Healthcare utilisation in patients with long-term conditions during the COVID-19 pandemic: a population-based observational study of all patients across Greater Manchester, UK.

OBJECTIVES: Data on population healthcare utilisation (HCU) across both primary and secondary care during the COVID-19 pandemic are lacking. We describe primary and secondary HCU stratified by long-term conditions (LTCs) and deprivation, during the first 19 months of COVID-19 pandemic across a large urban area in the UK. DESIGN: A retrospective, observational study. SETTING: All primary and secondary care organisations that contributed to the Greater Manchester Care Record throughout 30 December 2019 to 1 August 2021. PARTICIPANTS: 3 225 169 patients who were registered with or attended a National Health Service primary or secondary care service during the study period. PRIMARY OUTCOMES: Primary care HCU (incident prescribing and recording of healthcare information) and secondary care HCU (planned and unplanned admissions) were assessed. RESULTS: The first national lockdown was associated with reductions in all primary HCU measures, ranging from 24.7% (24.0% to 25.5%) for incident prescribing to 84.9% (84.2% to 85.5%) for cholesterol monitoring. Secondary HCU also dropped significantly for planned (47.4% (42.9% to 51.5%)) and unplanned admissions (35.3% (28.3% to 41.6%)). Only secondary care had significant reductions in HCU during the second national lockdown. Primary HCU measures had not recovered to prepandemic levels by the end of the study. The secondary admission rate ratio between multi-morbid patients and those without LTCs increased during the first lockdown by a factor of 2.40 (2.05 to 2.82; p<0.001) for planned admissions and 1.25 (1.07 to 1.47; p=0.006) for unplanned admissions. No significant changes in this ratio were observed in primary HCU. CONCLUSION: Major changes in primary and secondary HCU were observed during the COVID-19 pandemic. Secondary HCU reduced more in those without LTCs and the ratio of utilisation between patients from the most and least deprived areas increased for the majority of HCU measures. Overall primary and secondary care HCU for some LTC groups had not returned to prepandemic levels by the end of the study.

Platelet-Rich Plasma in acute Achilles tendon ruptures: A systematic review and meta-analysis.

BACKGROUND: Platelet Rich Plasma (PRP) is known to exert multi-directional biological effects favouring tendon healing. However, conclusions drawn by numerous studies on its clinical efficacy for acute Achilles tendon rupture are limited. We performed a systematic review and meta-analysis to investigate this and to compare to those without PRP treatment. METHODS: The Cochrane Controlled Register of Trials, Pubmed, Medline and Embase were used and assessed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) criteria with the following search terms: ('plasma' OR 'platelet-rich' OR 'platelet-rich plasma' or 'PRP') AND ('Achilles tendon rupture/tear' OR 'calcaneal tendon rupture/tear' OR 'tendo calcaneus rupture/tear'). Data pertaining to biomechanical outcomes (heel endurance test, isokinetic strength, calf-circumference and range of motion), patient-reported outcome measures (PROMs) and incidence of re-ruptures were extracted. Meta-analysis was performed for same outcomes measured in at least three studies. Pooled outcome data were analysed by random- and fixed-effects models. RESULTS: After abstract and full-text screening, 6 studies were included. In total there were 510 patients of which 256 had local PRP injection and 254 without. The average age was 41.6 years, mean time from injury to treatment 5.9 days and mean follow-up at 61 weeks. Biomechanically, there was similar heel endurance, isokinetic strength, calf circumference and range of motion between both groups. In general, there were no differences in patient reported outcomes from all scoring systems used in the studies. Both groups returned to their pre-injured level at a similar time and there were no differences on the incidence of re-rupture (OR 1.13, 95% CI, 0.46-2.80, p = 0.79). CONCLUSION: PRP injections for acute Achilles tendon ruptures do not improve medium to long-term biomechanical and clinical outcomes. However, future studies incorporating the ideal application and biological composition of PRP are required to investigate its true clinical efficacy.

