Severe maternal morbidity in Scotland

Using a cohort study design, we analysed 17 diagnoses and 9 interventions (including critical care admission) as a composite measure of severe maternal morbidity for pregnancies recorded over 14 years in Scotland. There were 762,918 pregnancies, of which 7947 (10 in 1000 pregnancies) recorded 9345 severe maternal morbidity events, 2802 episodes of puerperal sepsis being the most common (30%). Severe maternal morbidity incidence increased from 9 in 1000 pregnancies in 2012 to 17 in 1000 pregnancies in 2018, due in part to puerperal sepsis recording. The odds ratio (95%CI) for severe maternal morbidity was higher for: older women, for instance 1.22 (1.13-1.33) for women aged 35-39 years and 1.44 (1.27-1.63) for women aged > 40 years compared with those aged 25-29 years; obese women, for instance 1.13 (1.06-1.21) for BMI 30-40 kg.m-2 and 1.32 (1.15-1.51) for BMI > 40 kg.m-2 compared with BMI 18.5-24.9 kg.m-2 ; multiple pregnancy, 2.39 (2.09-2.74); and previous caesarean delivery, 1.52 (1.40-1.65). The median (IQR [range]) hospital stay was 3 (2-5 [1-8]) days with severe maternal morbidity and 2 (1-3 [1-5]) days without. Forty-one women died during pregnancy or up to 42 days after delivery, representing mortality rates per 100,000 pregnancies of about 365 with severe maternal morbidity and 1.6 without. There were 1449 women admitted to critical care, 807 (58%) for mechanical ventilation or support of at least two organs. We recorded an incidence of severe maternal morbidity higher than previously published, possibly because sepsis was coded inaccurately in our databases. Further research may determine the value of this composite measure of severe maternal morbidity.

Intensive care utilization and outcomes after high-risk surgery in Scotland: a population-based cohort study

BACKGROUND

The optimal perioperative use of intensive care unit (ICU) resources is not yet defined. We sought to determine the effect of ICU admission on perioperative (30 day) and long-term mortality.

METHODS

This was an observational study of all surgical patients in Scotland during 2005-7 followed up until 2012. Patient, operative, and care process factors were extracted. The primary outcome was perioperative mortality; secondary outcomes were 1 and 4 yr mortality. Multivariable regression was used to construct a risk prediction model to allow standard-risk and high-risk groups to be defined based on deciles of predicted perioperative mortality risk, and to determine the effect of ICU admission (direct from theatre; indirect after initial care on ward; no ICU admission) on outcome adjusted for confounders.

RESULTS

There were 572 598 patients included. The risk model performed well (c-index 0.92). Perioperative mortality occurred in 1125 (0.2%) in the standard-risk group (n=510 979) and in 3636 (6.4%) in the high-risk group (n=56 785). Patients with no ICU admission within 7 days of surgery had the lowest perioperative mortality (whole cohort 0.7%; high-risk cohort 5.3%). Indirect ICU admission was associated with a higher risk of perioperative mortality when compared with direct admission for the whole cohort (20.9 vs 12.1%; adjusted odds ratio 2.39, 95% confidence interval 2.01-2.84; P<0.01) and for high-risk patients (26.2 vs 17.8%; adjusted odds ratio 1.64, 95% confidence interval 1.37-1.96; P<0.01). Compared with direct ICU admission, indirectly admitted patients had higher severity of illness on admission, required more organ support, and had an increased duration of ICU stay.

CONCLUSIONS

Indirect ICU admission was associated with increased mortality and increased requirement for organ support.

TRIAL REGISTRATION

UKCRN registry no. 15761.

Evaluation of Staphylococcus aureus eradication therapy in orthopaedic surgery

PURPOSE

Despite WHO recommendations, there is currently no national screening and eradication policy for the detection of methicillin-sensitive Staphylococcus aureus (MSSA) in the UK prior to elective orthopaedic surgery. This study aimed to evaluate the effectiveness of current standard methicillin-resistant S. aureus (MRSA) eradication therapies in the context of S. aureus (both MRSA and MSSA) decolonization in an elective orthopaedic population.

METHODOLOGY

A total of 100 patients awaiting joint replacement surgery who were positive for S. aureus on PCR nasal screening underwent the current standard MRSA pre-operative decolonization regimen for 5 days. Prior to commencement of the eradication therapy, swabs of the anterior nares, throat and perineum were taken for culture. Further culture swabs were taken at 48-96 h following treatment, at hospital admission for surgery and at hospital discharge. Following the completion of treatment, patients were asked to provide feedback on their experience using Likert rating scales. The primary outcome of this study was S. aureus clearance 48-96 h following eradication treatment.Results/Key Findings. Clearance of S. aureus 48-96 h following treatment was 94 % anterior nares, 66 % throat and 88 % groin. Mean completion with nasal mupirocin was 98 %. There was no statistically significant recolonization effect between the end of the eradication treatment period and the day of surgery (P>0.05) at a median time of 10 days.

CONCLUSION

Current MRSA decolonisation regimens are well tolerated and effective for MSSA decolonization for the anterior nares and groin. The decolonization effect is preserved for at least 10 days following treatment.

Underestimation of Staphylococcus aureus (MRSA and MSSA) carriage associated with standard culturing techniques: One third of carriers missed

OBJECTIVES

Nasal carriers of Staphylococcus (S.) aureus (MRSA and MSSA) have an increased risk for healthcare-associated infections. There are currently limited national screening policies for the detection of S. aureus despite the World Health Organization's recommendations. This study aimed to evaluate the diagnostic performance of molecular and culture techniques in S. aureus screening, determine the cause of any discrepancy between the diagnostic techniques, and model the potential effect of different diagnostic techniques on S. aureus detection in orthopaedic patients.

METHODS

Paired nasal swabs for polymerase chain reaction (PCR) assay and culture of S. aureus were collected from a study population of 273 orthopaedic outpatients due to undergo joint arthroplasty surgery.

RESULTS

The prevalence of MSSA nasal colonization was found to be between 22.4% to 35.6%. The current standard direct culturing methods for detecting S. aureus significantly underestimated the prevalence (p = 0.005), failing to identify its presence in approximately one-third of patients undergoing joint arthroplasty surgery.

