Coagulopathy Pregnancy Evidence of abdominal wall skin infection or bowel obstruction 723 \212Hypotension from rapid changes in pressure and fluid of abdominal cavity; rarely, by intravascular shift to abdominal compartment. Equipment \212 \212 Paracentesis kit Specimen collection tubes and/or vacuum bottles \212 Intravenous albumin for large volume paracentesis. Technique 1 Place patient in supine position. 2 Preferably, the target site for procedure m ay be determined by US and marked on the patient \200\231s skin. If not available, percuss the ascites, marking a point where fluid level was identified but avoiding scars or vessels . 3 Clean the skin with iodine. 4 Anesthetize skin at the insertion site. The ideal site is m idline, 1 \200\2232 cm below the umbilicus. Do not use a midline site if a previous midline inci- sion is present (due to risk of bowel adhesion to abdominal wall). The lateral site is between the anterior-superior iliac crest and the lateral border of the rectus abdominus , at the level of the umbilicus. 5 Insert a 21F needle on a 20 mL syringe into the skin and advance while aspirating until a scitic fluid is withdrawn. Remove desired amount of fluid. 6 Remove the needle and apply a sterile dressing. 7 If indicated, send fluid for chemistry, microscopy, culture, and cytology. 8 Replace ascitic fluid with albumin if large volume pa racentesis (>4 \200\2235 L) is planned. Replace 6 \200\2238 g (25%) for every liter removed . Can consider replacement for lower volumes removed as well Transudate occurs when a patient \200\231s serum-ascites albumin gap (SAAG) level is \211 1.1 g/dL. Exudative ascites occurs when patients have SAAG levels <1.1 g/dL. Thoracentesis Indications \212 \212 Contraindications \212 Local skin infection, \212 U ncooperative patient Complications Bleeding; infection; pneumothorax; hemothorax; pulmo- na ry contusion or laceration; diaphragm, spleen, or liver puncture; bron- chopleural fistula; reexpansion of pulmonary edema. Equipment \212 \212 \212 \212 \212 \212 Technique 1 Position patient sitting on edge of bed resting head and extended arms on a bedside table. If the patient is unable to sit, place the patient in the lateral decubitus position. Diagnosis (malignancy, infection, inflammation) Therapeutic Thoracentesis kit Sterile gauze pad Iodine Fenestrated drape Oxygen by nasal cannula Specim en collection tubes and/or vacuum bottles 2 Preferably, the target site for the procedure may be determined by US and marked on the patient \200\231s skin. 3 If US marking is not available, confirm location of fluid by percussion, 724 auscultation, and chest x-ray. Mark site with a marker. 4 Locate needle insertion site, 1 \200\2232 interspaces below the fluid level, but not below the eighth rib. 5 Prep and drape area with proper sterile technique. 6 Anesthetize skin and then insert nee dle until it touches the superior border of a rib while aspirating and advancing. Move need le over the superior margin of the rib and anesthetize the intercostal muscle layers. s e r u d e c o r p 7 Insert the thoracentesis needle in the same tract as the anesthesia needle. 8 Draw off 10 \200\22330 mL of pleural fluid. 9 Send fluid to the lab for chemistry (protei n, glucose, pH, lactate dehy- drogenase [LDH], amylase); bacteriology (microscopy and cultu re, acid-fast bacillus [AFB] stain, tuberculosis [TB] culture); cytology. l a c i t c a r P 10 If large-volume removal is needed, use the Seldinger technique and insert catheter through the needle and into the chest. 11 Obtain a postprocedure chest x-ray. A pleural effusion is likely exudative if at least o ne of the following exists (Light \200\231s criteria): \212 \212 \212 Pleural protein-to-serum protein ratio >0.5 pleural LDH-to-serum LDH ratio >0.6 Pleural LDH >0.6 or two-thirds the upper limit for serum LDH Inserting a chest tube NB: This is a sterile procedure. Indications \212 \212 \212 \212 \212 Contraindications \212 \212 \212 \212 Hemothorax, trauma Chylothorax Empyema Effusion Pneumothorax Previous thoracic surgery Pulmonary blebs Oscillator ventilation Prior pleural adhesions Complications \212 \212 Scar formation Injury to lung or surrounding organs \212 \212 \212 Bleeding Pain Pneumothorax Equipment \212 \212 Chest tube kit Sterile gloves, sterile gown, hair cover mask, eye protection Sterile drape Sterile gauze pads Needle driver Suture scissors Iodine 1% lidocaine \212 \212 \212 Scalpel Suture tube: 10 \200\22314F usually; Chest 28 \200\22330F if trauma or hemothorax P leuri-Vac container with water seal Connection tubes Petroleum gauze Occlusive dressing Com pleted x-ray request form \212 \212 \212 \212 \212 \212 \212 \212 \212 \212 \212 Technique 1. Obtain preprocedure x-ray to confirm location for chest tube insertion. 