Dec 31, 2013
Iceland to the foreigner
Dec 7, 2013
Chest pain with subtle yet serious ECG changes
1) Posterior (V1-3) ST depressions
2) ST elevation >1mm in aVR along with depression of anterior leads
3) de Winter ST/T wave complexes anteriorly
This article is free to view in link below but our great colleague and emergency physician Andy Neill in Ireland has reviewed the article nicely on his blog.
Wellens syndrome is a chronic coronary artery occlusion and therefore not a STEMI equivalent. It is nonetheless a serious and unstable condition that requires prompt intervention and every physician should be able to recognize it.
Our patient was admitted to the cardilogy ward and was scheduled for cardiac catheterization the following day. She was stable and pain free on admission. A few hours later she developed a circulatory collapse and underwent acute catheterization which revealed critical stenosis of the left main coronary artery, LAD, circumflex artery and right coronary artery.
* IC Rokos, WJ French, A Mattu, G Nichol, ME Farkouh, J Reiffel, GW Stone. Appropriate Cardiac Cath Lab activation: Optimizing electrocardiogram interpretation and clinical decision-making for acute ST-elevation myocardial infarction. Am Heart J, 160 (2010), pp. 995–1003.
Read more about Wellens at LITFL What is Wellens syndrome?
Nov 1, 2013
A case of extreme heart failure
In the emergency department, the patient is awake but tired and has resting dyspnea. Cheyne-Stokes breathing pattern is noted (frequency of 30 respirations/minute with few seconds of apnea intermittently). She has central and peripheral cyanosis and is peripherally cold, her skin is not marmorized or clammy. Vital signs show varying blood pressure, initial measurement 128/70, pulse 90/min. Intermittently her systolic pressure is as low as 75mmHg. Pulsoximeter shows show saturation of 74% with 3L O2, it has been placed on both hands and even earlobes and always has same values. She is afebrile.
Patient has a previous history of 3-vessel coronary disease and end-stage heart failure, EF has previously been evaluated as 15-20%.
Patient was evaluated as critically ill but did not show clincal signs of immediate threatening circulation or organ failure; she was awake and alert so we decided we had some time to work her up and wanted to start with blood samples, first of all blood gas. The patient was cachetic and we had a hard time finding proper, pulsating arteries; the radial pulses could not be found and the inguinal ones were very vague.
Using sterile techniques the infection risk can be minimized and the fact that we are only punctuating, not inserting a catheter, makes the risk even lower. Bleeding risk with a small needle such as the one mounted to the blood gas syringe is minimal. The risk of hitting the femoral nerve is overestimated, especially if ultrasound is used where the needle can be seen to hit the artery and nothing else. Even in the case of touching or even penetrating the thick sheath of the femoralis nerve, the risk of permanent damage is astronomical with needle so small. This has been thoroughly documented in the literature from research of femoral nerve blocks where complications are extremely rare. Expect the femoral artery at 1,5cm depth in the normal-sized patient and expect problems in obese patients where it may lay as deep as 5-7cm, far beyond reach for the short ABG needle.
Despite very low risk of injury, punctuating the femoralis artery (or vein even) is in my opinion rarely seen unless in extremis such as cardiac arrest and should be considered as a valid option when other sites are not possible.
An alternative for those not so intrigued would be to find the brachialis artery which in most patients is easily palpated in the antecubital fossa, between the medial epicondyle and biceps brachii tendon.
The brachialis artery lies much deeper and will commonly move away from needle and thus harder to get to. It is though though commonly used in pediatrics where it is easier to maneuver.
A decent brachialis vein was seen and a venous blood gas (VBG) was drawn, revealing the following values:
- pH 7.280
- pCO2 6.42 kPa
- pO2 2.74 kPa
- Na 128
- K 4.8
- Crea 86 umol/L
- Ca 1.13 mmol/L
- Cl 95 mmol/L
- Glu 6.1 mmol/L
- Lactate 7.0
- Hb 153 g/L
- CO-Hb 6.9%
- MetHb 0.8%
- calcluated SatO2 27.6%
- HCO3 19.0mmol/L
- BE -3.8mmol/L
A lactate of 1.0 was found only a week ago. This VBG shows a state of mixed respiratory (uncompensated) and metabolic acidosis with normal anion gap (14) - most likely explained by lactic acidosis. As expected, the patient is sick! Increased lactate tells us that tissues are not being perfused adequately and most likely this is because of the heart failure and impending respiratory failure - the patient was getting tired of prolonged hyperventilation and needs help.
