Increased tracheostomy rates in head and neck cancer surgery during the COVID-19 pandemic.

Surgical practice during the coronavirus disease 2019 (COVID-19) pandemic has changed significantly, without supporting data. With increasing experience, a dichotomy of practice is emerging, challenging existing consensus guidelines. One such practice is elective tracheostomy. Here, we share our initial experience of head and neck cancer surgery in a COVID-19 tertiary care centre, emphasizing the evolved protocol of perioperative care when compared to pre-COVID-19 times. This was a prospective study of 21 patients with head and neck cancers undergoing surgery during the COVID-19 pandemic, compared to 193 historical controls. Changes in anaesthesia, surgery, and operating room practices were evaluated. A strict protocol was followed. One patient tested positive for COVID-19 preoperatively. There was a significant increase in pre-induction tracheostomies (28.6% vs 6.7%, P=0.005), median hospital stay (10 vs 7 days, P=0.001), and postponements of surgery (57.1% vs 27.5%, P=0.01), along with a significant decrease in flap reconstructions (33.3% vs 59.6%, P=0.03). There was no mortality and no difference in postoperative morbidity. No healthcare personnel became symptomatic for COVID-19 during this period. Tracheostomy is safe during the COVID-19 pandemic and rates have increased. Despite increased rescheduling of surgeries and longer hospital stays, definitive cancer care surgery has not been deferred and maximum patient and healthcare worker safety has been ensured.

Maximising tubing functionality, Part II: Processing guidelines.

Maximising tubing functionality requires a systematic approach and a basic understanding of the idiosyncrasies of polymer characteristics and morphology. The right selection of polymers is 50% of the solution with the remaining 50% found in the processing and handling stages of manufacture. Batch-to-batch variations in polymer MI is a given; the wisdom is to accept and deal with it intelligently.

Maximising tubing functionality, Part I: Proper selection of resins.

Making an incorrect selection of polymeric materials, formulations and compounding can result in a compromised design and impaired functionality of the end product. Part I of this article provides guidance on how to simplify and expedite materials selection.

Regulation of apoptosis by angiotensin II in the heart and lungs (Review).

Cell death by apoptosis is now known to be an important mechanism of cell population control in organ development and in normal tissue homeostasis. Inappropriate apoptosis also contributes to the pathogenesis of a number of diseases involving the heart and lungs. Knowledge of the regulation of apoptosis in these organs is therefore of fundamental importance. A growing body of evidence suggests that the renin-angiotensin system (RAS), traditionally viewed as an endocrine system in the regulation of blood pressure, also functions as a regulator of apoptosis in a variety of cell types through both paracrine and autocrine mechanisms that are likely independent of the endocrine RAS. Much of the evidence in support of this premise comes from investigations of cardiac myocytes, endothelial cells and epithelial cells of the lung, both in culture and in situ within human pathological specimens and animal models of heart, vascular and pulmonary disease. Evidence from each of these areas is reviewed and discussed in relation to diseases of the heart, vascular system and lungs.

Effects of symbiosis with Frankia and arbuscular mycorrhizal fungus on the natural abundance of 15N in four species of Casuarina.

The effect of interactions between Casuarina species, Frankia strains and AMF on nitrogen isotope fractionation within the plant were determined under conditions where changes in source nitrogen were minimized by growing plants in mineral nitrogen-deficient conditions and without added organic N. Casuarina cunninghamiana, C. equisetifolia, C. glauca, and C. junghuniana were inoculated singly with three Frankia strains or were dual inoculated with Frankia and Glomus fasciculatum. The %N and delta 15N of separated parts of plants inoculated with the three Frankia strains or with Frankia + Glomus were not significantly different within Casuarina species. However, the slow-growing C. junghuniana differed in several variables from the other three species. There was a highly significant, linear relationship between the natural logarithms of cladode N content and delta 15N of plants of the four Casuarina species when inoculated with Frankia or with Frankia + Glomus, showing that nitrogen supply and the correlated variable, plant growth rate, were major determinants of delta 15N. Provision of small quantities of (NH4)2SO4 or KNO3 increased several-fold the growth of three of the Casuarina species when inoculated with Frankia alone or with Frankia + Glomus. Within species, mycorrhizal and non-mycorrhizal plants receiving supplementary soluble phosphate were of similar dry weights at harvest. delta 15N values for cladodes of C. cunninghamiana, C. equisetifolia and C. glauca were similar, but values for the poor growing C. junghuniana were more variable and, with the exception of plants receiving KNO3, were lower than those of the other three species. Reduced growth due to suboptimal availability of N or P had a major influence on delta 15N and, in these conditions where plants could not access significant amounts of organic N, outweighed any effects on cladode delta 15N of colonization by Glomus. delta 15N values of nodules were higher than other parts of Frankia or Frankia + Glomus inoculated Casuarinas, conceivably due to retention in nodules of fixed N, with delta 15N close to zero.

Fatal pulmonary embolism following spinal anaesthesia for caesarean section.

Pulmonary embolism remains one of the commonest causes of maternal death. Regional blockade is reported to decrease the incidence of postoperative thrombo-embolic disease. We describe a case in which a fatal pulmonary embolism followed an emergency Caesarean section for which the patient was given a spinal anaesthetic. We believe it to be the first time this has been reported.