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Biomedical subjects

J Qvist

Publications and source records attributed to J Qvist.

At least 55 records · Page 3Linked to original sources

Outcome from intensive care. II. A 5-year study of 1308 patients: short-term outcome.

All patients (n = 1308) admitted to a multidisciplinary intensive care unit (ICU) during a 5-year period (1979-83) were followed prospectively. The in-unit mortality was 18% and the in-hospital mortality (mortality during ICU-stay plus mortality during the ensuing hospital stay) was 29%. Increasing age was associated with increasing in-hospital mortality, up to 40% mortality rate in patients aged 80 years and older. Using multiple logistic regression analyses, prognostic factors for mortality were identified. Risk factors for death in the ICU included age, cardiovascular diseases, sepsis, adult respiratory distress syndrome and acute renal failure. Cancer did not appear as a risk factor. The mortality during the ensuing hospital stay, however, was significantly influenced by cancer as well as the aforementioned risk factors. When controlled for severity of illness, expressed by the level of organ system failure after 48 h of ICU treatment, only sex, sepsis and severity of illness showed significant influence on the mortality in the ICU, and only sex and severity of illness significantly influenced mortality during the ensuing hospital stay after discharge from the ICU.

Adult↗

Outcome from intensive care. III. A 5-year study of 1308 patients: activity levels.

In a prospective study of 1308 intensive care unit (ICU) patients, we studied the patients' activity levels, using a brief questionnaire posted to the patients every third month, for up to 1 year after the day of ICU admission. Patients were asked to indicate their present activity level compared with their perceived pre-hospital activity level. The response rate was 91%. One year after ICU admission 42% of the patients were dead; 44% of the survivors were recorded to have normal and 26% limited activity. Age influenced both the 1-year mortality and the activity level, the mortality increased from 25% among the youngest to 56% in the oldest patients. In the youngest age group 60% of the survivors reported having normal activity while almost 30% of the oldest survivors had returned to normal activity level within 1 year. Medical patients had a higher mortality and fewer of the survivors returned to their normal activity level compared with surgical patients. Having survived critical illness, a realistic hope of regaining a normal or near-normal activity level exists for many patients.

Activities of Daily Living↗

Arterial gas tensions and hemoglobin concentrations of the freely diving Weddell seal.

Heart rate, body temperature, arterial blood gas tensions, pHa and hemoglobin concentrations were measured during and after free diving of the Weddell seal (Leptonychotes weddelli), beneath the fast ice of McMurdo Sound, Antarctica. To examine arterial nitrogen tensions (PaN2), 47 samples of arterial blood were obtained from 4 seals diving up to 23 min to depths of 230 m. Peak arterial nitrogen tensions between 2000 and 2500 mmHg were recorded at depths of 40-80 m during descent, indicating that the seal's lung collapses by 25-50 m. Then arterial blood nitrogen tensions slowly decreased to about 1500 mmHg near surfacing. Thus during diving alveolar collapse and redistribution of blood nitrogen allow the seal to avoid nitrogen narcosis and decompression sickness. The arterial PO2 (PaO2) at rest (78 +/- 13 mmHg, mean +/- SD) increased with diving compression to a maximum measured value of 232 mmHg and then rapidly decreased to 25-35 mmHg. The lowest diving PaO2 was 18 mmHg just before the seal surfaced from a 27-min dive. A consistent increase of arterial hemoglobin concentrations occurred during each dive. We suggest that an extension of the sympathetic outflow of the diving reflex caused profound contraction of the Weddell seal's spleen.

Animals↗

ARDS after accidental inhalation of zinc chloride smoke.

Five soldiers were injured by inhalation of hexite smoke (ZnCl2) during military training. Two soldiers, not wearing gas masks breathed hexite for 1 or 2 min, they slowly developed severe adult respiratory distress syndrome (ARDS) over the ensuing 2 weeks. This slow, progressive clinical course has not been previously described. In both patients, an increased plasma zinc concentration was measured 3 weeks after the incident. Intravenous and nebulized acetylcysteine increased the urinary excretion of zinc, and briefly decreased the plasma levels. In an attempt to arrest collagen deposition in the lungs, L-3,4 dehydroproline was administered. Both patients died of severe respiratory failure (25 and 32 days after inhalation). At autopsy diffuse microvascular obliteration, widespread occlusion of the pulmonary arteries and extensive interstitial and intra-alveolar fibrosis was observed. Three soldiers wearing ill fitting gas masks, immediately developed severe coughing and dyspnea. They improved, and 12 months after exposure their lung function tests were nearly normal, but they still had slight dyspnea on exercise.

