboratory data from the winter season following the 2009 influenza A(H1N1) outbreak to investigate rates of respiratory virus co-infections, virus prevalence in different age groups and temporal variations in virus detection. The Health Protection Agency Public Health Laboratory (HPA PHL) Birmingham, UK, routinely uses polymerase chain reaction (PCR) to detect common respiratory viruses. The results from specimens received for respiratory virus investigations from late September 2009 to April 2010 were analysed. A total of 4,821 specimen results were analysed. Of these, 323 (13.2 %) had co-detections of two viruses, 22 (0.9 %) had three viruses and four (0.2 %) had four viruses. Reciprocal patterns of positive or negative associations between different virus pairs were found. Statistical analysis confirmed the significance of negative associations between influenza A and human metapneumovirus (HMPV), and influenza A and rhinovirus. Positive associations between parainfluenza with rhinovirus, rhinovirus with respiratory syncytial virus (RSV) and adenovirus with rhinovirus, parainfluenza and RSV were also significant. Age and temporal distributions of the different viruses were typical. This study found that the co-detection of different respiratory viruses is not random and most associations are reciprocal, either positively or negatively. The pandemic strain of influenza A(H1N1) was notable in that it was the least likely to be co-detected with another respiratory virus.

Microbial contamination of non-invasive ventilation devices used by adults with cystic fibrosis

BACKGROUND

There is currently little evidence regarding potential risks of bacterial contamination of non-invasive ventilation (NIV) devices used by cystic fibrosis (CF) patients.

AIM

The aim of this study was to determine the extent of bacterial contamination of NIV devices in our regional adult CF centre.

METHODS

Seven NIV devices recently used by CF patients chronically infected with Pseudomonas aeruginosa or Burkholderia cepacia complex (BCC) were swabbed in seven areas, both external and internal. Two devices had undergone ethylene oxide (EtO) sterilization between patient use and swabbing, and five devices had not undergone EtO sterilization.

FINDINGS

Swabs from five devices had insignificant growth of environmental organisms and two devices had significant growth of environmental organisms. No CF pathogens were isolated from any machine.

CONCLUSIONS

No evidence was found of pathogenic microbial contamination of NIV devices used by CF patients in this small study. We suggest that further studies examine for evidence of bacterial contamination of NIV devices and that this issue should be included in future CF infection control guidelines.

The problem with using computer programmes to assign ethnicity: immigration decreases sensitivity

OBJECTIVES

It is recognized that ethnic group is important in describing differences in infection and disease, but is often not routinely available to surveillance systems. Computerized programmes, such as NamPehchan, can assign ethnicity according to name; however, sensitivity and positive predictive value (PPV) can vary. The aim of this study was to assess whether the sensitivity and PPV of NamPehchan had changed, after an observation that surnames previously associated with South Asians were increasingly reported as Black.

STUDY DESIGN

Cross-sectional.

METHODS

NamPehchan was used to classify women as South Asian using name, and compared with the gold standard (midwife-reported ethnicity). Sensitivity and PPV were calculated overall and by year. Frequency of infection by ethnic group was estimated.

RESULTS

A total of 627 women positive for hepatitis B surface antigen were identified. The majority were from minority ethnic groups, particularly Asian. The overall sensitivity of NamPehchan was 74.5% and PPV was 68.5%. Almost 50% of Black African women were classified as South Asian by NamPehchan.

CONCLUSIONS

Immigration from African countries has reduced the sensitivity of NamPehchan in this group. Care is needed when using NamPehchan for groups which include Africans from Muslim areas, as misclassification is likely to occur.

