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Biomedical subjects

B Gunnarsson

Publications and source records attributed to B Gunnarsson.

At least 19 recordsLinked to original sources
PubMed2001

Anaesthetic technique for transoesophageal echocardiography in children.

OBJECTIVE: To document the safety and efficacy of an anaesthetic technique in paediatric patients undergoing transoesophageal echocardiography (TOE). METHODS: Prospective descriptive study performed in a children's hospital with all patients undergoing TOE. Topical analgesia of the pharynx was achieved with lidocaine. Anaesthesia was induced with midazolam (25 microg.kg-1), fentanyl (1 microg.kg-1), and propofol (0.5-1 mg.kg-1), followed by a continuous infusion of propofol (5-10 mg.kg-1.h-1). RESULTS: Thirty patients are reported. The mean age was 11.4 +/- 5.1 years (range 1-22) and weight 40.5 +/- 22.1 kg (range 10-110). All the patients tolerated the procedure well. Two patients experienced brief oxygen desaturations during induction, 10 patients coughed during the procedure, and six patients had significant muscle activity requiring supplemental doses of propofol. None of the patients experienced nausea or vomiting. CONCLUSION: We conclude that our anaesthetic technique in spontaneously breathing paediatric patients during TOE is effective and appears to be safe in children with heart disease.

Adolescent↗
PubMed2001

Comparison of lung protective ventilation strategies in a rabbit model of acute lung injury.

OBJECTIVE: To determine the impact of different protective and nonprotective mechanical ventilation strategies on the degree of pulmonary inflammation, oxidative damage, and hemodynamic stability in a saline lavage model of acute lung injury. DESIGN: A prospective, randomized, controlled, in vivo animal laboratory study. SETTING: Animal research facility of a health sciences university. SUBJECTS: Forty-six New Zealand White rabbits. INTERVENTIONS: Mature rabbits were instrumented with a tracheostomy and vascular catheters. Lavage-injured rabbits were randomized to receive conventional ventilation with either a) low peak end-expiratory pressure (PEEP; tidal volume of 10 mL/kg, PEEP of 2 cm H2O); b) high PEEP (tidal volume of 10 mL/kg, PEEP of 10 cm H2O); c) low tidal volume with PEEP above Pflex (open lung strategy, tidal volume of 6 mL/kg, PEEP set 2 cm H2O > Pflex); or d) high-frequency oscillatory ventilation. Animals were ventilated for 4 hrs. Lung lavage fluid and tissue samples were obtained immediately after animals were killed. Lung lavage fluid was assayed for measurements of total protein, elastase activity, tumor necrosis factor-alpha, and malondialdehyde. Lung tissue homogenates were assayed for measurements of myeloperoxidase activity and malondialdehyde. The need for inotropic support was recorded. MEASUREMENTS AND MAIN RESULTS: Animals that received a lung protective strategy (open lung or high-frequency oscillatory ventilation) exhibited more favorable oxygenation and lung mechanics compared with the low PEEP and high PEEP groups. Animals ventilated by a lung protective strategy also showed attenuation of inflammation (reduced tracheal fluid protein, tracheal fluid elastase, tracheal fluid tumor necrosis factor-alpha, and pulmonary leukostasis). Animals treated with high-frequency oscillatory ventilation had attenuated oxidative injury to the lung and greater hemodynamic stability compared with the other experimental groups. CONCLUSIONS: Both lung protective strategies were associated with improved oxygenation, attenuated inflammation, and decreased lung damage. However, in this small-animal model of acute lung injury, an open lung strategy with deliberate hypercapnia was associated with significant hemodynamic instability.

Animals↗
PubMed2000

Successful lysis of an obstructive aortic and renal artery thrombus in a neonate on extracorporeal membrane oxygenation.

We describe a neonate on venoarterial extracorporeal membrane oxygenation (ECMO) with acute renal failure associated with extensive aortic and bilateral renal artery thrombosis. Concurrent anticoagulation and continuous systemic thrombolytic therapy with tissue plasminogen activator (t-PA) resulted in complete thrombolysis as evaluated by Doppler flow. The relative risk and benefits of thrombolytic therapy in heparinized patients undergoing ECMO needs to be further studied.

Aortic Diseases↗
PubMed2000

Partial liquid ventilation with perflubron attenuates in vivo oxidative damage to proteins and lipids.

