Greenland Ice Sheet surface melt amplified by snowline migration and bare ice exposure.

Greenland Ice Sheet mass loss has recently increased because of enhanced surface melt and runoff. Since melt is critically modulated by surface albedo, understanding the processes and feedbacks that alter albedo is a prerequisite for accurately forecasting mass loss. Using satellite imagery, we demonstrate the importance of Greenland's seasonally fluctuating snowline, which reduces ice sheet albedo and enhances melt by exposing dark bare ice. From 2001 to 2017, this process drove 53% of net shortwave radiation variability in the ablation zone and amplified ice sheet melt five times more than hydrological and biological processes that darken bare ice itself. In a warmer climate, snowline fluctuations will exert an even greater control on melt due to flatter ice sheet topography at higher elevations. Current climate models, however, inaccurately predict snowline elevations during high melt years, portending an unforeseen uncertainty in forecasts of Greenland's runoff contribution to global sea level rise.

Unusual partnerships: The Corfe-McMurdie anaesthetic inhaler of 1918 and the 2nd Australian Casualty Clearing Station.

This World War 1 ether/chloroform vaporiser-inhaler was designed by and made for Captain Anstruther John Corfe by Private Eric Aspinall McMurdie, both of the 2nd Australian Casualty Clearing Station (ACCS), Australian Army Medical Corps (AAMC). It has a plaque attached labelled 25 May 1918. It is a perfect example of the ingenuity forced by the realities of war, and is one of the unique pieces in the Harry Daly Museum at the Australian Society of Anaesthetists (ASA) headquarters in Sydney, Australia. While serving in Blendecques, France, Private McMurdie ingeniously fashioned this vaporiser from discarded items he found on the battlefield. These included Horlick's Malted Milk bottles, on which he etched measurements for ether and chloroform, and a spent brass artillery shell, which made the heating component of the inhaler. The 2nd ACCS triaged and operated on thousands of troops, and this inhaler is a reflection of the skills and innovative expertise of the staff of the 2nd ACCS which included X-rays to localise foreign bodies, and locally made splints and apparatus to treat trench foot.

Effects of nonsteroidal anti-inflammatory drugs on postoperative renal function in adults with normal renal function.

BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDs) can play a major role in the management of acute pain in the peri-operative period. However, there are conflicting views on whether NSAIDs are associated with adverse renal effects. OBJECTIVES: The primary objective of this review was to determine the effects of NSAIDs on postoperative renal function in adults with normal preoperative renal function. SEARCH STRATEGY: Electronic searches for relevant randomised and quasi-randomised controlled trials in Cochrane Central Register of Controlled Trials, MEDLINE and EMBASE were performed. Attempts were also made to identify trials from citation lists of relevant trials, review articles and clinical practice guidelines. Handsearching of conference abstracts published in major anaesthetic journals was also performed. Date of most recent search: May 2006 SELECTION CRITERIA: The inclusion criteria were randomised or quasi-randomised comparisons of individual NSAIDs with either each other or placebo for treatment of postoperative pain, with relevant postoperative renal outcome measures, in adult surgical patients with normal renal function. DATA COLLECTION AND ANALYSIS: The data were extracted independently by two authors. The primary outcome measure was creatinine clearance within the first two days after surgery. Secondary outcome measures included serum creatinine, urine volume, urinary sodium level, urinary potassium level, fractional excretion of sodium, fractional excretion of potassium and need for dialysis. Weighted mean differences for continuous outcomes and relative risk (RR) and risk difference (RD) for dichotomous outcomes were estimated with 95% confidence intervals (CI). MAIN RESULTS: Twenty-three trials (1459 patients) fulfilled the selection criteria for this review. NSAIDs reduced creatinine clearance by 16 mL/min (95%CI 5 to 28) and potassium output by 38 mmol/day (95%CI 19 to 56) on the first day after surgery compared to placebo. There was no significant difference in serum creatinine on the first day (0 umol/L, 95%CI -3 to 4) compared to placebo. No significant reduction in urine volume during the early postoperative period was found. There was no significant difference in serum creatinine in the early postoperative period between patients receiving diclofenac, ketorolac, indomethacin, ketoprofen or etodolac. No cases of postoperative renal failure requiring dialysis were described. The trials were not heterogeneous for the primary outcome. AUTHORS' CONCLUSIONS: NSAIDs caused a clinically unimportant transient reduction in renal function in the early postoperative period in patients with normal preoperative renal function. NSAIDs should not be withheld from adults with normal preoperative renal function because of concerns about postoperative renal impairment.