Neck of Femur Fractures in the First Eight Months of the COVID-19 Pandemic: A UK Systematic Review and Meta-Analysis.

Neck of femur (NOF) fracture patients have significant 30-day mortality. The incidence of NOF fractures remained high during the coronavirus disease 2019 (COVID-19) pandemic in the United Kingdom. Consequently, numerous cases were complicated with concurrent severe acute respiratory syndrome coronavirus 2 infection. We performed a systematic review and meta-analysis of all studies from the United Kingdom related to NOF fractures and 30-day mortality outcomes during the pandemic.   A systematic review and meta-analysis was performed and reported as per the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. Two reviewers independently searched on Medline for studies that were published between the 1st of March 2020 and the 1st of November 2020 in the United Kingdom. The following outcomes were compared: 30-day mortality, time to surgery, and anaesthetic risk.   A total of five articles were included in this review. In total, 286 patients with NOF fractures and COVID-19 infection were identified, with 30-day mortality ranging from 30.5% to 50% (odds ratio = 6.02; 95% confidence interval = 4.10-8.85; χ2 = 4.82; I2 = 58%). Increased time to surgery due to COVID-19-related delays was also noted for the majority of patients in some studies. Mortality scores (Charlson Comorbidity Index, Nottingham Hip Fracture Score) failed to accurately predict the mortality risk. Concurrent infection of COVID-19 in patients with NOF fractures increases the 30-day mortality sixfold compared to the COVID-19-negative group. Efforts should be made to optimise time to surgery as well as consideration of postoperative care in higher dependency units. Future updates in mortality predicting scores should include COVID-19 infection as a significant factor.

Diagnosis of physical and mental health conditions in primary care during the COVID-19 pandemic: a retrospective cohort study.

BACKGROUND: To date, research on the indirect impact of the COVID-19 pandemic on the health of the population and the health-care system is scarce. We aimed to investigate the indirect effect of the COVID-19 pandemic on general practice health-care usage, and the subsequent diagnoses of common physical and mental health conditions in a deprived UK population. METHODS: We did a retrospective cohort study using routinely collected primary care data that was recorded in the Salford Integrated Record between Jan 1, 2010, and May 31, 2020. We extracted the weekly number of clinical codes entered into patient records overall, and for six high-level categories: symptoms and observations, diagnoses, prescriptions, operations and procedures, laboratory tests, and other diagnostic procedures. Negative binomial regression models were applied to monthly counts of first diagnoses of common conditions (common mental health problems, cardiovascular and cerebrovascular disease, type 2 diabetes, and cancer), and corresponding first prescriptions of medications indicative of these conditions. We used these models to predict the expected numbers of first diagnoses and first prescriptions between March 1 and May 31, 2020, which were then compared with the observed numbers for the same time period. FINDINGS: Between March 1 and May 31, 2020, 1073 first diagnoses of common mental health problems were reported compared with 2147 expected cases (95% CI 1821 to 2489) based on preceding years, representing a 50·0% reduction (95% CI 41·1 to 56·9). Compared with expected numbers, 456 fewer diagnoses of circulatory system diseases (43·3% reduction, 95% CI 29·6 to 53·5), and 135 fewer type 2 diabetes diagnoses (49·0% reduction, 23·8 to 63·1) were observed. The number of first prescriptions of associated medications was also lower than expected for the same time period. However, the gap between observed and expected cancer diagnoses (31 fewer; 16·0% reduction, -18·1 to 36·6) during this time period was not statistically significant. INTERPRETATION: In this deprived urban population, diagnoses of common conditions decreased substantially between March and May 2020, suggesting a large number of patients have undiagnosed conditions. A rebound in future workload could be imminent as COVID-19 restrictions ease and patients with undiagnosed conditions or delayed diagnosis present to primary and secondary health-care services. Such services should prioritise the diagnosis and treatment of these patients to mitigate potential indirect harms to protect public health. FUNDING: National Institute of Health Research.