OBJECTIVE: To determine the impact of partial liquid ventilation on the degree of pulmonary damage by reactive oxygen species in a model of acute lung injury caused by systemic endotoxemia. DESIGN: A prospective, controlled, in vivo, animal laboratory study. SETTING: Animal research facility of a health sciences university. SUBJECTS: Forty New Zealand White rabbits. INTERVENTIONS: Mature rabbits were anesthetized and instrumented with a tracheostomy and vascular catheters. Animals were assigned to receive either partial liquid ventilation (n = 16) with perflubron (18 mL/kg via endotracheal tube) or conventional mechanical ventilation (n = 16). Both groups were ventilated using similar strategies, with an Fio2 of 1.0 and tidal volume as required to obtain a normal Paco2. Animals were then given 0.9 mg/kg Escherichia coli endotoxin intravenously over 30 mins. Eight uninjured instrumented and mechanically ventilated animals served as controls. Partial liquid ventilation or conventional ventilation was continued for 4 hrs before the animals were killed. Lung homogenates were analyzed for malondialdehyde (MDA) and 4-hydroxy-2(E)-nonenal (4-HNE) concentrations using a colorimetric assay. To assess protein oxidative damage, carbonyl groups in protein side chains were derivatized with 2,4-dinitrophenylhydrazine followed by Western blotting with a dinitrophenylated-specific primary antibody. MEASUREMENTS AND MAIN RESULTS: MDA (713.42+/-662 vs. 1601.4+/-1156 nmol/g protein; p = .023) and MDA plus 4-HNE (1480.24+/-788 vs. 2675.2+/-1628 nmol/g protein; p = .038) concentrations were lower in animals treated with partial liquid ventilation compared with conventionally ventilated animals, respectively. Animals treated with partial liquid ventilation exhibited attenuation of dinitrophenylated-derivatized protein bands by Western blotting, indicating a reduction in protein oxidative damage. The presence of perfluorocarbon did not interfere with the MDA assay when assessed by independent analysis in vitro. Perflubron did not serve as a sink for peroxyl radicals produced in the aqueous phase during separate in vitro oxidation experiments. CONCLUSIONS: Partial liquid ventilation attenuates oxidative damage to lipids and proteins during experimental acute lung injury. This finding is not caused by binding of lipid peroxidation products to perflubron or by the peroxyl radical scavenging properties of perflubron.

Animals↗
PubMed1999

Partial liquid ventilation influences pulmonary histopathology in an animal model of acute lung injury.

PURPOSE: The aim of this study was to assess the effect of partial liquid ventilation (PLV) and conventional mechanical ventilation (CMV) in the pattern of distribution of lung injury in a rabbit model of acute lung injury. MATERIALS AND METHODS: Animals (1.5 to 3.5 kg) were assigned to receive CMV (tidal volume of 10 mL/kg and a PEEP of 5 cm H2O) or PLV with 18 mL/kg of intratracheal perflubron (tidal volume of 10 mL/kg and a PEEP of 5 cm H2O). Lung injury was elicited by intravenous administration of Escherichia coliendotoxin. Uninjured animals ventilated as the CMV group served as controls. After 4 hours of mechanical ventilation, the lungs were removed and tissue injury was assessed by light microscopy using a scoring system. RESULTS: Animals in the CMV group had higher lung injury scores in comparison to the PLV group (10+/-4.5 vs. 5+/-3.3, respectively, P < .05). The injury scores were similar for nondependent lung regions (CMV: 8+/-4.3, PLV: 6+/-2.9) but significantly different for the dependent regions (CMV: 12+/-4.6, PLV: 5+/-3.8, P< .05). CONCLUSIONS: PLV is associated with significant attenuation of lung injury, in comparison to CMV. This effect is predominantly due to attenuation of injury in the dependent region of the lung.

Analysis of Variance↗
PubMed1999

Promoting medical self-care: evaluation of a family intervention implemented in the primary health care by pharmacies.

BACKGROUND: Medical self-care is the range of behaviours undertaken by people to promote or restore health when dealing with a medical problem. OBJECTIVES: The aim of the study was to evaluate medical self-care effects of a family intervention implemented in primary health care by pharmacies, in terms of non-professional and professional involvement. METHODS: The intervention was implemented in one of two primary health care areas during a 4-month period and involved consecutive families acting as an intervention (IG, n = 94) or a control (CG, n = 93) group. Eight telephone interviews were conducted with each family. The families were asked about complaints of illness, how long they prevailed and how they were treated. RESULTS: The results showed (P < 0.05-0.0001) that the IG had more medical problems (931 versus 621) compared with the CG, were less hospitalized (4 versus 10), stayed at home more to take care of sick children (84 versus 40), read more medical brochures (121 versus 31), tried more non-medical treatments (228 versus 116), and had fewer visits to the department of paediatrics but more visits to primary health care (69 and 98 versus 90 and 68). CONCLUSIONS: Due to the non-randomization procedure, some caution with regard to generalization of the results must be taken, but they are in concordance with established knowledge of the usefulness of medical self-care. The results indicate that a brief intervention for families can change the use of health authorities. It therefore seems meaningful to implement the intervention in a more comprehensive way in the primary health care setting, while at the same time trying to implement it as a large-scale randomized experimental study, comprising aspects such as the individual's need for care, the use of the right organization level and the assessment of economic costs and savings.

