Extremely low oxygen tension in the rectal lumen of human subjects.
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Dialysis↗
Biomedical subjects
J Bonde
Publications and source records attributed to J Bonde.
Classification for coding procedures in the intensive care unit.
BACKGROUND: There is no commonly accepted coding system for non-operative procedures in general, including intensive care unit (ICU) procedures. In order to create a classification of codes for ICU procedures, a system developed at the University Hospital of Bergen was evaluated in four Nordic countries. METHODS: Classification codes were constructed using seven main groups of related procedures that were given a letter from A to G. Within each group major procedures were given a number from 00 to 99, with the possibility of up to 10 subclassifications within each procedure. A simple questionnaire regarding the use of coding general ICU procedures and some specific procedures was sent to 171 ICUs in Sweden, Finland, Denmark, and Norway. They were also asked to give their comments on the new classification coding system, which was attached. RESULTS: One hundred and fifty-four questionnaires were returned (response rate 90%). Some or most of the ICU procedures were registered in the ICUs (82.2%). However 38% did not use any coding system and 24% used a specific internal system. The new classification coding system was well received, and was given a mean value of 7.5 using a VAS scale from 0 to 10 (best). Most ICUs would consider using this system if introduced at a national level. CONCLUSION: Most Nordic ICUs do register some or most of the procedures performed. Such procedures are however, registered in very different ways, using several different systems, and are often home-made. The new classification system of ICU procedures was well rated.
Critical Care↗
Lactic acidosis in the rectal lumen of patients with septic shock measured by luminal equilibrium dialysis.
BACKGROUND: Gut ischaemia may contribute to morbidity in sepsis, but little is known about the metabolic state of the gut mucosa in such patients. METHODS: Nine patients with abdominal septic shock treated with norepinephrine, and ten healthy subjects, were subjected to equilibrium dialysis with a rectal balloon. pH, PCO(2) and concentrations of L-lactate were measured by auto-analyser. RESULTS: In rectal dialysis fluid from patients with septic shock, acidosis was present (pH 7.23, 95% CI 7.11-7.36) and concentrations of L-lactate were approximately five times greater than controls (2.5-5.8 vs 0.5-1.2 mmol litre(-1)). The lactate concentration was related to the dose of norepinephrine (P<0.001). In contrast, values of dialysate PCO(2) did not differ significantly between patients and controls (6.4-11.0 vs 8.9-13.8 kPa). CONCLUSIONS: The results suggest that, either lactic acidosis in rectal mucosa is related to shock severity, or that norepinephrine causes mucosal ischaemia. In any case, metabolic dysfunction is present in the rectal mucosa in patients with abdominal septic shock treated with norepinephrine.
Acidosis, Lactic↗
Assessment of the respiratory exchange ratio in mechanically ventilated patients by a standard anaesthetic gas analyser.
BACKGROUND: The respiratory exchange ratio (R) is the CO2 production divided with O2 consumption. R is an essential factor included in several formulas during routine blood gas analysis. Instant and individual measurement of R may be of particular interest to improve the evaluation of each single patient. A standard anaesthetic gas analyser has been recommended for measurement of R among spontaneously breathing healthy subjects, but there is no experience using this method among mechanically ventilated critically ill patients. This study validates the assessment of R by a Brüel & Kjaer gas analyser (B & K) during positive pressure ventilation of intensive care patients. METHODS: The B & K sampled gas from 11 mechanically ventilated patients over a period of 5 min. The recordings of end-tidal values of O2 and CO2 based on fractions (RF) allowed for calculation of RF by the alveolar equation solved for R. The continuous recordings of corresponding values were depicted into an O2-CO2 diagram. A developed computer program calculated estimates of R as the slope of the regression lines related to the full cycle (Rfull) and the expiratory phase only (Rexp). Corrected values of the full respiratory cycle (Rfull*) were also calculated assuming changes of CO2 and O2 volumes during gas exchange. The different estimates of R were compared with simultaneous measurement of a Deltatrac indirect calorimeter (Rdelta). RESULTS: Ten values of RF were within the expected interval of 0.72 < R < 1.00. For the full respiratory cycles, the mean R-value was 0.94 +/- 0.07 and for the expiratory phase the mean R-value was 0.82 +/- 0.08. The O2-CO2 diagram appeared as a convexo-convex loop during each cycle. The agreement of Rexp and Rdelta (Rexp-Rdelta: 0.01 +/- 0.13) were good. CONCLUSION: This study demonstrates that gas measurements by a standard anaesthetic gas monitor can be used for determination of R, and thereby we present an alternative to R calculation made by the Deltatrac monitor.