Physician staffed emergency medical service for children: a retrospective population-based registry cohort study in Odense region, Southern Denmark.

OBJECTIVES: The aim of this study is to determine diagnostic patterns in the prehospital paediatric population, age distribution, the level of monitoring and the treatment initiated in the prehospital paediatric case. Hypothesis was that advanced prehospital interventions are rare in the paediatric patient population. SETTING: We performed a retrospective population-based registry cohort study of children attended by a physician-staffed emergency medical service (EMS) unit (P-EMS), in the Odense area of Denmark during a 10-year study period. PARTICIPANTS: We screened 44 882 EMS contacts and included 5043 children. Patient characteristics, monitoring and interventions performed by the P-EMS crews were determined. RESULTS: We found that paediatric patients were a minority among patients attended by P-EMS units: 11.2% (10.9 to 11.5) (95% CI) of patients were children. The majority of the children were <5 years old; one-third being <2 years old. Respiratory problems, traffic accidents and febrile seizures were the three most common dispatch codes. Oxygen supplementation, intravenous access and application of a cervical collar were the three most common interventions. Oxygen saturation and heart rate were documented in more than half of the cases, but more than one-third of the children had no vital parameters documented. Only 22% of the children had respiratory rate, saturation, heart rate and blood pressure documented. Prehospital invasive procedures such as tracheal intubation (n=74), intraosseous access (n=22) and chest drainage (n=2) were infrequently performed. CONCLUSION: Prehospital paediatric contacts are uncommon, more frequently involving smaller children. Monitoring or at least documentation of basic vital parameters is infrequent and may be an area for improvement. Advanced and potentially life-saving prehospital interventions provide a dilemma since these likely occur too infrequently to allow service providers to maintain their technical skills working solely in the prehospital environment.

Reducing risk of spinal haematoma from spinal and epidural pain procedures.

BACKGROUND AND AIMS: Central neuraxial blocks (CNB: epidural, spinal and their combinations) and other spinal pain procedures can cause serious harm to the spinal cord in patients on antihaemostatic drugs or who have other risk-factors for bleeding in the spinal canal. The purpose of this narrative review is to provide a practise advisory on how to reduce risk of spinal cord injury from spinal haematoma (SH) during CNBs and other spinal pain procedures. Scandinavian guidelines from 2010 are part of the background for this practise advisory. METHODS: We searched recent guidelines, PubMed (MEDLINE), SCOPUS and EMBASE for new and relevant randomised controlled trials (RCT), case-reports and original articles concerning benefits of neuraxial blocks, risks of SH due to anti-haemostatic drugs, patient-related risk factors, especially renal impairment with delayed excretion of antihaemostatic drugs, and specific risk factors related to the neuraxial pain procedures. RESULTS AND RECOMMENDATIONS: Epidural and spinal analgesic techniques, as well as their combination provide superior analgesia and reduce the risk of postoperative and obstetric morbidity and mortality. Spinal pain procedure can be highly effective for cancer patients, less so for chronic non-cancer patients. We did not identify any RCT with SH as outcome. We evaluated risks and recommend precautions for SH when patients are treated with antiplatelet, anticoagulant, or fibrinolytic drugs, when patients' comorbidities may increase risks, and when procedure-specific risk factors are present. Inserting and withdrawing epidural catheters appear to have similar risks for initiating a SH. Invasive neuraxial pain procedures, e.g. spinal cord stimulation, have higher risks of bleeding than traditional neuraxial blocks. We recommend robust monitoring routines and treatment protocol to ensure early diagnosis and effective treatment of SH should this rare but potentially serious complication occur. CONCLUSIONS: When neuraxial analgesia is considered for a patient on anti-haemostatic medication, with patient-related, or procedure-related risk factors, the balance of benefits against risks of bleeding is decisive; when CNB are offered exclusively to patients who will have a reduction of postoperative morbidity and mortality, then a higher risk of bleeding may be accepted. Robust routines should ensure appropriate discontinuation of anti-haemostatic drugs and early detection and treatment of SH. IMPLICATIONS: There is an on-going development of drugs for prevention of thromboembolic events following surgery and childbirth. The present practise advisory provides up-to-date knowledge and experts' experiences so that patients who will greatly benefit from neuraxial pain procedures and have increased risk of bleeding can safely benefit from these procedures. There are always individual factors for the clinician to evaluate and consider. Increasingly it is necessary for the anaesthesia and analgesia provider to collaborate with specialists in haemostasis. Surgeons and obstetricians must be equally well prepared to collaborate for the best outcome for their patients suffering from acute or chronic pain. Optimal pain management is a prerequisite for enhanced recovery after surgery, but there is a multitude of additional concerns, such as early mobilisation, early oral feeding and ileus prevention that surgeons and anaesthesia providers need to optimise for the best outcome and least risk of complications.

