Effects of diaspirin cross-linked haemoglobin on post-traumatic cerebral perfusion pressure and blood flow in a rodent model of diffuse brain injury

Diaspirin cross-linked haemoglobin (DCLHb) is a new oxygen carrying blood substitute with vasoactive properties. Vasoactive properties may be mediated via high affinity binding of nitric oxide by the haem moiety. Using a rodent model of head injury combined with ischaemia, we studied the effects of DCLHb on cerebral blood flow (CBF) and intracranial pressure (ICP). Twenty anaesthetized rats were allocated randomly to receive treatment with DCLHb 400 mg kg-1 i.v. or placebo (oncotically matched plasma protein substitute 4.5% i.v.). To produce diffusely increased ICP, after a severe weight drop injury, all animals underwent a 30-min period of bilateral carotid ligation combined with a period of induced hypotension. After reperfusion, DCLHb or placebo was infused and the animals instrumented for measurement of intraventricular ICP and CBF in the region of the sensorimotor cortex using the hydrogen clearance technique. Mean arterial pressure (MAP), ICP, cerebral perfusion pressure (CPP) (CPP = MAP - ICP) and CBF were measured 4 h after injury in all animals. DCLHb significantly reduced ICP from mean 13 (SEM 2) to 3 (1) mm Hg (P < 0.001), increased CPP from 52 (8) to 95 (6) mm Hg (P < 0.001) and increased CBF from 21 (2) to 29 (2) ml 100 g-1 min-1 (P = 0.032). We conclude that DCLHb improved CPP without a reduction in CBF in a rodent model of post-traumatic brain swelling.      

Leaving a mark: the frequency and accuracy of tattooing prior to laparoscopic colorectal surgery

Aim Intra‐operative localization of small cancers and polyps during laparoscopic colorectal surgery is difficult due to reduced tactile feedback. The consequences of failing to identify the lesion for resection can result in open conversion or removal of the wrong segment of bowel. Method Data were collected from a prospectively‐kept database over a 12‐month period from April 2008 to March 2009 and analysed retrospectively. Details concerning the documentation, visibility and accuracy of tattoos were recorded. Results Eighty‐five patients (88 lesions) underwent laparoscopic resection for a benign or malignant colorectal tumour during 1 year from April 2008. Eighty‐one patients underwent endoscopic visualization of the tumour as a first or second procedure. Of these 81 patients, 83 lesions were visualized endoscopically and 54 (65.1%) were tattooed in 52 patients. In the 52 patients, 36 (69%) of the tattoos were carried out on the first endoscopy. At operation the tattoo was judged to be visible and accurate in 70%, visible but inaccurate in 7% and not visible in 15%. It was significantly easier to see the tattoo in women (19/21 women vs 21/29 men; P = 0.03) but there was no relationship between tattoo visibility and BMI. An accurate tattoo did not reduce the conversion rate (P = 0.71). No tattoo‐related complications were encountered. Conclusion The practice of tattooing colorectal cancers is variable in frequency, technique and accuracy. We advocate that all colonic lesions suspicious for cancer should be tattooed during endoscopy at a defined distance below the tumour, adhering to a departmental protocol in case surgery is required.     

Anemia during and at discharge from intensive care: the impact of restrictive blood transfusion practice