2. Cho ose insertion site: 4th \200\2236th intercostal space, anterior to mid-axillary line, in the \200\234safe triangle, \200\235 see Figure 19.2. \212 A more posterior approach (e.g., the seventh space posterior), may be required to drain a l oculated effusion The second intercostal space in the mid-clavicular line may be used for a pical pneumothoraces. The posterior and anterior approaches are more uncomfortable. 725 \212 \212 3. Infiltrate down to the pleura with 10 \200\22320 cc of 1% lidocaine. \212 Verify that either air or fluid can be aspirated from the proposed insertion site; if not d o not proceed. Wait 3 min for the anesthetic to have an effect. \212 4. Make a 2-cm incision above anesthetized rib to avoid the neurovascular bundle under rib. \212 \212 \212 Blunt dissect with forceps down to the pleura. Puncture pleura with scissors or forceps. If inserting a large-bore tube (>24F), then sweep a finger inside chest to clear adherent lun g and exclude obstructing structures (e.g., in blunt abdominal trauma, stomach in the chest ). 5. Before inserting the chest tube, remove the metal trochar completely and introduce the t ube atraumatically using forceps to advance it. 6. Advance the tip upward to the apex of lu ng (or base of lung if draining an effusion). Stop when you meet resistance. 7. Attach the chest tube to the drainage container with water seal. Ensure that the chest t ube is bubbling with respiration. \212 8. With large-/medium-bore tubes, the incision should be closed with a mattress suture or suture across the incision. \212 Purse string sutures are not recommended as they may lead to scar- ring and increased wound pain. 9. Fix the chest tube with a second suture tied around the chest tube. 10. Cover with petro leum gauze and occlusive dressing. 11. Secure the tube with tape to prevent slippage. 12. O btain a postplacement x-ray to observe the position of the tube. 13. Give PO/IV/IM analgesi a. Tension pneumothorax In a tension pneumothorax air is drawn into the intrapleural space with each breath but cannot escape due to a valve-like effect of the tiny flap in the parie tal pleura. The increased pressure progressively compresses the heart and the other lung. 1 . Give the patient 100% oxygen. Figure 19.2 The \200\234safe triangle \200\235 for insertion of a chest tube 726 Redrawn from Thorax . 2003; 58(s II):ii55, with permission. 2. Insert a large-bore IV cannula through an intercostal space anywhere on the affected sid e (usually second intercostal space in the midclavicular line). Remove the stylet, which wi ll allow the trapped air to escape, usually \212 with an audible hiss. s e r u d e c o r p 3. Secure IV cannula with tape. 4. Insert chest tube as above. \212 Chest tube is to continue to release air from the pleural space until lung rift can seal. l a c i t c a r P Lumbar puncture Indication \212 \212 \212 Suspected central nervous system (CNS) infection Suspected subarachnoid hemorrhage Disease diagnosis: Pseudotumor cerebri, Guillain-Barr syndrome, mul- tiple sclerosis, systemic l upus erythematosus, meningeal carcinomatosis Infusion: Antibiotics, (myelography/ chemother apy, cisternography) Contraindications \212 Local skin infection \212 intracranial pressu re (except pseudotumor cerebri) \212 Supratentorial mass lesions (computed tomography [CT] first) \212 Platelet count <50,000/severe bleeding diathesis \212 Hemodynamically unstab le patient Complications Shooting pains in the lower extremities, infection, bleed- ing, sp inal fluid leak, hematoma, spinal headache (10 \200\22320%), brain herniation from supraten torial mass or extreme pressure. Spinal headache usually occurs 24 \200\22348 h after LP wi th resolution over hours to 2 wks: \212 \212 contrast Constant, dull, bilateral ache more frontal than occipital; it is positional \200\224 worse with upright positioning. Blood patch (injection of 20 cc of autologous venous blood into the epidural space) causes immediate relief in 95%. \212 Equipment \212 Spinal tray \212 Sterile gloves \212 Fenestrated drape \212 Topical anes thetic cream 1% lidocaine \212 Technique 1 Apply local anesthetic cream if sufficient time is available. 