Endovascular repair or open repair for ruptured abdominal aortic aneurysm: a Cochrane systematic review.

OBJECTIVES: Emergency endovascular aneurysm repair (eEVAR) may improve outcomes for patients with ruptured abdominal aortic aneurysm (RAAA). The study aim was to compare the outcomes for eEVAR with conventional open surgical repair for the treatment of RAAA. SETTING: A systematic review of relevant publications was performed. Randomised controlled trials (RCTs) comparing eEVAR with open surgical repair for RAAA were included. PARTICIPANTS: 3 RCTs were included, with a total of 761 patients with RAAA. INTERVENTIONS: Meta-analysis was performed with fixed-effects models with ORs and 95% CIs for dichotomous data and mean differences with 95% CIs for continuous data. PRIMARY AND SECONDARY OUTCOME MEASURES: Primary outcome was short-term mortality. Secondary outcome measures included aneurysm-specific and general complication rates, quality of life and economic analysis. RESULTS: Overall risk of bias was low. There was no difference between the 2 interventions on 30-day (or in-hospital) mortality, OR 0.91 (95% CI 0.67 to 1.22; p=0.52). 30-day complications included myocardial infarction, stroke, composite cardiac complications, renal complications, severe bowel ischaemia, spinal cord ischaemia, reoperation, amputation and respiratory failure. Reporting was incomplete, and no robust conclusion was drawn. For complication outcomes that did include at least 2 studies in the meta-analysis, there was no clear evidence to support a difference between eEVAR and open repair. Longer term outcomes and cost per patient were evaluated in only a single study, thus precluding definite conclusions. CONCLUSIONS: Outcomes between eEVAR and open repair, specifically 30-day mortality, are similar. However, further high-quality trials are required, as the paucity of data currently limits the conclusions.

Nurse-led rapid access vascular examination clinic triage reduces inappropriate referrals for peripheral arterial disease.

INTRODUCTION: Peripheral arterial disease causing intermittent claudication (IC) causes decreased quality of life and significant morbidity. We hypothesized that triage of patients referred with suspected IC at a nurse-led rapid access vascular examination (RAVE) clinic would identify those patients requiring vascular surgery assessment. METHODS: A prospective cohort study was performed. Patients referred with suspected IC were assessed using the Edinburgh claudication questionnaire (ECQ) and arterial Doppler assessment with segmental waveform analysis and calculation of ankle brachial pressure index (ABPI). Data were collected regarding cardiovascular risk and its modification. RESULTS: Of 451 consecutive patients, mean age was 65 years (range 30-89). Cardiovascular risk factors included: 173/451 (38%) current smokers (162/451 (36%) were ex-smokers); diabetes, 22%; hypertension, 46%; ischaemic heart disease (angina), 29%; dyslipidaemia, 27%. Therapeutic risk modifications included: antiplatelet therapy, 64.4%; lipid-lowering therapy, 57.8%. abnormal ABPI readings were present in 264/451 (59%), with ratio <0.9 in 209/451 (46.3%), >1.3 in 48/451 (10.6%), and incompressible vessels 7/451 (1.5%). Normal ABPI (ratio >0.9 and <1.3, triphasic Doppler waveforms) were found in 187/451 (41%), these patient were considered inappropriate referrals. Considering those patient with PAD diagnosed on abnormal ABPI (<0.9 or >1.3), Doppler waveform analysis was more sensitive and specific than ECQ. CONCLUSIONS: Diagnosis of IC with clinical history alone is inaccurate in 41 percent of cases, leading to inappropriate referral to vascular surgery. Doppler waveform analysis had excellent sensitivity and specificity for prediction of ABPI <0.9. ABPI measurement in primary care could result in a more efficient use of clinical resources.

Triglyceride to HDL ratio is a reliable predictor of adverse outcomes in risk stratification for candidates undergoing abdominal aortic surgery.