Pre- to postoperative coagulation profile of 307 patients undergoing oesophageal resection with epidural blockade over a 10-year period in a single hospital: implications for the risk of spinal haematoma.

BACKGROUND: Epidural anaesthesia and analgesia are indicated for oesophageal surgery. A rare but serious complication is spinal haematoma, which can occur on insertion, manipulation or withdrawal of catheters. Evidence and guidelines are vague regarding which tests are appropriate and how to interpret their results. We aimed to describe how routine coagulation test results change during oesophagectomy's perioperative course. METHODS: Following ethical approval, we retrospectively identified patients who had undergone oesophagectomy between 2002 and 2012. Blood test results and details of operations, haemorrhage and complications were recorded and analysed with Excel and R. A literature search was conducted using the PubMed terms 'epidural' AND 'coagulation' AND English language. Relevant articles published in 2000 and after were included. RESULTS: Three hundred and seven patients received a thoracic epidural infusion with bupivacaine and morphine while 51 received an intravenous morphine infusion. Tests taken preoperatively and before the planned withdrawal of the epidural catheter demonstrated increases in all three measures: aPTT (activated partial thromboplastin time), PT-INR (prothrombin international normalised ratio) and platelet count (Plc). Postoperative thrombocytopenia was almost non-existent while aPTT or PT-INR was elevated above the reference range in 129/307 patients: aPTT was elevated in 116/307 while PT-INR was elevated in 32/307. This is too small a sample to allow meaningful estimation of risk of spinal haematoma: it may be as high as 2.3%. The literature search returned 275 articles, of which 57 were relevant. Twenty-one concerned the natural history of postoperative coagulation; 16, the incidence of and risk factors for spinal haematoma; and 5, evaluation of specific blood tests. Postoperative coagulation is characterised by thrombocytosis and transient moderately abnormal routine coagulation test results. Viscoelastic tests are not validated in the stable postoperative setting. CONCLUSIONS: Screening for coagulopathy before removal of epidural catheters is of unclear benefit since elevated aPTT and PT-INR are usual and may not indicate hypocoagulation. A thorough clinical assessment is important. We nevertheless recommend caution when being presented with elevated routine tests of coagulation before withdrawing an epidural catheter: viscoelastic haemostatic tests may have a role in testing before withdrawal of epidural catheters but they are so far not validated. Future research should include advanced coagulation analysis as soon as a patient is unfortunate enough to have a spinal haematoma.

Coagulative safety of epidural catheters after major upper gastrointestinal surgery: advanced and routine coagulation analysis in 38 patients.