2 Position patient near edge of bed/table in the lateral decubitus or sittin g position. Flex spine anteriorly (flex hips, knees, and neck). 3 Locate L3 \200\223L4 interspace at the level of the iliac crests. See Figure 19.3. 4 Open spinal tray in a sterile manner, prepare skin at the selected inter- space with antiseptic solution, and cover with a fenestrated drape. 5 Anesthetize skin with 1% lidocaine. 6 Using the spinal needle, puncture the skin in the m idline just caudal to the palpated spinous process; angle needle about 15 degrees cephalad toward the umbilicus. 727 7 Advance needle about 3 \200\2234 cm then withdraw stylet to check for cerebral spinal flu id (CSF) flow. If no fluid, replace stylus and advance a fraction then repeat. 8 Usually, a slight \200\234pop \200\235 is felt as the needle penetrates the dura; advanc e 1 \200\2232 mm further. 9 If resistance is felt (bone), withdraw needle slightly and change its angle. 10 Once fluid is obtained, place end of stopcock with the attached manom- eter onto the needle hub to measure the opening pressure. 11 In a supine patient, normal opening pressure is 50 \200\223200 mm H 2 O; ele- vated >250 mm H 2 O. 12 Note color of fluid as well as opening pressure. 13 Opening pressure can only reliably b e measured while patient is lying quietly on his side in an unflexed position (have patient straighten legs and relax; this will help prevent an artificially elevated pressure). 14 Turn stopcock to allow the CSF to flow into the test tubes; label tubes in the order collected. 15 Collect 1 \200\2233 cc of CSF in each of 3 \200\2234 tubes. 16 Send tubes for appropriat e studies. Tube 1 Bacteriology Tube 2 Biochemistry Hematology Tube 3 Tube 4 Optional Culture and Gram stain Glucose Protein Cell count and differential Viral studies PCR Metabolic studies VDRL Fungus TB Electrophoresis Cytology 17 Replace stylus and withdraw the needle. 18 Cover with sterile dressing and have patient lay supine for next 2 h. NB: CSF normal values Lymphocytes <5/mm 3 Glucose 60 \200\22370% b lood glucose Protein 15 \200\22345 mg/dL Bloody tap This is an artifact due to piercing a blood vessel, which is indicated by fewer red cells in successive tubes and no yellowing of CSF (xanthochromia). If the patient \200 \231s blood count is normal, the rule of thumb is to subtract from the total CSF white bloo d cells (WBCs) (per mcL) one white cell for every 1,000 red blood cells (RBCs). To estimate the true protein level, subtract 1 mg/dL for every 1,000 RBCs/mm 3 (be sure to do the coun t and protein estimation on the same tube). Note : High protein levels in CSF make it appea r yellow. Subarachnoid hemorrhage Xanthochromia (yellow supernatant on spun CSF). Red cells in equal numbers in all tubes. RBCs can provoke an inflammatory response most marked after 48 h. Elevated protein Meningitis; multiple sclerosis (MS); Guillain \200\223Barr syndr ome. Very elevated CSF protein : Spinal block; TB; or severe bacterial meningitis. 728 s e r u d e c o r p Figure 19.3 Method of defining the interspace between the third and fourth lumbar vertebrae l a c i t c a r P After Vakil RJV, Udwadia FEU. Diagnosis and Management of Medical Emergencies 2nd ed. Delhi : Oxford University Press, 1988. Cricothyroidotomy This is an emergency procedure to overcome upper airway obstruction above the level of the larynx. Indications Upper airway obstruction when endotracheal intubation is not possible; e.g., irretrievable foreign body; facial edema (burns, angioe- dema); max illofacial trauma; infection (epiglottitis). Procedure Position the patient supine with nec k extended (e.g., pillow under shoulders). Run your index finger down the neck anteriorly i n the midline to find the notch in the upper border of the thyroid cartilage: Just below th is, between the thyroid and cricoid cartilages, is a depression \200\224the cricothyroid me mbrane (see Figure 19.4). Needle cricothyroidotomy: Pierce the membrane with a large-bore c annula (14F) attached to syringe: Withdrawal of air confirms position. Lidocaine may or may not be required). Slide cannula over needle at 45 degrees to skin in sagittal plane. Use a Y-connector or improvise connection to O 2 supply and give 15 L/min: Use thumb on Y-connec tor to allow O 2 in over 1 sec and CO 2 out over 4 sec ( \200\234transtracheal jet insuffla tion \200\235). See Figure 19.5. Figure 19.4 729 Figure 19.5 Surgical cricothyrotomy: Smallest tube for prolonged ventilation is 6 mm. Introduce high-vo lume, low-pressure cuff tracheostomy tube through hori- zontal incision in membrane. Compli cations Local hemorrhage, posterior perforation of trachea esophagus, laryngeal stenosis , tube blockage, subcutaneous tunneling. Pericardiocentesis Figure 19.6 Emergency needle pericardiocentesis Equipment 20 mL syringe, long 18F cannula, 3-way tap, electrocardio- gram (ECG) monitor, sk in cleanser Technique 1 If time allows , use aseptic technique, and, if conscious, local an esthesia technique and sedation, e.g., with midazolam: Titrate up to 0.07 mg/kg IV \200\224 start with 2 mg over 1 min, 1 mg in elderly. 