Emergency Medicine in the Developing World 2011 (Part 2)

You’ll remember from Part 1 that the 3rd biennial Emergency Medicine in the Developing Worldconference is being hosted in Cape Town, by the Emergency Medicine Society of South Africa (EMSSA).  LITFL friend Sa’ad Lahri (from GF Jooste Hospital) is on the conference committee and feeding us a series of key points and pearls typed on the fly by Ross Hofmeyer. These notes are from Day 2 of the conference.  The audio of these talks are to be made available on Free Emergency Medicine Talks in the near future.

Let’s rip into it…

  • Increase in demand for blood transfusion products but decreasing supply
  • African HIV epidemic straining supplies
  • Acute resus – Hb > 10g/dL probably required
  • ICU/longer term – Hb >7 g/dL should be sufficient unless background illness
  • Tissue oxygenation is what counts, not Hb (DO2 is the most important)
  • DO2 requires absolute minimum Hb 3 g/dL
  • Extraction reserve from Hb 25-75% (1-3 molecules ‘extra’ under normal conditions)
  • Increase a-v O2 gradient implies patient is nearing limit of reserve
  •  ScvO2 use paired with ABG can thus be used as a guide (ala Rivers EGDT)
  • Lactate increase follows after decrease in ScvO2
  • ScvO2 >70% and/or lactate >8 may be a good triage criterion
  • Patient’s blood is best – keep it in!
  • Maintain normothermia – one litre of room-air fluid can drop core temperature by 0.5-1 degree C
  • Blood conservation in trauma – permissive hypotension where it is not contra-indicated. In SA with long delays (>90 minutes) need some more resus – aim for SBP>100/MAP>60. Vasopressin being researched.
  • Hemopure:
  • 3 year shelf life
  • Bovine haemoglobin
  • Functions as a colloid – no clotting factors
  • Hypertension with rapid administration (due to NO binding)
  • Bridge to transfusion/neosynthesis of blood (Iron available in the Hemopure; increased EPO due to decreased red cell mass)
  • HBBS given a bad name by a very flawed meta-analysis
  • Potential uses of blood substitutes are legion
  • Blood conservation – intraoperative cell salvage (Takagi Arch Surg 2007). Can be used with a fresh bowel perforation
  • Anticoagulation:
  • Platelets effective in 4hrs after aspirin and 12 hrs after clopidogrel
  • Warfarin can be reversed in minutes with PCC(Haemosolvex), hours with FFP and days with Vitamin K
  • Best assessed with TEG if available.
  • Aim for
  • Platelets >50 (if bleeding)
  • PTT < 2x control
  • Fibrinogen <1 -> cryoprecipitate
  • Fibrinogen 1-2 -> 1-2u plasma
  • Fibrinogen >2 -> possible error; consider tranexamic acid

Conflicts of interest declared.

  • UMD Shock Trauma – about 70% of trauma patients need no more than 2-3 units of packed red blood cells
  • HBOC vs RBC – Bovine Hb vs human, higher O2 carrying capacity, much less viscosity, much shorter half-life; long shelf life. (Similar oncotic pressure etc).
  • Hemopure:
  • No cross-match/typing needed
  • Ready-to-use
  • No know disease transmission
  • Can be stored at 4-30 degrees for 3 years
  • Carries O2 and treats hypovolaemia
  • No known immune effects
  • Rheological advantage
  • Fewer resources and less infrastructure required to maintain a supply of HBOC rather than blood.
  • Transfusion errors are not an issue due to lack of cross-match requirement.
  • Testing blood for transmitted diseases now accounts for 50% of the cost of a unit.
  • Is Hemopure safe and efficacious?
  • HEM-115 study (n=688) – no mortality difference
  • Moderate needs (<3u) side effects and mortality identical
  • No MI’s in patients receiving <10u in Hemopure arm and one in RBC arm
  • Several case studies presented
  • Best use = when blood is not available or accessible.
  • JAMA meta-analysis (May 2008) – 5 different HBOC’s analysed as one group, 2 of which had already been withdrawn more than a decade before the meta-analysis was done. Removing 1 of these would change the result to positive!