High altitude hypoxia, a mask and a Street. Donation of an aviation BLB oxygen mask apparatus from World War 2.

The history of hypoxia prevention is closely inter-related with high altitude mountain and aviation physiology. One pioneering attempt to overcome low inspired oxygen partial pressures in aviation was the BLB mask-named after the three designers-Walter M Boothby, W Randolph Lovelace II and Arthur H Bulbulian. This mask and its variations originated just prior to World War 2 when aircraft were able to fly higher than 10,000 feet and pilot hypoxia affecting performance was an increasing problem. We give a brief description of the mask and its designers and discuss the donation of a model used by the British War Office in October 1940 and donated to the Harry Daly Museum at the Australian Society of Anaesthetists by the family of Dr Fred Street. Dr Street was a pioneering paediatric surgeon in Australia and served as a doctor in the Middle East and New Guinea in World War 2. He received the Military Cross.

Global safe anaesthesia and surgery initiatives: implications for anaesthesia in the Pacific region.

In 2015 three major events occurred for global anaesthesia and surgery. In January, the World Bank published Disease Control Priorities 3rd edition (DCP 3rd edition). This volume, Essential Surgery, highlighted the cost effective role of anaesthesia and surgery in global health. In April, the Lancet Commission on Global Surgery released its report "Global Surgery 2030: Evidence and solutions for achieving health, welfare, and economic development". The report focuses on five key areas to promote change including: access to timely surgery, surgical workforce and procedural capability, surgical volume, data collection such as perioperative mortality rate, and financial protection. In May, the 68th World Health Assembly (WHA) voted in favour of Resolution A68/31: Strengthening emergency and essential surgical and anaesthesia care as a component of universal health coverage. The resolution was passed unanimously and it is the first time that surgery and anaesthesia have received such prominence at WHA level. These three events all have profound implications for the provision and access of safe anaesthesia and surgery in the Pacific region in the next 15 years. This article considers some of the regional factors that affect these five key areas, especially with regard to anaesthetic specialist workforce density in different parts of the region. There are many challenges to improve anaesthesia access, safety, and workforce density in the Pacific region. Future efforts, initiatives and support will help address these problems.

Subcutaneous cannulae for morphine boluses in children: assessment of a technique.

Indwelling subcutaneous cannula for the administration of intermittent morphine boluses postoperatively have been used in several centers as an alternative to intramuscular (IM) injections. We introduced this technique to our hospital, assessed it for complications in 220 children, and conducted a survey to see if nursing staff preferred it to IM injections. The injections through the subcutaneous cannulae caused minimal distress to the children. There were no major complications, 95% of the nursing staff preferred this technique, and 74% would give morphine more readily to a child with a subcutaneous cannula in situ.

Continuous brachial plexus neural blockade in a child with intractable cancer pain.

A 6-year-old boy presented with a large, rapidly growing osteosarcoma of the upper humerus and severe neuropathic arm pain. Despite large doses of morphine (100 micrograms/kg/hr), which resulted in intermittent somnolence and respiratory depression, his pain was poorly controlled. An interscalene brachial plexus catheter was inserted, and bupivacaine was injected on ten occasions over 5 days, with markedly improved analgesia and decreased opioid requirement. Cancer pain in children can be controlled by opioids in 95% of cases; however, circumstances such as intractable neuropathic pain may require specific regional anesthetic techniques.

Patient-controlled analgesia: an appropriate method of pain control in children.

