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Biomedical subjects

C Carlsson

Publications and source records attributed to C Carlsson.

At least 73 records · Page 4Linked to original sources

Thrombosis following percutaneous radial artery cannulation.

A prospective study of the arterial supply of the hand was carried out in 100 ICU patients after cannulation of the radial artery. Patency of the radial artery was checked using a reversed Allen's test and Doppler ultrasonic technique. Furthermore, radial artery angiography was carried out in 15 patients with suspect thrombosis, and the artery was examined by microscopy in four patients at autopsy. Signs of thrombosis, Allen's test and Doppler technique, were found in 33/100 patients. In 10/15 angiograms a thrombosis was visualized, and in 3/4 patients at autopsy a thrombosis was found. The incidence of thrombosis was not correlated to sex, age, size of artery (judged by wrist circumference), cannulation technique or the presence of hypotension. It did, however, correlate to the presence of haematoma at the puncture site. After removal of the cannula recanalisation occurred soon in the majority of cases.

Adolescent↗

Effects of hypotension induced by adenosine on brain surface oxygen pressure and cortical cerebral blood flow in the pig.

Six pigs were anaesthetized with ketamine in combination with fentanyl and droperidol and paralysed with pancuronium. The pigs were tracheotomized and ventilated mechanically. Mean arterial blood pressure, MABP, was lowered from 97 +/- 21 mmHg stepwise to 58 +/- 2, 33 +/- 4 and 22 +/- 4 mmHg by intravenous infusion of adenosine (4-8 mg kg-1 min-1). Regional cerebral blood flow (rCBF) was measured directly onto the cortex of the brain by local atraumatic application of 133xenon. Brain surface oxygen pressure (PtO2) was obtained using a multiwire oxygen surface electrode. At the level of 60 mmHg, rCBF showed a significant increase, while flow values were not changed from initial values with further hypotension. Ten minutes after adenosine was discontinued, rCBF showed a rebound effect with higher values than initially. During normotension mean cortical PtO2 varied between 2.1 KPa and 3.9 kPa. During adenosine infusion PtO2 was increased at MABP-levels of 60 and 30 mmHg, while at 20 mmHg a decrease was seen in all animals. After discontinuation of the adenosine infusion, PtO2 values were higher than those measured at the initial normotension, a similar rebound phenomenon as seen with rCBF. During the experiments all hypotensive levels could be maintained at constant level without progressively increasing infusion rates, indicating no tachyphylaxis during these time periods. After discontinuation of the drug, blood pressure did not fully reach pre-hypotensive level within 10 min. Thus, hypotension induced by adenosine down to a MABP of 30 mmHg in animal experiments does not cause deterioration in either cerebral blood flow or oxygen pressure.

Adenosine↗

Pneumonia: a deadly disease despite intensive care treatment.

In a retrospective study of 30 patients with pneumonia treated in the intensive care unit, it was found that cultures from sputum and bronchial secretions did poorly correspond with blood cultures or serological tests. In only 15 of the patients a reliable etiological diagnosis was ever established. Mechanical ventilation was used in 22 patients, usually with a high oxygen need. At the start of this ventilation a significant blood pressure fall and a further pulmonary deterioration was observed. In fatal cases this pulmonary dysfunction was progressive. The overall mortality was 47%. When an FI02 above 0.6 was needed in the ventilator the mortality was 13/14 (93%).

Adult↗

Severity of illness in intra-abdominal infection. A comparison of two indexes.

The severity of illness in 58 surgical patients with high-grade intra-abdominal infection was measured with two methods, an acute physiology score and a septic severity score. Both methods are the summed weight of derangements in physiologic factors representing the function of the major organ systems of the body. Sixteen patients died (28%). Score values with both methods were significantly higher for nonsurvivors than for survivors. There was good interrelation between the methods, and the scores correlated better with mortality than did age, chronic disease, anatomy, or cause. Three risk levels were recognized, low, high, and intermediate, with respective mortality rates of less than 10%, greater than 80%, and approximately 45%. Three-fourths of the patients were assigned to the same risk group with both methods. The severity of illness in patients with intra-abdominal infection can suitably be measured with both methods.

Adolescent↗

Influence of sufentanil on cerebral metabolism and circulation in the rat.