Adult↗
Gentamicin dosing in critically ill patients.
Gentamicin is used worldwide in the treatment of serious infections in critically ill patients. The therapeutic efficacy of gentamicin is correlated to the peak serum concentration and the adverse effects to the trough concentrations. Information concerning the pharmacodynamics in critically ill patients is scarce, but pharmacokinetic data are available. A once-daily dosage regimen has replaced multiple dosing of gentamicin in most intensive care units. No studies evaluating the superiority of either of these dosage recommendations in critically ill patients have ever been conducted. Based on 8 meta-analyses performed addressing this issue on a wide range of patients and theoretical considerations, we consider a once-daily dosage regimen feasible in critically ill patients. In septic patients the volume of distribution is significantly increased compared to normal patients, implying that the initial dose should be increased in this patient population. Additionally a general trend towards using higher loading doses (5-7 mg/kg) has been observed in USA, and the appropriateness of this dosing strategy is based on a large descriptive American study. We recommend that the initial dosage of gentamicin in critically ill hyperdynamic septic patients should be 7 mg/kg. Optimal and appropriate monitoring of the treatment with gentamicin in the critically ill patient is still an issue for further investigation. The treatment period with gentamicin should be short (3-5 days), bearing the pharmacological properties of aminoglycosides (small volume of distribution and poor tissue penetration) in mind. In patients with reduced renal function the initial dose of gentamicin should also be increased and maintenance dose reduced preferentially by prolonging the dosing intervals. However, the use of aminoglycosides in a high dose regimen in oliguric or anuric patients or patients who present with a rapidly decreasing renal function needs further consideration.
Anti-Bacterial Agents↗
[The pattern of medication errors in connection with intravenous administration at an intensive care unit].
In a static study, medication errors in intravenous administration were registered in a multidisciplinary intensive care unit. The most frequent type of errors included administration of incorrect doses, but also administration of diluted drugs over an excessive time period, use of previously opened ampoules, administration of unauthorized drugs, wrong infusion rates, dissolution of drugs in incorrect media, dissolution of drugs in incorrect volumes of dissolution media and wrong dosage form errors were observed.
Denmark↗
[Dopamine in "kidney-friendly" doses].
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Acute Kidney Injury↗
[Incidence, severity and mortality of acute respiratory failure in Denmark].
To determine the incidence, severity and 90-day mortality of acute respiratory failure (ARF), acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) we conducted an eight-week prospective cohort study in 48 Danish ICUs, during which all ICU admissions (n = 6647) > 14 years of age were assessed. ARF was defined as intubation and mechanical ventilation > 24 hrs. ALI and ARDS were defined in accordance with the American-European Consensus Conference criteria. Among the 813 patients included, 552 were diagnosed with ARF, 117 with ALI and 95 with ARDS. The incidences (patients per 100.000/yrs) for ARF were 84.8, for ALI 17.8 and for ARDS 14.6. The 90-day mortality was 46.3% for ARF patients without ALI/ARDS, 47.3% for ALI patients and 46.2% for patients with ARDS. Compared to previously reported figures, the ARDS mortality is in the lower range whereas the incidence is slightly higher. This probably reflects a broader selection of patients when using the consensus criteria to define the ARDS population as opposed to definitions previously used.
Adult↗
[Nitrogen oxide inhalation in critically ill patients].
Inhaled nitric oxide (iNO) has been extensively used in the treatment of severe hypoxaemic respiratory failure and/or pulmonary hypertension. Although the majority of studies have almost consistently demonstrated a beneficial effect on oxygenation and a reduction in pulmonary artery pressures, none of the randomised trials have reported a reduced mortality using iNO on patients with severe respiratory failure. In neonates with severe respiratory failure and pulmonary hypertension, however, iNO can reduce the need of extracorporal membrane oxygenation. Prior to using iNO on adult patients we suggest other measures to be taken (i.e. optimising ventilator settings, ventilation in prone position).
