Biomedical subjects
Publications and source records attributed to H B Simon.
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Laparoscopic cholecystectomy (LSC) is being performed increasingly often. The carbon dioxide cavity increases end-expiratory carbon dioxide (exCO2), which can be regulated by mechanical ventilation. Because about 20-40% carbon dioxide remains in the patient at the end of surgery, we were interested in its influence on spontaneous respiration. PATIENTS AND METHODS. Fifteen patients classed as ASA 1-2 and undergoing LSC were compared with 15 patients (also ASA 1-2) undergoing laparotomy for cholecystectomy (LAP). All patients had balanced anaesthesia with fentanyl, enflurane, nitrous oxide and vecuronium. After surgery they were extubated when spontaneous respiration and vigilance were adequate. In the next 3 h we continuously determined exCO2 in the expired air through an intranasal catheter, and oxygen saturation (SAT), respiratory rate (RR) and heart rate (HR) using Oscar (Datex) and Ohmeda (Braun) apparatus while the patients were breathing room air. The blood pressure (BP) was determined intermittently. Postoperative pain treatment was standardized. RESULTS. The groups were reduced comparable with respect of the anthropometric data, because the weight was significantly higher in the LAP group. Fentanyl consumption was also significantly higher in the LAP group, reflecting the more pronounced trauma than with LSC. Mean exCO2 was 46 mmHg after LSC and 36 mmHg after LAP (P less than or equal to 0.05), continuously decreasing in the LSC group and increasing in the LAP group to 40 mmHg after 3 h. Mean RR was 18-20.min-1 after LSC and 12-15.min-1 after LAP during this period (P less than or equal to 0.05). There were no differences in SAT (94-96%), HR (75.min-1) and BP (130/80 mmHg). DISCUSSION AND CONCLUSIONS. The remaining carbon dioxide after LSC has important implications for postoperative spontaneous respiration. Probably due to an activation of carbon dioxide receptors, RR is increased to eliminate residual carbon dioxide. This is confirmed by a significantly increased exCO2 compared with that in the LAP group. This effect lasts at least 3 h, exCO2 being comparable in both groups, but RR is still increased after LSC. This different respiratory pattern does not affect SAT, being normal without hypoxic episodes. Cardiovascular parameters were also normal without group differences. We conclude that the carbon dioxide peritoneal cavity has important consequences for postoperative ventilation. Using our anaesthetic technique and postoperative treatment exCO2 reaches normal values after about 3 h due to an increased RR. If other methods, e.g., stronger opioids, which decrease carbon dioxide response are used, this effect may even be prolonged and more pronounced. We are now performing an investigation to evaluate this effect.
In an animal model the hemodynamic effects of three infusions of HES during the early stage of a septic syndrome were examined. In nine pigs with a body weight between 29 and 36 kg a septic syndrome was produced by infusion of E. coli endotoxin. 1, 4 and 7 hours after beginning of the endotoxin infusion 250 ml HES 200/0.5 were infused. After the 1st and 3rd infusion an increase of the cardiac output resulted, which was previously lowered, without changes of the CVP. During normal CO the 2nd infusion shows an increase of CVP and MAP. PWP did not change. The reactions of the hemodynamic parameters can be well explained physiologically. A volume supply at a reduced CO increases the latter without influence of the CVP. Normalized CO before the infusion resulted in a CVP-increase. The PWP is not evaluable under the conditions of an elevated pulmonary resistance, as it exists at the septic syndrome.