  • Talk focus: primary intraparencymal/intracerebral haemorrhage
  • Constitutes 10-15% of strokes with mortality between 35 and 52%
  • Locations: brainstem, cerebellum, thalamus, basal ganglia, lobar.
  • Initial diagnosis: abrupt headache, vomiting, seizure, altered mental state, any focal or generalised neurological symptoms, and otherwise the same for acute stroke.
  • EMS evaluation: ABCs, cardiac monitoring, IV access, O2 if hypoxic, NPO, alert and transfer
  • Initial care: as per ‘suspected stroke’. Balance risk of loss of airway against loss of neuro exam. CT head ASAP whenever available.
  • Major predictors of outcome: Initial GCS and ICH volume
  • Factors associated with poor outcome that we can treat:
  • Hematoma expansion
  • Hyperglycemia
  • Hematoma evacuation
  • Seizures
  • Hematoma expansion – 38% of patients presenting within 3 hours of onset have significant haematoma growth .
  • Blood pressure control is controversial – minimal literature available (most of it intra-operative from neurosurgery). ‘Resetting’ of CBF autoregulation to a higher-than-normal level is a concern. INTERACT study (SBP<180 vs SBP<140): 36% decreased risk of haematoma expansion, but no effect on outcome. INTERACT2 (specifically powered to measure outcome effect) is currently underway. AHA guidelines exist (all class C) advising a moderate decrease in BP
  • Anticoagulation reversal – FFP use to reverse warfarin (contains factors II, VII, IX and X required) can require 10u (2000ml) to reverse INR. This can be a problem in patients with background of cardiac disease (for which they get the warfarin…). Time to reversal varies in studies: 7-32 hours due to practical considerations. PCC (prothrombin complex concentrate) has rapid action (about 20 minutes) with minimum volume required, but they are expensive and carry a risk of thrombotic complications and DIC. IV Vitamin K has an effect as early as 4 hours, and can reverse the INR as early as 8 hours. Risks include anaphylaxis (rare). Factor VIIa also reverses the INR within minutes, but once again there is a risk of increased thrombotic complication.
  • Hyperglycaemia
  • Associated with poor outcome, even in the absence of diabetes. Hyperglycaemia is neurotoxic.
  • GIST trial – n=933 (12% ICH), intensive insulin vs. sliding scale: No difference in outcome
  • QASC trial – n=1696 (5% ICH), glucose control vs. none (intervention group also had swallow screen and paracetamol for fever): Poor outcome 42 vs 58%
  • Large haematoma: surgical evacuation
  • STICH trial – n=477+505: OR 0.89 (CI 0.66-1.19) therefore no benefit to urgent evacuation
  • EVD placement for intraventricular blood – never been studied and probably never will be, as most people presume drainage of obstructive hydrocephalus is obvious.
  • Clinical seizures should be treated with anti-epileptics; routine prophylaxis is not indicated.

  • Most discuss the anatomically difficult airway – what about the physiologically difficult airway?
  • Pre-oxygenation vs. denitrogenation
  • Patients who are not breathing adequately cannot pre-oxygenate adequately!
  • Most patients needing intubation have some degree of physiological shunt
  • Overcoming shunt relies on increasing the mean airway pressure
  • BVM pre-oxygenation relies on assisted ventilation and a good mask seal… and you NEED A PEEP VALVE
  • NIV (CPAP) can be used for pre-oxygenation in the ED
  • Concept – using nasal oxygen while performing intubation to allow continued insufflation
  • Patient position for intubation (ear to sternal notch) assists ‘apnoeic oxygenation’
  • “Delayed Sequence Intuabtion” for the delirious patient using ketamine (or dexmedetomidine or fentanyl & midaz titrated).
  • Bicarb to buy time in severe acidosis?
  • ‘Push dose’ pressors for pre-emptive control of drop in BP on induction – phenylephrine
  • Induction agents – ketamine or etomidate, but beware patients with maximum sympathetic stimulation – decrease dose.
  • Beware hypoventilation post intubation – measure ABG and watch pCO2