Patient-controlled analgesia (PCA) is an analgesic technique originally used in adults but now with an established role in paediatric practice. It is well tolerated in children as young as 5 years and has uses in postoperative pain as well as burns, oncology and palliative care. The use of background infusions is more frequent in children and improves efficacy; however, it may increase the occurrence of adverse effects such as nausea and respiratory depression. Monitoring involves measurement of respiratory rate, level of sedation and oxygen saturation. Efficacy is assessed by self-reporting, visual analogue scales, faces pain scales and usage patterns. This is optimally performed both at rest and on movement. The selection of opioid used in PCA is perhaps less critical than the appropriate selection of parameters such as bolus dose, lockout and background infusion rate. Moreover, opioid choice may be based on adverse effect profile rather than efficacy. The concept of PCA continues to be developed in children, with patient-controlled epidural analgesia, subcutaneous PCA and intranasal PCA being recent extensions of the method. There may also be a role for patient-controlled sedation. PCA, when used with adequate monitoring, is a well tolerated technique with high patient and staff acceptance. It can now be regarded as a standard for the delivery of postoperative analgesia in children aged >5 years.

Effects of nonsteroidal anti-inflammatory drugs on post-operative renal function in adults.

BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDs) can play a major role in the management of acute pain in the peri-operative period. However, there are conflicting views on whether NSAIDs are associated with adverse renal effects. OBJECTIVES: The primary objective of this review was to determine the effects of NSAIDs on post-operative renal function in adults. SEARCH STRATEGY: Electronic searches for relevant randomised and quasi-randomised controlled trials in Cochrane Controlled Trials Register, MEDLINE and EMBASE were performed. Attempts were also made to identify trials from citation lists of relevant trials, review articles and clinical practice guidelines. Hand-searching of conference abstracts published in major anaesthetic journals was also performed. SELECTION CRITERIA: The inclusion criteria were randomised or quasi-randomised comparisons of individual NSAIDs with either each other or placebo for treatment of post-operative pain, with relevant post-operative renal outcome measures, in adult surgical patients. DATA COLLECTION AND ANALYSIS: Of the 14 trials that fulfilled the selection criteria for this review, eight trials were relevant with sufficient data for meta-analysis. The data was extracted independently by two reviewers. The primary outcome measure was creatinine clearance within the first two days after surgery. Secondary outcome measures included serum creatinine, urine volume, urinary sodium level, urinary potassium level, fractional excretion of sodium, fractional excretion of potassium, need for dialysis and need for diuretic or dopamine treatment for renal insufficiency. Weighted mean differences for continuous outcomes and relative risk for dichotomous outcomes were estimated. MAIN RESULTS: As a group, NSAIDs reduced creatinine clearance by 18ml/min (95%CI: 6 to 31) and potassium output by 38mmol/day (95%CI: 19 to 56) on the first day after surgery compared to placebo. Serum creatinine clearance increased on the second day after surgery by 15umol/L (95%CI: 2 to 28) compared to placebo. No significant reduction in urine volume during the early post-operative period was found. There was no significant difference in serum creatinine in the early post-operative period between patients receiving ketorolac and diclofenac in one trial. No cases of post-operative renal failure requiring dialysis were described. REVIEWER'S CONCLUSIONS: NSAIDs caused a clinically unimportant transient reduction in renal function in the early post-operative period. NSAIDs should not be withheld from adults with normal pre-operative renal function because of concerns about post-operative renal impairment.

Nurse administered relative analgesia using high concentration nitrous oxide to facilitate minor procedures in children in an emergency department.

AIMS: To describe the experience of using high concentration nitrous oxide (N(2)O) relative analgesia administered by nursing staff in children undergoing minor procedures in the emergency department (ED) and to demonstrate its safety. METHOD: Data were collected over a 12 month period for all procedures in the ED performed under nurse administered N(2)O sedation. All children greater than 12 months of age requiring a minor procedure who had no contraindication to the use of N(2)O were considered for sedation by this method. The primary outcome measure was the incidence of a major complication namely respiratory distress or hypoxia during the procedure. Secondary outcome measures were minor complications and the maximum concentration of N(2)O used. RESULTS: Data were collected for a total of 224 episodes of nurse administered N(2)O sedation over a 12 month period. In 73.2% of children no complications were recorded. One major complication was recorded (respiratory distress) and the most common minor complication was mask intolerance in 17%. The mean maximum concentration of N(2)O used was 60.2%. CONCLUSIONS: N(2)O is a safe analgesic in children over the age of 1 year undergoing painful or stressful procedures in the ED. It may safely be administered in concentrations of up to 70% by nursing staff after appropriate training.