CONCLUSION

Modelling these results to national surveillance data, it was estimated that approximately 5000 to 8000 S. aureus surgical site infections could be prevented, and approximately $140 million to $950 million (approximately £110 million to £760 million) saved in treatment costs annually in the United States and United Kingdom combined, by using alternative diagnostic methods to direct culture in preoperative S. aureus screening and eradication programmes.Cite this article: S. T. J. Tsang, M. P. McHugh, D. Guerendiain, P. J. Gwynne, J. Boyd, A. H. R. W. Simpson, T. S. Walsh, I. F. Laurenson, K. E. Templeton. Underestimation of Staphylococcus aureus (MRSA and MSSA) carriage associated with standard culturing techniques: One third of carriers missed. Bone Joint Res 2018;7:79-84. DOI: 10.1302/2046-3758.71.BJR-2017-0175.R1.

Effect of day of the week on short- and long-term mortality after emergency general surgery

BACKGROUND

The effect of day of the week on outcome after surgery is the subject of debate. The aim was to determine whether day of the week of emergency general surgery alters short- and long-term mortality.

METHODS

This was an observational study of all patients undergoing emergency general surgery in Scotland between 1 January 2005 and 31 December 2007, followed to 2012. Multilevel logistic and Cox proportional hazards regression were used to assess the effect of day of the week of surgery on outcome after adjustment for case mix and risk factors. The primary outcome was perioperative mortality; the secondary outcome was overall survival.

RESULTS

A total of 50 844 patients were identified, of whom 31 499 had an emergency procedure on Monday to Thursday and 19 345 on Friday to Sunday. Patients undergoing surgery at the weekend were younger (mean 45·9 versus 47·5 years; P < 0·001) and had fewer co-morbidities, but underwent riskier and/or more complex procedures (P < 0·001). Patients who had surgery at the weekend were more likely to have been operated on sooner than those who had weekday surgery (mean time from admission to operation 1·2 versus 1·6 days; P < 0·001). No difference in perioperative mortality (odds ratio 1·00, 95 per cent c.i. 0·89 to 1·13; P = 0·989) or overall survival (hazard ratio 1·01, 0·97 to 1·06; P = 0·583) was observed when surgery was performed at the weekend. There was no difference in overall survival after surgery undertaken on any particular day compared with Wednesday; a borderline reduction in perioperative mortality was seen on Tuesday.

CONCLUSION

There was no difference in short- or long-term mortality following emergency general surgery at the weekend, compared with mid-week.

pRotective vEntilation with veno-venouS lung assisT in respiratory failure: A protocol for a multicentre randomised controlled trial of extracorporeal carbon dioxide removal in patients with acute hypoxaemic respiratory failure

One of the few interventions to demonstrate improved outcomes for acute hypoxaemic respiratory failure is reducing tidal volumes when using mechanical ventilation, often termed lung protective ventilation. Veno-venous extracorporeal carbon dioxide removal (vv-ECCO₂R) can facilitate reducing tidal volumes. pRotective vEntilation with veno-venouS lung assisT (REST) is a randomised, allocation concealed, controlled, open, multicentre pragmatic trial to determine the clinical and cost-effectiveness of lower tidal volume mechanical ventilation facilitated by vv-ECCO₂R in patients with acute hypoxaemic respiratory failure. Patients requiring intubation and mechanical ventilation for acute hypoxaemic respiratory failure will be randomly allocated to receive either vv-ECCO₂R and lower tidal volume mechanical ventilation or standard care with stratification by recruitment centre. There is a need for a large randomised controlled trial to establish whether vv-ECCO₂R in acute hypoxaemic respiratory failure can allow the use of a more protective lung ventilation strategy and is associated with improved patient outcomes.

Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine: Brussels, Belgium. 15-18 March 2016

[This corrects the article DOI: 10.1186/s13054-016-1208-6.].

Low-pathogenicity Mycoplasma spp. alter human monocyte and macrophage function and are highly prevalent among patients with ventilator-acquired pneumonia

BACKGROUND

Ventilator-acquired pneumonia (VAP) remains a significant problem within intensive care units (ICUs). There is a growing recognition of the impact of critical-illness-induced immunoparesis on the pathogenesis of VAP, but the mechanisms remain incompletely understood. We hypothesised that, because of limitations in their routine detection, Mycoplasmataceae are more prevalent among patients with VAP than previously recognised, and that these organisms potentially impair immune cell function.

METHODS AND SETTING

159 patients were recruited from 12 UK ICUs. All patients had suspected VAP and underwent bronchoscopy and bronchoalveolar lavage (BAL). VAP was defined as growth of organisms at >10(4) colony forming units per ml of BAL fluid on conventional culture. Samples were tested for Mycoplasmataceae (Mycoplasma and Ureaplasma spp.) by PCR, and positive samples underwent sequencing for speciation. 36 healthy donors underwent BAL for comparison. Additionally, healthy donor monocytes and macrophages were exposed to Mycoplasma salivarium and their ability to respond to lipopolysaccharide and undertake phagocytosis was assessed.

RESULTS

Mycoplasmataceae were found in 49% (95% CI 33% to 65%) of patients with VAP, compared with 14% (95% CI 9% to 25%) of patients without VAP. Patients with sterile BAL fluid had a similar prevalence to healthy donor BAL fluid (10% (95% CI 4% to 20%) vs 8% (95% CI 2% to 22%)). The most common organism identified was M. salivarium. Blood monocytes from healthy volunteers incubated with M. salivarium displayed an impaired TNF-α response to lipopolysaccharide (p=0.0003), as did monocyte-derived macrophages (MDMs) (p=0.024). MDM exposed to M. salivarium demonstrated impaired phagocytosis (p=0.005).

DISCUSSION AND CONCLUSIONS

This study demonstrates a high prevalence of Mycoplasmataceae among patients with VAP, with a markedly lower prevalence among patients with suspected VAP in whom subsequent cultures refuted the diagnosis. The most common organism found, M. salivarium, is able to alter the functions of key immune cells. Mycoplasmataceae may contribute to VAP pathogenesis.