Diagnosis of acute hepatitis C virus infection and estimated incidence in low- and high-risk English populations

The diagnosis of acute hepatitis C virus (HCV) infection is not straightforward; few people exhibit clinical symptoms and genome/antigen detection techniques do not indicate when infection had occurred. Here, a strategy to detect HCV RNA in the absence of antibody ('window-period') for diagnosis of acute infection is assessed. The sentinel surveillance of hepatitis testing study was used to retrospectively identify anti-HCV negative samples from high-risk individuals (2002-2003), for testing singly for HCV RNA. Additional samples were identified prospectively (2005) and tested in pools for HCV RNA. Positive samples were genotyped. Incidence and costs of adopting the pooling strategy were estimated. In the retrospective study, 8/390 (2.1%) samples were confirmed HCV RNA positive, anti-HCV negative. Prospectively, 3237 samples were tested in 325 pools. Five positive pools identified four confirmed HCV RNA positive patients (one false positive). Estimated incidence was 12.9 per 100 person-years in injecting drug users (IDUs) (retrospective study) and 3.7 per 100 person-years among drug/alcohol services and prison attendees (prospective study). Estimated costs were pound 850 per positive sample, in areas of higher risk. The yield from a window-period strategy depends upon the population tested. Pooled HCV RNA testing of anti-HCV negative samples from the current IDUs is realistic and relatively inexpensive to identify recently infected individuals.

Ante-natal screening and post-natal follow-up of hepatitis B in the West Midlands of England

BACKGROUND

We established at Queen Elizabeth Hospital in Birmingham a post-natal follow-up care service for hepatitis B virus (HBV) positive women diagnosed through ante-natal screening.

AIM

Virological and clinical follow-up of HBsAg positive mothers detected through ante-natal screening in Birmingham.

DESIGN

Retrospective observational study.

METHOD

We evaluated 117 post-natal mothers with chronic HBV infection between April 2003 and December 2006. Patients were first seen at least 3 months post-delivery and followed up.

RESULTS

Most of the women were of Asian or African origin (107 of 117 patients). Five out of 117 (4%) patients had undergone serum HBsAg clearance by the time of post-natal review, and 112 patients had persisting HBsAg-positivity (seven HBeAg positive and 105 HBeAg negative). HBeAg positive women were younger than HBeAg negative patients (median 21 vs 30-years old). Fifty percent of HBeAg negative women had detectable serum HBV DNA at the time of initial review. HBeAg positive women had higher serum HBV DNA titres than those negative for HBeAg (median 40 million copies/ml vs 4323 copies/ml). The majority of patients had normal serum transaminases. A single case of clinically significant liver disease was identified in a woman with HBV and delta virus infection.

CONCLUSION

Very few women who were diagnosed with chronic HBV infection at ante-natal screening have clinical evidence of liver disease. However, many have high levels of virus replication and remain at risk for the future development of liver disease.

Sentinel laboratory surveillance of hepatitis C antibody testing in England: understanding the epidemiology of HCV infection

This paper describes sentinel laboratory surveillance of hepatitis C antibody testing in England. Demographic and test result data were supplemented by follow-up questionnaires sent to the requesting clinician. Between October 2002 and September 2003 almost 75000 anti-HCV tests were performed in eight sentinel centres. More males were tested than females and over half of those tested were aged 25-44 years. Overall 5.7% (3333/58144, range 2.8-7.7%) individuals tested positive. Follow-up questionnaire data showed that 82% (1043/1277) of the positives had injecting drug use reported as the main risk exposure. The majority of negative individuals were undergoing routine screening as recommended for specific patient groups. Most individuals were asymptomatic. Antibody prevalence was estimated to be 34% in current injecting drug users and 42% in former injectors. Comparing positives to routine national surveillance suggests that only 53% (1782/3333) of diagnosed cases were reported. Sentinel laboratory data can provide valuable supplementary data to national surveillance.

Transfusion-transmitted hepatitis E in a 'nonhyperendemic' country

Indigenous hepatitis E is increasingly recognized in developed countries, where it may be a zoonosis. We describe the first case of transfusion-transmitted hepatitis E in the UK from a blood donor who had no history of recent travel abroad. Follow-up of the donor and recipients of the blood products was carried out using serological and molecular techniques. Acute hepatitis E was transmitted to one of two recipients. The infected patient would have received a larger volume of the donor's plasma. HEV subgenomic sequences carried by the donor and recipient were identical. This is the first case of post-transfusion hepatitis E in the UK. Secondary transmission of hepatitis E indigenous to a nonhyperendemic country may occur by blood transfusion. It is important that blood donors inform the transfusion service of all post-donation illnesses so that appropriate interventions can take place.