Evaluation Studies as Topic↗
PubMed1999

Lipid peroxidation during initiation of extracorporeal membrane oxygenation after hypoxia in endotoxemic rabbits.

Initiation of extracorporeal membrane oxygenation (ECMO) in septic children with severe respiratory failure often improves oxygenation but not pulmonary function. The factors affecting pulmonary function following onset of ECMO are not completely understood, but are thought to involve injury mediated, in part, by reactive oxygen species. We hypothesized that induction of ECMO using 100% oxygen as the sweep gas through the oxygenator would increase lipid peroxidation in endotoxin-primed animals after severe hypoxia. We further speculated that provision of oxygenated blood to the pulmonary circulation via venovenous ECMO would promote a greater degree of oxidative damage to the lung as compared to venoarterial ECMO. Eighteen New Zealand White rabbits were assigned to a control group (control) or two intervention groups subjected to 60 min of venoarterial or venovenous ECMO. ECMO was initiated following an intravenous challenge with 0.5 mg/kg of E. coli endotoxin and a period of global hypoxia leading to an arterial pH of 6.99 +/- 0.09, PaCO2 of 103 +/- 31 mmHg and PaO2 of 27 +/- 5 mmHg. Malondialdehyde (MDA), a marker of lipid peroxidation, was measured in lung tissue homogenates and in arterial plasma. Lung tissue MDA demonstrated a strong trend towards an increase in the venoarterial group (1884 +/- 945 nmol/g protein) and in the venovenous group (1905 +/- 758 nmol/g protein) in comparison to the control group (644 +/- 71 nmol/g protein) (p = 0.1; significance at 95% in Scheffe test). Lung tissue MDA in the venovenous group had a significant correlation with mean PaO2 during ECMO by regression analysis (r2 = 0.678, p = 0.044). The change in blood MDA concentration between pre-ECMO and post-ECMO values was greater in the venovenous group (pre 1.62 +/- 0.61 versus post 5.12 +/- 0.2.07 mumol/l, p = 0.043) compared with that seen in the venoarterial group (pre 1.46 +/- 0.38 versus post 3.9 +/- 0.93 mumol/l). Our data support the hypothesis that initiation of ECMO with a circuit gas oxygen concentration of 100% after global hypoxia enhances oxidative damage to lipids in endotoxin-challenged animals. During venovenous ECMO this finding is dependent on PaO2.

Animals↗
PubMed1998

Price indices of drugs and the switching to new drugs. Two empirical examples.

Standard price indices may not account for the price decrease that results when patients switch to pharmaceutical products for which their demand-reservation price exceeds the price of the new product. In a similar way, standard price indices may not account for the price increase that results when patients switch to pharmaceuticals for which the reservation price is below the price of the new drug. This study was designed to assess whether standard pharmaceutical price indices under- or overestimate the real price development resulting from new drug introductions. We illustrate that both situations may occur. In our first example, the switch from a branded to a generic drug, we showed that standard price indices recorded a price increase of about 16%, although the price actually decreased by about 5%. In our second example, the introduction of new formulation of a currently marketed drug, we showed that standard price indices recorded a price increase of about 6%, when the actual price increased by more than 65%.

Drug Industry↗
PubMed1998

The effect of changes in treatment patterns on drug expenditure.

This paper investigates the effects of changes in drug therapy on drug expenditure in Sweden between 1990 and 1995. Analyses have been carried out for both the aggregate drug expenditure and for drug expenditure according to the main groups of the Anatomical Therapeutic Chemical (ATC) classification system. Changes in expenditure can be divided into 3 components: the price of drugs, the quantity of drugs consumed and a residual. The size of the residual is a measure of the effect of changes in drug treatment patterns on drug expenditure. The aggregate real drug expenditure increased by 50% between 1990 and 1995. The relative retail price index of drugs decreased by 9% and the quantity index measured in terms of defined daily doses increased by 27%. The remaining residual increased by 30%. This implies that, if the residual had been unchanged during the study period, the aggregate expenditure would have increased by only 15%. The results also show that the size of the residual varies substantially across different ATC groups. The increase in the residual was largest for drugs that affect the nervous system (ATC group N); the residual increased by 86%. From the observed changes in residual values, it can be concluded that the underlying factor responsible for the increase in drug expenditure in Sweden is changes in drug therapy from less expensive to more expensive drugs.