AAGBI guidelines: the use of blood components and their alternatives 2016

Blood transfusion can be life-saving. Anaesthetists regularly request and administer blood components to their patients. All anaesthetists must be familiar with indications and appropriate use of blood and blood components and their alternatives, but close liaison with haematology specialists and their local blood sciences laboratory is encouraged. Considerable changes in approaches to optimal use of blood components, together with the use of alternative products, have become apparent over the past decade, leading to a need to update previous guidelines and adapt them for the use of anaesthetists working throughout the hospital system.

Costs and quality of life associated with acute upper gastrointestinal bleeding in the UK: cohort analysis of patients in a cluster randomised trial

OBJECTIVES

Data on costs associated with acute upper gastrointestinal bleeding (AUGIB) are scarce. We provide estimates of UK healthcare costs, indirect costs and health-related quality of life (HRQoL) for patients presenting to hospital with AUGIB.

SETTING

Six UK university hospitals with >20 AUGIB admissions per month, >400 adult beds, 24 h endoscopy, and on-site access to intensive care and surgery.

PARTICIPANTS

936 patients aged ≥18 years, admitted with AUGIB, and enrolled between August 2012 and March 2013 in the TRIGGER trial of AUGIB comparing restrictive versus liberal red blood cell (RBC) transfusion thresholds.

PRIMARY AND SECONDARY OUTCOME MEASURES

Healthcare resource use during hospitalisation and postdischarge up to 28  days, unpaid informal care, time away from paid employment and HRQoL using the EuroQol EQ-5D at 28  days were measured prospectively. National unit costs were used to value resource use. Initial in-hospital treatment costs were upscaled to a UK level.

RESULTS

Mean initial in-hospital costs were £2458 (SE=£216) per patient. Inpatient bed days, endoscopy and RBC transfusions were key cost drivers. Postdischarge healthcare costs were £391 (£44) per patient. One-third of patients received unpaid informal care and the quarter in paid employment required time away from work. Mean HRQoL for survivors was 0.74. Annual initial inhospital treatment cost for all AUGIB cases in the UK was estimated to be £155.5 million, with exploratory analyses of the incremental costs of treating hospitalised patients developing AUGIB generating figures of between £143 million and £168 million.

CONCLUSIONS

AUGIB is a large burden for UK hospitals with inpatient stay, endoscopy and RBC transfusions as the main cost drivers. It is anticipated that this work will enable quantification of the impact of cost reduction strategies in AUGIB and will inform economic analyses of novel or existing interventions for AUGIB.

TRIAL REGISTRATION NUMBER

ISRCTN85757829 and NCT02105532.

Nutritional care after critical illness: a qualitative study of patients' experiences

BACKGROUND

The present qualitative study aimed to explore the factors influencing nutritional recovery in patients after critical illness and to develop a model of care to improve current management of nutrition for this patient group.

METHODS

Patients were recruited into the study on discharge from a general intensive care unit (ICU) of a large teaching hospital in central Scotland. Semi-structured interviews were carried out after discharge from the ICU, weekly for the duration of their ward stay, and at 3 months post ICU discharge. Observations of ward practice were undertaken thrice weekly for the duration of the ward stay.

RESULTS

Seventeen patients were recruited into the study and, using a grounded theory approach, 'inter-related system breakdowns during the nutritional recovery process' emerged as the overarching core category that influenced patients' experiences of eating after critical illness. This encompassed the categories, 'experiencing a dysfunctional body', 'experiencing socio-cultural changes in relation to eating' and 'encountering nutritional care delivery failures'.

CONCLUSIONS

The findings from the present study provide a unique contribution to knowledge by offering important insights into patients' experiences of eating after critical illness. The study has identified numerous nutritional problems and raises questions about the efficacy of current nutritional management in this patient group. Adopting a more individualised approach to nutritional care could ameliorate the nutritional issues experienced by post ICU patients. This will be evaluated in future work.

Combined dysfunctions of immune cells predict nosocomial infection in critically ill patients

BACKGROUND

Nosocomial infection occurs commonly in intensive care units (ICUs). Although critical illness is associated with immune activation, the prevalence of nosocomial infections suggests concomitant immune suppression. This study examined the temporal occurrence of immune dysfunction across three immune cell types, and their relationship with the development of nosocomial infection.

METHODS

A prospective observational cohort study was undertaken in a teaching hospital general ICU. Critically ill patients were recruited and underwent serial examination of immune status, namely percentage regulatory T-cells (Tregs), monocyte deactivation (by expression) and neutrophil dysfunction (by CD88 expression). The occurrence of nosocomial infection was determined using pre-defined, objective criteria.

RESULTS

Ninety-six patients were recruited, of whom 95 had data available for analysis. Relative to healthy controls, percentage Tregs were elevated 6-10 days after admission, while monocyte HLA-DR and neutrophil CD88 showed broader depression across time points measured. Thirty-three patients (35%) developed nosocomial infection, and patients developing nosocomial infection showed significantly greater immune dysfunction by the measures used. Tregs and neutrophil dysfunction remained significantly predictive of infection in a Cox hazards model correcting for time effects and clinical confounders {hazard ratio (HR) 2.4 [95% confidence interval (CI) 1.1-5.4] and 6.9 (95% CI 1.6-30), respectively, P=0.001}. Cumulative immune dysfunction resulted in a progressive risk of infection, rising from no cases in patients with no dysfunction to 75% of patients with dysfunction of all three cell types (P=0.0004).

CONCLUSIONS

Dysfunctions of T-cells, monocytes, and neutrophils predict acquisition of nosocomial infection, and combine additively to stratify risk of nosocomial infection in the critically ill.

Multicentre cohort study of red blood cell use for revision hip arthroplasty and factors associated with greater risk of allogeneic blood transfusion

BACKGROUND

Revision hip arthroplasty (RHA) is associated with high rates of allogeneic blood transfusion (ABT). We aimed to determine factors associated with ABT in patients undergoing RHA in Scottish hospitals, with particular focus on perioperative cell salvage (PCS).

METHODS

A prospective observational cohort study of RHA procedures performed in 11 hospitals over 7 months was performed. We recorded predefined patient, surgery-related, and blood conservation factors that may influence perioperative ABT, together with postoperative haemoglobin (Hb) data and ABTs to day 7. We explored factors with strongest independent association with ABT during the perioperative period using multiple regression analysis.

