Dexmedetomidine-associated hyperthermia: a retrospective cohort study of intensive care unit admissions between 2009 and 2016.

Dexmedetomidine-associated hyperthermia has not been previously studied. Analysis is warranted to determine whether this potentially dangerous complication is more prevalent than previously realised. We aimed to examine the association between dexmedetomidine and temperature ≥39.5°C, including patient characteristics, temporality and potential risk factors. We conducted a retrospective cohort study of all intensive care unit (ICU) admissions between 1 July 2009 and 31 May 2016 in a tertiary ICU in Australia. Temperature data was available for 9,782 ICU admissions. Dexmedetomidine was given intravenously to 611 (6.3%) patients at a dose of 0 to 1.5 g/kg/hour. Temperatures ≥39.5°C were recorded in 341 (3.5%) patients. Overall hospital mortality was 10.8% for all admissions and 29.3% for patients with temperatures ≥39.5°C. Dexmedetomidine exposure was more frequent in patients with temperature recordings ≥39.5°C compared to those with temperatures <39.5°C, 11.94% versus 2.94% (odds ratio [OR] 4.49; 95% confidence intervals [CI] 3.37, 5.92; P <0.001). The association was stronger for patients post-open heart surgery (OHS) with temperatures ≥39.5°C (OR 12.9; 95% CI 5.01, 31.62; P <0.001). Multivariate analysis showed an independent association between dexmedetomidine and a temperature ≥39.5°C in two particular patient groups: OHS (OR 2.72; 95% CI 1.1, 6.9; P <0.001), and obesity (OR 3.44; 95% CI 1.5, 7.9; P <0.001). Dexmedetomidine exposure is associated with an increased risk of hyperthermia. Possible risk factors are open heart surgery and obesity.

Pseudomorphic growth of a single element quasiperiodic ultrathin film on a quasicrystal substrate.

An ultrathin film with a periodic interlayer spacing was grown by the deposition of Cu atoms on the fivefold surface of the icosahedral Al70Pd21Mn9 quasicrystal. For coverages from 5 to 25 monolayers, a distinctive quasiperiodic low-energy electron diffraction pattern is observed. Scanning tunneling microscopy images show that the in-plane structure comprises rows having separations of S=4.5+/-0.2 A and L=7.3+/-0.3 A, whose ratio equals tau=1.618... within experimental error. The sequences of such row separations form segments of terms of the Fibonacci sequence, indicative of the formation of a pseudomorphic Cu film.

Comparison of occlusal contacts in maximum intercuspation for two impression techniques.

STATEMENT OF PROBLEM: At the insertion of a fixed prosthesis, occlusal interferences in maximum intercuspation are often present. PURPOSE: This study investigated and compared the accuracy of interocclusal relationships in maximum intercuspation for mounted casts obtained from a quadrant dual-arch impression technique and conventional full-arch impression techniques. MATERIAL AND METHODS: Comparisons were made between an intraoral interocclusal record and interocclusal records made on mounted casts. Irreversible hydrocolloid, reversible hydrocolloid, polysulfide, polyether, and polyvinyl siloxane were used for the full-arch impression technique. For the quadrant dual-arch impression technique, rigid polyvinyl siloxane and light-body polyvinyl siloxane injection materials were used. RESULTS: Statistical analysis revealed a statistically significant difference (p = 0.0017) in the median values among treatment groups. All pairwise multiple comparison procedures (Student-Newman-Keuls) indicated the average error of the quadrant dual-arch records was significantly different from the average error of each group of records produced with the full-arch techniques (p < 0.05). Comparison of the records of the full-arch impressions did not reveal any statistically significant differences. The average error of the full-arch records was 72 +/- 33 microns and the quadrant dual-arch average error was 5 +/- 5 microns. CONCLUSION: The quadrant dual-arch impression technique produced mounted casts with significantly more accurate maximal intercuspal relationships than mounted casts from full-arch impressions.

Endodontic treatment of an unusual case of fusion.

This case report describes the endodontic and restorative treatment of two anterior permanent teeth with unusual external and internal anatomy due to lusion. A maxillary right central incisor had fused with a supernumerary and the maxillary left central incisor had fused with the left lateral incisor. The complexity of the root canal systems in each tooth required that different endodontic obturation techniques be used. The restorative treatment involved large complex chamber-retained composite buildups and direct veneers.

Chemical and biological properties of a purified lymphoreticular-stimulating fraction of Corynebacterium parvum (Propionibacterium acnes type I).