Objective To document the prevalence of anemia among patients admitted to intensive care (ICU) and, among survivors, at ICU discharge when restrictive transfusion practice was used.Design This was an observational cohort study.Setting Ten of the 26 general ICUs in Scotland.Patients and participants One thousand twenty-three sequential ICU admissions over 100 days, representing 44% of all ICU admissions in Scotland during the study period, studied daily from admission to discharge or death in the ICU.Interventions None.Measurements and results The median transfusion trigger used, in the absence of bleeding, was 78 g/l (interquartile range 73–84); <2% of transfusion triggers were above the upper limit of the national transfusion trigger guideline (100 g/l). Overall, 25% of admissions had a hemoglobin concentration <90 g/l at ICU admission. Seven hundred sixty-six patients admitted survived to ICU discharge. Among these, the prevalence of anemia (male <130 g/l; female <115 g/l) at ICU discharge was 87.0 (95% CI: 83.6 to 89.9)% for males and 79.6 (74.8 to 83.7)% for females. Of the male survivors 24.1 (20.3 to 28.3)% and of the female 27.9 (23.4 to 33.2)% had a hemoglobin <90 g/l at ICU discharge. The prevalence was similar for patients with and without pre-existing ischemic heart disease. Logistic regression found independent associations between having a hemoglobin concentration <90 g/l at ICU discharge and the first measured hemoglobin in ICU, the presence of acute renal failure and thrombocytopenia during ICU stay.Conclusions Anemia is highly prevalent in ICUs that use restrictive transfusion triggers. The impact of anemia on functional recovery after intensive care requires investigation.Electronic Supplementary Material Supplementary material is available in the online version of this article at The authors represent the Audit of Transfusion in Intensive Care in Scotland (ATICS) study group. The ATICS Study Group was made up of the organizing committee: T.S. Walsh (Chairman), M. Garrioch, C. Maciver (study coordinator), F. McArdle (study coordinator), J. Kinsella, R. Lee (statistician), G. Fletcher, D.B. McClelland, R. Green, A. Todd and F. MacKirdy and of the participating units: Aberdeen Royal Infirmary (S.A. Stott, J.L. Scott, M.G.K. Strachan); Borders General Hospital (T. Cripps, S. Hogg, D. Hedderly, L. Hume, J. Playfair, I. Gourlay); Glasgow Royal Infirmary (J. Kinsella, M.G. Booth, T. McMillan); Ninewells Hospital Dundee (S.L. Crofts, I. Mellor, S.J. Cole); Royal Alexandra Hospital Paisley (G. Fletcher, K. McIlravey); Royal Infirmary, Edinburgh (T.S. Walsh, F. McArdle, S.J. Dodds); Southern General Hospital, Glasgow (M. Garrioch, J. Sandbach, B. McMillan); St Johns Hospital, Livingston (M. Hughes, M. MacRury, L.M.M. Morrison); Western General Hospital, Edinburgh (C. Wallis, C.G. Battison, C. Hardcastle, E.D. Fox); Western Infirmary, Glasgow (A.R. Binning, M. Pollock, S. Kelly); Scottish National Blood Transfusion Service (D.B. McClelland, R.H.A. Green, A.M.M. Todd, I. McKechnie, C.R. Maciver); Scottish Intensive Care Society Audit Group (F. MacKirdy); Clinical Audit Resource Centre, Western General Hospital, Edinburgh (M.L. Hughes); Medical Statistics Unit, Edinburgh University (R.J. Lee).     

Haemodynamic effects of diaspirin crosslinked haemoglobin (DCLHb) given before abdominal aortic aneurysm surgery

We studied 34 patients undergoing elective repair of an abdominal aortic aneurysm under combined general anaesthesia and epidural block to evaluate the acute effects of diaspirin crosslinked haemoglobin (DCLHb) 50, 100 and 200 mg kg-1 i.v. Haemodynamic variables were measured continuously using pulmonary and radial artery catheters, and oxygen delivery and consumption were calculated at regular intervals. DCLHb was shown to be vasoactive, producing an increase in mean arterial pressure of approximately 25% with each dose, with small decreases in cardiac index and calculated oxygen delivery. These effects persisted beyond the end of infusion and provided a degree of cardiovascular stability during the operative procedure. The effects of DCLHb on oxygen consumption at these doses were minimal.      