The diagnostic significance of an assay for 'total' hepatitis C core antigen

A measurable serological response to hepatitis C infection is delayed on average until 70 days after infection. In addition, it may not occur in some immunocompromised people. Detection of free hepatitis C (HCV) core antigen in blood has enabled diagnosis in the pre-seroconversion period. The ability to detect 'total' HCV core antigen, both free and antibody bound, would widen its use for confirming anti-HCV antibody positive patients and monitoring a therapeutic response. This study has evaluated a prototype 'total' HCV core antigen immunoassay. Sera from 145 HCV negative blood donors gave a mean value of 54.9 (+/-46.2) pg/ml based on recombinant antigen standards. Using these figures, the HCV core antigen cut-off was set as 200 pg/ml. Two hundred blood donors sera with indeterminant (a single-band on recombinant immunoblot assay) HCV antibody statuses gave fully concordant HCV core antigen results compared to their polymerase chain reactions (PCRs)--three positive, and 197 negative. HCV core antigen and PCR results were compared for 59 sera from 19 HCV positive liver disease patients. The HCV core antigen results were in complete agreement with their PCRs for the nine patients always PCR positive and the three continuously negative. For six patients on antiviral therapy whose qualitative PCRs changed from positive to negative, the HCV core antigen results paralleled the PCR results. The only discrepant results were from one patient whose PCR results went from negative to positive. 'Total' HCV core antigen testing will greatly improve the scope of diagnostic tests for hepatitis C.

A dose ranging study of the pharmacokinetics, safety, and preliminary efficacy of lamivudine in children and adolescents with chronic hepatitis B

Fifty-three patients with chronic hepatitis B and active viral replication were studied for 4 weeks while on treatment and for 12 weeks after treatment with the oral nucleoside analogue lamivudine. Children aged 2 to 12 years were randomized to receive twice-daily doses of 0.35, 1.5, or 4 mg of lamivudine solution per kg of body weight or once-daily doses of 3 mg of lamivudine solution per kg. Adolescents aged 13 to 17 years received lamivudine at 100 mg (as tablets). Blood samples for pharmacokinetic assay were taken on days 1 and 28. Lamivudine was rapidly absorbed following oral administration, with the maximum concentration in serum being reached 0.5 to 1 h postdosing. Apparent oral clearance (CL/F) was higher in younger children and decreased with age, with CL/F values for adolescents reaching those seen for adults by the age of 12. All doses produced a dramatic fall in serum hepatitis B virus (HBV) DNA levels, with a median reduction of >/=99.5% after 4 weeks of treatment and with the levels returning to the baseline levels posttreatment. The correlation of dose, area under the concentration-time curve (AUC), and changes in HBV DNA levels, as measured by the Chiron Quantiplex assay, showed maximal antiviral effects (99.9% inhibition and a reduction of the amount of HBV DNA of approximately 3 log(10)) at 3 mg/kg/day, with no discernible increase in effect seen whether the drug was given at 4 mg/kg twice daily or whether it was given once daily or twice daily. The limit of detection of the assay (2.5 pg/ml) was reached for some but not all patients across the dose ranges, with the smallest number (n = 2) of those having values negative by the Chiron Quantiplex assay being in the lowest-dose group. The 13- to 17-year-olds showed a similar overall response in terms of the HBV DNA level reduction compared to that for patients younger than age 13. Analysis of the same samples by PCR, which has a lower limit of sensitivity than the Chiron Quantiplex assay, also showed average drops in HBV DNA levels of about 3 log(10) at 4 weeks for patients for which the AUC was >/=4,000 ng. h/ml, confirming the conclusions given above. Lamivudine treatment was well tolerated at all doses, with no significant adverse events or laboratory data changes. On the basis of pharmacokinetic and pharmacodynamic data, a 3-mg/kg/day dose in children (ages 2 to 12 years) with chronic hepatitis B provides levels of exposure and trough concentrations similar to those seen in adults following the receipt of doses of 100 mg. The 100-mg dose is being evaluated in a large phase III study with HBV-infected pediatric patients.

