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Biomedical subjects

B Juhl

Publications and source records attributed to B Juhl.

At least 73 records · Page 4Linked to original sources
PubMed1982

[Intragastric volume and acidity in acute surgery patients].

The volume and pH of the gastric contents aspirated prior to anaesthesia were measured in 640 acute surgical patients. The material comprises 100 patients aged between 0 and 15 years, 415 between 16 and 60 years, and 125 between 61 and 93 years. The possible relation between the gastric contents and the patients' sex, age, weight, and surgical disease (abdominal or orthopaedic) was examined. Relations to fasting time, composition of meal (solid/liquid), the consumption of alcohol, the use of tobacco, the injection of analgesics, gastritis/ulcus anamnesis, nausea and pains were also calculated. The volume of gastric contents was higher in women than in men, and the number of potential risk patients among women was higher (p less than 0.02). However the difference is not considered to be of any clinical importance. In relation to body weight children have a relatively high volume of gastric contents, and these are more acid in children and young people than in grownups. If we delimit potential risk patients by means of the volume and pH of the gastric contents, there are for these reasons more risk patients among young than among elderly people. The groups with orthopaedic and abdominal diseases had the same number of potential risk patients, but the patients in the former group were younger than in the latter. Analgesics do not increase the number of risk patients; however, the number was higher among patients having pains (p less than 0.05). The consumption of alcohol did increase the number of risk patients (p less than 0.001). The length of fasting time also considerable influenced the volume of gastric contents in the acute surgical patient.

Adolescent↗
PubMed1979

Effect of non-carbonic acidosis on total splanchnic perfusion and cardiac output during anaesthesia with O2-N2O-barbiturate-relaxant.

Seven dogs were anaesthetized using mebumal natrium-O2-N2O-gallamonijdidum. The PaCO2 was kept at a constant level by means of mechanical ventilation, and non-carbonic acidosis was induced with HCl infusion (0.3 normal). The arterial pH varied from 7.45 to 6.88. During this acidosis, a rising arterio-venous oxygen difference was observed, with an unchanged total oxygen consumption. The pulse fell, but the mean pressures in the right atrium and aorta were unchanged. The peripheral resistance rose by 50%, whereas the fall in cardiac output of 20% was non-significant (0.10 greater than P greater than 0.05). The total splanchnic perfusion fell by 28%, and the change in flow was correlated to the change in pH. Total splanchnic perfusion (ml min-1) = -4078+655x pH (N = 42, r = 0.67, P less than 0.001). Total splanchnic perfusion as a fraction of the cardiac output remained unchanged. The resistance in the splanchnic area rose by 50%. The oxygen saturation in the portal vein and mixed venous blood changed in parallel. It is concluded that contraction of the blood vessels is the most important effect on the circulation resulting from non-carbonic acidosis during the anaesthesia employed here.

Abdomen↗
PubMed1979

Effect of non-carbonic acidosis on total splanchnic perfusion and cardiac output during anaesthesia with O2-N2O-halothane.

Six dogs, premedicated with pethidine 10 mg kg-1 b.w, were anaesthetized with mebumal natrium (NFN) 25 mg kg-1 b.w. and 80 mg gallamoni jodidum (NFN). Anaesthesia was continued with O2-N2O-halothane and artificial ventilation. Non-carbonic acidosis was induced by i.v. infusion of hydrochloric acid, during which the related values of pulse, blood pressure, cardiac output, total splanchnic prefusion and portal pressure were measured. The pulse remained unchanged down to pH 7.0. At this pH, arrhythmia suddenly occured and developed into ventricular fibrillation. Before this occured falling cardiac output was observed (cardiac output 1 min-1 = -21.49+3.21 x pH, N = 23, r = 0.75, P less than 0.001) and rising oxygen consumption (O2 ml min-1 kg-1 = 25.79--2.96 x pH, N =28, r = 0.52, P less than 0.01), rising oxygen extraction and rising peripheral resistance, while the mean pressure in the aorta was almost unaltered. During this course towards circulatory failure, an unchanged to slightly rising total splanchnic perfusion (Qsp1) was demonstrated, which with the lowest pH, represented up to 40% of the cardiac output (Qtot): Qsp1/Qtot = 3.11--0.39 x pH (N = 28, r = 0.52, P less than 0.01). Portal pressure rises slightly during acidosis, and oxygen saturation in the portal vein is high. It is probable that the retained splanchnic blood flow is caused by retention of the portal flow. This is quite different from observations during anaesthesia with barbiturates. It is concluded that halothane modifies considerably the circulatory response in the systemic circulation and the splanchnic region during non-carbonic acidosis.

Abdomen↗
PubMed1979

Arterial carbon dioxide tensions during anaesthesia with manual ventilation. A descriptive study of the effects of various non-polluting circuits.

In 660 supine, intubated and anaesthetized, healthy patients scheduled for various elective surgical procedures, the distribution of arterial carbon dioxide tension (PaCO2) was investigated during manual non-monitored ventilation. The study comprised six equal groups: group 1: ventilation with a circle circuit absorber system; group 2: ventilation with the Hafnia A circuit using a total fresh gas flow (FGF) of 100 ml . kg-1 . min-1; groups 3-6: ventilation with a Hafnia D circuit with fresh gas flows of 100, 80, 70 and 60 ml . kg-1 . min-1, respectively. The mean PaCO2's of the first three groups were situated in the lower range of normocapnia (the observations in the first group having the greatest total range), whereas the rebreathing (Hafnia A and D) circuits resulted in a clustering of observed data. Employing the rebreathing circuits, protection against hypocapnia can be achieved by lowering the fresh gas flow. The most satisfying result was obtained with the Hafnia D circuit with a fresh gas flow of 70 ml . kg-1 . min-1 resulting in normocapnia with a modest and limited spread towards hypo- and hypercapnia. FGF in excess of this level must be considered as wasted. The study indicates that corrections of fresh gas flows for age are superfluous. Use of relaxants and type of surgery had no influence on the observations.

