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Biomedical subjects

G Settergren

Publications and source records attributed to G Settergren.

At least 19 recordsLinked to original sources
PubMed1992

Incidence of sore throat and patient complaints after intraoperative transesophageal echocardiography during cardiac surgery.

To evaluate the incidence of postoperative side effects and patient complaints following transesophageal echocardiography (TEE), 57 patients were interviewed by questionnaire and examined by pharyngeal inspection, preoperatively. The patients were randomized to undergo surgery with or without intraoperative TEE, and a second interview and examination were performed in 48 patients on the second postoperative day using a double-blind protocol. Twenty-four of the patients were investigated by TEE over a period of 5.4 +/- 2.3 hours and 24 had surgery without TEE. The intubation time for the two groups did not differ. There was no difference between controls and TEE patients with regard to painful swallowing evaluated by a visual analog scale. Furthermore, there was no difference between the controls and TEE patients regarding nausea or time elapsed from extubation to the first oral intake. No differences between the groups were found regarding the findings on pharyngeal inspection and no major complication attributable to the use of TEE occurred. A sore throat with painful swallowing was not a great problem for the patients in the present study; this indicates that endotracheal intubation rather than TEE caused the minor complaints. It is concluded that intraoperative TEE can be used without harmful postoperative pharyngeal side effects.

Aged↗
PubMed1991

Left ventricular end-systolic pressure estimated from measurements in a peripheral artery.

Aortic and radial arterial pressure measurements were compared after cannulation and before cardiopulmonary bypass in 26 patients scheduled for coronary artery bypass grafting. The radial artery blood pressure range was 89 to 147 mm Hg systolic and 44 to 75 mm Hg diastolic. A difference was found between the central and peripheral dicrotic notch pressures, the former being 7.9 +/- 2.7 (SD) mm Hg higher than the latter. When 8 mm Hg was added to the notch pressure measured in the radial artery to construct a calculated end-systolic pressure, there was good agreement with the centrally measured notch pressure. The mean difference was -0.15 mm Hg with a 95% confidence interval of -1.2 to 0.9 mm Hg. It was not possible to calculate peak systolic aortic pressure with the same accuracy from the systolic and diastolic pressure measurements in the radial artery. It is concluded that left ventricular end-systolic pressure measured as the aortic dicrotic notch pressure can be calculated from the dicrotic notch pressure in the radial artery with reasonable accuracy.

Aorta↗
PubMed1991

A comparative study of five different techniques to reduce left ventricular dysfunction during endotracheal intubation.

Thirty-five non-selected, consenting patients were studied during induction of anesthesia before coronary artery bypass grafting. Anesthesia was induced with diazepam, thiopentone and fentanyl, followed by pancuronium. Before induction, 200 MBq Tc 99 m - HSA was given i.v. and ejection fraction (EF) of the left ventricle was measured with a collimated single-crystal probe. The patients were allocated to five groups (seven patients in each) treated with: Group A: nitroglycerin i.v. bolus 4 micrograms x kg-1 given 30-60 s before laryngoscopy; Group B: nitroglycerin i.v. in continuous infusion, 1 micrograms x kg-1 x min-1 started before induction; Group C: two-stage topical anesthesia of the vallecula region and larynx with lidocain; Group D: a combination of nitroglycerin and topical anesthesia (as in Group B and C); and Group E: propranolol i.v. 0.01 mg x kg-1 given 5 min before intubation. All groups reacted in the same way during induction of anesthesia up to the point of laryngoscopy. End-diastolic volume and systemic arterial pressure decreased while cardiac index remained unchanged and EF increased. During laryngoscopy and intubation, however, differences between the groups were evident. Nitroglycerin i.v. as a bolus effectively prevented a reduction in EF and an increase in left ventricular volume. In addition to these beneficial hemodynamic effects, there was a moderate increase in heart rate and a reduction of stroke index. Continuous infusion of nitroglycerin and propranolol i.v. had no effect, since EF fell and left ventricular volume increased. Patients receiving topical anesthesia demonstrated a blunted response to endotracheal intubation with a moderate decrease in EF and an unchanged (Group C) or slightly increased (Group D) left ventricular volume.

Adult↗
PubMed1990

Release of neuropeptide Y and noradrenaline from the human heart after aortic occlusion during coronary artery surgery.

