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H Opdahl

Publications and source records attributed to H Opdahl.

At least 19 recordsLinked to original sources
PubMed2007

Grave acidosis after severe anaphylactic bronchospasm: friend or foe?

In a 20-year-old woman with known asthma, anaphylactic bronchospasm induced a grave combined respiratory and metabolic acidosis (pH(a) 6.66) with marked hypoxaemia (S(a)O(2) 45%). The beneficial effects of the rightward shift of the oxyhaemoglobin dissociation curve on tissue O(2) unloading at such pH was more than offset by the negative effect on S(a)O(2) at the reduced P(a)O(2) (7.0 kPa) found in this patient. This case illustrates the detrimental effect of grave acidosis on arterial blood oxygen content at subnormal P(a)O(2) values, the beneficial effect of a supranormal P(a)O(2) on the S(a)O(2) in such patients, and the rapid remission rate of life-threatening acidosis and blood lactate after adequate ventilation and tissue oxygenation were secured. The initial treatment of the patient and clinically relevant considerations are discussed.

Acidosis↗
PubMed2005

Acute myocardial infarction and thyrotoxic storm--a difficult and dangerous combination.

We describe an unusual case of acute myocardial infarction (AMI) and cardiogenic shock in a 25-year-old woman. After coronary revascularization, a thyrotoxic storm developed and the patient's cardiac failure changed into a hyperdynamic circulation without obvious changes in the patient's vital signs. This report will focus on three issues: (1) the benefit of advanced hemodynamic monitoring in circulatory unstable patients, (2) the confounding effects of untreated hyperthyroidism on the circulation, and (3) previous cancer treatment as a cause of AMI in young persons.

Acute Disease↗
PubMed2000

Effects of short-term nitrogen monoxide inhalation on leukocyte adhesion molecules, generation of reactive oxygen species, and cytokine release in human blood.

Increased nitrogen monoxide (NO) concentrations change leukocyte function under a multitude of experimental conditions. NO inhalation is an experimental treatment for lung failure and exposes leukocytes to increased NO concentrations during passage through the lungs. To investigate whether short-term NO inhalation induces lasting changes in the function of circulating human leukocytes, venous blood samples were drawn from eight healthy male volunteers before and at the end of a 35-min period of breathing 40 ppm NO in 30% O(2). The leukocytes in the samples were subsequently analyzed for NO-induced changes in expression of cell surface molecules, generation of reactive oxygen species (ROS), and cytokine production by flow cytometry and ELISA techniques. The results were (1) NO inhalation changed neither the baseline nor the Escherichia coli lipopolysaccharide (LPS)-induced expression of the cell adhesion molecules CD11a, CD11b, CD11c, and CD62L (l-selectin) on neutrophilic granulocytes (PMN) or monocytes (Mo). The expression of CD14 and HLA-DR was also unchanged. (2) The generation of ROS in response to activation with phorbol myristate acetate increased in PMN after NO inhalation; an increase in Mo did not reach significance. (3) Baseline and LPS-stimulated production of IL-1beta decreased after NO inhalation, while the LPS-stimulated production of TNF-alpha increased. No changes in IL-6 production were detected.

Administration, Inhalation↗
PubMed1999

Inhalation of nitric oxide inhibits ADP-induced platelet aggregation and alpha-granule release.

To gather further information about the effects on blood platelet activation of in vivo exposure to nitric oxide (NO), platelet reactivity was studied in blood from healthy, non-smoking male volunteers before and after 30 min inhalation of 40 ppm NO. Whole blood was stimulated in vitro with adenosine diphosphate or thrombin receptor activation peptide (TRAP-6). In an ex vivo perfusion model, non-anticoagulated blood was exposed to immobilised collagen at arterial blood flow conditions (2600 s(-1)). Blood samples from both the in vitro and ex vivo experiments were stained with fluorochrome-labelled Annexin-V and antibodies against CD42a, CD45, CD49b, CD61, CD62P and fibrinogen, and analysed with a three-colour flow cytometry technique. NO inhalation reduced the platelet activation response to adenosine diphosphate (ADP) stimulation by decreasing platelet-platelet aggregation, alpha-granule release and platelet-leukocyte conjugate formation. TRAP-stimulated platelet activation, collagen-induced platelet activation and thrombus growth was unaffected by NO inhalation. We therefore suggest an ADP receptor inhibitor mode of action of inhaled NO, selective on the newly suggested G protein- and phospholipase C-coupled P2Y1 receptor. Our results demonstrate that blood platelet activation in healthy subjects is modulated by inhalation of NO in therapeutically relevant doses, although the clinical impact of our findings remains unclear.