2 Ensure you have IV access and full resuscita tion equipment at hand. 3 Introduce needle at 45 degrees to skin just below and to left of xiphis- ternum, aiming for tip of left scapula. (See Figure 19.4.) Aspirate continu- ously and watch ECG. Frequent ventricular ectopics or an injury pattern (ST segment falls) on ECG implies myocardial penetration: Withdraw slightly. 730 (Continued) s e r u d e c o r p Figure 19.6 (Continued) 4 Evacuate pericardial contents through the syringe and 3-way tap. Removal of only a small amount of fluid (e.g., 20 mL) can produce marked clinical improvement. If you are not sure whether the fluid you are aspi- rating is pure blood (e.g., on entering a ventricle), see i f it clots (heavily bloodstained pericardial fluid does not clot). 5 You can leave the cann ula in situ temporarily, for repeated aspiration. If there is reaccumulation, pericardiecto my may be needed. Send fluid for microscopy and culture, as needed, including tests for TB. Complications Laceration of ventricle or coronary artery ( subse- quent hemopericardium) ; aspiration of ventricular blood; arrhythmias (ventricular fibrillation); pneumothorax; pu ncture of aorta, esophagus ( mediastinitis), or pericarditis. l a c i t c a r P Cardioversion/defibrillation Indications Ventricular fibrillation or tachycardia, fast atri al fibrillation (AF, p. 123), supraventricular tachycardias if other treatments (p. 121) ha ve failed or there is hemodynamic compromise. The aim is to completely depolarize the heart using a direct current. Unless critically ill, conscious patients require sedating medicat ion. Procedure (for monophasic defibrillators) Do not wait for a crisis before familiarizin g yourself with the defibrillator. 1 Set the energy level (e.g., 200 J for ventricular fibr illation or ventricular tachycardia; 100 J for atrial fibrillation; 50 J for atrial flutter). 2 Place pads on chest, one over apex and one below right clavicle (less chance of skin arc than jelly). 3 Make sure no one else is touching the patient or the bed . 4 Disconnect oxygen circuit tu bing during shock delivery. 5 Press the button(s) on the electrode(s) to give the shock. 6 Watch ECG. Repeat the shock at a higher energy if necessary. NB: For AF and supraventricula r tachycardia (SVT), it is necessary to syn- chronize the shock on the R-wave of the ECG (b y pressing the \200\234SYNC \200\235 button on the machine). This ensures that the shock d oes not initiate a ventricular arrhythmia. If the SYNC mode is engaged in ventricular fibri llation (VF), the defibrillator will not discharge! \212 \212 It is only necessary to anesthetize the patient if he or she is conscious. After giving the shock, monitor ECG rhythm. Consider anticoagulation, as the risk of emboli is increased. G et a postprocedure 12-lead ECG. 731 Inserting a temporary cardiac pacemaker Possible indications in the setting of acute myocar dial infarction \212Complete arteriovenous (AV) block: With inferior MI (right coronary ar tery occlusion), pacing may only be needed if symptomatic; spontaneous recovery may occur. With anterior myocardial infarction (MI) (representing massive septal infarction) \212 \212Second-degree block: Wenckebach (p. 116) implies decremental AV node con-duction; may respond to atropine in inferior MI; pace if anterior MI. Type 2 block is usually associated with distal fascicular disease and carries high risk of complete heart block, so pace in b oth types of MI. \212First-degree block: Observe carefully: 40% develop higher degrees of block. \212Bundle branch block: Pace prophylactically if evidence of trifascicular dis- ease (p. 96) or nonadjacent bifascicular disease. \212Sinoatrial disease + serious symptoms: Pace unless patient responds to atropine. Other indications in which temporary pacing may be needed \212 \212 \212 \212 \212 Drug poisoning (e.g., with Symptomatic bradycardia, unresponsive to atropine Suppression of drug-resistant VT and SVT (overdrive pacing; do in ICU) Asystolic cardiac arrest with P-wa ve activity (ventricular standstill) During or after cardiac surgery (e.g., around the AV n ode or bundle of His) - blockers, digoxin, or verapamil) Method and technique for temporary pacing Learn from an expert. 