RESULTS

Two hundred and ten cases were studied, of whom 58% received ABTs (mean 1.8 units), most of which (52%) occurred on the day of surgery. Eighty-eight (42%) patients received PCS, of whom 68 had red cells re-infused [mean re-infusion volume 312 ml (1st, 3rd quartile: 260, 363 ml)]. In unadjusted comparisons, patients receiving PCS had lower intraoperative (9% vs 40%) and total (55% vs 63%) exposure to ABTs. The mean (95% confidence interval) theatre blood loss was 1013 (899-1128) ml and was higher for combined femoral/acetabular revision and femoral revision than other categories. The mean postoperative Hb transfusion trigger was 80 g litre(-1). In multivariable models, preoperative Hb [odds ratio (OR) 0.35; P<0.001], patient weight (OR 0.96; P=0.004), operating theatre blood loss (OR 1.002; P<0.001), and re-infusion of PCS blood (OR 0.31; P=0.02) were independent predictors of ABT exposure.

CONCLUSIONS

PCS is an effective blood conservation strategy for RHA, especially for patients with preoperative anaemia, low body weight, or both.

Responsiveness of the frontal EMG for monitoring the sedation state of critically ill patients

BACKGROUND

Excessive sedation is associated with adverse patient outcomes during critical illness, and a validated monitoring technology could improve care. We developed a novel method, the responsiveness index (RI) of the frontal EMG. We compared RI data with Ramsay clinical sedation assessments in general and cardiac intensive care unit (ICU) patients.

METHODS

We developed the algorithm by iterative analysis of detailed observational data in 30 medical-surgical ICU patients and described its performance in this cohort and 15 patients recovering from scheduled cardiac surgery. Continuous EMG data were collected via frontal electrodes and RI data compared with modified Ramsay sedation state assessments recorded regularly by a blinded trained observer. RI performance was compared with Entropy™ across Ramsay categories to assess validity.

RESULTS

RI correlated well with the Ramsay category, especially for the cardiac surgery cohort (general ICU patients ρ=0.55; cardiac surgery patients ρ=0.85, both P<0.0001). Discrimination across all Ramsay categories was reasonable in the general ICU patient cohort [P(K)=0.74 (sem 0.02)] and excellent in the cardiac surgery cohort [P(K)=0.92 (0.02)]. Discrimination between 'lighter' vs 'deeper' (Ramsay 1-3 vs 4-6) was good for general ICU patients [P(K)=0.80 (0.02)] and excellent for cardiac surgery patients [P(K)=0.96 (0.02)]. Performance was significantly better than Entropy™. Examination of individual cases suggested good face validity.

CONCLUSIONS

RI of the frontal EMG has promise as a continuous sedation state monitor in critically ill patients. Further investigation to determine its utility in ICU decision-making is warranted.

The Swine Flu Triage (SwiFT) study: development and ongoing refinement of a triage tool to provide regular information to guide immediate policy and practice for the use of critical care services during the H1N1 swine influenza pandemic

OBJECTIVES

To use, existing critical care and early pandemic, data to inform care during the pandemic influenza A 2009 (H1N1) pandemic (with a possible use for triage - if the demand for critical care seriously exceeded supply). To monitor the impact of the H1N1 pandemic on critical care services, in real time, with regular feedback to critical care clinicians and other relevant jurisdictions to inform ongoing policy and practice.

DESIGN

Modelling of data and cohort study.

SETTING

Modelling - 148 adult, general critical care units in England, Wales and Northern Ireland in the Intensive Care National Audit & Research Centre Case Mix Programme. Cohort study - 192 acute hospitals in England, Wales, Northern Ireland, Scotland and the Republic of Ireland.

PARTICIPANTS

Modelling - 105,397 admissions to adult, general critical care units. Cohort study - 1728 H1N1 pandemic-related admissions referred and assessed as requiring critical care.

MAIN OUTCOME MEASURES

Modelling - requirement for organ support and acute hospital mortality. Cohort study - survival to the end of critical care.

RESULTS

Modelling - cancelled or postponed, elective or scheduled surgery resulted in savings in calendar days of critical, Level 3 and advanced respiratory care of 17, 11 and 10%, respectively. These savings varied across units. Using routine, physiological variables, the best triage models, for all and for acute respiratory admissions, achieved only satisfactory concordance of 0.79 and 0.75, respectively. Application of the best model on all admissions indicated that approximately 12.5% of calendar days of critical care could be saved. Cohort study - research governance approvals were achieved for 192 acute hospitals, for 91 within 1 day of central research and development approval across the five countries. A total of 1725 cases (562 confirmed) were reported. Confirmed cases were young (mean age of 40 years), had low severity of acute illness on presentation [61% CURB-65 (confusion, urea, respiratory rate, blood pressure, age over 65 years) 0-1], but had long stays in critical care (median 8.5 days) and were likely to be ventilated (77% for median 9 days). Risk factors for acute hospital death were similar to those for general critical care admissions.

CONCLUSIONS

SwiFT was rapidly established. Models based on routine physiology suggested limited value for triage. More data and further modelling are warranted. The magnitude of the pandemic did not approach the worst-case scenario modelling, and UK-confirmed H1N1 cases appeared similar to those reported internationally.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

A national clinical scenario-based survey of clinicians' attitudes towards fresh frozen plasma transfusion for critically ill patients

BACKGROUND

It is known that 20-30% of fresh frozen plasma (FFP) is used in intensive care units (ICUs), but little is known about variations in decision making between clinicians in relation to coagulopathy management. Our aim was to describe ICU clinicians' beliefs and practice in relation to FFP treatment of non-bleeding coagulopathic critically ill patients.

METHODS

Two patient-based scenarios were developed and sent to 2700 members of two UK intensive care professional societies. Scenario 1 was a non-bleeding septic patient with coagulopathy; scenario 2 was a non-bleeding critically ill patient with hepatic cirrhosis and coagulopathy. Responses were sought in relation to FFP prophylaxis, and prior to central venous cannulation. A supplementary question asked clinicians' view of prophylaxis in relation to other ICU procedures.