STUDY OBJECTIVE: The aim was to study the influence of complete myocardial ischaemia during aortic occlusion on release of neuropeptide Y and noradrenaline from the human myocardium. DESIGN: Coronary sinus neuropeptide Y and noradrenaline were measured after 46(SEM 7) min of aortic occlusion with cold cardioplegia in patients undergoing coronary artery surgery. Patients - Seven patients (all male), aged 64(SEM 3) years, were studied. All were undergoing coronary artery bypass grafting. MEASUREMENTS AND MAIN RESULTS: Reperfusion was associated with an increase in coronary sinus blood flow as determined by thermodilution. Simultaneously there was cardiac release of both neuropeptide Y and noradrenaline during the first two sampling periods: 3(0.6) and 7(0.6) min after the start of reperfusion. The outflow of neuropeptide Y and noradrenaline returned to preischaemic values by 14(1) min after reperfusion. Coronary sinus blood lactate and pyruvate concentrations were also increased at the start of reperfusion, while the lactate/pyruvate ratio remained unchanged. Myocardial oxygen uptake was not influenced by cardiac ischaemia. CONCLUSIONS: Ischaemia of the human heart in vivo is associated with an enhanced outflow of neuropeptide Y and noradrenaline from the heart. Since arterial blood concentrations of these substances were also increased on reperfusion, their release is probably due to increased sympathetic nerve activity, though other mechanisms such as temperature change and local metabolite formation could also participate. Local release of neuropeptide Y during cardiac ischaemia may be involved in the regulation of coronary vascular tone as well as in the release of noradrenaline and acetylcholine.

Aorta, Thoracic↗
PubMed1989

Isoflurane and intravenous anesthesia used for induction before coronary artery bypass grafting.

Induction of anesthesia with isoflurane in combination with fentanyl, thiopentone, nitrous oxide and pancuronium was studied in nine patients scheduled for coronary artery bypass grafting. Ejection fraction (EF) of the left ventricle was monitored with a single crystal probe linked to a microcomputer, after injection of 200 MBq Tc 99m-HSA. Stroke volume index determined by thermodilution and EF were used to calculate left ventricular end-diastolic volume index (LVEDVI). The degree of ischemia was numerically scored as evaluated from the ECG (modified V5 lead). The study protocol covered seven periods from awake before induction to 5 min after intubation. EF decreased moderately during intubation (P less than 0.05). Systemic vascular resistance index (SVRI) was decreased (P less than 0.05) at all times except during intubation when it was unchanged compared to control. LVEDVI decreased during induction (P less than 0.05), while left ventricular filing pressure remained unchanged. Heart rate did not change. Systolic arterial pressure decreased from 147 mmHg (19.6 kPa) to about 100 mmHg (13.3 kPa) during induction (P less than 0.05). Two patients were given vasoconstrictors because of low arterial pressure. The mean ischemic score did not change. One patient, however, had signs of progressive ischemia. In this patient isoflurane administration was stopped after the last recording and the ECG normalized within 20 min.

Aged↗
PubMed1989

The effect of arterial pH on whole body oxygen uptake during hypothermic cardiopulmonary bypass in man.

To test the hypothesis of Rahn and Reeves that the optimal arterial pH during hypothermia follows the alpha-stat concept, we studied 50 patients during coronary artery bypass grafting or valve replacement (or both) and aortic occlusion. Intravenous anesthesia was produced by high-dose fentanyl. Thiopentone 3 mg.kg-1 body weight and pancuronium 0.1 mg.kg-1 body weight were given at the start of cardiopulmonary bypass to prevent shivering. When the temperature of venous blood reached 25 degrees C, pump flow was reduced to 1.8 L.m-2.min-1. In 17 patients (group I), arterial pH was changed in a randomized order either from high to low or from low to high by adjusting the carbon dioxide fraction of the gas flow to the bubble oxygenator. At the end of 10-minute periods with stable arterial pH, oxygen uptake was calculated by multiplying pump flow and the arteriovenous oxygen difference. In 33 other patients (group II), arterial pH was kept constant during the period of stable hypothermia at 25 degrees C, and two to five determinations of oxygen uptake were performed in each patient. The carbon dioxide fraction in the gas and arterial pH varied between the patients. In group I, oxygen uptake was 31.4 ml.m-2.min-1 at pH 7.31 and 40.3 ml.m-2.min-1 at pH 7.52-a significant difference (p less than 0.001). In group II, oxygen uptake was positively correlated to arterial pH (r = 0.52, p less than 0.01). Thus the results were in line with the alpha-stat concept of acid-base management during hypothermia.

Acid-Base Equilibrium↗
PubMed1988

Changes in ejection fraction during induction of anesthesia with two different i.v. techniques.