  • ABCDE approach as a basis
  • E = ECG – get a rhythm strip as a minimum, 12 lead ECG by preference
  • The Feeble – Bradycardia:
  • Signs of instability: hypotension, altered mental state, signs of shock, ischaemic pain/discomfort, acute heart failure.
  • Before giving atropine, exclude: hypoxia, hypothermia and head injury. Be cautious in head injury, hyperkalaemia and heart transplant.
  • If atropine is unsuccessful, consider adrenaline, dopamine, glucagon (beta- or Ca-channel blockage OD) or pacing
  •  The Fast – Narrow Complex Tachycardia
  • HR>150 with QRS<0.12sec
  • If unstable: Cardiovert!
  • If stable: vagal manoeuvres – Valsalva, facial application of ice water, carotid sinus massage
  • or: drugs — Amiodarone, Beta-blockers, Ca-channel blockers, Digoxin
  • The Furious – Wide Complex Tachycardia
  • Usually unstable, but if stable, consider adenosine but amiodarone is the drug of choice
  • Cardiovert if unstable

  • Diagnosis is difficult based on common variables – limited sensitivity of physical examination, ECG and CXR (normal in 20%)
  • BNP >100pg/ml is more accurate than clinical criteria for diagnosis, but cannot be used alone. Greatest value is for the ‘intermediate’ patients. May be lower than expected in flash pulmonary oedema. Mild elevation can be found in cor pulmonale, PE and COPD. Inverse relationship with BMI and higher with renal failure.
  • Ultrasound for “lung comets” has proven to have good sensitivity in initial studies
  • ASCEND-HF clinical decision pathway useful in hypertensives
  • Morphine has gone out of favour – not good evidence. Perhaps good if intubation is inevitable
  • Nitrates very effective in controlling BP and reducing afterload
  • ACE-I may work – small studies showed decreased intubation rates
  • Furosemide helpful in the acute setting but nitrates better
  • NIV excellent
  • Hypotensive patients – fluid bolus if intravascularly depleted, then inotropes
  • Don’t forget to consider palliative care in the correct cases.
  • Ultrafiltration can be useful if it is available (although it is expensive and time intensive)

  • See Free Emergency Medicine Talks for talks – everything from this conference will also be there soon!
  • Be a skeptic, not a cynic
  • There are now more than 10 000 medical journals (a logarithmic increase!)
  • Remember that journals need to make money to survive. They have no fiduciary relationship with patients!
  • Peer review is the best we have – but it is a “flawed process at the heart of science” (in the words of the editor of the BMJ). It is prone to bias and abuse, and hopeless at spotting fraud and error. “Like poetry, love or justice”. “If peer review was a drug, it would never get onto the market.”
  • Publishing negative results, despite the quality of the study, is unpopular with readers and journal editors alike. However, consistent bias in reporting positive findings only skews the statistics when meta-analysis is done.
  • Peer review misses things – demonstrated in studies (see Baxt WB et al 1998)
  • Looking at articles, watch out for independent predictors, strong associations, citation bias, amplification, invention, work-up bias, spectrum bias, referral bias and so on
  • Least favourite statistic – Negative Predictive Value. If disease prevalence is low, the NPV will OF COURSE be low.
  • Citation bias – citing only articles that support our hypothesis
  • Beware multiple hypotheses!
  • Absolute vs relative risk reductions (eg. statins – JUPITER trial). Absolute risk from 0.7% to 0.4% is a 43% relative risk reduction…
  • Beware surrogate and composite endpoints!
  • Full slideset available from Prof Lex via email (as are the references)