Journal Article↗
PubMed1997

Effect of extreme metabolic acidosis on oxygen delivery capacity of the blood--an in vitro investigation of changes in the oxyhemoglobin dissociation curve in blood with pH values of approximately 6.30.

OBJECTIVES: To determine the oxyhemoglobin dissociation curve in blood with pH of approximately 6.3 due to metabolic and superimposed respiratory acidosis, and to evaluate the oxygen delivery capacity of the blood under these circumstances. DESIGN: In vitro study. SETTING: A blood gas laboratory in a university institute for respiratory physiology. SUBJECTS: Heparinized normal human blood. INTERVENTIONS: The oxyhemoglobin dissociation curve was determined by measuring PO2, pH, PCO2, and hemoglobin oxygen saturation at 37 degrees C in mixtures of blood from two reservoirs, both prepared by titration with lactic acid to a pH of 6.3 during tonometry with gases containing 4.2% CO2 and high and low oxygen percentages, respectively. For determination of the effect of additional increases in PCO2, the reservoir blood thus produced was prepared by further tonometry with gases containing 12.8% CO2 and the same oxygen percentages. MEASUREMENTS AND MAIN RESULTS: With the same degree of lactic acidosis (blood lactate concentration of 52 mmol/L), the position of the oxyhemoglobin dissociation curve was the same for blood with PCO2 of 30 torr (4 kPa) and pH of 6.295 and for blood with PCO2 of 90 torr (12 kPa) and pH of 6.165. During tonometry with a gas with PCO2 of 30 torr (4 kPa) and PO2 of 20 torr (2.7 kPa) and addition of increasing amounts of lactic acid, leading to a stepwise change in pH from 6.7 to 6.0, hemoglobin oxygen saturation decreased with decreasing pH from 6.7 to 6.4, but remained the same at a pH of between 6.4 and 6.0. The measured rightward shift of the oxyhemoglobin dissociation curve at such a low pH was clearly less pronounced than that calculated using commonly applied equations, in particular, at the lowest pH. The beneficial effects of the rightward shift of the oxyhemoglobin dissociation curve on the estimates of extractable oxygen at a given venous PO2 decrease with decreasing pH, and disappear rapidly when the Pao2 is reduced below normal. CONCLUSIONS: The acidemia-induced rightward shift of the oxyhemoglobin dissociation curve does not increase further at a pH < 6.4, and is, at such extreme acidemia, less pronounced than calculated by the commonly used equations. To obtain optimal tissue oxygenation in patients with severe circulatory failure and extreme metabolic acidosis, Pao2 should be > 250 torr (> 33.3 kPa).

Acidosis, Lactic↗
PubMed1993

[Upper airway obstruction].

The general symptoms of upper airway obstruction are described, as well as the specific symptoms expected to be found in various conditions that cause such obstruction. An algorithm, intended primarily for general practitioners and other physicians who seldom confront such problems, describes the procedures for establishing an unobstructed airway in different situations. It also outlines the interventions necessary to ensure adequate oxygenation and ventilation when such procedures fail. Special emphasis is placed on the use of emergency tracheotomy, or oxygenation by means of cricothyreoid membrane puncture, as an alternative to emergency intubation by unskilled physicians.

Airway Obstruction↗
PubMed1993

Direct and indirect effects of E. coli lipopolysaccharide on isolated human polymorphonuclear granulocytes and mixed leukocytes.

Polymorphonuclear neutrophil granulocytes (PMN) may contribute to the lung injury induced by nonpulmonary infections with gram-negative bacteria. The direct effect of E. coli lipopolysaccharide (LPS) on isolated human PMN or mixed leukocytes (ML), as well as the priming effect of preincubating cells with LPS, was examined in assays measuring the maximal rate of oxygen consumption (OC), cell chemiluminescence (CHML), and aggregation (AGG). LPS, 1-10 micrograms/ml, caused no acute response in PMN or ML suspended in Fisher's-HEPES medium with BSA (FHA), but increased both CHML and AGG of cells suspended in autologous plasma. Preincubation in FHA with LPS, 1 microgram/ml, for more than 15 min increased the OC of PMN activated with zymosan-activated plasma (ZAP) or n-formyl-methionyl-leu-cyl-phenylalanine (FMLP) by more than 100%. A similar increase in the CHML of such cells was seen after FMLP, but not after ZAP. ZAP, however, primed the CHML response of the cells to subsequent activation with FMLP more than did preincubation with LPS. Previous exposure to both agents had an additive effect. Preincubation of PMN with LPS decreased the time interval from addition of phorbol myristate acetate (PMA) to peak OC response, but less so than previous activation with FMLP. Neither agent affected the maximal rate of OC after addition of PMA. LPS also increased the PMN aggregation induced by ZAP and FMLP, but not by PMA. Cells preincubated with LPS, 0.01 microgram/ml, increased their CHML in response to FMLP if suspended in Krebs-Ringer balanced salt solution, but not if suspended in FHA. Such preincubation had no effect on OC of similarly activated cells in any of the media.