BACKGROUND: The risk of spinal haematoma in patients receiving epidural catheters is estimated using routine coagulation tests, but guidelines are inconsistent in their recommendations on what to do when results indicate slight hypocoagulation. Postoperative patients are prone to thrombosis, and thromboelastometry has previously shown hypercoagulation in this setting. We aimed to better understand perioperative haemostasis by comparing results from routine and advanced tests, hypothesizing that patients undergoing major upper gastrointestinal surgery would be deficient in vitamin K-dependent coagulation factors because of malnutrition, or hypocoagulative because of accumulation of low molecular weight heparin (LMWH). METHODS: Thirty-eight patients receiving epidural analgesia for major upper gastrointestinal surgery were included. We took blood at the time of preoperative epidural catheterization and at catheter withdrawal. Prothrombin time-international normalized ratio (PT-INR), activated partial thromboplastin time (aPTT) and platelet count (Plc) were analysed, and also albumin, proteins induced by vitamin K absence (PIVKA-II), rotational thromboelastometry (ROTEM®), multiple electrode aggregometry (Multiplate®) and activities of factors II, VII, IX, X, XI, XII and XIII. RESULTS: Postoperative coagulation was characterized by thrombocytosis and hyperfibrinogenaemia. Mean PT-INR increased significantly from 1.0 ± 0.1 to 1.2 ± 0.2 and mean aPTT increased significantly from 27 ± 3 to 30 ± 4 s. Activity of vitamin K-dependent factors did not decrease significantly: FIX and FX activity increased. FXII and FXIII decreased significantly. Mean Plc increased from 213 ± 153 × 106/L while all mean ROTEM-MCFs (maximal clot firmnesses) especially FIBTEM-MCF increased significantly to above the reference interval. All mean ROTEM® clotting times were within their reference intervals both before and after surgery. ROTEM® (HEPTEM minus INTEM) results were spread around 0. There were significant correlations between routine tests and the expected coagulation factors, but not any of the viscoelastic parameters or PIVKA-II. Multiplate® area under curve and EXTEM-MCF correlated significantly to Plc as did EXTEM-MCF to fibrinogen, FIX, FX and FXIII; and FIBTEM-MCF to Plc, FII, FXI and FXIII. CONCLUSIONS: The increase in PT-INR may be caused by decreased postoperative FVII while the elevated aPTT may be caused by low FXII. The mild postoperative hypocoagulation indicated by routine tests is not consistent with thromboelastometry. The relevance of ROTEM® and Multiplate® in the context of moderately increased routine tests remains unclear. Trial registration number is not applicable since this is not a clinical trial.

Thromboelastometry versus free-oscillation rheometry and enoxaparin versus tinzaparin: an in-vitro study comparing two viscoelastic haemostatic tests' dose-responses to two low molecular weight heparins at the time of withdrawing epidural catheters from ten patients after major surgery.

BACKGROUND: Monitoring low molecular weight heparins (LMWH's) in the perioperative period is prudent in patients at high risk of coagulative complications, especially when the patient has an epidural catheter requiring withdrawal, which is associated with the risk of spinal haematoma. The aim of this study was to evaluate the in vitro dose-responses of two different LMWH's on two different viscoelastic haemostatic tests, using blood sampled from patients with normal routine coagulation parameters, on the day after major surgery when their epidural catheters were due to be withdrawn. METHODS: Enoxaparin or tinzaparin were added in vitro to blood from ten patients who had undergone oesophageal resection, to obtain plasma concentrations of approximately 0, 0.5, 1.0 and 1.5 IU/mL. Coagulation was monitored using thromboelastometry (ROTEM®) using the InTEM® activating reagent; and free oscillation rheometry (FOR: ReoRox®), activated using thromboplastin. Clot initiation was measured using ROTEM-CT, ReoRox-COT1 and ReoRox-COT2. Clot propagation was measured using ROTEM-CFT, ROTEM-Alpha Angle and ReoRox-Slope. Clot stability was measured using ROTEM-MCF and ReoRox-G'max, and clot lysis was measured using ROTEM-ML and ReoRox-ClotSR. RESULTS: Clot initiation time assessed by thromboelastometry and FOR was prolonged by increasing concentrations of both LMWH's (P < 0.01). Equivalent doses of tinzaparin in international units (anti-FXa units) per millilitre prolonged clot initiation more than enoxaparin (P < 0.05). There was significant inter-individual variation - the ranges of CT and COT1 at LMWH-concentrations of 0 and 1.5 IU/mL overlapped. None of the tests reflecting clot formation rate or stability showed a dose-response to either LMWH but clot lysis showed a tentative negative dose-response to the LMWH's. CONCLUSIONS: Clot initiation time's dose-dependent prolongation by LMWH's in this study agrees with previous research, as does tinzaparin's stronger anti-coagulative effect than enoxaparin at equivalent levels of anti-FXa activity. This casts doubt on the validity of using anti-FXa assays alone to guide dosage of LMWH's. The significant inter-individual variation in dose-response suggests that the relationship between dose and effect in the postoperative period is complicated. While both ROTEM and FOR may have some role in postoperative monitoring, more research is needed before any conclusion can be made about their clinical usefulness.

