May be a family history of DVT or PE. Hyperventilation syndrome (see p.138) - Anxiety/panic - Hyperventilation - Per-oral tinglin g - Carpopedal spasm - Tinnitus - Chest tightness. Respiratory compensation for a metabolic acidosis - Difficult to diagnose definitively pre- hospital - May be secondary to: Diabetic ketoacidosis - Tricyclic antidepressant poisoning. CHAPTER 2 Acute medical and surgical problems 78 Pre-hospital investigations and monitoring Pre-hospital investigations are only of value if the results will alter patient management. Most investigations can be undertaken more effe ctively, more comfortably, and more quickly after arrival in hospital. Under no circumstanc es should the transfer of a critically ill or injured patient be delayed. All patients with significant injuries or medical problems should have the following monitoring: - ECG - Pulse oximetry - Non-invasive BP (during transfer) ALL pa tients whose level of conscious is reduced should have a BM stix (blood sugar measurement ). This page intentionally left blank CHAPTER 2 Acute medical and surgical problems 80 Pulse oximetry The pulse oximeter probe contains two light-emitting diodes (producing red a nd infrared light) and a light detector which measures the intensity of the light after it has passed through the tissues. Oxygenated and reduced haemoglobins show different light-ab sorbing properties which affect the relative amounts of light measured by the sensor. Pulse oximetry measures pulse and oxygen saturation; it does not measure PaO2. Applications - Measurement of oxygenation during transportation. - Assessment of limb viabi lity following injury. - Assessment of pulse and saturation in ill patients. Limitations - Does not measure CO2, therefore may provide false reassurance in respiratory failure or inadequacy with rising CO2 levels. May be ineffective in poor tissue perfusion (including due to cold). - Effected by bright a mbient light. - Ineffective through metallic nail varnish. - Does not distinguish met- or c arboxyhaemoglobins and may, therefore, give a falsely high O2 reading in carbon monoxide poisoning. PULSE OXIMETRY1 81 Altitude (x 1000ft) 5 15 10 Sea level 100 90 80 70 b H n o i t a r u t a S % 60 50 40 30 20 10 0 0 10 20 30 40 50 60 70 80 90 100 110 Partial pressure of arterial oxygen (mmHg) Fig. 2.1 Hemoglobin-oxygen dissociation curve. CHAPTER 2 Acute medical and surgical problems 82 Cardiological emergencies Patient assessment The assessment of the patient with a known or suspected cardiac prob- lem is as follows: - Observe Responsiveness - Pallor - Sweating - Dyspnoea (count the respiratory rate!) - Cyanosis - Ju gular venous pressure Listen Noise of airway obstruction - Wheeze - Added sounds (crepitations or rhonchi) - Heart sound s Feel Pulse (volume, rate, and character) - Distal pulses where appropriate - Chest expansion. Cardiac arrest The most common arrhythmias associated with cardiac arrest are ven- tricular fibrillation (VF) and pulseless ventricular tachycardia (pulseless VT). Providing good-qua lity advanced life support is available, there is little if any justification for transport ing patients with one of these rhythms to hospital until cardiac output has been restored. Cardiac arrest may also occur with pulseless electrical activity (PEA) and asystole. Immediate actions in cardiac arrest: Assess response - Assess airway - Assess breathing - Call for help Expose chest - Commence CPR 30 compressions: 2 breaths. As soon as a diagnosis of cardiac arrest is established, professional assistance must be so ught if a defibrillator is not available, even if this means leaving the patient for a shor t period. Safety Safety is vital at a cardiac arrest. Careful attention should be paid to ensuring th at rescuers are not at risk during defibrillation. Defibrillation may take place in the rai n (the patient \200\231s chest should be wiped dry first) but is dangerous if the patient i s lying in a pool of water (for example, at the side of a swimming pool). CARDIOLOGICAL EMERGENCIES1 83 (a) (b) (c) Fig. 2.2 Placing a patient in the recovery position. Reprinted with permission from Greaves I and Porter K (1997). Pre-hospital medicine \200\224the principles and practice of immedi ate care. Edward Arnold (Publishers) Ltd. CHAPTER 2 Acute medical and surgical problems 84 Basic life support Good basic life support is the key to the treatment of cardiac arrest. P rolonged absence of BLS makes a successful outcome extremely unlikely. If a patient has not had BLS for 15 minutes or more after a collapse, and the monitor shows asystole, ALS is no t indicated. The Joint Royal Colleges Ambulance Liaison Committee (JRCALC) recognizes the following as b eing reasons for NOT commencing resusci- tation: - Decapitation - Massive cranial and cereb ral destruction - Hemi-corporectomy - Decomposition - Incineration - Hypostasis - Rigor mor tis - Submersion for