A non-invasive method of measuring the systolic time intervals (STI) during anesthesia is described. Using the ratio between the pre-ejection period and the left ventricular ejection time (PEP/LVET-ratio) as an expression of cardiac function, it is shown in 39 patients that thiopentone exerted a marked depression on the heart (increase in PEP/LVET-ratio). This depression was further aggravated by halothane, while fluroxene caused an improvement of PEP/LVET-ratio. In the immediate post-anesthetic period PEP/LVET-ratio almost reached control value after discontinuation of fluroxene in contrast to halothane, where an increased PEP/LVET-ratio (25%) still persisted. The changes were mainly due to a prolongation of PEP without any specific change in LVET. During the study, PEP/LVET-ratio showed a close correlation to the reciprocal value of the square of the pre-ejection period (1/PEP-2). STI form 27 volunteers were measured and compared to the values from the patients before anesthesia was induced. PEP and PEP/LVET-ratio were significantly shorter in the patient group.

Adolescent↗

PubMed1975

Serum cholinesterase activity in burned patients. I: biochemical findings.

The purpose of the study was to determine the magnitude and the aetiology of alterations in serum cholinesterase activity (pseudocholinesterase) in burned patients. Sixty burned patients with an estimated area of burn between 3 and 72% of body surface were investigated. Serum cholinesterase activity, serum albumin concentration and serum bilirubin were measured at various time intervals. The magnitude as well as the rate of fall of serum cholinesterase activity was found to be closely correlated with the severity of burn injury. Minimum levels were often reached 5 to 6 days after the burn injury, at which time the activity might have been depressed by more than 80 per cent. In the most severely burned patients, the activity sometimes remained low for months despite wound healing. Apart from the severity of the burn injury in the individual patient, several important factors determined the level of serum cholinesterase activity at a given time. These included the presence or absence of local or systemic infections, the event of recent surgery such as slough removal or skin grafting, and blood transfusions. The decrease in serum albumin concentration following the burn injury occurred earlier than the decrease in serum cholinesterase activity. Minimum levels were often reached during the first 24 h, after which time the concentration rose to reach fairly constant but decreased levels after 4 to 5 days. Apart from this initial phase, the changes in serum albumin concentration were roughly proportional to the changes in serum cholinesterase activity. The possible reasons for these findings are discussed.

Adolescent↗

PubMed1975

Evaluation of impedance cardiography as a non-invasive means of measuring systolic time intervals and cardiac output.

Impedance cardiography was used for non-invasive determinations of systolic time intervals (STI) and cardiac output. The results were compared with simultaneously obtained invasive measurements of STI from central aortic pressure curves and of cardiac output using the dye-dilution technique. The study was performed on eight dogs during increasing halothane concentration. A close correlation was found between non-invasively and invasively measured left ventricular ejection time = LVET (r = 0.986) and pre-ejection period - PEP (r - 0.948). Measurements of cardiac output derived from changes in thoracic impedance were determined 1) using a fixed value of p (p - the resistivity of blood) and 2) using an individual value of p based on the actual hematocrits. When compared to cardiac outputs obtained by dye-dilution the correlation coefficients were r = 0.806 and r = 0.816, respectively. Impedance cardiography is a useful method of evaluating changes in cardiac output. The method permits simultaneous observations of changes in STI and cardiac output as an index of cardiac function.

Animals↗

PubMed1975

[The endotoxin from S-, R- and M-forms of enteropathogenic E. coli O 149: pyrogenicity, Shwartzman-phenomenon and hypersensitivity (author's transl)].

The authors are interested in elucidation of the role of endotoxin from S, R- and M-forms of E. coli O 149, and of the role of hypersensitivity in pathogenesis of Colibacillosis. It was shown in this experiment that all S, R- and M-form of E. coli O149 possess endotoxin with almost the same pyrogenicity in normal rabbits. The pyrogenicity increases enormously in the hypersensitized rabbit. There were also not observed differences between endotoxins extracted from S, R, M-mutnants. All 3 endotoxins evoke in normal rabbits the skin Shwartzman-Phenomenon, the S-endotoxin was there much stronger. This phenomenon increases in capacity in hypersensitized rabbits. Thus again, the role of hypersensitivity in Colibacillosis was proved to be important.

Animals↗

PubMed1975

[Toxicity of S-, R- and M-forms of enteropathogenic E. coli O149:K91:H10].

Toxicity of freeze-dried lysates of the organism for unweaned mice (3-4 days old) increased in the order:smooth-mucoid-rough. The toxicity was neutralized by mixing the toxin with immune serum of group O149. All toxins of the smooth, rough and mucoid variants of the Escherichia coli strain possessed hypersensitivity, skin necrosis, abortion and diarrhoea factors, which could be partly or completely neutralized by binding with homologous immune serum.

Animals↗

PubMed1973