UNLABELLED: AIM OF THE INVESTIGATION: The effects of fentanyl on spontaneous respiration have been investigated in both animals and humans. The investigations in humans have been performed under circumstances and using methods that do not relate the results to clinical practice, e.g., predicting the effects of opioids used for postoperative pain relief on the ward. We investigated the effects of fentanyl on mechanical parameters, oxygen saturation (SAT), and end-expiratory CO2 (exCO2) in humans. METHODS: Fifteen male volunteers took part in this study, which was approved by the local ethics committee. Each received 3 micrograms/kg fentanyl intravenously after 5 min measurement of base-line values and were observed for 30 min. We continuously registered thoracic (A1) and abdominal (A2) extension and respiratory rate (RR) using piezoceramic elements. SAT, heart rate (HR), and exCO2 were measured with a pulse oximeter and infrared absorption (OSCAR, Datex). All data were transferred to a high-performance microcomputer (Multitalent, ZAK). The statistical analysis included descriptive and correlation statistics. RESULTS: After the injection of fentanyl A1, A2, RR, HR, and SAT were reduced; exCO2 increased. After a few minutes A1 increased, occasionally exceeding the base-line value. A2, RR, HR, and SAT increased without reaching base-line values. ExCO2 remained increased. The best overall correlation was found between A2 and SAT (r = 0.87). DISCUSSION: As far as comparable, our results are in accordance with those of the majority of other investigators. The difference between thoracic and abdominal extension, the latter being closely correlated with tidal volume, has not previously been described quantitatively. We attribute this result to the different innervation of the phrenic and intercostal nerves. Whereas the influence of fentanyl on SAT and exCO2 during the first 8 min can easily be explained, the varying behavior in the following minutes has not previously been described and may be due to the different binding characteristics of O2 and CO2. Alteration of the CNS setting for pCO2 may also contribute to this result. The time course of the measured parameters seems to be of clinical importance for the detection of respiratory problems in spontaneously breathing patients.
The estimation of serum digoxin is a usual method in intensive care. In a case report the detection of digoxin-like-immunoreactive-factor (DLIF) is shown, which gives false high levels. DLIF is observed in renal damage, high cardiac activity, pregnancy and newborn.
METHOD: In 56 patients undergoing arthroscopy of the knee blood pressure (BP), heart rate (HR) and plasma catecholamines were measured during induction of anaesthesia. To a standard treatment including etomidate (K), either 1 (A1), 2 (A2) or 3 (A3) mg alfentanil were added. The control-group included 8 patients, the other groups consisted of 16 patients. Blood pressure and heart rate were measured the day before anaesthesia (T1), at the arrival in the operation theatre (T2), 1 minute after the induction (T3) and 1 minute after intubation (T4). Catecholamines were analysed at T2 and T4. - RESULTS: At T1 and T2 no significant differences were measured. The control-group had a significant rise of BP, HR and adrenalin at T4. In group A1 (1 mg alfentanil) BP and catocholamines remained at the same levels, HR rose significantly. In group A2 all parameters did not change. The group A3, BP dropped significantly, whereas the other parameters remained stable.- DISCUSSION: 2 mg Alfentanil given 1 minute before endotracheal intubation depress the sympathoadrenergic reactions but do not impair the circulation.
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Although hyperthermia is a component of many endocrine diseases, it is uncommon for fever to be the presenting manifestation of hormonal disorders. During a four year period we encountered six patients, hospitalized principally because of fever, who were found to have endocrine causes for the fever. In all, the admitting diagnosis was infection; three were suspected of having tuberculosis, two of gram-negative bacteremia and one of endocarditis. Except for asymptomatic bacteriuria in one patient (who remained febrile despite appropriate antibiotic therapy) infection was ruled out in all cases, and fever was attributed to "masked" thyrotoxicosis, triiodothyronine (T3) toxicosis, subacute thyroiditis, primary adrenal insufficiency, secondary adrenal insufficiency and pheochromocytoma. In a seventh patient, extreme pyrexia developed in the setting of the thyroid storm. The importance of hormonal mechanisms in thermoregulation is discussed.
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Twenty-eight cases of extreme pyrexia seen in a five-year period were analyzed retrospectively. All of the patients had temperatures between 41.1 C (106 F) and 42.2 C (108 F) with a mean maximum temperature of 41.4 C (106.6 F). Infection, thermoregulatory defects, or a combination thereof accounted for fever in these patients. There was little evidence of direct tissue damage caused by fever, and standard therapy with aspirin or acetaminophen, vigorous surface cooling, and volume expansion was generally sucessful. Mortality could be related to the extreme pyrexia in only 7% (2) but an additional 21% (6) of these patients later died from serious underlying diseases.
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A patient with lymphadenopathic toxoplasmosis characterized by prolonged symptoms and repeated relapses with isolation of toxoplasma from lymph nodes is described. As the disease persisted and progressed, striking immunologic changes occurred that ultimately resulted in a state of extreme hyperglobulinemia associated with impaired delayed hypersensitivity responses. The case in question illustrates that progressive infection may occur in the face of high antibody levels of all immunoglobulin types whereas the only demonstrable immunologic impairment was of delayed hypersensitivity.