The syndromic child and anaesthesia

Many systems that are relevant to anaesthetists may be affected in syndromic children. These include the spine, airway, respiratory, cardiovascular, genitourinary and neuromuscular systems, as well as coagulation, endocrine and metabolic functions. Embryological development may explain some co-existing anomalies. Although each syndromic child must be managed individually, an approach to evaluating syndromic children and knowledge of common syndromes may be useful.Keywords: anaesthesia, syndrome, atlantoaxial joint, branchial arches, Down’s syndrome, 22q11 deletion syndrom

Intraoperative glucose management in children < 1 year or < 10 kg: an observational study

Background: Infants may be at risk of hypoglycaemia in the perioperative period. Current evidence has led to the global use of maintenance fluid with low-concentration dextrose in these patients. This study aimed to analyse the current practice of anaesthetists in the authors’ institution with regard to blood glucose management, and to assess its adequacy.Methods: Ninety-nine patients under one year of age, or less than 10 kilograms, who required anaesthesia were enrolled. The intraoperative management of intravenous dextrose administration and blood glucose monitoring was at the discretion of the attending anaesthetists. Data collected included patient demographics, period of starvation, dose of dextrose administered and blood glucose measurements taken.Results: Nine infants had at least one glucose value lower than 3.7 mmol/l at any time during the procedure, while all received intravenous dextrose intraoperatively. The hypoglycaemic episode occurred on initial measurement (start of surgery) in five infants and later on in the procedure in four infants. This subgroup had an average age of 1.5 months, and average weight of 2.9 kg. Seven of these infants had significant co-morbidities and/or prematurity and low birthweight.Conclusions: The findings indicate that anaesthetists adhere to current recommendations regarding glucose management, and confirmed the safety of intraoperative administration of 0–2.5% dextrose in isotonic solution to healthy infants. The authors’ observations also emphasised that smaller infants and those with significant co-morbidities are at particular risk of developing hypoglycaemia, despite preoperative and intraoperative dextrose administration. It remains important to check glucose levels in patients at risk of hypoglycaemia.Keywords: dextrose, infants, intraoperative, hypoglycaemia, hyperglycaemi

Paediatric burns anaesthesia: the things that make a difference

Anaesthesia and pain management for paediatric burns continues to challenge and frustrate healthcare professionals in this field of medicine. This review aims to provide some practical management strategies to enable the improved care of burned children. The pathophysiology of burns, toxic shock syndrome, inhalational injuries and perioperative care of paediatric burns is addressed.Keywords: paediatric, burns, pathophysiology, anaesthesia, analgesia, inhalational injurie

Importance of second-order piezoelectric effects in zincblende semiconductors

We show that the piezoelectric effect that describes the emergence of an electric field in response to a crystal deformation in III-V semiconductors such as GaAs and InAs has strong contributions from second-order effects that have been neglected so far. We calculate the second-order piezoelectric tensors using density functional theory and obtain the piezoelectric field for [111]-oriented In$_x$Ga$_{1-x}$As quantum wells of realistic dimensions and concentration $x$. We find that the linear and the quadratic piezoelectric coefficients have the opposite effect on the field, and for large strains the quadratic terms even dominate. Thus, the piezoelectric field turns out to be a rare example of a physical quantity for which the first- and second-order contributions are of comparable magnitude.Comment: 4 pages, 3 figures, Submitted to Phys. Rev. Let

Methodologies for the analysis of pesticides and pharmaceuticals in sediments and plant tissue

Eco-technologies that utilize natural processes involving wetland vegetation, soil and their associated microbial assemblages are increasingly used for the removal of contaminants of emerging concern (CECs) from polluted water. However, information on removal processes in these systems is not always available, possibly due to the lack of simple and robust methodologies for analysis of CECs in complex matrices such as sediment and plant tissue. The aim of the present study was to use a simple and fast procedure based on ultrasonic extraction (USE) and reduced clean-up procedures to analyse 8 pesticides and 9 pharmaceuticals by high-performance liquid chromatography (HPLC) coupled with diode array detector. The established methods demonstrated suitable sensitivity and reliability, and proved fit-for-purpose in quantifying multiple classes of pesticides and pharmaceuticals. For sediments, extraction with methanol/acetone (95:5, v/v) followed by a simple evaporation to dryness and redissolution (water:methanol 50:50) provided acceptable recovery (50 - 101%) and RSD 64%) with RSD < 22% determined using different types of wetland plants. The methodology has been successfully applied in different studies on the fate of emerging contaminants in water treatment eco-technology systems