  • 119 million patients seen in ED’s in USA in 2009
  • Who drives patient care in emergency settings? Doctors, nurses, hospitalists, patients?
  • Ethnographic study of acuity assignation (2010)
  • Sample of emergency nurses, ethnographic approach, 12 participants, 150 initial patient encounters over 3 months
  • Patients reported acuity to be a function of patient presentation, complaint, duration of symptoms and body habitus. Acuity was also influenced by environmental and contextual challenges: language barriers, patient volume, unit leadership, communication with patients and providers, and length of time in waiting room prior to triage.
  • “Who’s in the back?” phenomenon – some nurses made decisions about acuity, further assessment and initial diagnostic tests based solely on the physician was.
  • Physiologic data was not rigorously collected nor considered as a primary determinant of acuity.
  • Moral reasoning and drive surfaced as an important factor.
  • Investigation of triage competency (2011)
  • Lack of understanding around critical cues – the signs, symptoms and history that send the provider down one path and away from another.
  • Intuitive vs hypothetico-deductive thinking – the former is efficient but inaccurate, where the latter is accurate but time-consuming
  • Core, intermediate and influential elements need to be considered in an integrative model for clinical decision making
  • Unit leadership is the best surrogate for (the almost impossible to teach concept of) moral reasoning
  • Proclivity for high moral reasoning is the factor that closes the loop in critical thinking; it inspires us to ask the questions “Am I right?” and “Is there a way I can be wrong?”
  • Important elements to consider:
  • Knowledge base
  • Moral reasoning
  • Drive to act
  • Environmental structure:
  • Standards
  • Communication
  • Teamwork
  • Autonomy of practice
  • “The end result of critical thinking is not thought: it is action”

  • Preparation and practice are key to being ready to manage difficult airways
  • Four important questions:
  • Is the airway difficult – Anatomic concerns?
  • Is the patient compromised – Physiologic concerns?
  • What is your primary approach?
  • What is your rescue approach?
  • Difficult airway situations to anticipate:
  • Difficult DL – LEMON – Look externally, Evaluate 3-3-2, Mallampati, Obstruction & Obesity, Neck movements
  • Difficult facemask – MOANS – Mask seal (anatomical abnormality, wounds, beards, etc), Obstruction & Obesity, Age (extremes), No teeth, Stiff (difficult ventilation)
  • Difficult EGD (Extraglottic device) – RODS – Restricted mouth opening, Obstruction & Obesity, Distortion, Stiff lungs or c-Spine
  • Difficult cric – SHORT – Surgery or disrupted airway, Haematoma (or other mass), Obstruction & Obesity, Radiation therapy, Tumour
  • Difficult airway principles:
  • Patients need oxygen… not necessarily and ETT
  • Patients with multiple difficult airway attributes may be unsafe for paralytics
  • “One-shot” airways may need paralysis if you’re forced to act
  • Always have a backup plan
  • Primary Airway Management Plan?
  • RSI?
  • Sedated, awake intubation?
  • Primary surgical airway?
  • One always needs an airway rescue plan: Double set-up, extraglottic, or something else?

Airway rescue plan?

  • RSI?
  • Rescue surgical airway?
  • Alternative airway devices
  • Alternative airway devices
  • Blind insertion device?
  • Optical stylet?
  • Video laryngoscopy?
  • Flexible fiberoptic?
  • Case 1: Angio-oedema (68yr female, just started on ACE-I)
  • Good plan – Awake intubation, flexible fiberoptic if possible, surgical airway as ultimate backup.
  • Dry and anaesthetise the airway – atomised and nebulised lignocaine. Nasal approach with flexible fiberscope. Judicious sedation or none at all. Surgical airway if precipitous failure.
  • Case 2: Aspirated foreign body (62yr male, “choking”, collapses in ED)
  • Good plan – “crash airway” -> immediate DL, remove foreign body if seen, intubate and ventilate if possible.
  • If obstruction is infraglottic, use ETT to push it all the way down into a bronchus, retract ETT and try again to ventilate.
  • Case 3: Severe Asthmatic (25yr female, tachycardic & tachypnoeic, beginning to desaturate)
  • Rapid RSI; EGD as backup; cric if complete failure
  • Lignocaine nebusised if time to reduce reactive airways
  • Ketamine good
  • Summary: All in the evaluation
  • Know your mnemonics
  • Always have a plan B
  • Remember some nuacnces of specific cases
  • Practice practice practice