Study of parasitic resistance effects in nanowire and nanoribbon biosensors.

In this work, we investigate sensor design approaches for eliminating the effects of parasitic resistance in nanowire and nanoribbon biosensors. Measurements of pH with polysilicon nanoribbon biosensors are used to demonstrate a reduction in sensitivity as the sensor length is reduced. The sensitivity (normalised conductance change) is reduced from 11% to 5.5% for a pH change from 9 to 3 as the sensing window length is reduced from 51 to 11 µm. These results are interpreted using a simple empirical model, which is also used to demonstrate how the sensitivity degradation can be alleviated by a suitable choice of sensor window length. Furthermore, a differential sensor design is proposed that eliminates the detrimental effects of parasitic resistance. Measurements on the differential sensor give a sensitivity of 15%, which is in good agreement with the predicted maximum sensitivity obtained from modeling.

Monitoring low molecular weight heparins at therapeutic levels: dose-responses of, and correlations and differences between aPTT, anti-factor Xa and thrombin generation assays.

BACKGROUND: Low molecular weight heparins (LMWH's) are used to prevent and treat thrombosis. Tests for monitoring LMWH's include anti-factor Xa (anti-FXa), activated partial thromboplastin time (aPTT) and thrombin generation. Anti-FXa is the current gold standard despite LMWH's varying affinities for FXa and thrombin. AIM: To examine the effects of two different LMWH's on the results of 4 different aPTT-tests, anti-FXa activity and thrombin generation and to assess the tests' concordance. METHOD: Enoxaparin and tinzaparin were added ex-vivo in concentrations of 0.0, 0.5, 1.0 and 1.5 anti-FXa international units (IU)/mL, to blood from 10 volunteers. aPTT was measured using two whole blood methods (Free oscillation rheometry (FOR) and Hemochron Jr (HCJ)) and an optical plasma method using two different reagents (ActinFSL and PTT-Automat). Anti-FXa activity was quantified using a chromogenic assay. Thrombin generation (Endogenous Thrombin Potential, ETP) was measured on a Ceveron Alpha instrument using the TGA RB and more tissue-factor rich TGA RC reagents. RESULTS: Methods' mean aPTT at 1.0 IU/mL LMWH varied between 54s (SD 11) and 69s (SD 14) for enoxaparin and between 101s (SD 21) and 140s (SD 28) for tinzaparin. ActinFSL gave significantly shorter aPTT results. aPTT and anti-FXa generally correlated well. ETP as measured with the TGA RC reagent but not the TGA RB reagent showed an inverse exponential relationship to the concentration of LMWH. The HCJ-aPTT results had the weakest correlation to anti-FXa and thrombin generation (Rs0.62-0.87), whereas the other aPTT methods had similar correlation coefficients (Rs0.80-0.92). CONCLUSIONS: aPTT displays a linear dose-response to LMWH. There is variation between aPTT assays. Tinzaparin increases aPTT and decreases thrombin generation more than enoxaparin at any given level of anti-FXa activity, casting doubt on anti-FXa's present gold standard status. Thrombin generation with tissue factor-rich activator is a promising method for monitoring LMWH's.

