Prolonged weaning: from the intensive care unit to home.

Weaning is the process of withdrawing mechanical ventilation which starts with the first spontaneous breathing trial (SBT). Based on the degree of difficulty and duration, weaning is classified as simple, difficult and prolonged. Prolonged weaning, which includes patients who fail 3 SBTs or are still on mechanical ventilation 7 days after the first SBT, affects a relatively small fraction of mechanically ventilated ICU patients but these, however, requires disproportionate resources. There are several potential causes which can lead to prolonged weaning. It is nonetheless important to understand the problem from the point of view of each individual patient in order to adopt appropriate treatment and define precise prognosis. An otherwise stable patient who remains on mechanical ventilation will be considered for transfer to a specialized weaning unit (SWU). Though there is not a precise definition, SWU can be considered as highly specialized and protected environments for patients requiring mechanical ventilation despite resolution of the acute disorder. Proper staffing, well defined short-term and long-term goals, attention to psychological and social problems represent key determinants of SWU success. Some patients cannot be weaned, either partly or entirely, and may require long-term home mechanical ventilation. In these cases the logistics relating to caregivers and the equipment must be carefully considered and addressed.

[Principles of selective decontamination from the radiobiological point of view]. / Prinzipien der selektiven Dekontamination aus strahlenbiologischer Sicht.

Presented is the method of selective decontamination by van der Waaj. It is based on the conception of colonisation resistance deduced from animal experiments. So it means the concurrence of defense mechanisms which prevent the settlement of pathogenic germs and stabilize the normal microflora. First clinical and experimental results are reported.

Iopentol (Imagopaque) in vascular procedures. A multi-centre monitoring trial assessing adverse events and diagnostic information--results from 3,587 patients in Germany.

The aims of the present open, non-comparative survey were to study the safety and efficacy of iopentol (Imagopaque, Nycomed Imaging AS, Oslo, Norway) in a large patient group. In a series of German centres, 3,587 patients underwent various contrast-enhanced examinations with iopentol. The most frequent examinations were computed tomography (CT) (1,740), phlebography (462), and digital subtraction angiography (DSA) (493). Only 82 patients (2.3%) experienced one or more adverse events. Sixty-one (1.7%) of these events were possibly or probably caused by the contrast medium. A total of 111 adverse events were registered, 54 of mild, 42 of moderate and 12 of strong intensity, and 51 events required treatment. The most frequent adverse events were nausea (34), erythema (14) urticaria (9), taste sensation (6), circulatory reactions (5) and angina pectoris (5). The frequencies of adverse events were 2.9% in CT, 2.0% in DSA, 2.0% in phlebography, 1.6% in cardioangiography, and 0.4% in urography. Patients with arteriosclerosis, an earlier contrast medium reaction, multimorbidity or age over 70 years had a statistically significantly higher risk of experiencing an adverse event. Patient tolerance was very good; the mean score was 83% on a visual analogue scale (VAS) ranging from extremely bad (0%) to extremely good (100%). Efficacy, as measured on VAS, was determined. Technical quality was scored as 80%, contrast enhancement within the vessels as 80% and delineation of lesions as 79%. The results from this large patient population confirms the experience from clinical practice that iopentol is a safe, well tolerated and efficient contrast medium.

Iodixanol in cerebral computed tomography: a randomized, double-blind, phase-III, parallel study with iodixanol and iohexol.

Iodixanol is a new nonionic dimer, isotonic with blood at all clinically relevant concentrations. Iodixanol (270 mg I/ml) was compared in a double-blind, randomized, parallel-group, phase-III study to the monomeric nonionic iohexol (300 mg I/ml) for evaluation of safety, tolerability and radiographic efficacy during cerebral CT. One hundred adult patients scheduled to undergo contrast-enhanced cerebral CT were randomly allocated to receive either iodixanol or iohexol. All completed the trial. Safety was evaluated by recording discomfort and other adverse events, tolerance by assessing intensity and incidence of discomfort. Radiographic efficacy was assessed from the diagnostic information and the radiographic density. No serious adverse events occurred. One patient (2 %) in the iodixanol group and one patient (2 %) in the iohexol group experienced a transient reddening at the neck and lower neck-line, respectively. Both contrast agents were well tolerated. One patient (2 %) in the iodixanol group and two patients (4 %) in the iohexol group experienced a sensation of warmth (discomfort) in connection with the injection. No difference between the two contrast media were noted radiographically. This comparison between iodixanol and iohexol showed both contrast media to be safe, well-tolerated and efficacious for use in cerebral CT.

Prospective randomized study for an injection protocol for intravenous contrast media in abdominal and pelvic helical CT.

OBJECTIVE: To develop an injection protocol for intravenous administration of contrast media in abdominal and pelvic helical CT which provides optimal contrast enhancement of arterial and venous vessels. MATERIAL AND METHODS: For the study on a Somatom Plus 4 unit, a standard helical CT examination procedure of abdomen and pelvis consisted firstly of a native helical examination of the liver, a second one of the liver after intravenous injection of 120 ml nonionic contrast medium with a constant start delay of 50 s, and subsequently a third helical CT of the lower abdomen and pelvis. 125 patients were randomized for examination under different protocols, varying the injection flow from 2.0-4.0 ml/s and the time delay between the second and the third helical examinations from an additional 20-40 s. The efficacy of the contrast injection was checked by region of interest (ROI) measurements of HUs in aorta, inferior vena cava, and in femoral arteries and veins. The results were compared by t-test statistics. RESULTS: A slow flow rate of 2.0 ml/s led to a higher contrast enhancement in the aorta than a flow rate of 3.0 and 4.0 ml/s. The difference between 2.0 ml/s and 4.0 ml/s was statistically significant. In the inferior vena cava, a flow of 3.0 ml/s caused a better contrast than a flow of 2.0 ml/s or 4.0 ml/s, but the measurements did not reach statistical significance. The measurements in the femoral arteries and veins did not show any significant differences. Maximal enhancement in the pelvic vessels was achieved when the third helical examination was started immediately after the second one had ended. Adding any delay (20 s, 40 s) led to a reduced contrast in the pelvic vessels, with a significant reduction in aorta and femoral arteries. CONCLUSION: For routine abdominal and pelvic helical CT, we recommend an injection of 120 ml contrast medium with a flow rate of 3.0 ml/s. Contrast-enhanced examination of the liver should be started after 50 s, and examination of the lower abdomen and pelvis region should be performed without any further delay. This gives an appropriate contrast in the major vessels.

Impact of CT in patients with sepsis of unknown origin.

PURPOSE: To evaluate the diagnostic relevance of CT in patients with sepsis of unknown origin. MATERIAL AND METHODS: Sixty-three consecutive intensive care patients with suspicion of an abscess and negative or inconclusive previous radiological examinations were included. CT was performed using the helical technique. A total of 45 abdominal and 38 chest examinations were evaluated. RESULTS: 5/38 examinations of the chest revealed the source of sepsis (pleural empyema 2, lung abscess 1, mediastinitis 1, retrosternal abscess 1). 7/45 abdominal CT examinations showed the source of sepsis (intraabdominal abscess 2, hepatic abscess 3, intestinal perforation 1, gangrenous colitis 1). CONCLUSION: CT is useful for the evaluation of patients with fever or sepsis without a known source. Due to the detection of a septic focus by CT, 19% of the patients in our study could be immediately referred to causal therapy as percutaneous drainage or surgery.