A method is described in which washed whole cells of Corynebacterium parvum were chemically and enzymatically extracted to remove cytoplasm and cell-wall lipids. The resultant insoluble cell-wall residue possessed lympho-reticular stimulating properties as measured by their ability to increase spleen weight and protect against tumour-cell challenge. Analysis of the final product by chromatography and infrared spectroscopy has shown it to consist of carbohydrate and peptidoglycan, both of which appear to be necessary for the activities measured.

Comparative studies on the cell wall composition of some anaerobic coryneforms of varying lympho-reticular stimulatory activity.

Anaerobic diphtheroids possessing lympho-reticular stimulatory properties may differ considerably in their peptidoglycan composition. Spleen weight-increasing activity of strains directly parallels their antitumour properties. P. granulosum strains, inactive in assays for lympho-reticular stimulation, appear to have a higher cell wall alanine content than most of the P. acnes and P. avidum strains tested. Two P. acnes strains, however, had equivalently high alanine ratios and were stimulatory. The presence of galactose does not appear to be required for activity since P. acnes II strains which lack this sugar can be fully stimulatory. The existence of the species P. lymphophilum (Torrey) is further supported by the finding of two more serologically identical strains which do not cross react serologically with the other species in the group. These organisms are fully stimulatory but have lysine rather than DAP as their cell wall diamino acid.

Endometrial carcinoma associated with Sheehan's syndrome and stilbestrol therapy.

PIP: At the age of 25, pregnant with her 2nd child, a woman was diagnosed as having pituitary necrosis resulting from hemorrhagic shock, in turn the result of a clotting defect caused by an amniotic fluid embolism. For the next 17 years, her daily replacement therapy included 50 mg ma of cortisone, 120 mg of thyroid, and .5-1 mg of diethylstilbestrol given cyclically (21 days). When an exploratory laparotomy was performed on her at age 42 because of abdominal mass,an endometrial adenocarcinoma and varying degrees of hyperplasia were found. A total abdominal hysterectomy was performed, but a year later it became clear that the patient had diffuse carcinomatosis, and 2 months later she died. Prolonged unopposed estrogen therapy is suggested as the cause of the endometrial cancer, rather than pituitary disturbance.^ieng

Hypernatremia from intravascular saline infusion during therapeutic abortion.

In response to a question on how to avoid the rare, inadvertent intravascular or ip injection of hypertonic saline solution during therapeutic abortion, 3 consultants replied. According to Reid and Frigoletto, to avoid intravascular or ip infusion, place a small indwelling polyethylene catheter in the amniotic sac rather than a metal needle. This virtually precludes the possibility of inadvertent iv injection. When and if necessary, correct catheter placement may be confirmed by the use of fluoroscopy and amniography prior to the injection of hypertonic saline solution. The chemical imbalances associated with this accident are those encountered in severe hypernatremia with resultant brain edema and hemorrhagic softening. Bizarre paresthesia, pyrexia, altered consciousness, and, eventually, convulsions preceded the fatal cases. Peritoneal dialysis may be life saving in the event of ip injection. Naturiuretics, appropriate parenteral fluid administration, and possibly exchange transfusion might be indicated for intravascular accidents. In Goodlin's hospital there have been no cases of acute hypernatremia in the last 500 therapeutic abortions done with hypertonic saline solution. This is believed to be related to 2 changes in technique: 1) not losing the amniotic space by removing only as much amniotic fluid as can easily be obtained and 2) using a simple gravity infusion technique for the instillation of the hypertonic saline solution. During infusion it is essential that the patient be alert, for the first symptoms of intravascular injection are a slight pain, burning, or a feeling of warmth in the pelvis. If these minor symptoms are ignored and the procedure is continued, a sensation of flushing occurs throughout the body with tingling in the scalp and ringing in the ears followed finally by seizures, apnea, or coma or both. Late symptoms are those of hemolytic anemia and renal failure. From experience, serum sodium levels during these events are as high as 185 mEq/1. Along with occurrence of acute hypernatremia the contents of the amniotic cavity are sometimes extruded extraovularly through the fallopian tube into the peritoneal cavity when labor begins. Cases with serum sodium levels of 170 mEq/1 some 6-7 hours after saline instillation were observed, but by contrast these patients' only symptoms were extreme thirst and peritoneal discomfort (Lancet 1: 305, 1968). The treatment of hypernatremia is to force fluids either by mouth or iv. Since most commercial 5% dextrose in water solutions are actually 4.5% (regulations permit a 10% error), such hypotonic fluids are useful for treating hypernatremia.