  • 1:2:4 principle
  • most casualties on the battlefield still bleed to death
  • Emergency care/ ALS within 1 hour
  • Surgical resuscitation within 2 hours
  • Definitive care within 4 hours
  • Level 1 resuscitation post as close to the battlefield as possible
  • Forward surgical capabilities near the battlefield
  • Rapid evacuation to definitive care at field hospital care on land/rail/sea and even in the air.
  • Caring for patients under the special circumstances such as chem/bio/nuke threats
  • Military fatality rates – major death in <5min and 11-30min time brackets.  <5 usually fatally wounded; focus on the 11-30min bracket
  • 78% of injuries now are blast injuries rather than gunshots in modern warfare
  •  Potentially survivable deaths – 85% due to haemorrhage! Of this, 31% is compressible haemorrhage…
  • Algorithm starts with a C – Catastrophic Haemorrhage Control
  • Tourniquets save lives and red blood cells
  • Combat ready clamp for femoral artery and abdominal aorta tourniquet (inflatable wedge)
  • Internal Compression tourniquet especially useful in “junctional trauma” (shoulder and groin)
  • Extensive use of topical hemostatic agents (haemostatic bandages and combat guaze)
  • Tranexamic acid extensively supported in military literature
  • 10-15% of preventable deaths due to airway obstruction
  • NPA useful and well tolerated in semi-conscious patients and is extensively used
  • Endotracheal intubation in the battlefield is not the answer (1 survival out of 492 cases)
  • Surgical airway is the first and last resort
  • Tension pneumothorax is a common cause of preventable death – bilateral needle decompression performed before calling death
  • Hemopure for blood substitute
  • Hypotensive resuscitation used
  • Intra-osseous lines in sternum and tibia very useful
  • Focus on resuscitation with blood products early
  • “In combat settings, casualties without head injury who are of normal mental status with a palpable radial pulse should not receive fluid resuscitation”
  • 1:1:1 resus (or even higher ratios – 2:3)
  • Body warming bags and fluid warmers in vehicles
  • Damage control surgery very well adopted
  • Low threshold for early damage control
  • Ethical challenges:
  • Law of war (especially peace missions)
  • Civilian casualties
  • Own vs. enemy forces
  • Iraq – 93% of casualties are non-combatants, 34% under 14 years of age
  • Patients full of explosives… children with explosive belts… incubators with babies booby-trapped with explosives…
  • Prisoners of war
  • Paradigm challenges
  • Triage is fighting force orientated – get the healthiest fighting again fast
  • Quality compassionate care is possible under austere conditions
  • Unique approaches are required.

  • Consensus – mutually acceptable agreement that integrates interests of all parties, but does not require unanimous consent. All parties should be committed to its implementation.
  • Consensus on science is the most important.
  • Consensus on treatment recommendations is desirable, but only if there is good agreement
  • We need professionals with good research skills to develop evidence-based guidelines for SA EMS
  • (ILCOR process for analysing evidence and presenting it to consensus meeting demonstrated)
  • GRADE approach is becoming the standard assessment tool
  • HPCSA has begun the processes to review and develop protocols along these lines.
  • Questions and debates:
  • What is the role of protocols for independent practitioners in SA?
  • What is the role of protocols for EMS Professionals?
  • Varying levels of experience, training, scope of practice, clinical governance, models and self-regulation.
  • How to integrate changes quickly into guidelines to reflect current best evidence?

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  1. Minh Le Cong says

    I suspect that if emergency medicine were an international team sport, South Africa would take the cup running for quite a number of years!

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