Intubations this month: 27
Airway Registry learning points reflect the challenges described and wisdom shared by Sydney HEMS personnel and guests at the Clinical Governance Airway Registry presentation for January 2018. Cases are discussed non-contemporaneously, anonymised and amalgamated over a time period to draw together unifying take-home messages. Details of specific cases are removed and/or changed, such that any similarity to real-life patients or scenarios is coincidental.
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Some of our work takes us to the beach, particularly during the summer months, although the NSW climate is such that beaches are frequented by residents and tourists year-round.
This month we talked about the specific challenges inherent in undertaking our prehospital work in a beach setting.
We have been collaborating hard to put together the programme of the next education day with our colleagues across the airfield at NETS. All NSW Health employees are welcome to join us for a day of paediatric and neonatal case reviews, cutting-edge and evidence-based medicine, simulation and workshops. See you there!
Although Sydney is currently enjoying an extended summer, last week’s education day had a frosty feel to it as we were treated to two presentations on the perils of cold weather. This is currently being typed as it’s 34 degrees outside, but it is worth remembering that temperatures in both the Blue Mountians and the Snowy Mountains can hover around zero in winter time and catch some unprepared hikers (and medics!) unaware.
(Photo Credit: Bob Lisle)
Critical care paramedic Bob Lisle discussed how best to look after ourselves and our patients in cold weather and gave us these survival tips:
(Photo Credit: Bob Lisle)
A reminder on the medical aspects of hypothermia is below.
Severity:
Hypothermia occurs when core body temperature is < 35 C
Effects of Hypothermia:
Central nervous system effects
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Acid-base changes:
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Cardiovascular consequences
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Endocrine and metabolic consequences
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Respiratory consequences
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Renal consequences
· Decreased GFR and RBF. · Reduced vasopressin >> “Cold diuresis” GIT consequences
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Haematological consequences
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Immunological consequences
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Management:
Resuscitation
Passive warming – useful in conscious patients who are able to shiver (1.5C per hour)
Active warming:
Supportive care and monitoring
What is in our packs?: Buddy lite fluid warmer, space blankets, EasyWarm Active Self-Warming Blanket
Our second speaker was Dr Andrew Peacock, a part time emergency medicine physician and part time expedition doctor. In the course of his travels around the world he has also developed incredible skill as an award winning photographer. We heard about his recent trip to Denali (Mt McKinley) which, at 6190m above sea level, poses the dual challenge of freezing temperatures and altitude. The main issues Andrew faced on Denali were altitude sickness, frostbite and hypothermia.
(Photo credit: CNN, Andrew Peacock)
Altitude related medical issues can occur at altitudes above 2500m but this isn’t the only risk factor; rate of ascent and previous medical issues at altitude are more relevant predictors.
Altitude sickness comprises a spectrum ranging from AMS (Acute Mountain Sickness) through to HAPE (High Altitude Pulmonary Oedema) and HACE (High Altitude Cerebral Oedema).
Symptoms
AMS: headache, nausea, anorexia, dizziness, general malaise
HAPE: dry cough, decreased exercise tolerance, shortness of breath
HACE: headache, nausea, vomiting, truncal ataxia, altered mental status
Treatment
Mild AMS can be treated by stopping the ascent, acetazolamide (125mg bd) and simple analgesia. However both HAPE and HACE (and severe AMS) warrant descent and supplemental oxygen. In addition HACE can be treated with dexamethasone (8mg stat dose then 4mg q6h) and HAPE with nifedipine (30mg slow release bd)
Andrew also provided a broader classification for hypothermia which is easier to apply in the field and is a helpful guide to treatment
Mild: Shivering and normal mental function (temp 32-35 degrees)
Severe: Absence of shivering and abnormal mental function (temp <32 degrees)
Andrew’s top tip for managing frostbite was to avoid rewarming the affected digits until you can guarantee that further frost bite will not occur. Then, rewarm in a bath of 37-39 degrees. This is a painful process and requires liberal analgesia. Finally, splint, elevate and protect.
Andrew’s beautiful travel photographs can be seen on his website www.footloosefotography.com and on his instagram page https://www.instagram.com/footloosefotography/?hl=en.
If they dont give you an acute case of wanderlust, then nothing will.
References and resources
An algorithm is an illustration of a series of medical decisions that address certain patient specific conditions outlining appropriate responses intended to lead to an outcome.
The goals of an algorithm are to identify diagnostic alternatives, treatment options, and outcomes by weighing decision benefits against risks and costs.
These algorithms can be explicit and published based on best evidence such as in Fig. 1 or individual critical decision making based on expertise and experience.
Decision pathways reach knots or nodes, from which several options are available.
A primary benefit of a well – developed algorithm is that it focuses the reader on the critical decision points in any clinical scenario and specifically lists the input data that leads to a decision. Algorithms can be applied to specific problems, processes, or diseases. They allow for evolution of a disease related topic with new information or clinical conditions that may affect decision making later in the time course of a situation. They can convey the scope of a clinical condition from presentation, through testing and assessment, followed by a clinical judgment and action leading to an eventual outcome. Annotations are added to appropriate points on the algorithm and are necessary for all decision nodes. The purpose of the annotation is to explain all critical factors affecting decisions in as concise a manner as possible. The primary advantage of an algorithm is that it can summarize an evidence based guideline into an easily and quickly available practice protocol for use in the clinical care setting. Fig. 1 is an example of such an algorithm published by the Western Trauma Association.