Administration, Inhalation↗
Bioavailability and pharmacokinetics of isradipine after oral and intravenous administration: half-life shorter than expected?
Isradipine is a calcium channel-blocking agent of the dihydropyridine type, used in the treatment of hypertension. A terminal half-life of 8-9 hr has been reported, in several pharmacokinetic studies after oral administration of isradipine. In a yet unpublished study a much shorter half-life was observed, and the present trial was therefore conducted in order to estimate the half-life after intravenous administration of isradipine. The bioavailability was estimated as well. In a randomised cross-over design ten healthy young volunteers were given either isradipine orally or an intravenous infusion. The two study periods were separated by at least 3 days. Blood samples for measurement of isradipine concentration were collected for 10-12 hr after administration and half-life and bioavailability were estimated. Mean terminal half-life after intravenous administration was calculated to be 2.8 hr, and the bioavailability to be 0.28. None of the 10 subjects suffered from side effects. In the present intravenous study the half-life of isradipine seems to be of much shorter than demonstrated in previous oral studies.
Administration, Oral↗
Implementation of percutaneous dilation tracheotomy--value of preincisional ultrasonic examination?
BACKGROUND: In this observational study we have evaluated the implementation of percutaneous dilation tracheotomy (PDT), using the forceps dilation technique (Portex) in a multidisciplinary ICU. METHODS: We included a preincisional ultrasonic evaluation of the neck in order to visualise the isthmus glandula thyroidea and major vessels. The observational period comprised one year. PDT was performed in 28 patients. RESULTS: Implementation of PDT was uneventful. Duration of insertion was 10 min (4-40 min). Total time of tracheostomy was 8 days (1-65 days). In nine cases, the proximal end of the isthmus was overlying the space between the 1st and 2nd tracheal ring, which was considered the optimal insertion site. This resulted in seven cases of insertion between the cricoidea and the 1st tracheal ring and in two cases in a more distal insertion. Nineteen tracheotomies were performed in the interstice between the 1st and 2nd tracheal ring. In nine patients, major vessels were overlying the trachea. In none of the patients did this information result in an altered insertion site. Two cases of minor bleeding were observed; both stopped upon compression. In two patients the primary tube size (8.0) was too big and a smaller tube had to be inserted. In one patient the tube was maladapted to the stoma and had to be interchanged with an ordinary tracheostomial tube on the 5th day of tracheostomy. CONCLUSION: Based on the experience gathered in this study and information from the literature, we have abandoned the routine use of ultrasonic examination of the neck prior to PDT. In order to achieve and maintain routine, we suggest that the procedure is performed by a restricted number of doctors.
Adolescent↗
Incidence and mortality after acute respiratory failure and acute respiratory distress syndrome in Sweden, Denmark, and Iceland. The ARF Study Group.
To determine the incidence and 90-d mortality of acute respiratory failure (ARF), acute lung injury (ALI), and the acute respiratory distress syndrome (ARDS), we carried out an 8-wk prospective cohort study in Sweden, Denmark, and Iceland. All intensive care unit (ICU) admissions (n = 13,346) >/= 15 yr of age were assessed between October 6th and November 30th, 1997 in 132 of 150 ICUs with resources to treat patients with intubation and mechanical ventilation (I + MV) >/= 24 h. ARF was defined as I + MV >/= 24 h. ALI and ARDS were defined using criteria recommended by the American-European Consensus Conference on ARDS. Calculation to correct the incidence for unidentified subjects from nonparticipating ICUs was made. No correction for in- or out-migration from the study area was possible. The population in the three countries >/= 15 yr of age was 11.74 million. One thousand two hundred thirty-one ARF patients were included, 287 ALI and 221 ARDS patients were identified. The incidences were for ARF 77.6, for ALI 17.9, and for ARDS 13.5 patients per 100,000/yr. Ninety-day mortality was 41.0% for ARF, including ALI and ARDS patients, 42.2% for ALI not fulfilling ARDS criteria, and 41.2% for ARDS.