1 Preparation: Monitor ECG; have a defibrillator at hand. Create a sterile field and ensure that the pacing wire fits down the cannula easily. Insert a peripheral cannula. 2 Insertion: Place the cannula into the subclavian or internal jugular vein (p. 721). Pass the pacing wire through the cannula into the right atrium. It will either pass easily throu gh the tricuspid valve or loop within the atrium. If the latter occurs, it is usually possi ble to flip the wire across the valve with a combined twisting and withdrawing movement. Ad vance the wire slightly. At this stage, the wire may try to exit the ventricle through the pulmonary outflow tract. A further withdrawing and rotation of the wire will aim the tip at the apex of the right ventricle. Advance slightly again to place the wire in contact with the endocardium. Remove any slack to decrease risk of subsequent displacement. (See Figure 19.5) 3 Checking the threshold: Connect the wire to the pacing box and set the \200\234demand \200\235 rate slightly higher than the patient \200\231s own heart rate and the output to 3 V. A paced rhythm should be seen. Find the pacing threshold by slowly reducing the voltage until the pacemaker fails to stimulate the tissue (pacing spikes are no longer followed by paced beats). The thresh- old should be less than 1 V, but a slightly higher value may be acceptable if it is stable (e.g., after a large infarction). 4 Setting the pacemaker : Set the output to 3 V or >3 times the threshold value (whichever is higher) in \200\234demand \200\235 mode. Set the rate as required. Suture the wire to t he skin and fix with a sterile dressing. 5 Check the position of the wire (and exclude pneumothorax) with a CXR. 732 Recurrent checks of the pacing threshold are required over the next few days. The formation of endocardial edema can be expected to raise the threshold by a factor of 2 \200\2233. Se e Figure 19.7. s e r u d e c o r p Figure 19.7 Pulmonary artery SVC RV l a c i t c a r P Tricuspid valve IVC 733 Emergency medicine Rodney Omron , M.D., M.P.H. and Arjun S. Chanmugam , M.D. e n i c i d e m y c n e g r e m E Contents Introduction to emergencies 735 Cardiorespiratory arrest 736 Emergency presentations Headache 739 Shortness of breath 740 Chest pain: Differential diagnosis 740 Coma 741 The Gl asgow Coma Scale 743 Shock 745 Anaphylactic shock 748 Cardiovascular emergencies Acute myocardial infarction 749 Acute coronary syndrome 752 Severe pulmonary edema 754 Card iogenic shock 755 Wide complex tachycardia 757 Narrow complex tachycardia 760 0 2 Respiratory emergencies Acute severe asthma 761 Acute exacerbations of COPD 763 Pneumothora x 765 Tension pneumothorax 765 Pneumonia 766 Massive pulmonary embolism 768 Gastrointestinal emergencies Acute upper GI bleeding 769 Acute liver failure 772 Neurological emergencies Meningitis 772 Cerebral abscess 774 Status epilepticus 774 Head injury 775 Raised intracran ial pressure 778 Endocrinological emergencies Diabetic ketoacidosis 779 Other diabetic emergencies 782 Thyroid emergencies 782 Addisonian crisis 783 Hypopituitary coma 784 Pheochromocytoma emergencies 784 Acute renal failure (AR F) 784 Acute poisoning: General measures 787 Acute poisoning: Specific points 788 Some specific poisons and their antidotes 789 Salicyla te poisoning 791 734 Acetaminophen poisoning 792 Burns 794 Hypothermia 796 Major disasters 797 e n i c i d e m y c n e g r e m E To manage an emergency condition, you must be prepared to treat and diag- nose at virtually the same time. Patients who present with an emergency condition generally fall into two ca tegories: They either have a life-threatening condition or an organ-threatening condition. Knowledge of some basic disease processes and an understanding of how to approach patients who may be critically ill is important in managing their care. Recognizing that an emergent condition is present is the key first step; the second step is to activate the appropriate resources as quickly as possible. Remember, if you suspect an emergent condition, call for help as soon as possible, even if you are not