more than one hour - Presence of a \200\230Do Not Resuscitate \200 \231 (DNR) order or living will. Artificial ventilation In order to avoid the risk of transmission of infection, not to ment ion for esthetic reasons, mouth-to-mouth resuscitation cannot be recom- mended for use by h ealth-care professionals. Whenever possible, mouth-to-mask ventilation should be used with supplemental oxygen. A resuscitation face shield or pocket mask is an alternative. If mouth-to-mouth is carried out, the nose should be closed by pinching and poorly fitting dentures and foreign bodies removed from the mouth. Well- fitting dentures should be left i n place. Summary of BLS CHECK FOR SAFETY - Check for responsiveness (shake the shoulders* and ask \200\230are you alright? \200\231). If the patient responds, leave them as they are; attempt to gain further information and seek help if necessary. If there is no response, SHOUT FOR HELP. - Use simple maneuvers to open the airway. - If th ey are breathing normally, put them in the recovery position and obtain help, otherwise: Give 30 compressions \200\224DO NOT check the pulse first (for technique, see below). Give 2 rescue breaths (for technique, see below). - Repeat cycle of 30 compressions followe d by 2 rescue breaths**. - Continue until spontaneous breathing recommences or assistance (with a defibrillator) arrives. NOTES Care if there is a possibility of C spine injury. ** Compression only CPR may be used as an alternative in situations where the rescuer is unable or unwilling to provide artificial r espiration. CARDIOLOGICAL EMERGENCIES1 85 UNRESPONSIVE? Shout for help Open airway NOT BREATHING NORMALLY? Call 999 30 chest compressions 2 rescue breaths 30 compressions Fig. 2.3 Adult basic life support algorithm. Reprinted wth permission from Resus- citation Council (UK) (2005). Resuscitation Guidelines. CHAPTER 2 Acute medical and surgical problems 86 Technique of mouth-to-mask ventilation - The airway is cleared and the chin tilted (ideally not if there is a risk of C spine injury, although it may be necessary). Well-fitting fals e teeth are left in situ. The mask is applied over the nose and mouth and the face \200\230lifted \200\231 into it with the hands in the position shown opposite (Fig. 2.4a) Breaths lasting 1 second are given, whilst watching for the chest to rise. - During the \200\230expiration \200\231 phase, the mouth is lifted from the mask which continues to be held in place Irrespective of the number of rescuers, ventilations are delivered at a ratio of 2 breaths to 30 compressions. Technique of chest compressions (see Fig. 2.4b) - The heal of the hand is placed at the mid point between the suprasternal notch and the xiphisternum. The other hand is placed on top of the first and the fingers interlocked. - Keeping the arm s vertical and straight, the chest is compressed one-third of the thickness of the chest. The pressure is released. - The compression is repeated 100 times per minute in a ratio 30 compressions to 2 breaths. The compression and release phases should take approximately the same time. Abandoning resuscitation Resuscitation may be abandoned after 20 minutes of full ALS with s ystole, unless: - The patient is a child. - The patient is hypothermic. - The patient is a victim of drowning. - The patient may have, or is known to have taken an overdose of drugs. - The situation is in any way \200\230unusual \200\231. CARDIOLOGICAL EMERGENCIES1 87 (a) (b) Fig. 2.4 (a) Artificial ventilation and (b) chest compression. Reprinted with permis- sion from Greaves I et al. (2005), Emergency Care \200\224a textbook for paramedics. CHAPTER 2 Acute medical and surgical problems 88 CHOKING IN ADULTS The algorithm for the management of choking in adults is given opposite i n Fig. 2.5. CARDIOLOGICAL EMERGENCIES1 89 Assess severity Mild airway obstruction (Effective cough) Severe airway obstruction (Ineffective cough) Encourage cough Conscious Unconscious Continue to check for deterioration to ineffective cough or relief of obstruction 5 back blows Start CPR 5 abdominal thrusts Fig. 2.5 Adult choking algorithm. Reprinted with permission from the Resuscitation Council (UK) (2005), Resuscitation guidelines. CHAPTER 2 Acute medical and surgical problems 90 Advanced life support General comments - If there is any doubt about the rhythm, it should be treated as VF. - Ensure that the monitor is reading from leads or paddles as appropriate. Ensure that the monitor is reading from the correct lead (lead II). - Ensure that the patie nt is connected to the correct monitor (if arriving after paramedics or first responders). Drugs in cardiac arrest There is no role for either central venous access or intracardiac i njec- tions in pre-hospital care. Drugs should be given by IV access via a large peripheral vein, external jugular vein, or femoral vein. Intraosseons access is an effective alternat ive. Defibrillation