Correction of hypothermic and dilutional coagulopathy with concentrates of fibrinogen and factor XIII: an in vitro study with ROTEM.

BACKGROUND: Fibrinogen concentrate treatment can improve coagulation during massive traumatic bleeding. The aim of this in vitro study was to determine whether fibrinogen concentrate, or a combination of factor XIII and fibrinogen concentrates, could reverse a haemodilution-induced coagulopathy during hypothermia. METHODS: Citrated venous blood from 10 healthy volunteers was diluted in vitro by 33% with 130/0.42 hydroxyethyl starch (HES) or Ringer's acetate (RAc). The effects of fibrinogen concentrate corresponding to 4 gram per 70 kg, or a combination of the same dose of fibrinogen with factor XIII (20 IU per kg), were measured using rotational thromboelastometry (ROTEM). The blood was analysed at 33°C or 37°C with ROTEM EXTEM and FIBTEM reagents. Clotting time (CT), clot formation time (CFT), alpha angle (AA) and maximal clot formation (MCF) were recorded. RESULTS: Fibrinogen with or without factor XIII improved all ROTEM parameters in either solution irrespective of temperature, with the exception of EXTEM-AA and EXTEM-CFT in HES haemodilution. Fibrinogen increased FIBTEM-MCF more in the samples diluted with RAc than HES, particularly in presence of factor XIII. CONCLUSIONS: Fibrinogen improved in vitro haemodilution-induced coagulopathy at both 33°C and 37°C, though more efficiently after crystalloid than HES haemodilution. Factor XIII had an additional effect on FIBTEM-MCF, but only after crystalloid dilution.

Rotational thromboelastometry and multiple electrode platelet aggregometry in four patients with abnormal routine coagulation studies before removal of epidural catheters after major surgery: a case series and research study.

INTRODUCTION: Routine coagulation tests have a low predictability for perioperative bleeding complications, and spinal hematoma after removal of epidural catheters is very infrequent. Thromboelastometry and point-of-care platelet aggregometry may improve hemostatic monitoring but have not been studied in the context of safety around epidural removal. METHODS: Twenty patients who received an epidural catheter for major thoracoabdominal and abdominal surgery were included prospectively. In addition to routine coagulation tests, rotational thromboelastometry and multiple electrode platelet aggregometry were carried out. RESULTS: A coagulation deficit was suggested by routine coagulation tests on the intended day of epidural catheter removal in four out of 20 patients. Prothrombin time-international normalized ratio was elevated to 1.5 in one patient (normal range: 0.9 to 1.2) while rotational thromboelastometry and multiple electrode platelet aggregometry parameters were within normal limits. Activated partial thromboplastin time was elevated to 47 to 50 seconds in the remaining three patients (normal range 28 to 45 seconds). Rotational thromboelastometry showed that one of the patients' results was due to heparin effect: the clotting time with the HEPTEM® activator was 154 seconds as compared to 261 seconds with INTEM. The three remaining patients with prolonged routine coagulation test results had all received over 1L of hydroxyethyl starch (Venofundin®) and thrombosis prophylaxis with low-molecular-weight heparin (enoxaparin). Rotational thromboelastometry and multiple electrode platelet aggregometrygave normal or hypercoagulative signals in most patients. CONCLUSIONS: This case series is new in that it examines rotational thromboelastometry and multiple electrode platelet aggregometry postoperatively in the context of epidural analgesia and shows that they may be clinically useful. These methods should be validated before they can be used for standard patient care.

The volume-expanding effects of autologous liquid stored plasma following hemorrhage.