INTRODUCTION: The aim of this study was to establish if an elevated triglyceride to high-density lipoprotein (HDL) ratio (THR) is not only a risk factor for cardiovascular and overall morbidity as the updated evidence shows, but could also be employed as a significant predictor for surgical adverse outcomes and hence be a valid tool for risk stratification of candidates undergoing abdominal aortic surgery. METHODS: This is a single-centre retrospective analysis of 2224 patients who underwent open abdominal aortic surgery between January 1996 and 2009. This cohort was divided into quartiles of THR. A list of covariates has been entered with THR into a multiple logistic model with forwards stepwise selection. The obtained result is an adjusted model, conceived to establish the association between THR and perioperative adverse events. Discrimination of the model so obtained and comparison with vascular-specific risk stratification scoring systems were evaluated using the area under the receiver operating characteristic (AUROC). RESULTS: THR had the highest predictive value for the outcomes of interest. The adjusted odds ratios (ORs) per every 0.1 augmentation of THR were 1.41 (1.08-1.88) for cardiac, 1.38 (1.09-1.84) for respiratory, 1.27 (1.06-1.54) for renal adverse events and 1.02 (0.84-1.23) for mortality. Regarding mortality, either of the scoring systems Vascular Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM) and customised probability index (CPI) and the THR ranked as moderate discriminators, with THR performing the worst (AUROC 0.71) compared with Vascular POSSUM (AUROC 0.76) and CPI (AUROC 0.78). THR performed as a very strong predictor of morbidity (AUROC 0.86), ranking above Vascular POSSUM (AUROC 0.72). CONCLUSIONS: THR is a significant predictor of perioperative morbidity and mortality. THR offers a broad outlook on the metabolic state of patients undergoing major abdominal aortic surgery and hence their propensity to adverse events, allowing us to risk-stratify the prognostic outcome of surgical intervention and possibly intervene preoperatively to optimise results.

Do Doppler waveforms at the common femoral artery accurately predict iliac stenosis?

OBJECTIVE: Evaluate whether common femoral artery (CFA) Doppler waveform assessment predicted the presence of significant iliac artery stenosis as visualised on magnetic resonance angiography (MRA). METHOD: Three-year retrospective study of patients investigated using CFA Doppler waveforms and MRA. The patients were identified from vascular/radiology databases. Waveforms were reported real time as monophasic, biphasic or triphasic. Results were compared with MRA findings. RESULTS: In 76 patients, 119 waveforms were assessed. MRA demonstrated 37 iliac vessels with significant stenosis. 32 (86%) had abnormal waveforms (monophasic/biphasic), 5 were triphasic. In 82 cases where MRA showed no significant stenosis, waveforms were abnormal in 35 (43%). Abnormal CFA waveforms have sensitivity of 86% and specificity of 57%. Monophasic waveforms alone were more specific (88%) but less sensitive (57%) for predicting iliac lesions. CONCLUSION: Whilst CFA waveform morphology is a useful adjunct in detection of iliac disease, normal triphasic waveforms do not exclude iliac stenosis.

Successful delayed secondary open conversion after endovascular repair using partial explantation technique: a single-center experience.

BACKGROUND: Endovascular aneurysm repair (EVAR) reduces the morbidity and mortality associated with abdominal aortic aneurysm repair, but in some patients endoleak or aneurysm expansion may necessitate secondary open conversion (SOC). We reviewed the outcomes after delayed SOC following EVAR in consecutive patients at a single center. METHODS: We retrospectively reviewed all patients undergoing EVAR to identify a cohort undergoing delayed SOC in a single center between 1998 and 2008. We analyzed delayed SOC patients for operative indications, technique, and early outcomes. We made specific comment on the surgical techniques used, with respect to partial or total endograft explantation. RESULTS: Delayed SOC was carried out in 10/285 (3.5%) consecutive patients implanted with the Zenith endograft; during this period, two further patients had SOC after initial EVAR in another center. Graft types were Zenith (n = 10), Talent (n = 1), and AneuRx (n = 1). Indications for open conversion were infected graft (n = 3), sac expansion (n = 3), type 1 endoleak (n = 2), type 2 endoleak (n = 2), juxtarenal aneurysm (n = 1), and rupture (n = 1). Explantation techniques were partial explantation with in situ replacement (n = 7), full explantation with axillobifemoral bypass (n = 3), in situ replacement (n = 1), and suturing (n = 1)Complete stent explantation was required in 4 patients with axillo-bifemoral bypass in three of them. 7 patients had partial stent explantation and one patient stent was left insitu. Postoperative morbidities included myocardial infarction (n = 1), renal dialysis (n = 1), and chest infection (n = 3). No 30-day mortality was noted, and all patients were discharged from hospital and remain well with median follow-up of 5 months (interquartile range 1.7-26.7). CONCLUSION: SOC after EVAR is feasible in selected patients with low morbidity and mortality. Partial explantation with in situ replacement, in the absence of sepsis, may be the preferred revascularization option but may require long-term follow-up.