Acute Disease↗
Evaluation of five oxygen delivery devices in spontaneously breathing subjects by oxygraphy.
Oxygen supply systems may be divided into constant and variable performance systems. As the variable performance systems are widely used, it is relevant to investigate the variation in performance between devices and the influence of oxygen supply on the inspired oxygen fraction. Data were collected from 10 healthy volunteers during the use of one constant performance system and four variable performance systems at different gas flows and inspired oxygen fractions. A thin sampling catheter was placed in the nasopharynx to allow the measurement of the end-tidal oxygen fraction. When oxygen was supplied to variable performance systems, end-tidal oxygen fraction values measured in this way varied less and were more easily quantifiable than inspired oxygen fraction. End-tidal oxygen fraction was used to calculate inspired oxygen fraction. With the variable performance systems, inspired oxygen fraction varied considerably between subjects whereas a constant and equal rise was found for each subject with the fixed performance system. A large nasal catheter was capable of delivering the highest inspired oxygen fraction, whereas the Venturi mask delivered the most precise inspired oxygen fraction. We found oxygraphy useful in the interpretation of measurements made in patients receiving unknown inspired fractions of oxygen.
Adult↗
Chemotaxis and IL-8 receptor expression in B cells from normal and HIV-infected subjects.
To date, the activities of the alpha chemokines for human peripheral B cells from normal subjects (N-B cells) or from HIV-infected subjects (HIV-B cells) are not well established. No report on the IL-8R expression on N-B cells and HIV-B cells has been seen. We report in this work that the alpha chemokines IL-8 and growth-regulatory oncogene-alpha (GRO-alpha) induce a chemotactic migration of N-B cells and HIV-B cells via stimulating the IL-8RB on these cells. The chemotaxis of N-B cells can be inhibited by IFN-gamma and IL-2, and augmented by IL-4 and IL-13, whereas TNF-alpha and IL-10 have no influence. The chemotaxis of HIV-B cells can be inhibited by IFN-gamma and IL-2, and augmented by TNF-alpha, IL-4, and IL-10, whereas IL-13 has no influence. IL-8R are expressed more abundantly on freshly isolated HIV-B cells than N-B cells (51% and 15%, respectively). The IL-8R on N-B cells can be down-regulated by IFN-gamma, IL-2, and TNF-alpha (selectively on IL-8RA), and up-regulated by IL-4 and IL-13, whereas IL-10 has no influence. The IL-8R on HIV-B cells can be down-regulated by IFN-gamma and IL-2, and up-regulated by TNF-alpha, IL-4, and IL-10, whereas IL-13 has no influence. Importantly, N-B cell and HIV-B cell chemotaxis toward IL-8 and GRO-alpha can be blocked by anti-IL-8RB polyclonal Ab, but not by anti-IL-8RA polyclonal Ab. Our results demonstrate that IL-8 and GRO-alpha are important inflammatory mediators that stimulate the directional migration and recruitment of B lymphocytes. The migratory behavior and the expression of IL-8R on HIV-B cells and some of the reactions to Th1- and Th2-like cytokines are modified significantly during HIV infection.
Adult↗
Dopamine natriuresis in salt-repleted, water-loaded humans: a dose-response study.