RESULTS

Two-thousand-and-seven-hundred clinicians were surveyed from whom 601 responses were received (22·3% response rate). For scenario 1 52% of respondents stated that they would never routinely administer prophylactic FFP, but this decreased to 9% when central venous cannulation was planned (P < 0·01). There was wide variation in the 'trigger' INR (international normalised ratio) value used prior to central vein cannulation, the most common range being 2·0-2·4. For scenario 2, responses were very similar. More than 80% of clinicians stated that they would routinely treat coagulopathy prior to lumbar puncture, epidural catheterisation, intracranial pressure monitoring and tracheostomy; and 54% prior to chest drain insertion.

CONCLUSION

Our survey demonstrated a wide range of responses consistent with important variations in clinical practice and substantial clinical uncertainty in relation to FFP treatment for non-bleeding ICU patients.

Do simple ventilation and gas exchange measurements predict early successful weaning from respiratory support in unselected general intensive care patients?

BACKGROUND

The value of respiratory variables as weaning predictors in the intensive care unit (ICU) is controversial. We evaluated the ability of tidal volume (Vt(exp)), respiratory rate (f), minute volume (MV(exp)), rapid shallow breathing index (f/Vt), inspired-expired oxygen concentration difference [(I-E)O(2)], and end-tidal carbon dioxide concentration (Pe'(co(2))) at the end of a weaning trial to predict early weaning outcomes.

METHODS

Seventy-three patients who required >24 h of mechanical ventilation were studied. A controlled pressure support weaning trial was undertaken until 5 cm H(2)O continuous positive airway pressure or predefined criteria were reached. The ability of data from the last 5 min of the trial to predict whether a predefined endpoint indicating discontinuation of ventilator support within the next 24 h was evaluated.

RESULTS

Pre-test probability for achieving the outcome was 44% in the cohort (n=32). Non-achievers were older, had higher APACHE II and organ failure scores before the trial, and higher baseline arterial H(+) concentrations. The Vt, MV, f, and f/Vt had no predictive power using a range of cut-off values or from receiver operating characteristic (ROC) analysis. The [I-E]O(2) and Pe'(co(2)) had weak discriminatory power [area under the ROC curve: [I-E]O(2) 0.64 (P=0.03); Pe'(co(2)) 0.63 (P=0.05)]. Using best cut-off values for [I-E]O(2) of 5.6% and Pe'(co(2)) of 5.1 kPa, positive and negative likelihood ratios were 2 and 0.5, respectively, which only changed the pre- to post-test probability by about 20%.

CONCLUSIONS

In unselected ICU patients, respiratory variables predict early weaning from mechanical ventilation poorly.

The development and feasibility of a ward-based physiotherapy and nutritional rehabilitation package for people experiencing critical illness

Objective: To investigate ward-based rehabilitation after critical illness and undertake a pilot study exploring the feasibility of delivering enhanced physiotherapy and nutritional rehabilitation.

Design: Service evaluation (part A) and pilot feasibility randomized controlled trial (part B).

Setting: Hospital inpatient wards following discharge from intensive care.

Participants: Part A involved 24 people with an intensive care stay of four days or more. Part B involved 16 participants randomized into a control (n = 8) or intervention (n = 8) group.

Interventions: Part A defined the current ‘standard’ physiotherapy and nutritional interventions. In part B the control group received this ‘standard’ service while the intervention group received this ‘standard’ service plus enhanced rehabilitation.

Main measures: Part A collected process outcomes of current interventions and outcomes that included calorie and protein intake and the Rivermead Mobility Index. In part B process outcomes determined differences between groups. Outcomes included those undertaken in part A plus an incremental shuttle test, handgrip dynamometry and visual analogue scales.

Results: Part A found low levels of ward-based physiotherapy (walking and transfer practice once per week) and dietetic input (0.8 visits per week). Part B found an increased frequency of both physiotherapy (P = 0.002) and dietetic (P = 0.001) visits in the intervention group. Physical and nutritional outcomes were suitable for use after critical illness, but no statistically significant differences were found between groups. Power calculations indicated 100 participants per group would be required for a definitive study.

Conclusions: This feasibility pilot work has informed the design of a larger study to evaluate enhanced rehabilitation following critical illness.

Evaluation of the effect of diagnostic methodology on the reported incidence of ventilator-associated pneumonia

BACKGROUND

The optimal method for diagnosing ventilator-associated pneumonia (VAP) is controversial and its effect on reported incidence uncertain. This study aimed to model the impact of using either endotracheal aspirate or bronchoalveolar lavage on the reported incidence of pneumonia and then to test effects suggested from theoretical modelling in clinical practice.

METHODS

A three-part single-centre study was undertaken. First, diagnostic performance of aspirate and lavage were compared using paired samples from 53 patients with suspected VAP. Secondly, infection surveillance data were used to model the potential effect on pneumonia incidence and antibiotic use of using exclusively aspirate or lavage to investigate suspected pneumonia (643 patients; 110 clinically suspected pneumonia episodes). Thirdly, a practice change initiative was undertaken to increase lavage use; pneumonia incidence and antibiotic use were compared for the 12 months before and after the change.

RESULTS

Aspirate overdiagnosed VAP compared with lavage (89% vs 21% of clinically suspected cases, p<0.0001). Modelling suggested that changing from exclusive aspirate to lavage diagnosis would decrease reported pneumonia incidence by 76% (95% CI 67% to 87%) and antibiotic use by 30% (95% CI 20% to 42%). After the practice change initiative, lavage use increased from 37% to 58%. Although clinically suspected pneumonia incidence was unchanged, microbiologically confirmed VAP decreased from 18 to 9 cases per 1000 ventilator days (p = 0.001; relative risk reduction 0.61 (95% CI 0.46 to 0.82)), and mean antibiotic use fell from 9.1 to 7.2 antibiotic days (21% decrease, p = 0.08).

CONCLUSIONS

Diagnostic technique impacts significantly on reported VAP incidence and potentially on antibiotic use.

Cytomegalovirus colitis in a critically ill patient following elective repair of an abdominal aortic aneurysm

We describe a case of cytomegalovirus colitis in a critically ill but otherwise immunocompetent 61-year-old male. Infection was demonstrated by histology and confirmed by plasma polymerase chain reaction and detection of cytomegalovirus IgM antibody. The patient was treated with ganciclovir with resolution of the cytomegalovirus viraemia. Cytomegalovirus colitis may be an under-recognised problem in immunocompetent patients who are critically ill. Quantification of plasma cytomegalovirus DNA by polymerase chain reaction is a non-invasive method of supporting the diagnosis and can be used to monitor the treatment of cytomegalovirus infection in the immunocompetent.