should not be delayed during attempts at cannulation. The ONLY indicati on for sodium bicarbonate in pre-hospital care is cardiac arrest due to known or suspected tricyclic antidepressant overdose. Although adrenaline, atropine, and lignocaine can be giv en via the ET tube, this should be considered a last resort. Patient handover The following information should be recorded and handed over to medi- cal staff on arrival at the emergency department: - Presence/absence of bystander CPR and durat ion. - Duration of advanced life support. - Number of defibrillating shocks. - Duration of cardiac arrest/apnoea. - Other treatment given. - Past medical history/drug history. Following cardiac arrest, no attempt should be made to warm the patient up since moderate h ypothermia (32 \200\22334o) appears to be beneficial. ADVANCED LIFE SUPPORT1 91 Ventricular fibrillation (VF)/pulseless ventricular tachycardia (pulseless VT) Fig. 2.6 Ventricular fibrillation. Reprinted with permission from Myerson SG et al. (2005) Emergencies in Cardiology. Oxford University Press, Oxford. Fig. 2.7 Ventricular tachycardia. CHAPTER 2 Acute medical and surgical problems 92 Defibrillation Rapid defibrillation is the key to optimal resuscitation and offers the best chance of success. Therefore, there is no need to carry out a pulse check between shocks u nless the monitor shows a change of rhythm to one compatible with an output. Chest compress ions should not be carried out between shocks. - The anterior paddle is placed just to the right of the upper sternum below the clavicle. The second paddle is placed over the cardiac apex. - Paddles should be kept at a maximum po ssible distance from implanted pacemakers. Nitrate patches should be removed. - A single shock is given at 360J (150 \200\223200J for a biphasic defibrillator \210\227). - After 2 minutes of CPR (30:2) and a pulse check, a se cond shock is given at 360J monophasic (150 \200\223360J biphasic). All subsequent shocks are at 360J monophasic (150 \200\223360J biphasic). If there is doubt about whether the rhythm is fine VF or asystole, DO NOT defibrillate but continue compressions and ventilations. In out-of-hospital cardiac arrest attended by but UNWITNESSED by health care professionals, 2 minutes of CPR should be given before defi- brillation. In WITNESSED arrest, the first shock is given IMMEDIATELY. When defibrillating, check: - That the monitor is set on leads or paddles, as appropriate - That the leads are connected to the monitor/defibrillator - That the monitor trace has not changed before each shock If VF/pulseless VT fails to respond to repeated defibrillation, considera- tion should be given to: - Moving the defibrillator pads - Changing defibrillator Using an automated external defibrillator AED Some first responders will use an AED with th e result that this type of defibrillator is available before a manual defibrillator. Notes - Amiodarone 300mg IV should be considered if there has been no response to three shocks. A further dose of 150mg may be given for recurrent or refractory VF. If amiodarone is not available, lignocaine 1mg/kg \200\2231 may be used as an alternative (maximum dose 3mg/kg \200\2231 in first hour). Adrenaline 1mg (10ml 1:10,000) should be given every 3 \200\2235 minutes (before the third shock). \210\227 The energy values for biphasic defibrillators vary between machines. ADVANCED LIFE SUPPORT1 93 Unresponsive? Open airway Look for signs of life Call Resuscitation Team CPR 30:2 Until defibrillator/monitor attached Assess rhythm During CPR: - Correct reversible causes* - Check electrode position Shockable (VF/puseless VT) and contact - Attempt/verify IV access airway and oxygen - Give uniterrupted 1 Shock 150 \200\223360 J biphasic or 360 J monophasic compressions when airway secure Give adrenaline 1mg every 3 \200\2235 min Immediately resume CPR 30:2 for 2 min Consider: amiodarone, atopine, magnesium Reversible Causes Tension pneumothorax Tamponade, cardiac Toxins Thrombosis (coronary or pulmonary) Hypoxia Hypovolaemia Hypo/hyperkalaemia/metabolic Hypothermia Fig. 2.8 Adult advanced life support algorithm. Reprinted with permission from the Resuscit ation Council (UK) (2005), Resuscitation guidelines. 