Acetylcysteine↗

Severity of illness and outcome of treatment in alcoholic patients in the intensive care unit.

To study whether critically ill alcoholics were more sick and had a worse outcome than other patients treated in the intensive care unit, data were collected during the initial 24 h on 216 consecutive patients admitted to an intensive care unit. Twentysix patients (12%) met the criteria for alcohol abuse. The patients' chronic health 6 months prior to admission and the extent of physiological derangement (Acute Physiology Score and Chronic Health Evaluation (APACHE] were recorded just as the type and amount of treatment (Therapeutic Intervention Scoring System (TISS]. Alcoholics were found to be significantly more sick and had a higher mortality (50% compared to 26%) than other critically ill patients. However, when analyzing the TISS points, no difference was found between the two groups. All survivors were, every third month up to 1 year after admission, asked to fill in a questionnaire indicating their level of activity. No differences were found between the two groups 1 year after admission, but the alcoholics had lost more time due to death. It is concluded that studies with larger number of patients will reveal whether alcoholics constitute a special category of patients with a different prognosis than other ICU patients.

Alcoholism↗

Cardiovascular adjustments to pulmonary vascular injury in dogs.

The hemodynamic effects of blood volume augmentation and mechanical ventilation (MV) with positive end-expiratory pressure (PEEP) were studied in nine Beagles anesthetized with halothane before and after thrombin-induced pulmonary hypertension. The effect of therapy with dopamine, norepinephrine with and without nitroglycerin (NTG), and intraaortic balloon pumping (IABP) were studied in a second series of six Beagles. Before thrombin, dextran (35 ml.kg-1) caused a significant increase in right and left ventricular end-diastolic and end-systolic volumes (RV and LVEDV, and RV and LVESV). However, RV and LV performance, as estimated by ejection fraction, was unchanged during volume loading and MV with PEEP when the pulmonary vasculature was intact. The response to volume loading and MV with PEEP was altered significantly once PVR had been increased with the administration of thrombin. Stroke volumes were decreased, and remained so, despite volume loading and MV with PEEP. LVEDV decreased without a decrease in LVEDP, indicating a decreased LV compliance. Dopamine and norepinephrine with and without NTG increased stroke volumes and RV ejection fraction in contrast to IABP. Assessment of LV performance, according to the Frank-Starling mechanism, requires a measure of end-diastolic volume when diffuse pulmonary vasoconstriction leads to RV distension and LV hypovolemia secondary to septal shift. Measurement of LV filling pressures can provide misleading values to estimate changes in LV volume in this setting. Measurement of ventricular volumes is required for optimal management of patients with severe acute respiratory failure and pulmonary hypertension.

Animals↗

Replica patterns on composite restorations performed in vitro with different acid-etch procedures and dentin adhesives.

160 experimental Class V restorations using two chemically cured composite resins were inserted in extracted human teeth with conventional and modified acid-etch restorative procedures. The modifications included cavity treatment with non-composite resin, ethanol, or four different dentin adhesives. Following demineralization of the teeth the fillings were examined in the SEM concerning their replica patterns of the etched cavity walls. In vitro conditions favored resin penetration into pretreated enamel and dentin, but resulted in minor variations between different acid-etch procedures compared with those previously seen on resin restorations placed in vivo in teeth with vital pulps.

Acid Etching, Dental↗

Heart rate and body temperature during free diving of Weddell seals.

We have developed and successfully used the first microprocessor-controlled monitors for collection of data on depth, heart rate, and body temperature of one fetal and five adult male freely swimming Weddell seals. Adult seals almost invariably experienced a prompt bradycardia at the start of each dive, and the mean heart rate during diving was significantly lower for dives greater than 20 min (P greater than 0.999). The heart rate was also significantly greater during the ascent portion of dives when compared with the descent portion (P greater than 0.95). The fetal seal experienced a slow onset of bradycardia when its mother dived; during diving the fetal heart rate decreased by an average of 1.1 beats/min for each minute of the dive. The fetal heart rate generally took approximately 10 min to recover to predive levels after its mother resurfaced to breathe. The body temperature of one adult male Weddell seal showed a decrease of greater than 1.5 degrees C from resting levels before dives of greater than 15 min were initiated and a drop of over 2 degrees C before dives of greater than 30 min duration.