Prevalence of anaemia before major joint arthroplasty and the potential impact of preoperative investigation and correction on perioperative blood transfusions

BACKGROUND

Preoperative investigation and treatment of anaemia is recommended before orthopaedic surgery. We measured the prevalence of anaemia among admissions presenting for elective major joint arthroplasty (MJA), assessed their transfusion requirements, and investigated factors associated with perioperative blood transfusion.

METHODS

All admissions to a dedicated elective orthopaedic hospital during 2000-2001 were studied. The patients' database was merged with the haematology and transfusion databases. Population estimates for different types of anaemia and their blood transfusion requirements were generated using local reference ranges (males <130 g litre(-1); females <115 g litre(-1)).

RESULTS

One thousand three hundred and twenty-two admissions were included; haematology data were complete for 1142 (544 primary hip, 490 primary knee, 77 revision hip, 31 revision knee). About 19.6% were anaemic [7.1% haemoglobin (Hb) <110 g litre(-1); 1.6% Hb<100 g litre(-1)]. Overall, 21.3% of admissions were transfused (mean 0.58 units per case: 95% CI 0.50-0.61). For anaemic admissions, 42.0% were transfused (mean 1.11 units per case: 95% CI 0.90-1.32). Mean red cell use for admissions with normocytic normochromic anaemia (12.7% of admissions) and hypochromic anaemia (4.6%) was 1.04 (95% CI 0.78-1.31) and 1.14 (95% CI 0.71-1.57) units per admission, respectively. Factors strongly associated independently with transfusion were preoperative haemoglobin </=110 g litre(-1) [odds ratio: 13.92 (95% CI 7.77-24.9) and revision hip surgery (OR: 17.80 (9.59-33.02)].

CONCLUSIONS

The prevalence of preoperative anaemia among admissions undergoing elective MJA is approximately 20%. Patients most likely to avoid transfusions with preoperative intervention are those with low haemoglobin undergoing revision hip surgery.

A study of blood product use in patients with major trauma in Scotland: analysis of a major trauma database

OBJECTIVES

(1) To define blood product requirements in patients with trauma whose underlying injuries are consistent with major blood loss; (2) to use these data to estimate the annual number of patients in Scotland who sustain significant trauma and require substantial blood product replacement; and (3) to place these data in the context of recent findings concerning the efficacy of recombinant factor VIIa in patients with major trauma.

METHODS

A retrospective case note review study was conducted for patients who presented with trauma at each of four Scottish hospitals. The four sites were selected from the 26 hospitals that were the source of data for the Scottish Trauma Audit Group (STAG) database. Collected between 1991 and 2002, STAG encompasses approximately 53 000 patients. 129 patients whose trauma codes were likely to be linked to injuries associated with major blood loss were selected. Data on the use of blood products for each patient were collected and analysed for three periods: (1) time spent in the emergency department (ED); (2) time from leaving the ED to the end of the first 24 h; and (3) time from the end of the first 24 h to 7 days. Blood product use for each period and for the entire first week of care was described for all patients and for blunt and penetrating injury subgroups. Using national population data estimates, the incidence of major trauma requiring blood transfusion was calculated for Scotland.

RESULTS

Among the patients with trauma codes predicting significant blood loss, the proportion of patients requiring any blood transfusion within the first 7 days was 53.9%. 27.4% of patients received > or =8 units of red cell concentrate (RCC) within the first 24 h of hospitalisation. By direct extrapolation, we estimated that the annual number of Scotland's patients (aged >13 years) with a significant blood transfusion requirement secondary to traumatic injury was 67. Of these, 35 patients would require > or =8 units of RCC within the first 24 h.

CONCLUSION

In summary, this study estimates that approximately 67 patients annually in Scotland, above the age of 13 years, require blood transfusion as a direct result of significant traumatic injury. Of these 67 patients, an estimated 35 patients (28 of whom had a blunt form of trauma) require > or =8 units of RCC during the first 24 h in hospital. On the basis of the current limited trial evidence, the potential benefit in using recombinant factor VIIa in such patients, in Scotland, is small-approximately seven patients per million population aged >13 years, per year.

The impact of organ failures and their relationship with outcome in intensive care: analysis of a prospective multicentre database of adult admissions

The database of a multicentre cohort study was analysed to determine the impact of intensive care unit (ICU) organ failures and their association with ICU mortality using sequential organ failure assessment (SOFA). A consecutive sample of 873 adult patients with a non-neurological diagnosis was identified. SOFA scores were measured every 24 h of ICU stay. The odds of ICU death within 7 days doubled (95% CI 1.3-2.9) for a 5-unit increase in total SOFA score at admission, p < 0.001. However ICU death after 7 days was not associated with total SOFA score at admission, p = 0.36. Compared to patients with a day 6 total SOFA score = 5, there was a 1-unit (95% CI 0.8-3.1) increase in the odds ratio of ICU death after 7 days with every 5-unit increase in SOFA score on day 6, p = 0.009. Continuous assessments of organ failures during an ICU admission are more useful than scores measured at admission to determine outcome and to compare ICUs.

How much time is needed for hand hygiene in intensive care? A prospective trained observer study of rates of contact between healthcare workers and intensive care patients

There are few data measuring rates of contact by healthcare workers (HCWs) with intensive care unit (ICU) patients (direct contacts) and their immediate environment (indirect contacts), or estimates of the time needed for 100% hand hygiene compliance. We measured this using a prospective trained observer study in a 12-bedded UK adult general ICU admitting > 600 mixed medical/surgical patients annually. HCWs were observed in ICU bed spaces for 1-h periods by a single researcher using a pre-determined plan, such that all 12 beds were observed for similar times and throughout the day. Mean daily rates of direct and indirect contact between HCWs and ICU patients were calculated. Observed post-contact hand hygiene compliance was also measured. Numbers of contacts/day that were or were not followed by hand hygiene, and estimates of the time needed daily for 100% compliance were calculated. On average, each patient was contacted directly 159 [95% confidence intervals (CI) 144-178] times and contacted indirectly 191 (95% CI 174-210) times/day. Observed post-contact hand hygiene rates were 43% for direct contacts and 12% for indirect contacts. Staff contacting more than one patient during routine care, who carry the highest risk of transmitting infection between patients, made, on average, 22 direct and 107 indirect contacts without adequate hand hygiene/patient/day. One hundred percent hand hygiene compliance by all healthcare workers would require about 230 min/patient/day (100 min for direct and 130 min for indirect contacts).