1mg adrenaline IV should be given as s oon as IV access is obtained and repeated every 3 \200\2235 minutes thereafter until return of spontaneous circulation is obtained. CHAPTER 2 Acute medical and surgical problems 94 If the patient has taken an overdose of a tricyclic antidepressant (see p.459), the appropr iate treatment of their arrhythmias includes sodium bicarbonate. Unless this is immediately available, rapid evacuation to hospital is essential. Non-shockable rhythms (asystole/PEA) 4 Hs and 4 Ts The potentially reversible causes of asy stole/PEA arrest are: \200\2304 H \200\231s \200\231 Hypoxia - Hypovolaemia - Hypo/hyperkalaemia and other electrolyte disturbances - Hypothermi a And: \200\2304 Ts \200\231 Tension pneumothorax - Tamponade (cardiac) - Toxins (drugs) - Thromboembolism Thrombolysis at cardiac arrest Thrombolysis should be considered when cardiac arrest is tho ught to be due to proven or suspected pulmonary embolus. Consideration should be given to p erforming CPR for up to 60 \200\22390 minutes when thrombolytic agents have been given. Notes Hypoxia This cause of cardiac arrest is dealed with by the establishment of a pro- te cted patent airway, artificial ventilation, and effective chest compressions. Attention can then be transferred to seeking other potential causes. Hypovolaemia The most common cause of cardiac arrest due to hypovolaemia is probably trauma . The outcome is bleak. The diagnosis is usually apparent from the history. Other common po tential causes include: - Ectopic pregnancy \200\224women of child-bearing age, may be know n to be pregnant Abdominal aortic aneurysm \200\224severe sudden onset of abdominal pain radiating to back, with distension In all these cases, once cardiac arrest has occurred, the chances of a successful outcome a re extremely small and will depend on the patient reaching surgery as rapidly as possible. The clinical emphasis must, there- fore, be on immediate evacuation to hospital. IV access and fluid resusci- tation can be attempted en route. ADVANCED LIFE SUPPORT1 95 Unresponsive Call for help Open airway Not breathing normally Send or go for AED Call 999 CPR 30:2 Until AED is attached AED assesses rhythm Shock advised No Shock advised 1 Shock 150 \200\223360 J biphasic or 360 J monophasic Immediately resume CPR 30:2 for 2 min Immediately resume CPR 30:2 for 2 min Continue until the victim starts to breathe normally Fig. 2.9 Algorithm for use with an AED. Reprinted with permission from the Resuscitation Co uncil (UK) (2005), Resuscitation Guidelines. Non-Shockable (PEA /Asystole Immediately resume CPR 30:2 for 2 min Fig. 2.10 ALS algorithm non VF/pulseless VT. Adapted with permission from the Resuscitation Council (UK) (2005), Resuscitation Guidelines. CHAPTER 2 Acute medical and surgical problems 96 Hypo/hyperkalaemia, hypocalcaemia This diagnosis can usually only be made on presumptive gr ounds unless there is evidence of renal failure from the examination or history (such as a dialysis shunt or CAPD catheter) when hyperkalaemia can be assumed or it is clear that the patient has taken calcium channel blockers. In any case of EMD, administration of 10ml calc ium gluconate or chloride will do no harm and may be effective. Hypothermia Hypothermia <35*C. A patient is hypothermic if they feel cold centrally (i.e. o n the chest). The treatment is discussed on pp.554 \200\2237. Tension pneumothorax The signs of tension pneumothorax are: - Hyper-resonant percussion not e (ipsilateral) - Absent breath sounds (ipsilateral) - Reduced chest movement (ipsilateral) - Elevated JVP (unless the patient is hypovolaemic) - Trachea deviation to contralateral s ide (late) - Increasing difficulty in ventilating via an ET tube. The management is needle thoracocentesis. This should be performed if there is any possibility of tension pneumothor ax in the arrested patient. Clues to this diagnosis include a history of trauma, asthma, po sitive pres- sure ventilation, or external cardiac massage. Cardiac tamponade In blunt trauma, cardiac tamponade is invariably fatal. Fruitless pericar - diocentesis or thoracotomy are NOT indicated. The ONLY indication for either procedure pr e-hospital is in a patient who has sustained pene- trating trauma to the heart and who lose s output whilst the doctor is present or who has shown signs of life within the previous 10 minutes. In such rare circumstances, thoracotomy and sealing the cardiac perforation may b e lifesaving. Needle pericardiocentesis is valueless in the arrested patient. Toxins Unless the toxin is immediately apparent and an antidote is avail- able, there is li ttle that can be done in cardiac arrest due to toxins. Specific antidotes should be used on ly if the toxic substance is known, although administration of intravenous calcium (10ml gl uconate/chloride) is reasonable. Thromboembolism Thromboembolism (pulmonary embolism) large enough to cause cardiac arrest i s almost invariably fatal. In some rare cases, the embolus may fragment with vigorous chest compression. No other treatment is indi- cated pre-hospital. See p.117. ADVANCED LIFE SUPPORT1 97 Peri-arrest arrhythmias Tachycardias The management of peri-arrest tachycardias depends ult imately on whether the tachycardia is broad complex or narrow complex. The algorithms for b road and narrow complex tachycardias peri-arrest are given on the following pages. Table 2.1 Potentially reversible causes of asystole/PEA arrest Diagnosis Management Hypoxia History of inadequate ventilation or perfusion High-flow oxygen Ventilatory support Hypovolaemia History or signs of trauma