Drug Costs↗
PubMed1997

Cost and utilisation of pharmaceuticals in Sweden.

Issues of efficiency, access, equity and cost have informed Swedish national policy toward pharmaceuticals for many years. While retail pharmacies have been owned and operated by a single state company since 1971, the manufacturing of pharmaceuticals has remained privately owned and operated. Costs to the health care system for pharmaceuticals have been rising 4-8% in the last several years, despite greater use of generic substitutes. Beyond price-reduction pressures created by the state retail monopoly, by reference pricing, by positive lists, and by an expanded system of capped patient copayments, the national government is considering plans to decentralise responsibility for all outpatients as well as inpatient drug expenditures to the 26 country councils.

Cost Control↗
PubMed1989

Effects of simulated acid rain on growth rate in a spruce-living spider.

Growing juveniles of the spruce-living spider Pityohyphantes phrygianus were sprayed with water of different acidity--pH approximately 7 (control), 4.0 (acid rain) and 2.2-in a 2.5-month laboratory experiment. The growth rates did not differ between control and pH 4.0, while there was a significant growth reduction at pH 2.2. A low mortality occurred only in the pH 2.2 group. P. phrygianus seems to be resistant against acid rain although negative long-term effects cannot be ruled out.

Journal Article↗
PubMed1981

Measurement of fibrinopeptide A in the evaluation of heparin activity and fibrin formation during hemodialysis.

In order to monitor heparin activity during hemodialysis, were evaluated three commonly used methods; measurement of whole blood activated coagulation time (WBACT), whole blood thrombin time (WBTT) and heparin concentration in plasma, determined with a chromogenic substrate. Studies were performed on six regular dialysis patients during 4-hour dialysis sessions, employing three different heparin regimens; a single intravenous loading dose only, priming of the dialyzer with heparin followed by a heparin infusion and a pharmaco-kinetic model. Efficacy of heparinization was assessed by determination of fibrinopeptide A (FPA) which is a peptide split product of the fibrinogen molecule formed during thrombin-induced conversion to fibrin. There was a linear correlation (r = 0.95) between FPA-production in the dialyzer and the FPA content of the blood at the inlet to the dialyzer; the slope of the correlation line indicates that at least 65% of FPA formed in the dialyzer is disposed during passage through the patient. Considerably higher production of FPA was noted when the heparin concentration was below 0.5 IU/ml than at a higher level. This was a common finding at the end of a dialysis, regardless of regimen. No consumption of antithrombin (AT III) occurred during a dialysis with any of the heparin regimens. Good correlations were found between WBACT, WBTT and heparin concentration. Heparin activity during a dialysis may be monitored with any of these three methods with equal reliability. However, from a practical point of view, WBACT appears most attractive because of its simplicity. FPA generation, frequency of visible clots in the dialyzer and hemorrhagic manifestations were essentially the same for each of the heparin dose regimens. The simple administration of a single loading dose was as safe as the more complicated infusion technique.

Female↗
PubMed1981

The effects of three different heparin regimes on heparin concentrations in plasma and fibrin formation in dialyzers.

Anticoagulation effects were studied during a 4-hr hemodialysis in 6 patients using 3 different heparin regimens: I. Intravenous loading dose only; II. priming of the dialyzer and continuous infusion of heparin for 2 hr; III. intravenous loading dose and continuous infusion of heparin based on anticoagulation kinetics. In all regimens the difference of fibrinopeptide A (delta FPA) between the blood inlet and outlet of the dialyzers increased at the end of the dialyses, indicating increased fibrin formation. There was a good correlation between delta FPA and the fibrin deposition on the membranes measured with I-125-fibrinogen. delta FPA increased when heparin concentration in plasma was less than 0.5 IU/ml. The anticoagulation kinetic regimen offered no advantage over the single loading dose regimen with regard to the formation and deposition of fibrin in the dialyzers.

Female↗
PubMed1981

Influence of dialysate composition on cardiovascular function in isovolaemic haemodialysis.

Haemodynamic studies were made in eight patients before and during isovolaemic dialysis with five different dialysis solutions which varied with regard to concentration of sodium, acetate, bicarbonate and urea. Low sodium (133mmol/L) in the dialysate induced a fall in blood pressure both with and without urea removal, but no significant fall in peripheral vascular resistance. Acetate in the dialysate at higher sodium concentration (140mmol/L) resulted in peripheral vasodilation but no fall in blood pressure due to a compensatory increase in heart rate and cardiac output. We conclude that a fall in plasma tonicity (sodium) is the most important pathogenetic factor in dialysis associated hypotension; fall in total osmolality (mainly urea) is of no importance and acetate vasodilation can be compensated for haemodynamically provided that tonicity is kept stable.

Adult↗