Antibiotic prescription practice in an intensive care unit using twice-weekly collection of screening specimens: a prospective audit in a large UK teaching hospital

Controversy exists regarding the optimal method of managing intensive care unit (ICU)-acquired infection. Antibiotic prescriptions in 177 sequential admissions to our ICU, which collected twice-weekly screening samples, were audited. Seventy-seven percent of patients received at least one antibiotic prescription, and 45% of patients received at least one prescription for suspected or proven sepsis. Of the 353 antibiotic prescriptions audited, 86 were prophylactic and 61 were first prescribed prior to ICU admission. One hundred and eighty-three were prescribed for sepsis; of these, 108 (59%) were empirical prescriptions and only 21% of these were subsequently changed. For the 75 prescriptions for specific organisms, 28% targeted organisms isolated at least four days previously. Clinicians in our ICU reviewed the data and reached consensus that screening was associated with decision making that did not represent current evidence-based practice, because empirical prescriptions were rarely changed or stopped on the basis of new samples, and those prescribed for confirmed infection frequently targeted organisms isolated before the septic episode. After our audit, we stopped regular collection of screening samples and used more targeted and invasive sampling, in response to clinical suspicion, to guide therapy and maintain data concerning local microbial epidemiology.

Prevalence of ischaemic heart disease at admission to intensive care and its influence on red cell transfusion thresholds: multicentre Scottish Study

BACKGROUND

Restrictive transfusion triggers are safe for most critically ill patients, but doubts exist for patients with ischaemic heart disease (IHD). We investigated the prevalence of reported IHD at admission to the intensive care unit (ICU) and investigated how this influenced red cell transfusion triggers. We also compared observed practice with the clinicians' responses to clinical scenarios.

METHODS

We studied 1023 sequential ICU admissions over 100 days to 10 Scottish ICUs. Daily haemoglobin, red cell transfusion, and haemorrhage data were available for 99.4% of 5638 ICU patient days. We recorded if IHD was recorded in clinical records at ICU admission. We grouped admissions as having a non-cardiac primary ICU diagnosis and no documentary evidence of IHD (Group 1, n=697), a non-cardiac primary ICU diagnosis with evidence of IHD (Group 2, n=213), or a cardiac primary ICU admission diagnosis (Group 3, n=113). We examined pre-transfusion haemoglobin concentration (Hb) for transfusion episodes not associated with haemorrhage. Clinical transfusion scenarios were sent to intensivists in the ICUs after data collection, which were designed to explore the clinicians' attitude to transfusion triggers in patients with IHD.

RESULTS

Previous myocardial infarction was documented in 159 (16%), cardiac failure in 142 (14%), and angina in 167 (16%). Overall, 28.8% of admissions had >/=1 of these documented. The adjusted mean (se) pre-transfusion Hb concentrations varied across the groups. These were 74 (2.2) g litre(-1) in Group 1, 77 (2.3) g litre(-1) in Group 2, and 79 (3.1) g litre(-1) in Group 3 (P=0.003 across the groups). There was concordance between observed practice and responses to the scenario similar to Group 1, but discordance for patients with IHD (Groups 2 and 3). In scenario responses, intensivists stated these patients should have significantly higher transfusion triggers than were actually observed (median [IQR] response for both groups: 90 [80-100] g litre(-1)).

CONCLUSIONS

About 29% of patients admitted to Scottish ICUs had documented IHD, which was associated with small adjustments to Hb transfusion triggers. In response to scenarios, clinicians believe that patients with IHD require higher transfusion triggers than are observed in practice.

A prospective audit of cost of sedation, analgesia and neuromuscular blockade in a large British ICU

Bottom-up costs of sedative, analgesic and neuromuscular blocking drugs used in the intensive care unit have not been reported. We performed a prospective audit of the cost of these drugs using a bottom-up approach by prospectively recording the daily amount of drugs administered to patients over a 3-month period. Of 172 admissions, complete data were collected for 155 (92%). Propofol and alfentanil were the drugs most commonly used, being administered to 136 (88%) and 106 (68%) patients, respectively. The total cost was 14,070 pounds sterling, which was 81% of the pharmacy figure (based on central purchasing). Ninety-four per cent of the cost was for drugs administered to the 50% of patients who stayed in the intensive care unit longer than 48 h. The median (interquartile range [range]) cost per day was 9.30 pounds sterling (3.60-20.10 [0-61.20]). This represents less than 1% of reported total daily cost of intensive care per patient.

Evaluation of simple criteria to predict successful weaning from mechanical ventilation in intensive care patients

BACKGROUND

There is increasing evidence that weaning protocols improve outcome from mechanical ventilation, but it is unclear how best to implement such protocols in large intensive care units. We evaluated a checklist of simple bedside criteria to determine whether it could be used reliably to predict successful discontinuation of mechanical ventilation.

METHODS

We carried out a prospective observational cohort study in a 12-bedded general intensive care unit (ICU). We developed a checklist of metabolic, cardiorespiratory and neurological criteria that suggested that patients should start the weaning process. We performed daily assessments throughout ICU stay and recorded whether the criteria were met. Ultimate ventilator independence was used as the reference standard.

RESULTS

We studied 325 sequential admissions to the ICU. Data were available for 98% of patients; 97% of admissions were mechanically ventilated on admission to ICU. Overall, 205 of the 308 ventilated patients (67%) achieved ventilator independence during ICU admission; the other patients died or were transferred ventilated to other ICUs. Eighty-three per cent of the patients who achieved ventilator independence met the set criteria. Fulfilling the criteria was a moderately strong predictor of ultimate ventilator independence: specificity 89%, positive predictive value 94%, positive likelihood ratio (LR) 7.6. When we analysed data by the day from admission on which patients were examined, the test was a strong predictor of subsequent ventilator independence when criteria were met by day 1 (LR 11.1) or day 2 (LR 6.9), but weaker when met by more than/equal to 4 days (LR <3). Patients who met criteria after more than/equal to 4 days often had prolonged weaning and a high incidence of re-intubation. Patients who achieved ventilator independence without fulfilling the criteria (n=35) had a short duration of mechanical ventilation (median 2 days, interquartile range 1-3 days). The most frequent reason for failing criteria before ventilator independence was a Pa(O(2))/FI(O(2)) ratio less than 24 kPa (49% of cases).