The authors examined the effects of large intravenous doses of sufentanil (5-160 micrograms/kg) on cerebral blood flow (CBF) and cerebral metabolic rate for oxygen (CMRO2) in rats. CBF and CMRO2 were measured by a modified Kety-Schmidt technique using 133Xenon washout. Progressive decreases in CBF and CMRO2 occurred in animals receiving sufentanil. The maximum decrease was 53% and 40% for CBF and CMRO2 respectively, at a dose of 80 micrograms/kg. The values for CBF and CMRO2 in this group were 105 +/- 10 ml X 100 g-1 X min-1 (mean +/- SEM) and 6.5 +/- 0.5 ml X 100 g-1 X min-1, respectively, compared with 226 +/- 28 ml X 100 g-1 X min-1 and 10.9 +/- 1 ml X 100 g-1 X min-1 in the control group, which received N2O 70% in oxygen. Larger doses of sufentanil did not cause further significant changes in CBF and CMRO2. Sharp waves appeared on the electroencephalogram (EEG) of all the animals following sufentanil injection, and some animals had EEG changes develop consistent with seizure activity. This seizure-like activity appeared to consist of a single episode of short duration in the groups receiving 5, 10, and 20 micrograms/kg sufentanil. The incidence and frequency of seizure activity increased in the groups receiving higher doses of sufentanil, although the duration of seizures was still short. The results of this study indicate that sufentanil causes a significant decrease in CBF and CMRO2 similar to that previously reported for fentanyl, and high doses of sufentanil may cause frequent seizure-like patterns appearing on EEG.

Anesthetics↗

Local application of 133Xenon for measurement of regional cerebral blood flow (rCBF) during halothane, enflurane, and isoflurane anesthesia in humans.

It is well known that halothane causes an increase in cerebral blood flow (CBF). In this study the effects of halothane, enflurane, and isoflurane on regional cerebral blood flow (rCBF) in humans were determined in the presence of 70% N2O at a combined MAC concentration of 1.5. CBF was determined in 24 patients from the washout of locally applied 133Xenon with the use of an external scintillation. All 24 patients (control n = 6, halothane n = 6, enflurane n = 6, and isoflurane n = 6) were undergoing neurosurgical procedures. All patients were anesthetized with thiopental, fentanyl, droperidol, and 70% N2O in oxygen and paralyzed with pancuronium. The measurements were performed after the dura had been opened and before definitive surgery. The first measurement was done in the absence of any volatile agent, and the wash-out curve was registered for 6 min. The second measurement was done after one of the volatile agents had been added for at least 20 min and had reached a concentration of 0.58% for halothane, 1.14% for enflurane, or 1.0% for isoflurane in the expiratory gases in order to obtain about 1.5 MAC with each volatile anesthetic. The anesthetic concentrations were measured with the Engström multigas analyzer EMMA. The physiologic variables changed very little throughout the period of observation. Body temperature, heart rate, blood pressure, PaCO2, and PaO2 were stable. Ephedrine was used to maintain a stable arterial pressure. At approximately 1.5 MAC, halothane (plus N2O) increased rCBF to nearly three times (166%) the control value, while enflurane induced only a slight increase (35%) in rCBF.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Effects of fentanyl on local cerebral blood flow in the rat.

Fentanyl reduces the cortical cerebral blood flow and metabolic rate for oxygen in rats, though seizure activity occurs in some animals at high doses. However, the effects of fentanyl on blood flow and metabolism in subcortical structures have not been clearly delineated. The present study examines the effects of intravenous fentanyl (100 or 400 micrograms . kg-1) on local cerebral blood flow (1-CBF) in paralyzed, mechanically ventilated rats. Rats ventilated with 70% N2O in 30% O2 served as controls. Local CBF was measured using 14C-iodoantipyrine and autoradiography. Blood pressure, PaO2, PaCO2, pH, and temperature were comparable in all groups. The EEG showed slow wave activity in most animals given 100 micrograms . kg-1 fentanyl while seizure activity occurred in all animals given 400 micrograms . kg-1 fentanyl. With 100 micrograms . kg-1 fentanyl, CBF tended to be depressed in all cortical and subcortical areas, except the peri-aqueductal gray; and with 400 micrograms . kg-1 fentanyl, 1-CBF tended to be elevated (compared to 100 micrograms . kg-1 fentanyl) in most areas of the brain. The limbic system structures, however, were most affected by 400 micrograms . kg-1 fentanyl with statistically significant increases (compared to the 100 micrograms . kg-1 group) in 1-CBF of 86% and 67% respectively in the amygdala and septal nucleus. These results confirm that moderately high doses of fentanyl which cause slow wave activity on the EEG also depress 1-CBF in rats; moreover, doses of fentanyl that produce seizure activity produce increases in 1-CBF in most cerebral structures with greatest effects on limbic system 1-CBF.

Animals↗

A hemodynamic profile diagram and its application in septic patients.