Animals↗

Effects of a thromboxane antagonist (BM 13.177) during endotoxin-induced pulmonary vasoconstriction in sheep.

We investigated the effect of a thromboxane antagonist, BM 13.177, during endotoxin-induced pulmonary vasoconstriction in sheep. In control animals intravenous E-coli endotoxin (1 microgram/kg) caused a transient increase of pulmonary artery and airway pressure paralleled by large concentration increases of TXB2: in comparison peak plasma concentrations of 6-keto-PGF1 alpha (a prostacyclin metabolite) were small and delayed in time. Pre-treatment with BM 13.177 (bolus 5 mg/kg), followed by 0.75 mg/kg/min intravenously) abolished the rise of pulmonary artery and airway pressure. Plasma concentrations of TXB2 and 6-keto-PGF1 alpha were similar to controls. These and previous investigations imply that BM 13.177 specifically antagonizes TXA2 on the putative receptor in pulmonary vascular and airway smooth muscle.

6-Ketoprostaglandin F1 alpha↗

Microcomputer-assisted metabolic studies of voluntary diving of Weddell seals.

Utilizing a microprocessor-controlled peristaltic withdrawal pump, arterial blood samples were obtained from Weddell seals (Leptonychotes weddelli) while diving voluntarily under the sea ice at McMurdo Sound, Antarctica. Plasma concentrations of glucose, lactate, free fatty acids, urea, and amino acids were determined in seals at various times during rest, diving, and recovery. In addition, radiolabeled palmitate, glucose, lactate, p-aminohippurate, inulin, galactose, and cholate were injected into the descending aorta of seals in the resting state or during voluntary diving at sea. Sequential plasma samples were collected, and the kinetics of wash-in and clearance of each component were determined. Under resting conditions, the change in specific activity of palmitate, glucose, and lactate after bolus injection followed smooth multiexponential decay kinetics as in terrestrial animals. Similar decay curves for the clearance of organ-specific compounds were also obtained in seals at rest. If, during voluntary diving, Weddell seals were analogous to exercising animals, the wash-in and clearance kinetics of all metabolites and organ-specific compounds would be qualitatively similar to those observed at rest. In contrast, wash-in and clearance appeared to be qualitatively and quantitatively modified in a way consistent with utilization of the classical Scholander diving response in both short and long dives.

Amino Acids↗

Hemoglobin concentrations and blood gas tensions of free-diving Weddell seals.

Arterial blood gas tensions, pH, and hemoglobin concentrations were measured in four free-diving Weddell seals Leptonychotes weddelli. A microprocessor-controlled sampling system enabled us to obtain 24 single and 31 serial aortic blood samples. The arterial O2 tension (PaO2) at rest [78 +/- 13 (SD) Torr] increased with diving compression to a maximum measured value of 232 Torr and then rapidly decreased to 25-35 Torr. The lowest diving PaO2 we measured was 18 Torr just before the seal surfaced from a 27-min dive. A consistent increase of arterial hemoglobin concentrations from 15.1 +/- 1.10 to 22.4 +/- 1.41 g/100 ml (dives less than 17 min) and to 25.4 +/- 0.79 g/100 ml (dives greater than 17 min) occurred during each dive. We suggest that an extension of the sympathetic outflow of the diving reflex possibly caused profound contraction of the Weddell seal's very large spleen (0.89% of body wt at autopsy), although we have no direct evidence. This contraction may have injected large quantities of red blood cells (2/3 of the total) into the seal's central circulation during diving and allowed arterial O2 content to remain constant for the first 15-18 min of long dives. The increase of arterial CO2 tensions during the dive and the compression increase of arterial N2 tensions were also moderated by injecting red blood cells sequestered at ambient pressure. After each dive circulating red blood cells are oxygenated and rapidly sequestered, possibly in the spleen during the first 15 min of recovery.

Animals↗