Selection of hepatitis B surface "escape" mutants during passive immune prophylaxis following liver transplantation: potential impact of genetic changes on polymerase protein function

CASE REPORT

A patient is described who developed hepatitis B virus (HBV) reinfection five months following liver transplantation. Failure of hepatitis B immunoglobulin prophylaxis was associated with the emergence of mutations. HBV gene sequencing identified nucleotide substitutions associated with amino acid changes, one within the major hydrophilic region (MHR) of the HBV surface antigen at amino acid position 144 and one outside the MHR. Because of the overlapping reading frames of surface and polymerase genes, the latter surface antigen change was associated with an amino acid change in the polymerase protein. The patient developed significant allograft hepatitis and was treated with lamivudine (3TC) 100 mg daily. Rapid decline of serum HBV DNA was observed with loss of HBV e antigen and HBV surface antigen from serum. There was normalisation of liver biochemistry, and liver immunohistochemistry showed a reduction in HBV core and disappearance of HBs antigen staining.

CONCLUSION

Surface antigen encoding gene mutations associated with HBIg escape may be associated with alteration of the polymerase protein. The polymerase changes may affect sensitivity to antiviral treatment. Selection pressure on one HBV reading frame (for example, HBIg pressure on HBsAg, or nucleoside analogue pressure on polymerase protein) may alter the gene product of the overlapping frame. Such interactions are relevant to strategies employing passive immune prophylaxis and antiviral treatment.

High pre-treatment serum hepatitis B virus titre predicts failure of lamivudine prophylaxis and graft re-infection after liver transplantation

BACKGROUND/AIMS

Orthotopic liver transplantation has an established role for the treatment of patients with chronic liver failure secondary to hepatitis B virus (HBV) infection. Unfortunately, recurrent infection of the graft can be associated with aggressive disease, and with diminished graft and patient survival. Currently, the role of nucleoside analogues for prevention of graft re-infection is being evaluated. Preliminary results are encouraging, but treatment failure has been associated with emergence of drug-resistant virus.

METHODS

We have studied ten consecutive patients who received lamivudine prophylaxis for prevention of HBV graft reinfection. Sequential sera, collected prelamivudine then during treatment before and after liver transplantation, were examined. Conventional serological markers were measured, as were serum viral DNA levels with a sensitive quantitative polymerase chain reaction assay.

RESULTS

Lamivudine treatment effected a reduction in serum HBV levels, but six patients still had measurable viral DNA at the time of transplantation. Five patients developed graft re-infection with lamivudine-resistant virus. Resistant virus emerged 8 to 15 months post-transplant. The likelihood of emergence of resistant virus was related to the pre-treatment serum HBV titre. Persistent serum viral DNA positivity and evidence of graft re-infection during the early post-transplant period did not predict the subsequent emergence of resistant virus.

CONCLUSIONS

Our observations suggest that the resistant species may be present in the viral quasispecies in the serum and liver of patients with high-level replication prior to lamivudine exposure. The resistant species can persist during lamivudine treatment prior to transplantation, and emerge following transplantation. These observations suggest strategies which might prevent the emergence of drug-resistant species, and imply that graft re-infection may be a preventable phenomenon.