The role of transthoracic echocardiography in embolic acute limb ischaemia.

INTRODUCTION: Embolic acute limb ischaemia (ALI) is commonly treated by re-vascularization and long-term anticoagulant therapy. Transthoracic echocardiography (TTE) is commonly used to screen for cardiac embolic source, but may not affect management. REPORT: We reviewed 115 consecutive patients with embolic ALI, 61% underwent TTE, with cardiac thrombus identified in only 3%. Incidental severe abnormalities requiring further cardiological investigation were detected in 19% of patients. Inpatient TTE did not affect mortality, morbidity, amputation rate, or anticoagulation. DISCUSSION: Transthoracic echocardiography seldom identifies a cardiac embolic source, but identifies many patients with severe incidental cardiac abnormalities, suggesting cardiology screening of these patients remains important.

Positive fluid balance is associated with complications after elective open infrarenal abdominal aortic aneurysm repair.

BACKGROUND: Open abdominal aortic aneurysm (AAA) repair is associated with cardiac and respiratory complications and an overall mortality rate of 2 to 8%. We hypothesised that excessive fluid administration during the perioperative period contributes to complications and poor outcome after AAA repair. METHODS: This was a retrospective cohort study. Medical records were analysed for fluid balance and complications in 100 consecutive patients treated by open AAA repair at a single centre between 2002-2005. Mortality and all major adverse events (MAE) such as myocardial infarction (MI), cardiac arrhythmia (Arr), pulmonary oedema (PO), pulmonary infection (PI), and acute renal failure (ARF) were included in the analysis. Level of care and hospital stay, were also recorded. RESULTS: There were no in-hospital deaths. MAE occurred in 40/100 (40%): MI (6%); Arr (14%); PO (14%); PI (25%); ARF (8%). Complications were not predicted by preoperative cardiovascular risk factors, operative and clamp time, or blood loss. Patients with complications had significantly greater cumulative positive fluid balance on postoperative day 0 (p<0.01), day 1 (p<0.05), day 2 (p<0.03) and day 3 (p<0.04). This relationship also existed for individual complications such as MI, and pulmonary oedema. These patients had significantly longer ICU/HDU (p<0.002) and hospital stay (p<0.0001). CONCLUSIONS: Serious complications are common after elective open AAA repair, and we have shown that positive fluid balance is predictive of major adverse events increased HDU/ICU and overall hospital stay.

Endovascular ruptured abdominal aortic aneurysm repair (EVRAR): a systematic review.

BACKGROUND: To review evidence supporting the use of endovascular ruptured aneurysm repair (EVRAR) for treatment of ruptured abdominal aortic aneurysm (RAAA). METHODS: A systematic review of the medical literature was performed for relevant studies. We searched a number of electronic databases and hand-searched relevant journals until November 2006 to identify studies for inclusion. We considered studies in which patients with a confirmed ruptured abdominal aortic aneurysm were treated with EVRAR, which reported endpoints of mortality and major complications. RESULTS: There was 1 randomised controlled trial (RCT), 33 non-randomised case series (24 retrospective and 9 prospective) reports were identified comparing EVRAR (n=891) with conventional open surgical repair for the treatment of RAAA. Whilst no benefit in the primary outcome of mortality was noted in the only RCT, evidence from non-randomised studies suggest that EVRAR is feasible in selected patients, where it may be associated with a trend towards reductions in blood loss, duration of intensive care treatment, early complications, and mortality. CONCLUSIONS: For the treatment of symptomatic or ruptured abdominal aortic aneurysm, emergency endovascular repair (EVRAR) is feasible in selected patients, with early outcomes comparable to best conventional open surgical repair for the treatment of RAAA.

