On the 17th and 18th September 2010, I attended the Hong Kong Scientific Symposium on Emergency Medicine organized by the Hong Kong College of Emergency Medicine. The theme of this year was ABC for resuscitology: Advances, Beliefs and Consensus. This symposium included various fields, such as resuscitology, toxicology, trauma resuscitation, emergency imaging, critical care, sports and wilderness medicine and ethical issues, all of which I found very useful to my everyday work in the A&E. The topic which interested me most was "Pearls and Pitfalls in Caring for the Crashing Patient: Beyond A-B-C and ACLS" by Prof Amal Mattu, Maryland. The speaker concluded ten things to be considered in the crashing patient. These ten things can be memorized as a mnemonic of AABBCCDDEE.
Aortic disasters: Of all crashing patients, aortic disasters including thoracic aortic dissection (TAD) and abdominal aortic aneurysm (AAA) should be considered, regardless of atypical symptoms. Early routine ECHO/ ultrasonography in all crashing patients is suggested. TAD may be present as pericardial effusion while AAA present as a large aorta (>3cm diameter).
Acidosis: Primary metabolic acidosis is associated with compensatory respiratory alkalosis. If intubation is compulsory, a high respiratory rate is suggested in patients with acidosis. Or if condition is limited for hyperventilation, IV sodium bicarbonate before intubation is helpful.
Bagging/ breathing: In CPR, hyperventilation induces elevated intrathoracic pressure which decreases cardiac output, coronary and cerebral perfusion. Rescue breaths should be given every 5 seconds to make 12 breaths per minute. The speaker suggested the team leader to remind the rescurers to slow down the ventilation rate regularly during CPR.
Baby: Always consider ruptured ectopic pregnancy in the crashing female patients! Some of them may present as paradoxical relative bradycardia. Things to bare in mind in resuscitating the arresting mother includes: i) the most commonly used antidysrhythmic agent --amiodarone, is FDA D class, not recommended unless other drugs fail; ii) cardioversion and defibrillation is considered safe to fetus, since fetus has high fibrillation threshold; iii) left lateral tilt position can improve venous return and improve cardiac output, however, only 80% of the external compression forces of CPR are transmitted. Therefore, supine position with manual displacement of the uterus to the left is recommended.
Compressions: "Push hard, push fast and allow complete chest recoil". The survival rate decreases with lower chest compression rate. In adult CPR, the importance is emphasized more on compressions since most cardiac arrest patients are of cardiac origin. It is suggested no positive pressure ventilation/ intubation should be given for the first 8 to 12 minutes. This however, does not apply to pulmonary and pediatric arrest.
Cooling: Cooling to 32-34oC postresuscitation is found to be beneficial. External methods like cooling helmet or ice packs are commonly used whereas internal methods are generally considered too invasive for routine use.
Decline position (TrenDelenberg): It has been proved that the decline position does no good and therefore no longer be used.
Defibrillation: Monophasic and biphasic defibrillators show no difference in efficacy. Research indicates, however, that when doses equivalent to or lower than monophasic doses are used, biphasic waveform shocks are safe and effective for termination of VF.
Effusion (pericardial): It is a common cause of unexplained dyspnea. Early routine ECHO in crashing/ arresting patients is advised. Oxygen saturation usually appears normal because alveolar oxygen exchange remains unaffected. IV fluids can help with blood pressure whereas intubation with positive pressure ventilation will decrease output and lower blood pressure.
Embolus (pulmonary): Early routine ECHO will help with the diagnosis. ECG clues include new T-wave inversion in anteroseptal and inferior leads, and tall R-wave in lead V1. Contrary to pericardial effusion, IV fluids are harmful with PE. Early use of vasopressors like dobutamine, dopamine or norepinephrine, and intubation is beneficial. Hemodynamically unstable patients with suspected PE are reasonable indication for empirical thrombolytics.(Chang Pive Sok Cheng, AED)