ANZAC doctors at Gallipoli and their contributions to anaesthesia in Australia.

This year marks the centenary of the start of World War I and with the coming centenary of the involvement of the Australian and New Zealand Army Corps in the Gallipoli campaign. We look at the careers of four doctors who served at Gallipoli and their various contributions to anaesthesia. Drs Eric W.B. Woods, John W.B. Bean, Piero F.B. Fiaschi and Bernard T. Zwar all served as part of the Australian Army Medical Corps. All survived the war.

Failed intubation and failed oxygenation in a child.

A 'can't intubate, can't oxygenate' scenario in a child is fortunately extremely rare. We report a case of this life-threatening event in a four-year-old boy suffering from a rare genetic disorder, fibrodysplasia ossificans progressiva. He presented for manipulation of his dislocated jaw and was identified preoperatively as having a difficult airway. Despite extensive preparation, a catastrophic loss of airway control occurred minutes after induction of general anaesthesia, necessitating a life saving emergency tracheostomy. This report highlights the small evidence base and lack of definitive algorithms relating to how best to rescue a paediatric 'can't intubate, can't oxygenate' situation. Paediatric anatomical factors dictate that immediate procession to a tracheal surgical airway may be the optimal management.

Compartment syndrome and patient-controlled analgesia in children--analgesic complication or early warning system?

We present two cases of children who developed compartment syndrome after upper limb fractures. Morphine patient-controlled analgesia was used in a bolus-only mode for analgesia (bolus 20 microg/kg, five minute lockout and hourly limit of 150 microg/kg). An increase in patient-controlled analgesia use was observed up to 12 hours before the decision was made to proceed to fasciotomy but neither child exceeded the hourly limit or had an excessive increase in pain scores. Clinical risk factors for compartment syndrome should be identified and appropriate monitoring instituted. A subtle increase in patient-controlled analgesia use may be an early indicator of impending compartment syndrome before classical signs such as reporting of pain, pallor paraesthesiae, paralysis and pulselessness develop. These cases and review of the literature suggest techniques which may assist earlier diagnosis of compartment syndrome include setting a more conservative hourly limit of morphine patient-controlled analgesia such as 80 to 100 microg/kg/hour and graphing of patient-controlled analgesia demands and boluses, pain scores at rest and pain scores with passive flexion and extension of digits. These practices could identify trends that pain or analgesia requirement is increasing leading to earlier diagnosis of compartment syndrome.

Airway management for infants with severe micrognathia having mandibular distraction osteogenesis.

We retrospectively reviewed the charts of seven neonates and infants with severe micrognathia and upper airway obstruction who underwent mandibular distraction osteogenesis as an alternative to long-term tracheostomy at the Children's Hospital at Westmead, Sydney, from 2004 to 2007. All patients required a variety of airway interventions at an early age and had poor feeding or failure to thrive. These children had other anomalies and required many investigations and procedures and presented repeated airway challenges for the anaesthetist. The mean number of anaesthetics per child in this series was 6.7 (range 4 to 13). Under anaesthesia, four patients had grade 4 laryngoscopy, one was grade 3 but two were only grade 2. Patients with a preoperative grade 4 laryngoscopy were very likely to need fibreoptic endotracheal intubation. Duration of intubation after surgery for mandibular distraction was a mean of 8.17 days (range 1 to 19). Three were extubated in the operating theatre and three in intensive care. Five patients had an improved laryngoscopy grade after completion of mandibular distraction and one remained grade four The remaining patient had a tracheostomy from birth.