Validity of the Hardman index to predict outcome in ruptured abdominal aortic aneurysm.

This study assessed the validity of the Hardman index in predicting outcome following open repair of ruptured abdominal aortic aneurysm and whether this scoring system can be used reliably to select patients for surgical repair. Patients undergoing open repair of ruptured abdominal aortic aneurysm in two university teaching hospitals over a 5-year period were identified from a computerized hospital database. Thirty-day mortality was the main outcome measure. Five Hardman index factors were calculated and related to outcome retrospectively. There were 178 patients with a mean age of 73.9 years (range 51-94) and a male to female ratio of 5.4:1. The overall in-hospital mortality was 57.3% (102/178). Univariate analysis of risk factors showed that age >76 years (P = 0.007, odds ratio [OR] 2.34, 95% confidence interval [CI] 1.26-4.37) and electrocardiograghic evidence of ischemia on admission (P = 0.002, OR 3.75, 95% CI 1.57-8.93) were associated with high mortality. However, loss of consciousness (P = 0.155, OR 1.56, 95% CI 0.85-2.86), hemoglobin <9 g/dL (P = 0.118, OR 1.89, 95% CI 0.85-4.22), and serum creatinine >0.19 mmol/L (P = 0.691, OR 1.25, 95% CI 0.42-3.70) were not significant predictors of mortality. Using a multivariate analysis, age >76 years (P = 0.043, OR 2.29, 95% CI 1.03-5.11) and myocardial ischemia (P = 0.029, OR 2.93, 95% CI 1.12-7.67) were again found to be the significant predictors of mortality. The operative mortality was 44%, 46%, 68%, 79%, and 100% for Hardman scores of 0, 1, 2, 3, and 4, respectively. No patient had a score of 5. The Hardman index is not a reliable predictor of outcome following repair of ruptured abdominal aortic aneurysm. High-risk patients may still survive and should not be denied surgical repair based on the scoring system alone. Further evaluation of the risk factors is required to reliably and justifiably exclude those patients in whom the intervention is inappropriate.

Endovascular treatment for ruptured abdominal aortic aneurysm.

BACKGROUND: An abdominal aortic aneurysm (AAA) (the pathological enlargement of the aorta) can develop in both men and women as they grow older. It is most commonly seen in men over the age of 65 years. Progressive aneurysm enlargement can lead to rupture and massive internal bleeding, a fatal event unless timely repair can be achieved. Despite improvements in perioperative care, mortality remains high (approximately 50%) after conventional open surgical repair. A newer minimally invasive technique, endovascular repair, has been shown to reduce early morbidity and mortality, as compared to conventional open surgery, for planned AAA repair. Emergency endovascular repair (eEVAR) has been used successfully to treat ruptured abdominal aortic aneurysm (RAAA), proving that it is feasible in selected patients. However, it is not yet known if eEVAR will lead to significant improvements in outcomes for these patients or indeed if it can replace conventional open repair as the preferred treatment for this lethal condition. OBJECTIVES: To compare the advantages and disadvantages of eEVAR in comparison with conventional open surgical repair for the treatment of RAAA. SEARCH STRATEGY: The Cochrane Peripheral Vascular Diseases Group searched their trials register (last searched October 2006) and the Cochrane Central Register of Controlled Trials (CENTRAL) database (last searched Issue 4, 2006). We searched a number of electronic databases and handsearched relevant journals until March 2006 to identify studies for inclusion. SELECTION CRITERIA: Randomised controlled trials in which patients with a confirmed ruptured abdominal aortic aneurysm were randomly allocated to eEVAR, or conventional open surgical repair. DATA COLLECTION AND ANALYSIS: Studies identified for potential inclusion were independently assessed for eligibility by at least two reviewers, with excluded studies further checked by the agreed arbitrators. As no randomised controlled trials were identified at present no tests of heterogeneity or sensitivity analysis were performed. MAIN RESULTS: There were no randomised controlled trials identified at present comparing eEVAR with conventional open surgical repair for the treatment of RAAA. AUTHORS' CONCLUSIONS: There is no high quality evidence to support the use of eEVAR in the treatment of RAAA. However, evidence from prospective controlled studies without randomisation, prospective studies, and retrospective case series suggest that eEVAR is feasible in selected patients, with outcomes comparable to best conventional open surgical repair for the treatment of RAAA . Furthermore, endovascular repair in selected patients may be associated with a trend towards reductions in blood loss, duration of intensive care treatment, and mortality.