AIMS: The purpose of the present study was to define the dose-response relationship between exogenous dopamine and systemic haemodynamics, renal haemodynamics, and renal excretory function at infusion rates in the range 0 to 12.5 microg kg(-1) min(-1) in normal volunteers. METHODS: While undergoing water diuresis, eight subjects were infused with 0, 1, 2, 3, 5, 7.5, 10 or 12.5 microg of dopamine kg(-1) min(-1) over 2 h in a randomized and double-blind fashion. On each study day, renal clearance studies were performed during a 1 h baseline period and subsequently during the second 1 h infusion period. Lithium clearance (CL(Li)) was used to estimate proximal tubular outflow. RESULTS: Cardiac output increased with the four highest doses. Mean arterial pressure followed a biphasic pattern with a decrease during the two lowest doses and a dose-dependent increase from the 7.5 microg kg(-1) min(-1) dose onwards. Effective renal plasma flow increased with all doses of dopamine, but peaked with the 3 microg kg(-1) min(-1) infusion rate [from 617 (585-649) ml min(-1) with placebo to 915 (824-1006) ml min(-1) (means with 95% CI, P<0.001)]. None of the doses changed glomerular filtration rate (GFR). Sodium clearance (CL(Na)) and CL(Li) were elevated with the four lowest doses but increased further from 7.5 microg kg(-1) min(-1) onwards. Compared with placebo, the percentage increase in CL(Na) with increasing dose was 77 (5-159), 93 (13-172), 107 (24-190), 121 (60-181), 253 (65-441), 284 (74-494), and 212 (111-312) %, respectively. There were only small, inconsistent decreases in absolute proximal reabsorption rate (APR = GFR-CL(Li)). Fractional distal reabsorption of sodium (FDR(Na) = (CL(Li)-CL(Na))/CL(Li)) decreased with all doses, reaching its nadir with 7.5 microg kg(-1) min(-1) [from 95.9 (94.6-97.2) % with placebo to 91.5 (90.0-93.0) % (P<0.01)] whereafter a flat dose-response curve was observed. CONCLUSIONS: In conclusion, the renal vasodilating effect of dopamine was maximal with 3 microg kg(-1) min(-1). The dose-dependent attenuation seen with higher doses is consistent with an increased alpha-adrenergic stimulation opposing the effect on dopaminergic receptors. The present CL(Li) studies confirm that dopamine increases proximal tubular outflow. The results suggest that the natriuretic effect of depressor doses of dopamine was primarily caused by attenuation of the increase in distal sodium reabsorption normally seen after an increase in proximal tubular outflow. Pressor doses further increased sodium excretion, indicating the presence of pressure natriuresis at these high doses.
Adult↗
[Invasive ventilation. Classification, technique and clinical experiences with BiPAP/APRV (Biphasic Positive Airway Pressure/Airway Pressure Release Ventilation)].
BiPAP (bilevel or biphasic positive airway pressure) and APRV (airway pressure release ventilation) are new, and from a technical viewpoint closely related techniques recently introduced to the field of invasive ventilatory support. BiPAP/APRV can be described as a pressure controlled continuous high flow positive airway pressure system with a time-cycled change between a high inspiratory pressure level and a lower expiratory pressure level. Due to highly sensitive valves placed in the inspiratory and expiratory part of the system, unrestricted spontaneous breathing is possible at any moment of the mechanically supported ventilatory cycle. During invasive ventilation BiPAP offers potential advantages by allowing unrestricted spontaneous breathing thus reducing the need for sedation and facilitating weaning. APRV has primarily been investigated in conditions of moderate to severe acute lung injury and it seems that APRV is associated with less detrimental effects on the cardiopulmonary system compared to conventional ventilatory strategies. Apart from a review of the literature the article gives a classification and a technical description of the systems and focuses on the practical approach to BiPAP/APRV, e.g. the initiation and adjustment of respiratory support and the weaning from ventilatory support when applying these techniques.
Humans↗
Low-dose dopamine in surgical and intensive care unit patients.
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Acute Kidney Injury↗
Improved flow cytometric identification of myelopoiesis by the simultaneous labelling with CD13, CD14 and CD66 monoclonal antibodies.
The aim of the present study was to increase our knowledge of myelopoiesis evaluated by flow cytometry. We therefore designed a triple-marker assay employing monoclonal antibodies against the CD13 (immature), the CD14 (monocytic), and the CD66 (mature myeloid) antigens using three-colour immunofluorescence. In normal donor bone marrow the assay enables simultaneous identification of immature (CD13+, CD14-, CD66-), intermediate (CD13+, myelopoietic differentiation stages through the exclusion of CD14+ monocytic cells. In the diagnosis and longitudinal follow-up of AML patients the assay was of value in the fast determination of remission state. In MDS, the immature myeloid component could be distinguished in patients defined according to the FAB classification with the possibility of identifying aberrant phenotypes, the assay should also be of interest in other myeloproliferative disorders. Moreover, because it is easy to perform, time-saving, and yields comparable results to single antibody reactivity controls, it can replace more tedious and less-informative flow cytometric immunophenotyping procedures.
Acute Disease↗