BACKGROUND: Plasma use has increased since studies have suggested that early treatment with blood components in trauma with severe hemorrhage may improve outcome. Plasma is also commonly used to correct coagulation disturbances in non-bleeding patients. Little is known about the effects of plasma transfusion on plasma volume. We report a prospective interventional study in which the plasma volume-expanding effect of autologous plasma was investigated after a controlled hemorrhage. METHODS: Plasma obtained by plasmapheresis from nine healthy regular blood donors was stored at 2-6°C. Five weeks after donation the subjects were bled of 600 ml and then transfused with 600 ml of autologous plasma. Plasma volume was estimated using (125)I-albumin before and after bleeding, and immediately after plasma transfusion. Plasma volume changes were then estimated by measuring changes in hematocrit during the following 3-h period. RESULTS: Estimated plasma volume after bleeding was 3170 ± 320 ml and 3690 ± 380 ml (mean ± standard deviation) immediately following the transfusion of plasma (p 0.05). This increase in plasma volume corresponds to 86 ± 13% of the infused volume. Three hours after transfusion, plasma volume was still 3680 ± 410 ml. CONCLUSIONS: Stored liquid plasma has a plasma volume expanding effect up to 86% of its infused volume with a duration of at least 3 h.

Comparison of two infusion rates of antithrombin concentrate in cardiopulmonary bypass surgery.

BACKGROUND: Antithrombin concentrate (AT) is used to treat heparin resistance (HR) in cardiac surgery. It is usually given slowly due to the fear of anaphylaxis. This may delay cardiac catheterisation and the start of cardiopulmonary bypass (CPB). HR is often defined as the failure to reach or maintain a target activated clotting time (ACT) despite a standard dose of heparin. It is not generally possible to predict which patients will display HR, although there are known risk factors. Routine early administration of AT before heparinisation is probably not cost-effective. Infusing AT relatively quickly after demonstrating HR may be more cost-effective, while not delaying surgery. The aim of this study is to investigate the safety and side effects of a faster infusion of AT. METHODS: Forty patients undergoing elective heart surgery were included and randomised to two groups in a double-blind fashion. Each group received 1000 IU of AT intravenously (IV). One group received a slow infusion (100 IU/min) before full-dose heparinisation. The other group received a fast infusion (250 IU/min). Haemodynamic and respiratory data were recorded. Any adverse effects were noted. Thrombin-antithrombin, anti-Xa and antithrombin levels in plasma were measured. RESULTS: No anaphylaxis occurred in either group. No differences were found regarding haemodynamics, respiration or laboratory results. Two patients experienced major haemorrhage and recovered; there were two deaths, thought to be unrelated to the study drugs. CONCLUSION: AT can be infused at a rate of 250 IU/min. This is faster than the current recommendation of 100 IU/min. This rate of infusion allows restricting AT infusion to those patients who display HR, without delaying surgery. Optimal anticoagulant therapy for CPB probably includes point-of-care measurement of ACT and plasma AT and small, but rapid, infusions of AT in heparin-resistant patients.

Epidural lipomatosis and congenital small spinal canal in spinal anaesthesia: a case report and review of the literature.

INTRODUCTION: Complications after lumbar anaesthesia and epidural blood patch have been described in patients with congenital small spinal canal and increased epidural fat or epidural lipomatosis. These conditions, whether occurring separately or in combination, require magnetic resonance imaging for diagnosis and grading, but their clinical significance is still unclear. CASE PRESENTATION: A 35-year-old Caucasian woman who was undergoing a Caesarean section developed a longstanding L4-L5 unilateral neuropathy after the administration of spinal anaesthesia. There were several attempts to correctly position the needle, one of which resulted in paraesthesia. A magnetic resonance image revealed that the patient's bony spinal canal was congenitally small and had excess epidural fat. The cross-sectional area of the dural sac was then reduced, which left practically no free cerebrospinal fluid space. CONCLUSION: The combination of epidural lipomatosis of varying degrees and congenital small spinal canal has not been previously discussed with spinal anaesthesia. Due to the low cerebrospinal fluid content of the small dural sac, the cauda equina becomes a firm system with a very limited possibility for the nerve roots to move away from the puncture needle when it is inserted into the dural sac. This constitutes risks of technical difficulties and neuropathies with spinal anaesthesia.