The Belfast approach to managing complex lower limb vascular injuries.

INTRODUCTION: Complex lower limb vascular injuries (CLVIs) in high-energy penetrating or blunt trauma are associated with an unacceptably high incidence of complications including amputation. Traumatic ischaemia and ischaemia-reperfusion injury (IRI) of skeletal muscle often lead to limb loss, the systemic inflammatory response syndrome (SIRS) which affects remote organs and even the potentially fatal multiple organ dysfunction syndrome (MODS). Surgical care of CLVIs everywhere, including Northern Ireland until 1978, was governed by an anxiety to restore arterial flow quickly often using expedient and flawed repair techniques while a damaged major vein was frequently ligated. MATERIALS AND METHODS: A new policy centred on early intraluminal shunting of both artery and vein, restoring arterial inflow and venous outflow, respectively, was introduced at the Regional Vascular Surgery Unit of The Royal Victoria Hospital, Belfast in 1979. It imposed a disciplined one-stage comprehensive approach to treatment involving a sequence of operative manoeuvres in which all damaged anatomical elements receive meticulous and optimal attention unshackled by time constraints. RESULTS: Comparisons drawn between the pre-shunt period of unplanned treatment (1969-1978) and the post-shunt period centred on the use of shunts (1979-2000) showed that early shunting of both artery and vein in both penetrating (P) and blunt (B) injuries significantly reduced the necessity for fasciotomy (P: p=0.016, B: p=0.02) and caused a significant fall in the incidence of contracture (P: p=0.018, B: p=0.02) and of amputation (P: p=0.009, P: p=0.012). CONCLUSIONS: The policy of early shunting of artery and vein in CLVIs has proved to be of great benefit in terms of significantly improved outcomes, better operative discipline and harmonious collaboration among the specialists involved.

Periods of low atmospheric pressure are associated with high abdominal aortic aneurysm rupture rates in Northern Ireland.

Seasonal and circadian variation in the incidence of ruptured abdominal aortic aneurysm (RAAA) has been reported. We explored the role of atmospheric pressure changes on rupture incidence and its relationship to cardiovascular risk factors. During a three year-period, 1st April 1998 and 31st March 2001, data was prospectively acquired on 144 Ruptured Abdominal Aortic Aneurysm (RAAA) presenting to the Regional Vascular Surgery Unit at the Royal Victoria Hospital, Belfast, Northern Ireland. For each patient the chronology of acute onset of symptoms and presentation to the regional vascular unit was recorded, along with details of standard cardiovascular risk factors. During the same period meteorological data including atmospheric pressure and air temperature were recorded daily at the regional meteorological research unit, Armagh. We then analyzed the monthly mean values for daily rupture incidence in relation to the monthly values for atmospheric pressure, pressure change and temperature. Furthermore atmospheric pressure on the day of rupture, and day preceding rupture, were also analyzed in relation to days without rupture presentation and between individual ruptures for various cardiovascular risk factors. Data demonstrated a significant monthly variation in aneurysm rupture frequency, (p<0.03, ANOVA). There was also a significant monthly variation in mean barometric atmospheric pressure, (p<0.0001, ANOVA), months with high rupture frequency also exhibiting low average pressures in the months of April (0.24 +/- 0.04 ruptures per day and 1007.78 +/- 1.23 mB) and September (0.16 +/- 0.04 ruptures per day and 1007.12 +/- 1.14 mB), respectively. The average barometric pressures were found to be significantly lower on those days when ruptures occurred (n=1127) compared to days when ruptures did not occur (n=969 days), (1009.98 +/- 1.11 versus 1012.09 +/- 0.41, p<0.05). Full data on risk factors was available on 103 of the 144 rupture patients and was further analyzed. Interestingly, RAAA with a known history of hypertension, (n=43), presented on days with significantly lower atmospheric pressure than those without, (n=60), (1008.61 +/- 2.16 versus 1012.14 +/- 1.70, p<0.05). Further analysis of ruptures grouped into those occurring on days above or below mean annual atmospheric pressure 1013.25 (approximately 1 atmosphere), by Chi-square test, revealed three cardiovascular risk factors significantly associated with low-pressure rupture, (p<0.05). Data represents mean +/- SEM, statistical comparisons with Student t-test and ANOVA. These data demonstrate a significant association between periods of low barometric pressure and high incidence of ruptured aneurysm, especially in those patients with known hypertension. The association between rupture incidence and barometric pressure warrants further study as it may influence the timing of elective AAA repair.