Prospective observational survey of the utilisation of anaesthetists and the outcome following cardiac arrest calls

BACKGROUND AND AIMS: We wanted to determine whether the practice of routinely sending an anaesthetist to cardiac arrests is common within Scotland. We also wished to evaluate the interventions performed by our intensive care anaesthetist when responding to cardiac arrest calls. METHODS: We performed a telephone survey of the 26 Scottish hospitals with an intensive care unit. We conducted a prospective observational survey over a period of six months in one Scottish teaching hospital. Structured interviews with the anaesthetist who responded to the cardiac arrest call were undertaken. RESULTS: Routine attendance of an anaesthetist at cardiac arrests occurs in 25 of the 26 hospitals surveyed. We analysed 68 of 73 arrest calls. In 28 calls (41%) there was no requirement for anaesthetic intervention. In 40 (59%) the anaesthetist intervened. The interventions were for cardiac arrest procedures in 33 cases and ventilatory failure in the remaining 7 cases. One patient survived to hospital discharge: a mortality of 98%. CONCLUSIONS: Patients who remain in cardiac arrest upon the arrival of the anaesthetist have a very high mortality. The practice of routinely sending an anaesthetist to cardiac arrest calls is not justified.     

Reducing red cell transfusion by audit, education and a new guideline in a large teaching hospital

Safety concerns combined with the greatly increased costs and difficulties of maintaining the blood supply are major considerations for transfusion services. Previous local surveys demonstrated that hospital blood use at our hospital could be improved. Excessive cross-matching, unnecessary transfusion and high return rates of unused blood were commonplace. Transfusion practice was audited over a 3-month period. An education package with guidelines for transfusion was delivered to all clinician groups within the hospital, over the following 9 months. The audit was repeated exactly 1 year later at the same time period. During the second audit, inpatient hospital numbers increased by 1.02% (from n = 7262 to n = 7336) but no differences in length of stay, cardiovascular morbidity or mortality were demonstrated. Twenty percent (n = 254, 2002; n = 316, 2001) fewer patients received blood, and the number of red cell packs used reduced by 19% (from n = 1093 to n = 880). Total number of patients transfused reduced from 4.4% to 3.5% which, as an absolute difference, is a reduction of 0.9% (CI 0.3-1.5, P = 0.006). The audit, guideline and education package had a major impact on red cell use within the hospital with no adverse effects. Blood use can be improved by the implementation of a suitable education package and guideline. If it is possible to replicate the results of this education programme nationwide, the effect on blood use, with subsequent savings and enhanced patient safety could be significant.     

Red cell requirements for intensive care units adhering to evidence-based transfusion guidelines

BACKGROUND: Anemia commonly complicates critical illness. Restrictive transfusion triggers are appropriate in this setting, but no large studies have measured red cell (RBC) requirements for intensive care patients when evidence-based transfusion guidelines are followed consistently. STUDY DESIGN AND METHODS: Data were recorded daily for 1023 of 1042 sequential admissions to 10 intensive care units (ICUs) over 100 days. The sample comprised 44 percent of all ICU admissions in Scotland during this period. RBC transfusions and the occurrence of clinically significant hemorrhage were recorded for every ICU day. Transfusion episodes were classified as either associated with or not associated with hemorrhage. Measures of RBC use were derived for the cohort and for Scotland with national audit data. RESULTS: A total of 39.5 percent (95% confidence interval [CI], 36.5%-42.5%) of admissions received transfusions. Eighteen percent of admissions received at least one transfusion associated with hemorrhage and 26 percent received at least one transfusion not associated with hemorrhage. The median (interquartile range) transfusion trigger in the absence of hemorrhage was 78 (73-78) g/L. The overall mean RBC use was 1.87 (95% CI, 1.79-1.96) units per admission or 0.34 (95% CI, 0.33-0.36) units per ICU-day. Forty-seven percent of RBCs administered were not associated with clinically significant hemorrhage. Mean RBC requirements for intensive care in Scotland were estimated to be 3950 (95% CI, 3780-4140) per million-adult-population per year. This represented 7 to 8 percent of the Scottish blood supply. CONCLUSIONS: Despite evidence-based transfusion practice, 40 percent of ICU patients receive transfusions, which account for 7 to 8 percent of the national blood supply.