Cell Aggregation↗
PubMed1993

Effects of high dose E. coli lipopolysaccharide on rabbit lung function, and of subsequent addition of chemotactic granulocyte activators to their isolated, blood-perfused lungs.

E. coli LPS was infused (1 microgram/kg to 5 mg/kg over 30 min) to spontaneously breathing rabbits, and their arterial blood pressure (ABP), blood leukocyte count and blood gases were observed for 2.5-3.5 h. Pulmonary vascular and airway function were subsequently evaluated in vitro by comparing weight changes, fluid filtration rates, pulmonary vascular resistance (PVR) and airway pressures in their isolated, blood-perfused lungs with those in lungs from untreated rabbits. Lung preparations from both groups of animals were then exposed to autologous zymosan-activated plasma (ZAP) or n-formyl-methionyl-leucyl-phenylalanine (FMLP) and perfused for 2 more hours. LPS addition to isolated rabbit leukocytes increased cell aggregation; cell chemiluminescence after activation with FMLP was also enhanced. Infusion of 1-5 mg/kg LPS decreased the count of all types of leukocytes and caused a metabolic acidosis (BE < -8 mmol), but no decrease in ABP. PAO2-Pao2 increased by about 2.0 kPa. No vascular permeability increase was detected in the lungs of these animals during subsequent in vitro perfusion. Addition of ZAP or FMLP during perfusion markedly increased the PVR in lungs from LPS animals, but did not induce major microvascular leakage. No significant differences in edema between lungs from LPS-treated and control animals were found by microscopy.

Animals↗
PubMed1991

Pulmonary, hepatic and splenic sequestration of technetium-99m labelled autologous rabbit granulocytes: scintigraphic cell distributions after intravenous and intraarterial injections, exsanguination and intraarterial injection of cells passed through an intermediary host.

In man, about half the intravascular granulocytes are not freely circulating, but temporarily sequestered ('marginated'), so that they cannot be retrieved by bleeding. Where and how the sequestration occurs is not settled and is the subject of the present report. Isolated autologous rabbit granulocytes, labelled with two different 99mTc methods, were reinjected and followed with external scintigraphy. Intraarterial as well as intravenous injection led to rapid accumulation of radioactivity over the lungs. This finding was corroborated and extended by similar experiments, where the labelled cells had firstly been passed through an intermediary rabbit host to remove altered cells, i.e. cells damaged, 'primed' (pre-activated), or activated. In the final autologous host about two thirds of the label rapidly localized to the lungs and liver, and a few per cent to the spleen (which is very small in the rabbit). Even though more than half of the intermediary rabbit's calculated blood volume was removed, the blood sample contained only a few per cent of the rabbit's radioactivity; consequently, many of the labelled leucocytes had marginated during the bleeding. The proportional distribution of radioactivity over lungs, spleen, kidneys, and the rest of the intermediary animal was not markedly changed by this exsanguination, but there was a 4-20% decrease over the liver. Taken together, our findings indicate that normal granulocytes marginate in lungs, liver, and spleen--apparently explicable by the effects of cell size, vessel diameter, cell stiffness (visco-elastic properties) and size of the arterio-venous hydrostatic pressure difference. The liver and spleen seemed to play additional roles, since radioactivity over these organs decreased much slower than expected from reported blood half-times of intact and slightly damaged rabbit granulocytes. This led to a suggestion that macrophages exposed to blood normally phagocytose apoptotically dying granulocytes.

Animals↗
PubMed1988

Dual effect of thiopentone on human granulocyte activation. Non-intervention by ketamine and morphine.