Radial artery mycotic pseudoaneurysm in a haemophiliac: a potentially fatal complication of arterial catheterization.

We present a case of radial artery pseudoaneurysm formation in a haemophiliac patient, which developed after radial artery cannulation. Haematologists and anaesthetists should be aware of this potentially fatal condition.

Duplex Doppler ultrasonography of lower limb veins: detection of cardiac abnormalities.

AIM: We describe the detection of right sided cardiac abnormalities by Doppler ultrasonography of the lower limb veins. We also attempt to quantify the degree of tricuspid regurgitation (TR) by analysis of the femoral vein Doppler waveform (DW). MATERIALS AND METHODS: The DWs of the lower limb veins were examined in 276 patients over a 17-month period. The detection of abnormal pulsatile DW was compared with echocardiography on these patients. The reports of chest radiographs (CXR) obtained on 104 of the 276 patients were reviewed. RESULTS: Abnormal cardiac pulsatility of the DW was detected in nine patients (3.3%), with abnormally high retrograde velocity peak (RVP) recordings. These abnormal RVPs are compared to RVPs in a normal control group. The RVPs in the abnormal group revealed a statistically significant (Pearson's r = 0.9113) correlation with the degree of TR observed on echocardiography. All nine patients (100%) demonstrated cardiac enlargement on CXR compared to 16 of the 95 (16.8%) with a normal DW and available report of recently performed CXR. CONCLUSION: Doppler ultrasonography of lower limb veins is a frequently performed examination in most Radiology departments. We describe a simple, effective and reproducible ultrasound technique enabling detection of an underlying cardiac abnormality that may provide an estimation of the degree of TR. These important signs should alert the examining radiologist to the presence of an underlying cardiac dysfunction that may require further appropriate cardiac evaluation.McClure, M. J. (2000). Clinical Radiology 55, 533-536.

Bowel ischaemia and organ impairment in elective abdominal aortic aneurysm repair.

In 30 patients undergoing elective repair of abdominal aortic aneurysm the intramucosal pH (pHi) of the sigmoid colon was measured. Blood for endotoxin assay was taken at intervals before, during and after surgery. Daily measurements were made of liver transaminase activity and of arterial partial pressure of oxygen (PaO2). The mean (s.e.m.) peak systemic endotoxin concentration in those who developed intramucosal acidosis (pHi below 7.00) was 90(14) pg/ml, compared with 42(5) pg/ml in those who did not (P < 0.01). In the 14 patients whose pHi fell below 7.00, the mean (s.e.m.) postoperative rise in aspartate transaminase activity was 346(74) per cent, compared with 181(20) per cent in those whose pHi remained above this level (P < 0.05). The mean (s.e.m.) postoperative ratio of PaO2 to the fraction of inspired oxygen was 177(11) mmHg in those with intramucosal acidosis, compared with 260(24) mmHg in those whose pHi remained above 7.00 (P < 0.01). These results demonstrate a relationship between bowel ischaemia, endotoxaemia and organ impairment following elective aneurysm repair.

Endotoxaemia, the generation of the cytokines and their relationship to intramucosal acidosis of the sigmoid colon in elective abdominal aortic aneurysm repair.