Screening of pregnant women for hepatitis B

Neonatal infection with hepatitis B virus carries a very high risk of resulting in a persistent infection. Babies born to hepatitis B carrier mothers are at risk of infection through exposure to blood and body fluids during birth. These 'at risk' babies can only be identified through screening of all mothers during pregnancy. Prevention of infection in this group is a key element in any nation's strategy to reduce the incidence and eventually eliminate hepatitis B infection in its population as the persistently infected infants are a reservoir of infection throughout their lives. The infected adult carries a relatively low risk of becoming a chronic carrier (< 10%). Various strategies for screening in pregnancy have been adopted. These include attempts to identify women with a history of 'risk behaviour', testing only women who were born in areas of high endemicity, pooling of sera and universal antenatal screening. The advantages and disadvantages of the various strategies will be discussed.

The prevalence of hepatitis B and C in an antenatal population of various ethnic origins

A total of 3522 samples of serum, collected anonymously from women attending an antenatal clinic, was tested for hepatitis B surface antigen and antibody to hepatitis C. The prevalence of anti-HCV was low; only five confirmed positives were found (0.14%). The prevalence of hepatitis B overall was 0.56%, but was 1.04% in women from immigrant groups. Hepatitis B carriage is therefore four times more common than hepatitis C carriage in the antenatal population comprised of various ethnic origins. The patterns of infection in the two viruses are reversed, hepatitis B being more common in Asian, S.E. Asian and West Indian mothers and hepatitis C being more common in mothers of white Caucasian origin. Routine antenatal screening for anti-HCV is discussed.

Epidemiology of human T-cell leukaemia/lymphoma virus type 1 (HTLV-1) infections in a subpopulation of Afro-Caribbean origin in England

Epidemiological studies on neurological diseases in residents of Afro-Caribbean origin in the West Midlands region of England have identified eight patients with tropical spastic paraparesis (TSP), all of whom were found to be infected with human T-cell leukaemia/lymphoma virus type 1 (HTLV-1). The husband of one of the patients with TSP was also infected with HTLV-1 and had a T-cell lymphoma. In addition, six asymptomatic HTLV-1-infected first-degree relatives of the TSP patients have been found. By anonymous testing of over 700 sera obtained from individuals of Afro-Caribbean, African, or Asian ethnic origin, seven HTLV-1-infected individuals were detected, who were all immigrants from the Caribbean. Overall, these numbers yielded a seroprevalence of HTLV-1 infections of 3.4% among the immigrant population of Afro-Caribbean origin, which is comparable with the prevalence of HTLV-1 in Jamaica in an equivalent age and sex cohort. Sera were tested for HTLV-1 antibody by means of three different procedures: passive particle agglutination test (Serodia), indirect enzyme-labeled immunosorbent assay (ELISA; Dupont), and indirect immunofluorescence test (in-house, using HTLV-1-infected MT2 cells). The results of all three tests correlated very well with each other. HTLV-1 antibody titres in TSP patients were on the whole significantly higher than those of asymptomatic carriers, but some of the apparently healthy first-degree relatives and one anonymously tested individual had titres as high as most of the TSP patients.

Some 5-hydroxytryptamine-like actions of fenfluramine: a comparison with (+)-amphetamine and diethylpropion

The 5-hydroxytryptamine (5-HT)-like effects of fenfluramine have been investigated in mice in two different experiments. In a behavioural test in mice pretreated with tranylcypromine, fenfluramine caused stereotyped changes which were similar to those produced by 5-hydroxytryptophan (5-HTP) and were antagonized by methysergide or pretreatment with p-chlorophenylalanine (PCPA). Like 5-HTP, fenfluramine reduced the conditioned response in a one-trial conditioning test, an effect antagonized by methysergide or by PCPA pretreatment. The reduction in the conditioned response caused by a maximal electroconvulsion was also antagonized by PCPA, an effect prevented by 5-HTP. Equivalent anorectic doses of (+)-amphetamine and diethylpropion caused a small increase in stereotyped behaviour, but this was not modified by methysergide; both anorectic drugs were inactive in the one-trial conditioning test. It seems probable that the observed actions of fenfluramine are caused indirectly through the release of endogenous brain 5-HT.