Two intravenous induction techniques were compared with respect to changes in ejection fraction (EF) and central hemodynamics in 30 patients scheduled for coronary artery surgery. Left ventricular EF was measured with a collimated single crystal probe linked to a microcomputer, after injection of 200 MBq Tc 99 m HSA. Stroke volume index (SI) determined by thermodilution and EF were used to calculate left ventricular volume in end-systole and end-diastole. In 20 patients (Group I), anesthesia was induced with diazepam (94 micrograms x kg-1), thiopentone (3 mg x kg-1) and fentanyl (3 micrograms x kg-1). In 10 patients (Group II), fentanyl (30 micrograms x kg-1) was used for induction. In Group I, EF decreased from 0.43 to 0.26 at intubation, while systemic vascular resistance index (SVRI) showed an increase. Left ventricular volume decreased during induction of anesthesia except during intubation. In Group II, EF and left ventricular volume remained unchanged during the study period. SVRI showed no increase at intubation. No change in contractility was indicated from the relation between the end-systolic pressure and volume, in any of the groups.

Anesthesia, Inhalation↗
PubMed1986

The calculation of left ventricular stroke work index.

The relation between left ventricular mean systolic pressure (LVSP) determined by planimetric integration and systolic and diastolic pressure measured in a peripheral artery (SAP and DAP) was calculated using data published by Ross & Braunwald in 1964. The relation was LVSP = SAP-0.32 +/- 0.06 (s.d.) X (SAP-DAP). The formula SAP- 0.32 (SAP-DAP) was used to calculated LVSP, and the correlation between measured and calculated LVSP was found to be 0.91 (P less than 0.001). It is concluded that LVSP can be calculated with reasonable accuracy from measurements of arterial pressure in patients without aortic stenosis. At present three different formulas are in use for the calculation of left ventricular stroke work index (LVSWI). The pressure work is defined as SAP, LVSP or mean arterial pressure minus mean pulmonary capillary wedge pressure or left ventricular end diastolic pressure. This makes comparisons between different studies with respect to LVSWI difficult or impossible.

Blood Pressure↗
PubMed1985

Comparison of fentanyl and halothane as supplement to nitrous-oxide-oxygen anaesthesia for coronary artery surgery.

Twenty unselected patients suffering from incapacitating angina, in spite of medication with nitrates, beta-blockers and calcium antagonists, were studied before and during coronary artery bypass surgery. Fentanyl or halothane was randomly used in combination with nitrous oxide for maintenance of anaesthesia in order to compare the haemodynamic response to surgery and cardiopulmonary bypass with these two anaesthetic regimens. Systemic and pulmonary artery pressure were kept within normal limits with the aid of volume replacement and/or nitroprusside. The haemodynamic response to surgery and bypass was benign and almost identical in the two groups. Cardiac index increased markedly after bypass (P less than 0.02-0.001) from 2.0 to 3.0 1 X min-1 X m-2 due to an increase in heart rate with no change in stroke index (40 ml X m-2). Oxygen delivery remained unchanged at 17 mmol X min-1 X m-2 in spite of a marked reduction in blood erythrocyte volume fraction (B-EVF), from 38% before bypass to 24% after bypass (P less than 0.001). Oxygen uptake remained unchanged until the end of surgery and did not differ between the groups. Systemic vascular resistance, corrected for the change in viscosity due to the altered B-EVF, was unchanged during the study. No difference was observed between the groups in the relation between pulmonary artery diastolic pressure and left ventricular stroke work index or stroke index, either before or at the end of cardiopulmonary bypass when the patients were transfused from the oxygenator.

Adult↗
PubMed1985

Circulatory effects of pancuronium and alcuronium in patients with coronary artery stenosis.

Heart rate and systemic arterial blood pressure were recorded during induction of anaesthesia up to 9 min after endotracheal intubation in 92 patients scheduled for coronary artery bypass surgery, in order to study to what degree the circulatory response to induction of anaesthesia and intubation was modified by different relaxants. Pancuronium (pancuronium bromide) 0.1 mg X kg b.w.-1 and alcuronium (diallyl-nortoxiferine) 0.25 mg X kg b.w.-1 were randomly studied in 36 patients during induction with high-dose fentanyl and in 36 patients induced with thiopentone, diazepam, fentanyl and nitrous oxide. In patients given high-dose fentanyl anaesthesia, systolic blood pressure before, during and after intubation was significantly lower with alcuronium (P less than 0.01). The same difference between alcuronium and pancuronium was observed in balanced anaesthesia before endotracheal intubation. Induction of anaesthesia and intubation were followed by a moderate increase in heart rate, irrespective of the type of anaesthesia and relaxant. Subsequently, 20 patients (10 with high-dose fentanyl and 10 with balanced anaesthesia) were studied. They received pancuronium 0.05 mg X kg b.w.-1 + alcuronium 0.125 mg X kg b.w.-1. This mixture of relaxants produced an intermediate blood pressure response.