A VBG has been show to correlate very well with ABG except for very high pCO2 states, uncommonly encountered and mostly irrelevant (have you heard of the patient who was incredibly hypercapnic? Would you run faster than if he was "just" hypercapnic?). For obvious reasons, VBG cannot measure PO2 since it is always presumed to be arterial and more commonly denoted as PaO2 (note that extra "a") to indicate it's arterial origin. Thus the calculated SaO2 value will always be wrong from a VBG - something I learned by error in this case!
But more important is the distinction between PaO2 and SaO2, mistakenly believed to correlate pretty well. After all they both measure the amount of oxygen in the blood. But PaO2 does not measure effective oxygen, ready for use by the tissues. It's just free O2 molecules and they need to be bound to hemoglobin to be of any use peripherally in tissues. Indeed, too high PaO2 (eg FiO2 100% for longer periods) sets ground for harmful free radicals - Amal Mattu recently had a great post on this on EmRap, reminding us to use O2 sparingly in the post-resuscitative phase after cardiac arrest.
Nontheless - PaO2 clearly indicates how much O2 the patient is taking in through the alveoli and low values suggest you should increase FiO2 and/or assist ventilation and even intubate if everything else fails. What PaO2 does not indicate is if the tissues are *receiving* O2 - the intubated patient on 100% FiO2 can die from hypoxia if hemoglobin is not working (eg. CO poisoning, severe anemia) or perfusion decreased (heart failure, severe bleeding). Indeed, that's the definition of shock, whatever it's cause.
The "perfusing O2" in blood is called 'oxygen content', CaO2 and it's value is calculated by the following formula:
CaO2 = SaO2 * 1.34 * Hb + 0.003 * PaO2
Which underscores the above; perfusing oxygen is literally independent on PaO2. To actually measure tissue perfusion (or hyperperfusion to be accurate), we need... lactate (there are more advanced tools in the ICU eg. Picco)! It's not the most important clinical knowledge but one of the cornerstones of understanding O2 in clinical medicine and reminder to the physician to not only look at the PaO2 value but the whole clinical picture. Excellent in-depth explanation of difference between pO2 and SatO2 Amal Mattu on EmRap: Post Cardiac Arrest Syndrome
Because of hypotension the nurse was getting impatient and wanted to start fluids. A more thorough examination is done:
- Skin: no turgor but general, diffuse pitting edema of whole body, hands, feet, sacrum and even up to flanks.
- Cardiac: distant heart sounds, possibly S3 and a pansystolic murmur. Neck vein distension.
- Lungs: normal respiratory sounds, no crackles, no wheezing heard.
- Bedside ultrasound: a large liver but IVC was hard to visualize properly (this was in my first months of doing ultrasound, no pleural windows were done!). A rough "ECHO" shows all four chambers diffusely dilated and severe global hypokinesia of left ventricle, EF estimated 5-10%.
A chest x-ray is done revealing considerable amounts of pleural fluid on right side, none on left. Slightly dilated central veins, no edema, no infiltrates.
Diuretics may be causing more harm than good as admitted patients get electrolyte imbalances and kidney failure. Their immediate circulatory effects are minimal and very short living and thus doubtful if they fit in AHF treatment at all. Inotropic medicines such as dopamine or simdax are much more relevant in this scenario, even vasopressors to induce better perfusion to tissues.