WTA Pelvic fracture management algorithm.
In countries such as Australia which have very low volume of GSWs to the abdomen, there is a lower threshold for explorative laparotomy versus selective conservatism. The latter may involve observation for peritonism/bleeding and/or performing CT to look for tangential injury without peritoneal violation as is done in high penetrating GSW volume North American trauma centres. CT can be used to ascertain bullet trajectory and can assist in detecting retroperitoneal injury.
In general, management of GSWs such be based on objective physical examination, findings and diagnostic investigations and not on entry and exit sites or sizes.
Retrieved bullet
There are only a few indications to retrieve the bullet. These include bullets found in joints, CSF, or the globe of the eye. Fragments leading to impingement on a nerve or a nerve root, and bullets lying within the lumen of a vessel, resulting in a risk of ischemia or embolization, should be removed. Rare indications are lead poisoning caused by a fragment, and removal that is required for a medico-legal examination. In all other cases the indication should be critically reviewed.
Many prehospital teams carry refrigerated blood. This can be warmed with the Buddy Lite (Fig. 3). The Buddy Lite can heat 4.4 liters of fluid or blood to 38°C on a single charge. Its major limitation is that it is unable unable to heat fluid that is given rapidly.
As well as ordering INR/aPTT all major trauma patients suspected of bleeding should have fibrinogen level sent. Hyperfibrinolysis in major trauma (detected by fibrinogen level/viscoelastic tests) is associated with worse outcomes. It is treated with cryoprecipitate transfusion.
Belmont buddy Lite fluid warmer
‘Code Crimson’ is a term that has commonly been used by hospital-based teams managing patients with life-threatening haemorrhage that is refractory to resuscitation. The purpose of a ‘Code Crimson’ activation is to streamline patient access to definitive intervention, including an operating theatre or interventional radiology suite. This has recently been formalised in NSW and can be activated by prehospital teams.
Patients who fail aWPTAS with brain injury and who do not have a surgically evacuable intra-cranial lesion are at high risk of suboptimal management. Amnesia is only one symptom and symptoms may also include fatigue, dizziness, headache, cognitive and psychosocial changes. These patients may acutely require referral for in-patient Brain Injury Unit management prior to rehabilitation.
With Sydney temperatures consistently reaching the high 30’s and early 40’s recently it is perhaps timely to revise heat related illness. It is also worth considering the steps we can take to keep ourselves cool in the same environmental conditions.
Heat related illness covers a spectrum which, at the most extreme end, includes heat stroke. This is defined as hyperthermia >40 degrees, associated with neurological dysfunction. The neurological dysfunction can manifest in many ways including ataxia, delirium, seizures and coma. The patient may also be tachycardic and hypotensive (echo may show either a hypodynamic or hyperdynamic LV). Sweating may be absent. Unrecognised heat stroke carries a mortality of up to 30%.
Management
Aggressive cooling in the field can prevent a cascade of organ dysfunction and significantly improve prognosis. Initial management and cooling methods will be dictated by resources and environment but consider:
Don’t forget standard resuscitation measures:
A = RSI if patient is obtunded and unable to protect airway
B = Ventilate as required. Be aware that pulmonary oedema and ARDS may accompany heat stroke if you are having difficulty ventilating
C = iv fluids may be needed but don’t equate hyperthermia with hypovolaemia. Depending on clinical circumstances, the patient may be either mildly or profoundly volume depleted. Be aware of dilutional hyponatraemia in endurance athletes consuming lots of sports drinks. This can be an important differential for altered LOC and seizures.
Inotropes may be required if shock is refractory to fluid resuscitation but be aware that adrenaline and noradrenaline will cause vasoconstriction that may impair cooling.
D = Benzodiazepines for seizures, don’t forget to check a BSL
Self Care
Self-care is important on these missions as crew members are being exposed to the same environmental conditions as the patient and may have had to exert themselves to get there (winch, bush walk etc.) Make sure you are well hydrated pre mission and carry additional water. Urine colour is the best guide to your hydration status. Ice packs are available in the ready room and can be used by crew if needed. Consider your uniform sunhat if your head is exposed. Sun cream is also available in the ready room. If you are feeling unwell due to heat, communicate this immediately to your crew.
A significant number of our critical care patients are dependent on vasoactive drugs, so it is worth reviewing the process for managing these infusions during inter-hospital transfers.
The priming volume of the distal lumen of a central line is 0.44mls. Therefore an infusion running at 10mls / hour could take approximately 3 minutes to reach the patient if started de novo. The half-life of inotropes such as adrenaline and noradrenaline is short, approximately 1 minute. This leaves the patient vulnerable to a period of hypotension. Corrective bolusing of vasoactive drugs is not recommended as it can lead to large, and potentially detrimental, swings in blood pressure. Therefore a smooth transition between syringe pumps is recommended to maintain haemodynamic stability.
There are a number of different methods for double pumping but one suggested protocol is as follows:
Tips and tricks
Further reading:
Management of the changeover of inotrope infusions in childrenIntensive and Critical Care Nursing 2004 ArinoChangeovers of vasoactive drug infusion pumps impact of a quality improvement programCritical Care 2007 Argaud
AiR Videos
Greater Sydney Area HEMS 