CONCLUSIONS

A simple checklist can assist nurse assessment of suitability for weaning and could be used as a trigger to commence a weaning protocol. The day on which criteria are met is a useful way of stratifying patients for likely patterns of weaning.

Anaemia and red blood cell transfusion in the critically ill patient

Anaemia is a common finding in critically ill patients. There are often multiple causes. Obvious causes include surgical bleeding and gastrointestinal haemorrhage but many patients have no overt bleeding episodes. Phlebotomy can be a significant source of blood loss. In addition, critically ill patients have impaired erythropoiesis as a consequence of blunted erythropoietin production and direct inhibitory effects of inflammatory cytokines. The ability of a patient to tolerate anaemia depends on their clinical condition and the presence of any significant co-morbidity; maintenance of circulating volume is of paramount importance. There is no universal transfusion trigger. Current guidelines for critically ill and perioperative patients advise that at Hb values <70 g/L red blood cell transfusion is strongly indicated and at Hb values >100 g/L transfusion is unjustified. For patients with Hb values in the range 70 to 100 g/L the transfusion trigger should be based on clinical indicators. Most stable critically ill patients can probably be managed with a Hb concentration between 70 and 90 g/L. Uncertainties exist concerning the most appropriate Hb concentration for patients with significant cardio-respiratory disease.

Clinical evaluation of a continuous oxygen consumption monitor in mechanically ventilated patients

We measured oxygen consumption using a new noninvasive modular metabolic monitor, M-COVX trade mark, in ventilated critically ill patients. Oxygen consumption was measured continuously as part of routine monitoring for up to 24 h following mechanical ventilation in 27 patients admitted to a general intensive care unit. We explored several possible sources of error. Most errors related to inaccurate tidal volume measurement, which resulted in rejection of a median 14% (interquartile range 8-34%) of data. Water accumulation in the pneumotachograph was responsible and occurred more frequently with water bath humidifiers. After manual removal of erroneous data mean oxygen consumption values were virtually identical to calculated values in 24 of 27 patients. We conclude that in most ventilated patients averaging of continuous oxygen consumption data with the M-COVX module results in small errors.

Red cell transfusion practice following the transfusion requirements in critical care (TRICC) study: prospective observational cohort study in a large UK intensive care unit

BACKGROUND AND OBJECTIVES

The Transfusion Requirements In Critical Care (TRICC) study found that critically ill patients tolerate a restrictive haemoglobin transfusion threshold. We investigated red-cell transfusion practice since publication of the TRICC study in a large Scottish teaching hospital intensive care unit (ICU).

MATERIALS AND METHODS

We prospectively collected daily data for a 6-month period on haemoglobin concentrations, red-cell transfusions and indications for transfusions, throughout ICU stay for all patients who stayed for longer than 24 h in the ICU.

RESULTS

A total of 176 patients were studied, who utilized 1237 ICU days. Of these 176 patients, 52% received red-cell transfusions. A haemoglobin concentration of < or = 9 g/dl was measured in 55% of patients; this occurred by day 1 and day 2 in 52% and 77% of these cases, respectively. Overall the haemoglobin concentration was < or = 9 g/dl for 45% of all patient days. Total red-cell use was 3.1 units per admission (0.47 units per patient day). Only 18% of transfusion episodes were required as a result of haemorrhage. For 'non-haemorrhage' transfusion episodes, the median pretransfusion haemoglobin concentration was 7.8 g/dl (interquartile range: 7.4-8.4 g/dl), and 64% of transfusion episodes were for 2 units.

CONCLUSIONS

Clinicians in our centre were conservative, in keeping with recent transfusion guidelines, but deviated from the TRICC protocol by transfusing at haemoglobin concentrations of between 7 and 9 g/dl, rather than below 7 g/dl, and by prescribing 2 unit transfusions. Significant numbers of red-cell units are still used in the critically ill.

Comparison of hepatic artery and portal vein reperfusion during orthotopic liver transplantation

BACKGROUND

During orthotopic liver transplantation (OLT), it is standard procedure to reperfuse the liver via the portal vein (PV) despite having a lower oxygen content and perfusion pressure than the hepatic artery (HA). There are no published studies that describe graft function and outcome when the HA is used for reperfusion. We report a retrospective comparison of graft outcome after HA or PV reperfusion when the piggyback technique was used.

METHODS

We identified 26 patients who had undergone OLT with HA reperfusion and 26 patients reperfused via the PV. Demographics, primary diagnosis, surgeon, warm and cold ischemic times, and blood product use were recorded. In each patient, whole blood lactate concentration, prothrombin time (PT), and alanine aminotransferase (ALT) were measured at defined time points during and after surgery as indices of graft lactate metabolism, synthetic function, and reperfusion injury, respectively. Thirty-day and 1-year outcome data were recorded. Data were compared between the HA and PV groups.

RESULTS

Demographics, blood product use, primary diagnosis, cold ischemic time, and surgeon were similar between the groups. Warm ischemic time was longer in the HA group (mean [SD] HA 51.2 [14.7], PV 40 [9.1] min, P=0.002). Blood lactate concentrations were similar at all time points. There was no difference in 24-hr postoperative PT between the groups (median [InterQuartile (IQ) range] HA 17.5 [16-28.3], PV 19 [16-24] sec, P=0.85). Peak postoperative ALT values were comparable (median [IQ range] HA 1031 [668-1701], PV 1107 [754-1824] IU/ml, P=0.78). There were no statistically significant differences in 30-day or 1-year mortality, but more early deaths occurred in the HA group. Using our data, we calculated that a prospective randomized trial would need approximately 300 patients to be sure that mortality was the same with both techniques.

CONCLUSION

We have demonstrated no clinically or statistically significant differences in indices of graft function, reperfusion injury, or outcome between primary HA or PV reperfusion.