or other causes of blood loss Rapid intravenous fluid infusion Hypo/hyperkalaemia; hypocalcaemia Medical history of renal failure, presence of a dialysis shunt, clues from medication Hyperkalaemia \200\224calcium chloride 10ml* Hypothermia Feel skin temperature Patient warming Needle thoracocentesis Tension pneumothorax Signs of tension pneumothorax (see p.96) Tamponade Urgent transfer Usually penetrating trauma to the pericardium Toxins Antidote, if available Clues from history, scene, or medication Thromboembolism Clues from past medical history or recent activity May respond to vigorous cardiac compression. Consider thrombolysis or gluconate CHAPTER 2 Acute medical and surgical problems 98 Support ABCs: give oxygen; cannulate a vein - Monitor ECG, BP, SpO2 - Record 12-lead ECG if possible; if not, record rhythm strip - Identify and treat reversible causes (e.g. electro lyte abnormalities) Is patient stable? Signs of instability include: 1. Reduced conscious level 2. Chest pain 3. Systolic BP<90 mm Hg 4. Heart failure (Rate-related symptoms uncommon at less than 150 beats min \200\2231) TRANSFER Give amiodarone 300mg over 10 min Unstable Stable Is QRS narrow (<0.12 sec)? Broad Broad QRS Is QRS regular? Irregular Regular Seek expert help Possibilities include: - AF with bundle branch block treat as for narrow complex If Ventricular tachycardia (or uncertain rhythm): amiodarone 300mg IV over 20 \200\22360 mi n; then 900mg over 24 h Pre-excited AF consider amiodarone - Polymorphic VT (e.g. If previously confirmed SVT with bundle branch block: - Give adenosine as for regular narro w complex tachycardia torsade de pointes) give magnesium 2g over 10 min TRANSFER Fig. 2.11 Algorithm for peri-arrest broad complex tachycardia. Adapted with permission from the Resuscitation Council (UK) (2005), Resuscitation Guidelines. ADVANCED LIFE SUPPORT1 99 Support ABCs: give oxygen; cannulate a vein - Monitor ECG, BP, SpO2 - Record 12-lead ECG if possible; if not, record rhythm strip - Identify and treat reversible causes (e.g. electro lyte abnormalities) Is patient stable? Signs of instability include: 1. Reduced conscious level 2. Chest pain 3. Systolic BP < 90 mmHg 4. Heart failure (Rate-related symptoms uncommon at less than 150 beats min \200\2231) TRANSFER Give amiodarone 300mg over 10 min Unstable Stable Is QRS narrow (<0.12 sec)? Narrow Narrow QRS Is rhythm regular? Regular Irregular Use vagal maneuvers - Adenosine 6mg rapid IV bolus; if unsuccessful give 12mg if unsuccessf ul give further 12mg. TRANSFER Monitor ECG continuously TRANSFER Fig. 2.12 Algorithm for peri-arrest narrow complex tachycardia. Adapted with permission fro m the Resuscitation Council (UK) (2005). Resuscitation Guidelines. Note: In the majority of cases amiodarone and adenosine use should be restricted to hospital practice. Use may occa sionally be justified by medical practitioner of transfer times are prolonged. Short self-terminating runs of VT do not require any treatment. CHAPTER 2 Acute medical and surgical problems 100 Peri-arrest bradycardias Adverse signs? Give oxygen - Systolic BP <90 mmHg - Heart rate <40 beats min \200\2231 - Ventricular arrhy thmias Yes No compromising BP Heart failure Atropine 500mcg IV No Yes Satisfactory response? Risk of asystole? No Recent asystole - Mobitz II AV block - Complete heart block Yes Interim measures: with broad QRS Ventricular pause > 3 sec Atropine 50mcg IV repeat to maximum of 3mg - Adrenaline 2 \200\22310mcg min \200\2231 - Alternative drugs OR - Transcutaneous pacing No TRANSFER TRANSFER Fig. 2.13 Algorithm for peri-arrest bradycardias. Adapted with permission from the Resuscit ation Council (UK) (2005). Resuscitation Guidelines. This page intentionally left blank CHAPTER 2 Acute medical and surgical problems 102 Bradycardias Sinus bradycardia ECG abnormalities Normal morphology, heart rate <60 bpm. Clinical features Patient may be aware of a slow pulse. Initial management None required. Fig. 2.14 Sinus bradycardia. Reprinted with permission from Myerson SG et al. (2005). Emerg encies in Cardiology. Oxford University Press, Oxford. BRADYCARDIAS1 103 1st degree heart block ECG abnormalities Prolonged PR interval \211 0.2 sec (5 small squar es). Clinical features None. Initial management None required. Fig. 2.15 1st degree heart block. CHAPTER 2 Acute medical and surgical problems 104 2nd degree heart block: M bitz type 1 (Wenckebach) ECG abnormalities Progressive lengthening of PR interval with intermittent complete AV bloc k and failure of conduction of P wave. Clinical features Usually none. Initial management No specific treatment is required pre-hospital. Fig. 2.16 2nd degree heart block: I. M bitz type 1 (Wenckebach). BRADYCARDIAS1 105 2nd degree heart block: M bitz type 2 (irregular block) ECG abnormalities Normal constant PR interval but intermittent complete heart block (P wave with no corresponding QRS). Clinical features