A review of the peri-operative management of paediatric burns: Identifying adverse events

Background. Burn injuries are common in poverty-stricken countries. The majority of patients with large and complex burns are referred to burn centres. Of the children who qualify for admission, according to burn admission criteria, about half require some kind of surgical procedure to obtain skin cover. These range from massive full-thickness fire burns to skin grafts for small, residual unhealed wounds. Burn anaesthetic procedures are of the most difficult to perform and are known for high complication rates. Reasons include peri-operative sepsis, bleeding, issues around thermoregulation, the hypermetabolic state, nutritional and electrolyte issues, inhalation injuries and the amount of movement during procedures to wash patients, change drapes and access different anatomical sites. The appropriate execution of surgery is therefore of the utmost importance for both minor and major procedures.Objective. To review the peri-operative management and standard of surgical care of burnt children.Methods. This was a retrospective review and analysis of standard peri-operative care of burnt children at Red Cross War Memorial Children’s Hospital, Cape Town, South Africa. A total of 558 children were operated on and supervised by the first author. Factors that could adversely affect surgical and anaesthetic outcomes were identified.Results. There were 257 males and 301 females in this study, with an average age of 50.1 months and average weight of 19.5 kg. The total body surface area involved was 1 - 80%, with an average of 23.5%. Inhalational injury was present in 11.3%, pneumonia in 13.1%, wound sepsis in 20.8%, and septicaemia in 9.7%, and organ dysfunction in more than one organ was seen in 6.1%. The average theatre temperature during surgery was 30.0°C. Core temperatures recorded at the start, halfway through and at completion of surgery were 36.9°C, 36.8°C and 36.5°C, respectively. The average preoperative and postoperative haemoglobin levels were 11.28 g/dL and 9.64 g/dL, respectively. Blood loss was reduced by the use of clysis from 1.5 mL/kg/% burn to 1.4 mL/kg/% burn. Adverse intraoperative events were seen in 17.6% of children.Conclusion. Burn surgery is a high-risk procedure and comorbidities are common. Anaesthesia and surgery must be well planned and executed with special reference to temperature control, rapid blood loss, preceding respiratory illnesses and measures to reduce blood loss

Collateral and Debt Maturity Choice. A Signaling Model

This paper derives optimal loan policies under asymmetric information where banks offer loan contracts of long and short duration, backed or unbacked with collateral. The main novelty of the paper is that it analyzes a setting in which high quality firms use collateral as a complementary device along with debt maturity to signal their superiority. The least-cost signaling equilibrium depends on the relative costs of the signaling devices, the difference in firm quality and the proportion of good firms in the market. Model simulations suggest a non-monotonic relationship between firm quality and debt maturity, in which high quality firms have both long-term secured debt and short-term secured or non-secured debt.

MeerKAT follow-up of enigmatic GLEAM 4-Jy (G4Jy) sources

We present the results from studying 140 radio sources in the GLEAM (GaLactic and Extragalactic All-sky MWA [Murchison Widefield Array]) 4-Jy (G4Jy) Sample. These sources were followed-up with MeerKAT to assess their radio morphology and enable host-galaxy identification, as existing radio images of 25 to 45-arcsec resolution do not provide sufficient information. We refer to these sources as the MeerKAT-2019 subset. The aim is to identify the host galaxy of these sources by visually inspecting the overlays comprising radio data from four surveys (at 150, 200, 843/1400, and 1300 MHz). Our morphological classification and host-galaxy identification relies upon the ~7-arcsec resolution images from MeerKAT (1300 MHz). Through the visual inspection of the overlays, 14 radio sources in the MeerKAT-2019 subset have wide-angle tail (WAT) morphology, 10 are head-tail, and 5 have X-, S-/Z-shaped morphology. Most of the remaining sources have the radio morphology of typical symmetric lobes. Of 140 sources, we find host galaxies for 98 sources, leaving 42 with no identified host galaxy. These 42 sources still have ambiguous identification even with higher resolution images from MeerKAT.Comment: 20 pages, 16 figures, 4 tables. Accepted in MNRA