The immune system, defending our organism against infections, can also cause disease. Anaesthetics may impair immunological defence by modifying the number and functions of immunocompetent cells, including the polymorphonuclear leucocytes (PMN). We have studied the effects of thiopentone, ketamine and morphine on some stimulated PMN responses that presumably reflect their microbicidal activity, i.e. oxygen consumption, aggregation, and volume increase. Stimulators were N-formyl-methionyl-leucyl-phenylalanine (FMLP, affecting cells via specific membrane receptors) and phorbol-myristate-acetate (PMA, activating protein kinase C, thereby short-cutting intramembraneous steps in normal signal transmission, and presumably provoking near-maximal cell responses with the dose applied). Preincubation of PMN with low doses of thiopentone enhanced oxygen consumption in unstimulated cells as well as in response to FMLP, but not PMA. FMLP-stimulated volume and aggregation responses were not detectably affected. The highest concentration of thiopentone depressed both oxygen uptake and volume/aggregation responses in FMLP-stimulated PMN. The amount of oxygen consumed after PMA stimulation was not affected, but both the onset of increased consumption and the maximal response were delayed. The two other drugs investigated, ketamine and morphine, did not appreciably affect oxygen consumption or aggregation by PMN: neither the baseline values nor those obtained after FMLP or PMA stimulation.

Cell Aggregation↗
PubMed1988

Pulmonary effects of zymosan activated plasma and phorbol myristate acetate in anaesthetized and awake rabbits.

The ability of two polymorphonuclear granulocyte (PMN) activators, Zymosan activated plasma (ZAP) and Phorbol myristate acetate (PMA), to induce an adult respiratory distress syndrome (ARDS) type lung injury was compared in awake and anaesthetized rabbits. The preparatory procedure itself decreased the concentrations of circulating PMN and lymphocytes in anaesthetized animals. ZAP acutely lowered the number of circulating leukocytes due to a fall in PMN only, this was followed by a rebound. Both effects were more marked in awake than in anaesthetized animals. PMA caused a virtual disappearance of both PMN and lymphocytes from the blood. There was no rebound, and no difference between anaesthetized and awake animals. The activators caused equal increases in pulmonary arterial pressure (about 0.67 kPa) initially. This was followed by a return to baseline in ZAP animals, but a further increase in those given PMA. Increased airway pressure (0.4 kPa) was seen only in the PMA group; PaO2 decreased only in awake rabbits given PMA. Both activators, as well as the preparatory procedure itself, caused PMN accumulations in the alveolar septa, septal thickening, and modest perivascular edema with intact tissue architecture. PMA caused the most marked changes. Wet/dry lung weight ratios were only moderately increased. In conclusion, ZAP and PMA had different effects on circulating leukocytes, but gave nearly the same degree of PMN accumulation in the lungs. The modest edema indicated some increased microvascular leakage, but a fully developed ARDS-type lung injury did not occur.

Anesthesia↗
PubMed1987

Granulocytes in bronchial lavage fluid after major vascular surgery.

Increased numbers of polymorphonuclear granulocytes (PMN) in the airways, as measured by PMN content in bronchial lavage fluid (P less than 0.01), were found 3 h postoperatively in ten patients undergoing surgery for lumbar aortic aneurysms. An increase in plasma levels of the complement split product C3dg from 6 (0-19) AU/ml preoperatively to 20 (13-50) AU/ml 3 h after surgery (P less than 0.01), indicates an activation of the complement cascade. These changes were not accompanied by increased elastase activity in the bronchial lavage fluid or by major changes in pulmonary blood gas exchange or vascular resistance, indicating that massive PMN activation, analogous to that proposed in adult respiratory distress syndrome (ARDS) had not taken place. In conclusion, complement system activation and migration of PMN into the airways, as seen in connection with major vascular surgery, does not seem to contribute to ARDS-type pulmonary dysfunction.

Aged↗
PubMed1987

Differences and similarities between human and rabbit neutrophil granulocyte responses in vitro: the effects of zymosan-activated plasma, phorbol myristate acetate and n-formyl-methionyl-leucyl-phenylalanine.