A physiologic profile is presented in the form of a circular diagram, in which hemodynamic parameters, oxygen uptake and arterial lactate are displayed on 12 radial spokes. Results are presented as per cent of reference values. In the normal state the profile will be evenly circular, while different circulatory disturbances present typical patterns. This is shown in serial measurements on 12 septic patients, who displayed increases in cardiac output, oxygen metabolism, stroke volume, heart rate, pulmonary artery pressure, right atrial pressure, pulmonary capillary wedge pressure and arterial lactate, while pulmonary and systemic vascular resistances were decreased. Stepwise multiple regression analysis indicated that systemic vascular resistance was the best early discriminator between survivors and non-survivors. The hemodynamogram offers a compact and easily understood presentation of data, which makes it possible to follow the course of the disease and provides a diagnostic and didactic tool.

Adult↗

Gas exchange during mechanical ventilation.

In an experimental model using a Servo-ventilator (Siemens-Elema, Sweden) oxygen consumption (V'O2) and carbon dioxide production (V'CO2) were measured at varying FIO2. Gas exchange was simulated by adding N2 or CO2 to the inspiratory line of the ventilator. Inspiratory and expiratory gases were collected in Douglas bags for analyses by a mass spectrometer. The residual standard deviation for the regression of measured V'O2 on predicted V'O2 was 14 ml/min and did not significantly differ from the line of identity. For V'CO2 the corresponding residual standard deviation was 3 ml/min. This regression line deviated by -3% from the line of identity.

Carbon Dioxide↗

Traumatic aneurysms of cerebral arteries. A study of five cases.

Five cases of traumatic aneurysms of cerebral arteries are presented, two located at the internal carotid artery, and three at peripheral arterial branches. The manifestation of the aneurysm was a delayed neurological deterioration due to bleeding from the aneurysm, 4-35 days (mean 21 days) after the head trauma; four patients had an intracerebral haematoma and one patient had a subarachnoid haemorrhage. One patient died from extensive cerebral injuries with the aneurysm untreated. In four cases the aneurysm was treated surgically. Three patients returned to their former occupation and one patient died from late septic complications. It is concluded that signs of delayed intracranial bleeding after a head trauma should raise the suspicion of an underlying traumatic aneurysm, and in addition to a CT-scan an angiography should be performed.

Adult↗

Preparation of cells from pig gastric mucosa. Isolation of parietal cells by isopycnic centrifugation on linear density gradients of Percoll.

Cells were isolated from pig gastric mucosa by a combination of mechanical and enzymatic treatment. Isopycnic centrifugation on linear density gradients of Percoll provided a simple and rapid procedure for obtaining highly enriched parietal cells and chief cells. Their densities were 1.06 and 1.10 g/ml, respectively. Isolated mucosal cells attached to Petri dishes coated with fibronectin or collagen. Both parietal cells and chief cells adhered more readily to fibronectin than collagen. Mucosal cells and cells from the Percoll gradients were maintained for up to one week as primary cell cultures. The ability of free parietal cells to produce acid was tested by the 14C-aminopyrine accumulation technique. Maximal accumulation was 2.5 pmol aminopyrine per 10(4) parietal cells after incubation for 45 min at 10(-4) M histamine. The EC50 for histamine was 5 X 10(-6) M. The accumulation of aminopyrine at 10(-6) M carbachol and 10(-7) M pentagastrin were for both secretagogues about 0.9 pmol per 10(4) parietal cells.

Aminopyrine↗

Cardiovascular changes in pre-eclampsia.

Pre-eclampsia is associated with a hyperdynamic circulation (increased cardiac output, systemic vascular resistance) and increased mean arterial blood pressure, and a diminished plasma volume. Expansion of plasma volume without simultaneous measures on circulation or proper monitoring may be detrimental, leading to pulmonary and brain edema.

Blood Pressure↗

Metoprolol, fentanyl and stress responses to microlaryngoscopy. Effects on arterial pressure, heart rate and plasma concentrations of catecholamines, ACTH and cortisol.

Forty patients undergoing microlaryngoscopy were anaesthetized with thiopentone and nitrous oxide. Twenty patients received metoprolol 200 mg in a slow-release tablet once daily for 4 days up to, and including, the morning of operation, and 10 mg i.v. shortly before induction of anaesthesia. The other patients received placebo tablets and physiological saline i.v., instead. Both groups of 20 patients were further subdivided, half of the patients receiving fentanyl 1.0-1.5 mg during anaesthesia, the effect of which was antagonized by naloxone at the end of the procedure. The other patients received saline i.v. instead of fentanyl or naloxone. Metoprolol decreased heart rate and the general level of arterial pressure during anaesthesia, but did not affect the fluctuations in pressure. Arterial plasma noradrenaline concentrations during microlaryngoscopy were enhanced by metoprolol, in comparison with placebo, the reverse being the case for cortisol concentrations. Fentanyl decreased arterial pressure and plasma ACTH and cortisol concentrations regardless of whether the patient had received metoprolol. Plasma adrenaline and noradrenaline concentrations were decreased by fentanyl in the patients receiving metoprolol.

Adrenocorticotropic Hormone↗