Usually none. May develop low output state. Initial management - Following myocardial infarction (classically inferior MI), suggests possibility of progression to asystole, therefore administer atropine. If haemodynamically stable, no treatment. - If haemodynamic compromise, atropine 0.5mg repe ated if necessary, followed by external pacing if no response. Transfer to hospital, oxygen, intravenous access, monitor ECG, pulse, BP, and pulse oximetr y. Fig. 2.17 2nd degree heart block: II M bitz type 2 (irregular block). CHAPTER 2 Acute medical and surgical problems 106 2nd degree heart block: M bitz type 2 (2:1, 3:1, 4:1 block, etc.) ECG abnormalities Consta nt PR interval but every second, third, fourth (etc.) P wave is not conducted to the ventri cles (QRS absent). Clinical features Usually none. May suffer palpitation and a low output state. Immediate management - If haemodynamically stable, no treatment. - If haemodynamic compromi se, atropine 0.5mg repeated if necessary, followed by external pacing if no response. Transfer to hospital, oxygen, IV access, monitor ECG, pulse, BP, and pulse oximetry. Fig. 2.18 2nd degree heart block, M bitz type 2: III 2:1, 3:1, 4:1 block, etc. Reprinted w ith permission from Myerson SG et al. (2005). Oxford University Press, Oxford. Emergencies in Cardiology. BRADYCARDIAS1 107 3rd degree (complete) heart block ECG abnormalities Complete failure of conduction from atr ia to ventricles with independent atrial and ventricular activity. Presenting features Will vary with cardiovascular state of patient and the heart rate. - Pa lpitation - Hypotension - Heart failure. Immediate management Rapid transfer to hospital, oxygen, IV access, monitor ECG, pulse, BP, and pulse oximetry. - If asymptomatic and rate >40, no treatment. - If asymptomatic and ra te <40, atropine 0.5mg repeated if necessary. - If cardiovascular compromise, atropine 0.5m g repeated if necessary. - If no response to atropine (maximum 3mg), consider external paci ng. Fig. 2.19 3rd degree (complete) heart block. CHAPTER 2 Acute medical and surgical problems 108 Tachycardias Supraventricular tachycardia: I (AV nodal re-entrant tachycardia \200\224AVNRT ) ECG abnormalities Regular, rapid, narrow complex tachycardia. P waves not usually visible . Rate 140 \200\223200 bpm. Presenting features - Palpitation - Shortness of breath - Ischaemic chest pain Note: the sy mptoms of AVNRT may be remarkably mild in young fit individuals. Initial management Vasovagal maneuver. If this fails: - Urgent transfer to hospital or if t ransfer likely to be delayed or prolonged and patient is cardiovascularly compromised: Adenosine challenge (contraindicated in asthma) Warn patient about chest tightness and a feeling of panic - Run a continuous rhythm strip ( lead II) - Give 6mg adenosine followed by a 10ml flush - If unsuccessful, give 12mg adenosi ne followed by a 10ml flush If this fails: - Urgent transfer to hospital for further management. - Oxygen, IV access, m onitor ECG, pulse, BP, and pulse oximetry. Fig. 2.20 Supraventricular tachycardia: I (AV nodal re-entrant tachycardia \200\224AVNRT). TACHYCARDIAS1 109 Atrial fibrillation ECG abnormalities Irregular, narrow complex tachycardia. No P waves. Fi brillation waves (not always present). Rate very variable <200 bpm. Presenting features May be absent, will depend on cardiovascular status of patient, rate, a nd time since onset. Chronic AF is less likely to be symptomatic. - Palpitation - Shortness of breath - Heart failure - Ischaemic chest pain. Immediate management - New diagnosis: rapid transfer to hospital, oxygen, intravenous acces s, monitor ECG, pulse, BP, and pulse oximetry. If the patient is cardiovascularly compromised and evacuation is likely to be prolonged or delayed, amiodarone 300mg IV may be given. Fig. 2.21 Atrial fibrillation. CHAPTER 2 Acute medical and surgical problems 110 Atrial flutter ECG abnormalities Saw tooth flutter waves 300 per minute (best seen in II, I II aVF, and VI). Rate 75 \200\223175 depending on degree of block. Note: a heart rate of 15 0 is very strongly suggestive of flutter with 2:1 block. Presenting features - Palpitation - Shortness of breath - Heart failure - Ischaemic chest p ain. Immediate management - Carotid sinus massage may increase the degree of AV block, confirming the diagnosis but is unlikely to terminate the arrhythmia. - Transfer to hospita l, oxygen, IV access, monitor ECG, pulse, BP, and pulse oximetry. Fig. 2.22 Atrial flutter. TACHYCARDIAS1 111 Ventricular tachycardia ECG abnormalities Tachycardia with QRS width >120 ms (3 small squares). Note: without previ ous ECGs, it is extremely difficult to distinguish SVT with bundle branch block from VT. Al l broad complex tachycardias with haemodynamic compromise should be treated as VT. Presenting features - Palpitation - Shortness of breath - Heart failure - Ischaemic chest p ain. Immediate management No pulse