Measurement of arterial stiffness in subjects with and without renal disease: Are changes in the vessel wall earlier and more sensitive markers of cardiovascular disease than intima media thickness and pulse pressure?

There is increased cardiovascular (CV) mortality in subjects with chronic kidney disease (CKD). Arterial stiffness in these subjects is increased when compared to a healthy population. Markers of arterial stiffness and intima media thickness (IMT) are predictors of CV mortality. The aim of this study was to investigate whether there is any difference in markers of arterial stiffness and IMT between subjects with normal renal function and those with mild renal disease. The arterial distension waveform, IMT, diameter, and brachial blood pressure were measured to calculate Young's modulus (E) and elastic modulus (Ep) in the common carotid arteries of subjects with normal kidney function (estimated glomerular filtration rate [eGFR] >90) and those mild CKD (stage 2, eGFR 89-60). Data were available for 15 patients with normal kidney function and 29 patients with mild CKD. The subjects with mild CKD were older, but other co-variables were not significantly different. Both arterial wall stiffness parameters (E and Ep), but not IMT were significantly higher in the mild CKD group. Logistic regression demonstrated that only the arterial wall stiffness parameters (Ep and E) were independently associated with mild renal disease compared with normal, in a model adjusting for sex, age and diabetes and history of cardiovascular disease (CVD). E and Ep may be early markers of CVD in subjects with mild CKD that may manifest change before other more recognized markers such as IMT and pulse pressure.

Pericatheter herniation complicated by bowel incarceration in a patient on continuous ambulatory peritoneal dialysis (CAPD).

We report a rare case of pericatheter herniation with small bowel incarceration in a patient on continuous ambulatory peritoneal dialysis (CAPD). However, the predominant clinical features were signs of a severe catheter tunnel infection rather than ileus. We propose that pericatheter herniation should be considered as part of the differential diagnosis of CAPD tunnel infection, even when there are no clinical signs of bowel obstruction.

Effect of operating surgeon on outcome of arteriovenous fistula formation.

OBJECTIVE: To study whether surgical trainees can perform arteriovenous fistula (AVF) surgery to a standard comparable to consultants. PATIENTS AND METHODS: Retrospective study of all vascular access surgery over a three year period at a single centre. The operating surgeon was identified from theatre log books and categorised by grade. Fistula patency was used as the primary outcome measure and was determined from patients' case-notes and from a prospectively collected electronic record of dialysis sessions. Patency was defined as "used for dialysis" if the AVF was used for dialysis for at least 6 consecutive sessions. RESULTS: One hundred and eighty six cases were used for analysis. In 60 cases (32%) the operating surgeon was the consultant, in 53 cases (29%) a trainee was supervised by a consultant, in 56 cases (30%) a trainee performed the operation independently and in 17 cases (9%) the grade of the operating surgeon could not be established. Primary and primary assisted patency rates by operating surgeon did not differ significantly (P-values 0.25 and 0.16 respectively). Age of the patient was the only predictor of patency failure in a multivariate model. Grade of operating surgeon (logrank test chi(2)=3.1, p=0.38) and type of fistula (logrank test chi(2)=2.3, p=0.52) were not significantly related to the primary survival of the fistula. CONCLUSIONS: This study showed no significant differences in AVF patency rates between trainee and consultant surgeons. Allocation of appropriate cases can result in trainees obtaining similar outcomes as consultants, demonstrating that dialysis access surgery can provide good training opportunities for junior doctors without detriment to patient care.

Haemodynamics during remifentanil induction by high plasma or effect-site target controlled infusion.

BACKGROUND: During total intravenous anaesthesia, the target controlled infusion concentration of remifentanil can be achieved either in limiting maximum plasma concentration (Cp) to the effect site target concentration which corresponds to a plasma TCI technique (pTCI) or as fast as possible to achieve the effect-site target without limiting Cp (eTCI). The aim of this study was to compare the haemodynamic effects of remifentanil pTCI and eTCI during induction of anaesthesia in ASA III patients undergoing cardiac surgery. METHODS: 28 ASA III patients, scheduled for cardiac surgery, were randomized in two groups: Group pTCI received remifentanil to achieve an effect-site target of 15 ng ml(-1) by limiting Cp to 15 ng ml(-1) and group eTCI received remifentanil to achieve an effect-site target of 15 ng ml(-1) without limiting remifentanil Cp. Before induction, all patients received 30 microg kg(-1) of midazolam intravenously and 2 ml kg(-1) of a gelatin solution. Heart rate, invasive arterial pressure and bispectral index were continuously measured. Differences from baseline values were compared between the two groups using a Mann-Whitney U test. Baseline population characteristics were compared using an analysis of variance. RESULTS: There were no significant differences in haemodynamic parameters between the two groups. In the group pTCI final effect-site concentration was reached in 7.3 +/- 1.4 minutes and in the group eTCI in 2.2 +/- 0.2 minutes (p < 0.05). CONCLUSION: In ASA III patients scheduled for elective cardiac surgery, remifentanil eTCI can be preferred to remifentanil pTCI for induction because of its shorter onset with the same haemodynamic stability.

[Cerebral functions in brain-damaged patients. What is meant by coma, vegetative state, minimally conscious state, locked-in syndrome and brain death?]. / Zerebrale Funktionen bei hirngeschädigten Patienten. Was bedeuten Koma, "vegetative state", "minimally conscious state", "Locked-in-Syndrom" und Hirntod?

