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Biomedical subjects

D E Lees

Publications and source records attributed to D E Lees.

49 records · Page 3Linked to original sources
PubMed1979

Hyperthermia potentiates doxorubicin-related cardiotoxic effects.

The intercurrent administration of doxorubicin hydrochloride to a patient undergoing whole-body hyperthermia for the treatment of metastatic cancer repeatedly produced ventricular irritability and cardiac dysfunction. Individually, doxorubicin and hyperthermia were tolerated by the patient without incident. Catecholamine determinations showed that the administration of doxorubicin under hyperthermic conditions increased the liberation of both epinephrine and norepinephrine. The acute synergistic cardiotoxic effects occurred with doxorubicin dosages that were severalfold less than those associated with only mild and transient ECG disturbances under normothermic conditions.

Arrhythmias, Cardiac↗
PubMed1979

Auriculotemporal syndrome after combined modality therapy for cancer.

Auriculotemporal syndrome frequently follows trauma to the auriculotemporal nerve, a branch of the mandibular nerve. Classic symptoms are gustatory sweating and hyperemia, with pain occurring in less than 10% of cases. We have treated six patients for a variant of auriculotemporal syndrome following combined modality therapy for head and neck cancers. Unique was the presence of pain and the absence of gustatory sweating in all cases. The combination of radical surgery, chemotherapy, and irradiation obscured the "textbook" presentation, leading to initial misdiagnosis. Long-term relief (one year) from this atypical presentation of auriculotemporal syndrome was afforded by a simple mandibular nerve block, a technic that is of no sustained therapeutic benefit in the classic cases.

Antineoplastic Agents↗
PubMed1979

Vasodilator correction of hypotension in the postoperative period.

This case is unusual in that hypotension, as opposed to hypertension, was a consequence of increased sympathetic tone in the postoperative period, but it illustrates the well known fact that patients in compensated congestive heart failure do poorly when faced with an elevated myocardial oxygen need from either increased rate or afterload. Vasodilator therapy was effective in immediately reducing afterload and systolic regurgitant fraction, thereby increasing oxygen supply and lowering myocardial oxygen consumption.

Adult↗
PubMed1979

Hemodynamic and plasma catecholamine responses to hyperthermic cancer therapy in humans.

Cancer patients, treated with hyperthermia (to 41.5 degrees C) under thiopental and fentanyl anesthesia, had smaller increases in heart rate and cardiac index and lesser decreases in mean arterial pressure than those reported in normal volunteers. At basal body temperature anesthesia did not alter catecholamine levels. Increasing body temperature to 39.5 degrees C and 41.5 degrees C resulted in parallel increases in heart rate and cardiac index that were directly related to the increases in plasma norepinephrine levels. At basal temperature cutaneous venous plasma norepinephrine levels exceeded those of arterial; mixed-venous plasma levels were intermediate. At 39.5 degrees C and 41.5 degrees C there were sequential increases in plasma norepinephrine. The increases in mixed-venous and arterial norepinephrine were significantly greater than in cutaneous venous blood. The differential increases in norepinephrine levels in cutaneous venous, mixed-venous, and arterial blood indicate that during hyperthermia sympathetic nerve activity in skin is decreased while that in other areas is increased, suggesting that alterations in sympathetic activity modulate the hemodynamic changes that attend hyperthermia in man.

Adult↗
PubMed1978

Induced hyperthermia in sedated humans and the concept of critical thermal maximum.

The concept of critical thermal maximum (CTM) has been defined in the literature as the minimal high deep-body temperature that is lethal to an animal. In man the CTM has been estimated at 41.6--42.0 degrees C. Data are presented for sedated, unacclimatized, well-hydrated men heated 1 h at esophageal temperatures of 41.6--42.0 degrees C, without sequelae, except for modest elevation of serum enzymes in two of five patients. These data when combined with other observations in the literature suggest that CTM be redefined as the particular combination of exposure time at elevated body temperatures that results in either subclinical (CTM)s) or clinical (CTMc) injuries. Also presented is a mathematical technique, equivalent time at 42 degrees C (Teq 42 degrees), for expressing hyperthermia in terms of body temperature and exposure time.

Adolescent↗
PubMedDate not supplied

Probable amniotic fluid embolism during curettage for a missed abortion: a case report.

Diagnosis of amniotic fluid embolism is difficult in a patient under general anesthesia and may initially resemble several other conditions. Successful treatment requires maintenance of adequate cardiac output and oxygenation and prompt heparin treatment of the disseminated intravascular coagulation. The presented case exemplifies another group of patients who are ar risk for amniotic fluid embolism.

Abortion, Missed↗
PubMedDate not supplied

Display adaptor for the Vitatek #511 monitor and the Puritan-Bennett CO2 analyzer.

Many CO2 infrared analyzers require additional graphics devices for continuous CO2 waveform display. An adaptor was designed to integrate the output of a Puritan-Bennett infrared CO2 analyzer into the display of a Vitatek #511 patient monitor. The adaptor is made with inexpensive off-the-shelf components and proved successful during more than six months of use.

Anesthesiology↗
PubMedDate not supplied

An evaluation of liquid-crystal thermometry as a screening device for intraoperative hyperthermia.

Disposable liquid-crystal temperature-trend indicators were evaluated under clinical conditions that simulated the development of intraoperative hyperthermia during anesthesia. Comparison was made to forehead thermistors for rapidity, accuracy, and linearity of response as well as correlation with esophageal and rectal thermistor recordings. The liquid-crystal monitors were comparable to the forehead thermistors in both rapidity and linearity or response, but not in accuracy. A linear correlation existed with the esophageal thermistor temperatures. Correlation with the rectal temperatures was not as exact. It is concluded that liquid-crystal thermometers may adequately serve as screening devices for intraoperative hyperthermia.

Body Temperature↗
PubMedDate not supplied

Mechanism of defluorination of enflurane. Identification of an organic metabolite in rat and man.

Difluoromethoxydifluoroacetic acid (CHF2OCF2CO2H) has been identified as a metabolite of enflurane (CHF2OCF2CHCIF) in rat liver microsomes in vitro and in human urine by gas chromatography mass spectrometry. The formation of the metabolite in rat liver microsomes was dependent upon the presence of NADPH and O2, and was inhibited when SKF 525-A or CO/O2 (8:2, v/v) were present in the reaction mixture. When the C-H bonds of the CHCIF group of enflurane or of the CHCI group of isoflurane (CHF2OCHCICF3) were replaced with a C-CI bond, virtually no fluoride ion was produced from either derivative in rat liver microsomes. These results indicate that cytochrome P-450 catalyzes the oxidative dehalogenation of CHF2OCF2CHCIF at its CHCIF group to form CHF2OCF2CO2H and chloride and fluoride ions. In contrast, the CHF2 group does not appear to be appreciably susceptible to metabolic oxidative dehalogenation. These results can be used for the more rational design of new inhalation anesthetics that would not be appreciably metabolized to the potential kidney toxin, F-.

Animals↗