Adjuvants, Anesthesia↗
PubMed1985

Sequential myocardial depressant and non-depressant anaesthesia for coronary artery surgery.

Patients undergoing coronary artery surgery run a certain risk of developing myocardial infarction in situations with increased myocardial oxygen demand due to e.g. elevations in heart rate and blood pressure. After cardiopulmonary bypass (CPB) there is, however, also the risk of graft occlusion. The present study evaluated the haemodynamic effects of a sequential anaesthesiological technique using halothane 0.5-1.5% in combination with 50% nitrous oxide and droperidol 0.1 mg X kg b.w.-1 before CPB followed by fentanyl 0.2 mg X h-1 in continuous i.v. infusion and diazepam 10-15 mg during and after bypass. Fourteen patients were studied. In seven patients (Group I) halothane was discontinued immediately before CPB and in the following seven patients (Group II) 10-15 min before bypass. The aim was to depress moderately the inotropic state before bypass and to have a normalized myocardial oxygen demand after CPB in order to promote a good flow in the grafts. In Group II mean left ventricular stroke work index (LVSWI) was 0.54-0.79 J X m-2 after bypass as compared to 0.45-0.51 before at comparable filling pressure. Mean left ventricular power index (LVPI) increased from 0.42-0.55 W X m-2 before to 0.73-1.08 after CPB. The patients in Group I showed a similar pattern although with a less marked difference in LVSWI and LVPI values before and after bypass. No correlation was seen between oxygen delivery and oxygen uptake either below or above an oxygen delivery of 15 mmol X min-1 X m-2.

Adult↗
PubMed1985

The influence of isoflurane on blood flow in coronary bypass grafts.

The effects of isoflurane on graft blood flow, central hemodynamics and ECG were evaluated in 20 patients during coronary artery surgery in the period immediately after cardiopulmonary bypass (CPB). Intravenous anesthesia with thiopentone, diazepam, fentanyl (continuous infusion), droperidol and pancuronium supplemented with nitrous oxide was used before, and thiopentone and fentanyl were used during CPB. A first measurement of graft flow was performed during fentanyl infusion and the patients were randomly allocated to a control (n = 10) and a study (n = 10) group. In the study group isoflurane was administered in a dose that reduced systolic arterial blood pressure (SAP) to approximately 100 mmHg (13.3 kPa) (inspired concentration 0.5-1.5%) and a second measurement was performed after 30 min. In the control group the infusion of fentanyl was continued. Isoflurane reduced graft blood flow from 52 +/- 5 (mean and s.e. mean) to 40 +/- 5 ml . min-1 (P less than 0.01) concomitant with reductions in SAP, cardiac index, stroke index, left ventricular stroke work index and power index, while these parameters as well as graft flow remained unchanged in the control group. Isoflurane did not produce any change in the degree of ischemia as judged from the ECG. A high blood flow in recently established coronary artery bypass grafts is essential for the prevention of early graft occlusion; therefore the graft-flow-reducing effect of isoflurane has to be taken into consideration when evaluating different anesthetic regimens in the period after CPB.

Aging↗
PubMed1977

Total parenteral nutrition in infants. Blood levels of glucose, lactate, pyruvate, free fatty acids, glycerol, d-beta-hydroxybutyrate, triglycerides, free amino acids and insulin.

Two regimens (A and B) for TPN were designed to meet the requirements of newborn infants for calories, amino acids, fatty acids, electrolytes, trace elements and vitamins. Both "A" and "B" included fat emulsion (Intralipid). "A" contained fructose and glucose, "B" glucose only. "A" provided amino acids (Vamin) in proportions similar to those of whole egg, "B" similar to those of human milk. All nutrients were given simultaneously into peripheral veins by constant infusion. Nineteen patients (11 newborns, 8 infants) were studied for 1-28 days. Twelve infants recovered, 7 died. In none could TPN be regarded as the cause of death. Treatment was complicated by sepsis in 5 infants. During the course of treatment, blood levels of substrates and insulin were measured before, during and 30 min after discontinuation of TPN. Highly raised concentrations of circulating substrates seen in 3 infants seemed to be related to a poor clinical condition rather than to the regimen used. Infants in good condition tolerated TPN well. Low levels of branch-chained amino acids and tendency to ketonemia, when infusion was stopped, suggested that minimal rather than optimal supply of energy and of amino acids in relation to energy was provided with both regimens. Low insulin levels associated with elevated blood levels of substrates suggested that insulin administration to selected cases might be indicated. Fructose (0.30 g/kg X hour-1) given with regimen A increased blood lactate concentrations. Homocystinaemia appeared in 2 cases; disappearance after excess vitamin B6 administration indicated increased B6 requirement.

Amino Acids↗