Comatose, vegetative, minimally conscious or locked-in patients represent a problem in terms of diagnosis, prognosis, treatment and everyday management at the intensive care unit. The evaluation of possible cognitive functions in these patients is difficult because voluntary movements may be very small, inconsistent and easily exhausted. Functional neuroimaging cannot replace the clinical assessment of patients with altered states of consciousness. Nevertheless, it can describe objectively how deviant from normal the cerebral activity is and its regional distribution at rest and under various conditions of stimulation. The quantification of brain activity differentiates patients who sometimes only differ by a brief and incomplete blink of an eye. In the present paper, we will first try to define consciousness as it can be assessed at the patient's bedside. We then review the major clinical entities of altered states of consciousness encountered in the intensive care unit. Finally, we discuss the functional neuroanatomy of these conditions as assessed by positron emission tomography (PET) scanning.

Point of care and central laboratory determinations of the aPTT are not interchangeable in surgical intensive care patients.

PURPOSE: The objective of the study was to compare a bedside whole blood activated partial thromboplastin time (aPTT) performed by a point of care (POC) apparatus (CoaguCheck(R) Pro) in surgical intensive care (SIC) patients with a conventional aPTT obtained from the central laboratory. METHODS: The prospective concomitant measurements of the two aPTT were performed in 233 samples from 46 consecutive patients admitted after cardiovascular or major abdominal surgery. RESULTS: Inter-operator, inter-instrument and inter-cartridge variability of the new device measured in three healthy volunteers and in nine patients in stable condition (controls) was low (F test: P=0.86). The agreement by Bland and Altman between POC and central laboratory aPTT (-20.2 +/- 18.8 sec) was not satisfactory. The agreement between POC and central laboratory aPTT in patients after surgery was worst (-17 +/- 33.1 sec). Heparin treatment or timing of blood sampling after intensive care admission (<48 hr vs >48 hr) did not influence the agreement. The correlation between POC or central laboratory aPTT and anti-factor Xa activity was poor (r(2) 0.077 and 0.181 respectively). The test which correlated the best to heparin doses was anti-factor Xa activity (r(2) 0.714). CONCLUSION: POC aPTT and central laboratory aPTT showed a poor agreement in SIC patients admitted after surgery, although in healthy volunteers or in control patients, this agreement was better. The best test to monitor heparin treatment in this setting was anti-factor Xa activity.

Quality improvement report: Linking guideline to regular feedback to increase appropriate requests for clinical tests: blood gas analysis in intensive care.

PROBLEM: Need to decrease the number of requests for arterial blood gas analysis and increase their appropriateness to reduce the amount of blood drawn from patients, the time wasted by nurses, and the related cost. DESIGN: Assessment of the impact of a multifaceted intervention aimed at changing requests for arterial blood gas analysis in a before and after study. BACKGROUND AND SETTING: Twenty bed surgical intensive care unit of a tertiary university affiliated hospital, receiving 1500 patients per year. KEY MEASURES FOR IMPROVEMENT: Number of tests per patient day, proportion of tests complying with current guideline, and safety indicators (mortality, incident rate, length of stay). Comparison of three 10 month periods corresponding to baseline, pilot (first version of the guideline), and consolidated (second version of the guideline) periods from March 1997 to August 1999. STRATEGIES FOR CHANGE: Multifaceted intervention combining a new guideline developed by a multidisciplinary group, educational sessions, and monthly feedback about adherence to the guideline and use of blood gas analysis. EFFECTS OF CHANGE: Substantial decrease in the number of tests per patient day (from 8.2 to 4.8; P<0.0001), associated with increased adherence to the guideline (from 53% to 80%, P<0.0001). No significant variation of safety indicators. LESSONS LEARNT: A multifaceted intervention can substantially decrease the number of requests for arterial blood gas analysis and increase their appropriateness without affecting patient safety.

Induced hypertension after head injury.

The use of induced hypertension in head injury patients is controversial. We present the case of a 19-year-old man admitted with severe head trauma after a road accident and describe the beneficial effects that increasing arterial blood pressure had on the cerebral perfusion pressure, cerebral blood flow and jugular bulb oxygen saturation in this patient.

Is outcome from ARDS related to the severity of respiratory failure?

The characteristics and outcome of acute respiratory distress syndrome (ARDS) may have changed with time. Some studies have reported that mortality is more commonly related to the development of sepsis/multiple organ failure (MOF), and others that it is related to the severity of acute respiratory failure (ARF). The present study evaluates the relative importance of the two phenomena in a large series of patients. The clinical and biological data of all patients who developed ARDS during a 26 month period (January 1993 until February 1995) in our intensive care unit (ICU) were reviewed retrospectively. A total of 129 patients developed ARDS during the study period, representing an incidence of 2.4% of all ICU admissions. The mortality rate was 52%. The primary cause of death was sepsis/MOF (49%), followed by respiratory failure (16%), cardiac failure or arrhythmias (15%), neurological failure (10%), and other causes (8%). The mortality rate was related to age and degree of organ failure. MOF was not always a cause of late death, since half the deaths occurred within 5 days after admission. In addition, mortality was higher in septic than in nonseptic patients, and lower in trauma and surgical than in medical patients. We conclude that sepsis/multiple organ failure is still the most common cause of death in acute respiratory distress syndrome. Improvements in outcome of acute respiratory distress syndrome may depend more on treatment of sepsis and multiple organ failure than on oxygenation measures.