Follow cardiac arrest protocol and treat as VF. Pulse Short r uns (less than 30 sec) should not be treated. Runs longer than 30 sec: Amiodarone 300mg ove r 15 min or Lignocaine 50mg over 2 min, repeated every 5 min to a maximum of 200mg or Magne sium 8mmol over 2 \200\2235 min may also be given Fig. 2.23 Ventricular tachycardia. CHAPTER 2 Acute medical and surgical problems 112 Torsade de pointes ECG abnormalities Variation of VT in which appears to twist about the x axis. Presenting features - Palpitation - Shortness of breath - Heart failure - Ischaemic chest p ain. Immediate management Pulseless: manage as VF, otherwise as for VT, consider IV magnesium 4m l or 2mg by slow IV injection. Fig. 2.24 Torsade de pointes. This page intentionally left blank CHAPTER 2 Acute medical and surgical problems 114 Myocardial ischaemia Unstable angina In the early stages, unstable or crescendo angina is i ndistinguishable from non-Q wave myocardial infarction. Crescendo or unstable angina presents with ischaemic pain at rest, sudden onset disabling a ngina or rapid deterioration in previous long- standing stable angina. Symptoms - Crushing/tight central chest pain - Discomfort/heaviness in the arms (more often the left) - Discomfort in the neck and jaw - Nausea and vomiting - Sweating - Shortness of breath. Signs - Pallor - Sweating - Signs associated with complications or precipitants: Palpitation - Hypotension - Pulmonary oedema. ECG abnormalities (See Fig. 2.25) - T wave flattening or inversion - ST depression. Initial management - Rest - High-flow O2 - Monitor pulse oximetry, ECG, pulse respiratory r ate, and BP - Aspirin 300mg (unless recent major GI bleed or aspirin allergic) - Nitrate (b uccal or sublingual \200\224dose varies with formulation) - Diamorphine up to 5mg with meto clopramide 10mg - Urgent evacuation to hospital for further management. MYOCARDIAL ISCHAEMIA1 115 I II III aVR aVL aVF V1 V2 V3 V4 V5 V6 Fig. 2.25 ECG in unstable angina/non-Q wave infarction. Reprinted with permission from Wyat t J et al. (2005). Oxford Handbook of Accident and Emergency Medicine, 2nd edn. Oxford Univ ersity Press, Oxford. CHAPTER 2 Acute medical and surgical problems 116 Acute myocardial infarction Symptoms As for unstable angina, but: - Pain likely to be more severe - Sweating, nausea, and vomiting likely to be more marked. Signs As for unstable angina, but also: - Bradycardia/tachycardia - Cardiac failure/shock ( JVP, murmurs, basal crepitations, BP). ECG abnormalities May be absent in early stages. - Peaked T waves and ST elevation. Followe d by - ST elevation and \200\230mirror \200\231 ST depression. Followed by - Development o f Q waves. Followed by - T wave inversion. Location of changes: - Inferior MI II, III aVF (may extend laterally or posteriorly). Anterior MI V1 \200\223V3 (may extend to V4, anteroseptal or to V6, anterolateral). Posterior MI ST depression and R wave changes in V1 \200\223V2 (mirror image of anterior changes). Immediate management - Rest - High-flow O2 - Monitor pulse oximetry, ECG, pulse respiratory rate, and BP - Aspirin 300mg (unless recent major GI bleed or aspirin allergic) - Nitrate (buccal or sublingual) - Diamorphine up to 5mg with metoclopramide 10mg - CONSIDER thrombol ysis (see p.117) - Urgent evacuation to hospital for further management Therapy with betablockers or ACE inhibitors should be commenced following arrival in hospital. MYOCARDIAL ISCHAEMIA1 117 Pre-hospital thrombolysis In the majority of cases, thrombolysis or acute percutaneous coro nary intervention (PCI) will be carried out after arrival in hospital and the aim of pre-ho spital care must be to expedite arrival at hospital. In some circumstances, geographical lo cation or conditions will mean that pre- hospital thrombolysis is appropriate and thromboly sis is increasingly provided by ambulance service personnel. If this is likely to be the ca se in a particular area, appropriate protocols should be in place. Indications - Ischaemic chest pain (onset within 12 hours) AND 1mm ST elevation in 2 or more adjacent limb leads OR 2mm ST elevation in 2 or more adjacent chest leads. New left bundle branch block is also an indication for thrombolysis in the presence of chest pain, but old notes and ECGs are unli kely to be available in pre-hospital care. Contraindications See Table 2.2 Table 2.2 Contraindications to thrombolysis Absolute Stroke in last six months - Trauma with risk of major bleeding - Bleeding diathesis - Sever e liver disease - Coma - Lumbar puncture, visceral biopsy, or dental extraction in last mon th Active peptic ulcer disease - Recent GI bleeding - Acute pancreatitis - Oesophageal varices - Known aortic dissection - Abdominal, eye, or neuro- surgery in last month Relative Active menstruation - Pregnancy - Hypertension (systolic >200mmHg, diastolic >100mmHg) - Anticoagulant therapy - Abdominal aortic aneurysm - Traumatic CPR CHAPTER 2 Acute