sure whether there is an emergency. Introduction to emergencies Patients who have an emergent condition require immediate inter vention. As stated earlier, recognition is the critical first step. Any patient who has a p roblem with his airway, who has any trouble breathing, or who has diffi- culty maintaining his blood pressure (ABCs) should be considered as having a potential medical emergency. The next step is to activate the appropriate resources to support the patient, which means ask ing for help and applying the acronym \200\234 O h MI \200\235: O xygen, cardiac M onitor ing, and an IV catheter. While providing the patient with as much support as possible, cons ider the potential threats to life and the potential threats to any organ system. This list must be considered as soon as possible in order to provide the patient with the correct me dical interventions. By continuing to consider the potential life and organ threats, the we ll-prepared provider will be in a better position to craft the all-important management pla n \200\224the plan of action. When developing your management plan, two data sources must b e used. The subjective data, which includes all the historical elements, including the pati ent \200\231s version of the events leading to presentation, the medical record, and commen ts from other people (eye witnesses, paramedics, family). The second dataset is the objecti ve data, the physical findings, as well as any laboratory, radiological, or other studies. Very often, the heart of the diag- nosis lies in the subjective data and the objective data confirms the diag- nostic suspicion. The key to good management is to identify any abnorma lity, any source of concern \200\224or, to put it another way \200\224any red flag. Every r ed flag must be appropriately addressed. Whenever new data are acquired, regardless of the source, the treatment plan must be modified to incorporate these new data and the evolving condition of your patient. Continuous reevaluation is critically important because, by defi nition, an emergent condition is a state that can change dramatically and quickly. To that end, remember to dynamically review the temperature, pulse rate and quality, respiratory ra te and pattern, blood pressure, and oxygen saturation, as well as the most important vital sign of all \200\224the patient \200\231s mental status. All this should be done in the con text of the preliminary assessment shown in Table 20.1. 735 Table 20.1 Preliminary assessment (primary survey) Assessment: Any signs of airway obstruction? Ascertain Airway patency. Management: Establish a patent airway Key: Avoid manipulation of and protect the cervical spine if injury is possible, especially in the presence of a change in mental status Assessment: Determine respiratory rate, check bilateral Breathing chest movement, percuss, and auscultate. Management: If no respiratory effort, treat as arrest, intubate, and ventilate. If breathing is compromised, give high-concentration O 2 , manage according to findings, e.g., relieve tension pneumothorax. Assessment: Check pulse and blood pressure; check capillary refill; look for evidence of hy poperfusion Management: Peripheral or central IV catheters, fluids (crystalloids or blood p roducts), measure urine output; consider central venous pressure measure- ment, ultrasound inferior vena cava measurement; consider pressors. Circulation If no cardiac output, treat as arrest Assess level of consciousness with AVPU score ( A ler t? Responds to V oice? To P ain? U nresponsive?); check pupils: Size, equality, reactions. Glasgow Coma scale (GCS) if time allows. Disability Undress patient, but cover to avoid hypothermia. Exposure Quick history from relatives or significant others may assist with diag- nosis: Ev ents surrounding onset of illness, contributing issues, evidence of overdose/suicide attemp t, any suggestion of trauma? Past medical his- tory: Especially diabetes; asthma; chronic o bstructive pulmonary disease (COPD); alcohol, opiate, or street drug abuse; epilepsy or rec ent head injury; recent travel. Medication: Current drugs. Allergies . Once appropriate ven tilation and circulation support are adequate, a more complete history and examination, alo ng with more thor- ough investigations, should be undertaken as part of the appropriate man agement. Cardiorespiratory arrest Confirm absence of pulse, blood pressure, and/or respirations. Cau ses Myocardial infarction (MI), pulmonary