Ischaemia of the large bowel occasionally occurs following abdominal aortic aneurysm repair and may lead to multiple system organ failure (MSOF). Intramucosal acidosis of the sigmoid colon is a good indicator of sigmoid colonic ischaemia. Intramucosal pH of the sigmoid colon was measured using the silicone tonometer in 21 patients undergoing abdominal aortic aneurysmectomy. Samples were taken for plasma endotoxin, tumour necrosis factor (TNF) and interleukin-6 (IL-6) measurements preoperatively, half-hourly during the operation, 2-hourly for the next 12 h, 4-hourly for a further 48 h and 8-hourly thereafter until the fifth day. The intramucosal pH of the sigmoid colon fell to less than 7.00 peri-operatively in 10 patients, four of whom developed diarrhoea; in comparison, this did not occur in any of the 11 whose pH remained greater than 7.00 (p = 0.036). Higher peak concentrations of endotoxin, TNF and IL-6 were found in those patients whose intramucosal pH fell to less than 7.00 compared to those whose pH remained greater than 7.00 (mean +/- S.E.M. pg/ml, endotoxin = 112 +/- 24 vs. 58 +/- 6, p < 0.05; TNF = 26 +/- 8 vs. 7 +/- 2, p < 0.05; IL-6 = 213 +/- 59 vs. 87 +/- 12, p = 0.09). In the two patients who died, both from the group with pH level less than 7.00, concentrations of IL-6 were considerably higher than that in most of the other patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Lipid peroxidation as a cause of lower limb swelling following femoro-popliteal bypass grafting.

We examined the role of free radical induced lipid peroxidation in lower limb swelling in patients following femoro-popliteal bypass grafting. In 20 patients undergoing this operation blood samples were taken from the femoral vein via a cannula before the femoral artery clamp was applied, just prior to and immediately after clamp release and at 10 min intervals thereafter for 1 h for measurements of malondialdehyde (MDA) and vitamin E. The concentration of MDA was significantly elevated at 40 min after reperfusion (mean +/- S.E.M., 573 +/- 83 pmol/ml) compared to just before clamp release (359 +/- 41 pmol/ml; p < 0.01). This was associated with a corresponding fall in the concentration of vitamin E at the time of peak MDA rise (5.68 +/- 0.28 to 5.29 +/- 0.28 mumol/mM cholesterol, p < 0.05) suggesting its utilisation as an antioxidant. The degree of oedema was related to the changes in MDA and vitamin E. Thus, in the 15 patients with greater than 10% increase in lower limb volume the rise in the concentration of MDA was 364 +/- 44 to 693 +/- 76 pmol/ml (p = 0.0001) while that in the five, whose swelling was less than 10%, was 344 +/- 40 to 559 +/- 243 pmol/ml (p = 0.25). A significant fall in vitamin E was found only in the group with greater than 10% lower limb oedema (5.90 +/- 0.33 to 5.40 +/- 0.34 mumol/mM cholesterol, p < 0.01), in comparison to those with less than 10% swelling (5.01 +/- 0.35 to 5.04 +/- 0.50 mumol/mM cholesterol).(ABSTRACT TRUNCATED AT 250 WORDS)

Epidemiology of Pseudomonas aeruginosa in an intensive care unit using selective decontamination of the digestive tract.

Selective decontamination of the digestive tract (SDD) aims to reduce the rate of nosocomial infections in critical care patients. Pseudomonas spp. are common nosocomial pathogens and in this study isolates collected from patients and the environment during an SDD trial were examined. The study enrolled 161 SDD cases and 170 controls. Pseudomonads were isolated from 27% of SDD patients and 30% of controls. SDD partially suppressed colonization in the 'gastro-respiratory' mucosae but not in the rectum. A total of 108 isolates of pseudomonads were recovered from the environment. Resistance in rectal isolates was minimal but isolates from 'gastro-respiratory' sites showed increasing aminoglycoside resistance. Eighty-six per cent of aminoglycoside-resistant isolates from both patient groups and environment were pyocine type 1x. Episodes of infection were reduced in the SDD patients (6) compared with the controls (16), aminoglycoside-resistant strains being associated with zero episodes in SDD patients but with five in the control group.