medical and surgical problems 118 Thrombolytic agents The thrombolytic agent of choice in pre-hospital care is tenectaplase w hich activates plasminogen to form plasmin which degrades fibrin and breaks up thrombi. Dos e 500 \200\223600g/kg (maximum 50mg) by intravenous injection over 10 sec Side-effects - Nausea and vomiting - Bleeding - Reperfusion arrhythmias - Hypotension. MYOCARDIAL ISCHAEMIA1 119 Fig. 2.26 Acute inferior MI. Reprinted with permission from Myerson SG et al. (2005). Emerg encies in Cardiology. Oxford University Press, Oxford. CHAPTER 2 Acute medical and surgical problems 120 Fig. 2.27 Acute anterior MI. Reprinted with permission from Myerson SG et al. (2005). Emerg encies in Cardiology. Oxford University Press, Oxford. This page intentionally left blank CHAPTER 2 Acute medical and surgical problems 122 Pericarditis Etiology Causes include viruses, bacteria including tuberculosis, fungi, malig nancy, autoimmune disease, and post myocardial infarction. Many cases are idio- pathic. A r ecent history of a flu-like illness is suggestive of viral pericarditis. Symptoms Retrosternal or left-sided chest pain; may be pleuritic. Radiates to neck. Worse w ith coughing, lying flat, inspiration, or swallowing. May be associated with shortness of b reath. Other symptoms may reflect the underlying cause. Signs A pericardial rub may be heard in full inspiration or expiration with the patient lea ning forward. ECG abnormalities Concave upwards ST segment elevation. Immediate management Admission to hospital for investigation and management. No other immed iate treatment required. In the absence of contraindications, a NSAID can be given for anal gesia (ibuprofen 400 \200\223600mg tds). PERICARDITIS1 123 I III aVR aVL aVF II V2 V1 V3 V4 V5 V6 Fig. 2.28 Pericarditis: ECG abnormalities. Reprinted with permission from Myerson SG et al. (2005). Emergencies in Cardiology. Oxford University Press, Oxford. CHAPTER 2 Acute medical and surgical problems 124 Shingles (Herpes zoster) Shingles results from reactivation of herpes virus in sensory root ganglia. Symptoms and signs - Pain in distribution of one or more sensory dermatomes May precede - V esicular rash in the distribution of one or more sensory dermatomes. Rash may be disseminated in immunocompromised individuals. Management - The patient will need an oral antiviral agent such as acyclovir 800mg 5 x day. Shingles involving the face may cause eye complications. Exclude keratitis with fluorescein staining. If any evidence of decreased visual acuity or any othe r eye involvement, refer for specialist opinion. This page intentionally left blank CHAPTER 2 Acute medical and surgical problems 126 Acute pulmonary oedema Symptoms - Breathlessness (acute or acute on chronic) - Cough - Frot hy sputum (may be lightly blood stained) - Collapse - Shock, sweating, pallor, peripheral c oldness. Other symptoms reflect the underlying cause: - Chest pain - Palpitation. Signs - Patient dyspnoeic at rest and sitting upright - Bilateral basal pulmonary crepitati ons - Patient may be cold, clammy, and sweaty in severe cases - Tachycardia - Tachypnoea - Elevated JVP (in congestive failure). Immediate management - Rapid evacuation to hospital - Monitor pulse, respiratory rate, BP, O2 saturation, ECG - Give high-flow oxygen (care in COPD) - Give frusemide 40 \200\223120mg IV (40mg boluses) - Consider morphine 5 \200\22310mg IV with an antiemetic - Consider bucc al GTN 2 \200\2235mg - Consider 12-lead ECG to exclude MI. Signs indicating SEVERE pulmonary oedema Inability to speak, BP <100mmHg, severe dyspnoea, copious frothy (pink) sputum This page intentionally left blank CHAPTER 2 Acute medical and surgical problems 128 Acute exacerbations of asthma Classification A classification of asthma (adapted for pre-ho spital use ) is given in Table 2.3. Transportation to hospital is mandatory if any of the m arkers of near fatal, life-threatening, or acute severe asthma are present. Management. - Sit patient up, administer high-flow oxygen (15L/min) - Give salbutamol 5mg b y nebulizer (on oxygen); repeat if necessary - Gain IV access and give 200mg hydrocortisone - Monitor pulse, BP, respiratory rate, and O2 saturation (maintain above 95%) Consider IV magnesium 1.2 \200\2232g - Be prepared to provide ventilatory support if the pa tient deteriorates - Evacuate urgently to hospital (warn A&E to call an anesthetist if required). Always consider pneumothorax or tension pneumothorax as a cause of deterioration in an asth matic. ACUTE EXACERBATIONS OF ASTHMA1 129 Table 2.3 Classification of asthma for pre-hospital use Near fatal - Immediate requirement for ventilation Life-threatening - Severe airways obstruction - PEF <33% predicted - Silent chest - Feeble respiratory effort - Increased work of breathing Exhaustion - Systolic BP <100mmHg - Bradycardia or arrhythmia - Ventilation perfusion misma tch Cyanosis - Hypoxia (SpO2 <92%)