Adolescent↗
PubMed1978

Bronchoscopy with normoventilation. Automatic ventilation with Sanders technique. A clinical investigation.

Forty six patients, who had to be subjected to diagnostic bronchoscopy under general anaesthesia (thiopental, pethidine, O2-N2O, suxamethonium) were ventilated using Wolf's injectomat (automated Sanders principle) in an attempt to find a setting for the apparatus that would provide normoventilation of the patient, independently of the diagnostic procedure. The first 24 patients were ventilated with the apparatus having a fixed setting: the latter being presumed to provide normo- or hyperventilation. This was confirmed and a steady state of PaCO2 was reached after ventilation for 10 min. This PaCO2 was well correlated with the vital capacity of the patients expressed factorially, in relation to the expected normal value. The investigation renders probable the observation that patients with a greatly reduced vital capacity (less than 50% of the normal value) can rarely be ventilated with the apparatus. On the other hand, a reduced FEV1 has little influence on the efficiency of the apparatus. The apparatus was adjusted in agreement with the above mentioned relation to vital capacity for the following 21 patients, in as much as the change in ventilation was carried out by a change in frequency, while the driving pressure of the apparatus and the inspiration time were maintained unchanged. Normoventilation was obtained in these patients independently of the fact that the bronchoscope was constantly open for the insertion of instruments.

Bronchoscopy↗
PubMed1977

Acid-base status before and after arterial clamping.

The necessity of providing alkalizing therapy after re-establishment of the local circulation was studied in 10 otherwise healthy patients with intermittent claudication. No such necessity was found in providing stable peroperative circulation, normo- to slight hypothermia, adequate infusions, and normal acid-base values prior to arterial clamping. It is pointed out that alkalosis can cause circulatory problems that are just as serious as those occurring with acidosis; therefore the routine use of alkalizing agents during vascular surgery is inadvisable. Should unstable circulatory parameters occur and hypoperfusion be suspected, then repeated control of the acid-base values is indicated.

Acid-Base Equilibrium↗
PubMed1977

High precision mixing of anesthetic gases based on a new principle.

A machine has been constructed for mixing O2 and N2O. It consists of: (a) a proportional pressure and thereby flow regulator at the inlets for O2 and N2O; (b) a digital gas mixer which determines the gas mixture; and (c) a rotameter to measure the outlet flow. The contents of mixtures obtained from the machine were measured with a quadropole mass spectrometer (at 2 and 5 1 min--1 with downstream pressures of 500 and 3000 Pa). The mean numeric difference between desired and registered vol% O2 varied between 0.3 and 0.5 vol% at the four conditions tested. The maximal deviation was 1.2 vol%. Five conventional machines in daily use at the hospital were also tested. The mean numeric difference for these machines varied between 1.1 and 2.7 vol% O2. The maximum deviation was 7.4 vol%.

Anesthesia, Inhalation↗
PubMed1976

Hepatic blood flow and cardiac output during Fluoromar anaesthesia. An animal study.

Related values of cardiac output and hepatic blood flow were measured in eight premedicated (pethidine 10 mg/kg b.w.) dogs under varying depths of fluoromar anaesthesia. The measurements were first taken under basis anaesthesia with barbiturate (mebumal natrium 25 mg/kg b.w.) gallamine (80 mg)-N2O-O-O2 (ratio 2 to 1) with controlled normoventilation, and then under increasing depths of fluoromar anaesthesia: increasing stepwise to 1 1/2-3 and 6% inspiratory concentrations. Finally the measurements were repeated after the fluoromar had been discontinued. Using the basis anaesthesia as a reference, it was found that 6% fluoromar gave a reduction in cardiac output (34%), heart rate (11%) and mean pressure in the aorta (18%). The peripheral resistance was simultaneously increased by 22%. The effect on the splanchnic blood flow was far less and without significant changes from one step in the anaesthesia to the next. Using 6% fluoromar it was found that there was a maximum reduction in blood flow of 20% of the initial value. There was unchanged splanchnic resistance during the whole of the investigation. After discontinuation of the fluoromar for 15 min and continued controlled ventilation (O2-N2O), rising heart rate and blood pressure were observed; however, cardiac output and splanchnic blood flow were unchanged. Corresponding to this, an additional increase in peripheral resistance of 10% and an insignificant increase of 5% in the splanchnic resistance were observed.

Anesthesia, Inhalation↗
PubMed1975

A comparison between measured and calculated changes in the lung function after operation for pulmonary cancer.

Eighteen patients operated on for pulmonary cancer, the procedure varying from the removal of two segments to pneumonectomy, were subjected to measurement of the spirometric values VC, FEV1, FRC and RV preoperatively and 2-3 months postoperatively. The possibility of predicting the postoperative values from the number of segments removed was studied, partly with standard percentages (5.26%) per segment (method I), and partly with a percentage per segment in the affected area, calculated from the preoperative regional lung function tests using 133xenon. This latter test was carried out with a mobile apparatus using four detectors with tubular colimators and from the anterior surface of the thorax. Both methods of calculation gave, for the material as a whole, good agreement between the postoperative (measured) and the calculated values. However, with regard to certain patients, the regional lung function tests gave important information on preoperative reduced function in the affected area. In these patients, method No. II was by far the best for prediction of the postoperative values.

Aged↗