The amount of reactive oxygen intermediates (ROI) generated by activated polymorphonuclear neutrophils (PMN), as well as the closeness of contact between PMN and vessel wall, may determine whether PMN activators will induce the adult respiratory distress syndrome. We examined the ROI-generating and aggregating effects of zymosan activated plasma (ZAP), phorbol myristate acetate (PMA) and n-formyl-methionyl-leucyl-phenylalanine (FMLP), on isolated human and rabbit PMN. PMA, after a short lag phase, induced a large and long-lasting increase in ROI generation. The initial peak response was higher and more rapid in human than in rabbit cells. The reaction to FMLP occurred almost instantaneously, but was much weaker than that to PMA, and ROI generation returned to near baseline in less than 10 min. No species difference was seen. ZAP caused an FMLP-like ROI response in human cells, whereas no response was observed in rabbit PMN. PMN aggregation was induced by all three activators, most markedly by PMA. No species difference was detected for PMA; FMLP gave a stronger aggregation of rabbit than of human PMN, however, while the opposite was true for ZAP. In conclusion, ZAP was a potent stimulus for PMN aggregation, but had modest (or no) effects on the production of ROI. Marked differences between human and rabbit PMN responses were observed.

Animals↗
PubMed1987

Effects of zymosan-activated plasma and phorbol myristate acetate on isolated, perfused rabbit lungs.

The effects of complement activation on pulmonary vascular permeability are disputed. In rabbit lungs perfused with autologous blood, zymosan activated plasma (ZAP) induced a moderate increase in pulmonary vascular resistance (PVR), but did not detectably change the vascular permeability within 2 h. The stronger neutrophil granulocyte (PMN) activator, phorbol myristate acetate (PMA), usually gave larger PVR increases and also increased pulmonary vascular permeability. Lungs from neutropenic animals, similarly perfused and given PMA, showed unchanged PVR reactions but had no apparent increase in vascular permeability. Lungs perfused with cell-free medium and given PMA displayed modest PVR increases, and no measurable permeability change. The lung preparatory procedure itself markedly influenced leukocyte circulation. Exsanguination of lung donors decreased the concentration of circulating PMN significantly, and they virtually disappeared from the perfusate within minutes after start of lung perfusion. PMN-mediated effects must therefore have been caused by cells already sequestered in the lungs. We conclude that ZAP does not induce an increased pulmonary vascular permeability in isolated, perfused rabbit lungs, in contrast to PMA. The permeability effects of PMA appear to be PMN dependent.

Animals↗
PubMed1985

Interstitial fluid pressure in the isolated perfused rabbit lung.

Interstitial fluid pressure was measured in nine isolated perfused rabbit lungs with the servonull micropipette method. Bevelled glass micropipettes, with tip diameter 2-6 micrometers (o.d.) were inserted 2-6 mm into the left lung. At alveolar pressures of 3 to 5 cm H2O we found mean interstitial fluid pressures of 1.0 (SD 1.0) and 1.6 (SD 1.0) cm H2O relative to pleural pressure in the upper (n = 19) and lower (n = 21) lobes respectively. The vertical distance between the measuring sites in the upper and lower lobes was about 3 cm. Net filtration caused by elevated left atrial pressure caused practically no change in interstitial fluid pressure. Increased alveolar pressure either increased or decreased interstitial fluid pressure. The measured pressures probably represent interstitial fluid pressure in alveolar junctions or in the interstitium around small pulmonary arteries or veins. We conclude that interstitial fluid pressure in these sites is between alveolar and pleural pressure, and that it is only moderately affected by changes in alveolar pressure. The interstitial compliance appears to be high and there seem to be little or no vertical gradients in interstitial fluid pressure within the lung.

Animals↗
PubMed1985

White blood cell populations in patients undergoing major vascular surgery.

In 16 patients undergoing major vascular surgery, study was made of variations in white blood cell populations, cortisol concentration, pulmonary vascular resistance and intrapulmonary shunting. Six hours post-operatively the number of circulating lymphocytes and the relative proportion of T-lymphocytes were significantly reduced. During and after operation the relative proportion of T-suppressor cells rose from 20.5 to 44.8% of all lymphocytes. There was corresponding fall in T-helper cells. The proportion of lymphocytes with surface-bound Ig (B-lymphocytes) did not alter during surgery. No correlation was found between the number of circulating white blood cells and the haemodynamic parameters. Intrapulmonary shunting, which was increased already before operation, remained unchanged during and after surgery. Cortisol levels increased significantly and peaked 6 hours postoperatively. Significant correlations were found between cortisol levels and reduction in total number of lymphocytes and in percentage of T-lymphocytes. The study thus demonstrated significant changes in white blood cell populations following major vascular surgery and indicated a correlation between lymphocyte concentration and cortisol level.

Aged↗