As Amal Mattu has so excellently pointed out, what seems “most correct” is to use diuretics to treat volume overload, not AHF by itself. If the lungs are full of edema because the whole body is and that fluid puts even more strain on the decompensated heart - whole body fluid needs to be removed. But these patients most commonly will present with acute onset of symptoms and with high blood pressure and need nitro and CPAP, not diuretics. These are the SCAPE patients, standing for “Sympathetic Crashing Acute Pulmonary Edema”. Scott Weingart’s podcast about SCAPE is a must listen as you will encounter these patients often in the ED and with no time to prepare yourself. They will be terrified when you see them because their adrenaline levels are sky high - thus the hypertension. European Heart 2005 guidelines on acute heart failure
Cardiology was consulted and was a little puzzled on the diuretics question but decided it was worth trying small dose lasix on the assumption that some inotropy (contractility) might be gained by shifting the Frank-Sterling curve. Patient was not obviously dehydrated and hypotension is most likely because of low cardiac output. In the cardiology unit Simdax and vasopressors (noradrenaline) were infused to treat a previous diagnosed 'dilated cardiomyopathy' on ischemic basis. The patient had previously stated she didn't want to be operated and only wanted medicines for symptomatic relief.
Major learning points from case
- Standard pulsoximeters in the ED cannot be relied on for SaO2 in heart failure or any form of decreased circulation.
- VBG can be drawn from femoral vein, as long as sterile technique is used and navigated by ultrasound.
- VBG correlates excellently with ABG values except for PO2, in low perfusion states an ABG must be used since the pulsoximeter gives false values.
- Hypotension does not equal hypovolemia!
- Diuretics should not be pushed thoughtlessly in acute heart failure and are seldomly first line treatment anymore - not even in acute, pulmonary edema or congestive heart failure!
Sep 11, 2013
The state of emergency medicine in Iceland in 2013
Some resistance was met when the specialty was established about 20 years ago. The need was obvious and other specialties had minimal interest in working on the floor additionally to working daytime but some specialties had vested interests to keep a presumed position of power at the front line.
Jón Baldursson (board certified 1992) came back from US in 1991, having himself experienced the practice of modern emergency medicine in Cincinnati, where the first EM training program in USA was established in 1970. With patience and excellent personal skills and formal training in emergency medicine he was able to convince the hospital management and political bodies that EM was the only right way to go and of paramount importance as the speciality was unheard of in Iceland at the time.
A formal 2-year training program in EM was launched in 2002. It’s scope was and still is to provide physicians with the first half of the required training in the field. With an increasing interest worldwide and excellent conditions to practise emergency medicine in an academic hospital, a large group of ambitious and eager residents was recruited, many of whom are now returning having completed specialty training in the USA, UK, Australia, New Zealand and Sweden.
Now that more consultants have returned with expertise from abroad the group has taken over nearly all lines of acutely sick patients but not wholly psychiatry, pediatrics (we do ped. trauma) and gynaecology. Airway management and procedural sedation is mostly in our hands by now. Being located far up in the Atlantic we are far away from bigger and more specialised centers and thus are mostly on our own - a utopia for the emergency physician!
Our island is nearly half the size of the UK (103.000km2) but only populated with 320.000 inhabitants in a wild landscape of mountains and fjords. Thus, backup and medical consulting to rural clinics, EMS and HEMS (also serving surrounding Atlantic ocean for up to 250 miles off shore) is closely tied to our ED activity. Many rotating residents have thus had their first knowledge of emergency medicine through prehospital work which has helped to attract them to our program.
Being a nation of few inhabitants creates short communicative distances and working in the ED you are most likely to somehow know your colleagues working in other departments of the hospital. There is only one medical school in Iceland. Thus, collegiality is respected, interhospital communications are softer and problems are usually solved without conflicts. This friendly climate made the introduction of emergency medicine easier.
The relative isolation of the country increases need for communications with colleagues abroad and thus social media is greatly welcomed for emergency medicine in Iceland. We have 10 days per year set off for CME and strive to attend conferences overseas to stay up-to-date and establish relations with colleagues in the field.
We see a bright future for emergency medicine in Iceland. We are a large group of young and enthusiastic physicians building up an academic emergency department with ever growing number of patients in a country having just ducked a financial crisis. With a tight budget and a growing need of resources, management welcomes new ideas and solutions to old problems creating a flourishing environment for young and creative physicians whether they want to do academic research or improve flow and statistics.
It is worth noticing that all Icelanders learn English at school and speak the language fluently. Thus we have been able to invite colleagues from abroad who are interested in working in our department and thus become acquainted with the way we practice EM in our country and even see our country, from outside the ED.