embolism (PE), trauma, tension pneumothorax, elec trocution, shock (septic, cardiogenic, neurogenic, hypovolemic, and anaphylactic), hypoxia, hypercapnia, hypothermia, electrolyte/acid/base imbalance, drugs (e.g., digoxin). Basic li fe support Request help immediately. Check for responsiveness. Check breathing. Ask someone to call the arrest team and bring the automatic external defibrillator. Note the time. Che ck the pulse for no longer than 10 seconds. Place patient in a supine position. Begin cardi opulmonary resuscitation (CPR) as follows: Chest compressions: Give 30 compressions to 2 br eaths (30:2)in adults. CPR 736 should not be interrupted except to give shocks. Use the heel of hand with straight elbows. Center over the lower half of the sternum. Aim for 4 \200\2235 cm compression at 100/min. Allow the chest to return to normal position. Push hard and push fast. Airway: Open airway. If no contraindications, use head tilt chin lift. Clear the mouth. Breathing: Assess br eathing, if inadequate, give two breaths, each inflation 1 sec long. Use specialized bag-a nd-mask system (e.g., Ambu system) if available and two resuscitators are present. Otherw ise, mouth-to-mouth breathing. Advanced life support For algorithm and details, see Figure 20.1 . \212Notes : Place defibrillator paddles on chest as soon as possible and set monito r to read through the paddles if there is a delay in attaching leads. Assess rhythm: In VF/ ventricular tachycardia (VT), defibrillation must occur without delay: Monophasic 360 J (bi phasic maximum dose 120 \200\223200 J). Asystole and electromechanical dissociation (synony mous with pulse- less electrical activity) are rhythms with a worse prognosis compared to V F/VT, but potentially remediable (see Figure 20.1 ). Treatment may be life-saving. Obtain I V/IO access and intubation if possible. Look for reversible causes of cardiac arrest and tr eat accordingly. Check for pulse if ECG rhythm is compatible with a profusible rhythm. Reas sess ECG rhythm. All shocks now Monophasic 360 J (biphasic 200). CPR for 2 min, epinephrine every 3 \200\2235 min; consider advanced airway/ capnography. If there is a shockable rhyt hm, then shock and, while you perform CPR for another 2 min, start amiodarone. Repeat these steps while there is a shockable rhythm. Send someone to find the patient \200\231s chart and the patient \200\231s usual doctor. These may give clues as to the cause of the arrest. n aloxone, a tropine, diazepam ( V alium), e pinephrine, and If IV access fails, l idocain e ( NAVEL )may be given down the tracheal tube but absorption is unpredictable. Give 2 \200 \2233 times the IV dose diluted in 10 mL 0.9% saline followed by five ventilations to assis t absorption. Intracardiac injection is not recommended. Consider intraosseous line (all me ds, blood, and crystalloid can be given). e n i c i d e m y c n e g r e m E \212 \212 Is this ventricular fibrillation (VF)/pulseless VT? \212 \212 \212 \212 \212 \212 \212 When to stop resuscitation: This is one of the most difficult decisions to make, and there are no definitive recommendations. Consider stopping re- suscitation after 20 min if there is refractory asystole or electromechanical dissociation. In general, in those patients wit hout myocardial disease, resus- citations are often continued until core temperatures are > 33 C and pH and potassium are normal. After successful resuscitation: \212 12-lead electrocardiogram (ECG); chest x-ray (CXR), comprehensive metabolic panel, glucose, blood gasses, CBC, creatine kinase (CK), CK MB/troponin. Transfer to appropriate unit, suc h as a CCU/ICU. Monitor vital signs. Whatever the outcome, explain to relatives what has ha ppened. \212 \212 \212 When \200\234do not resuscitate \200\235 may be a valid decision \212 \212 If a patient \200\231s condition is such that resuscitation is unlikely to succeed. If a me ntally competent patient has consistently stated or recorded the fact that he or she does n ot want to be resuscitated. \212 If the patient has signed an advanced directive forbiddin g resuscitation. \212Ideally, involve patients and relatives in the decision before the em ergency. 737 When in doubt, resuscitate. Figure 20.1 Cardiac arrest: 2010 guidelines for advanced life support Management of cardiac arrest Pulseless Patient Oxygen / Monitor / Defibrillator Check rhythm VF/VT Asystole/PEA Deliver 1 shock CPR for 2 Min Epinephrine Repeat every 3-5 min Advanced Airway/capnography IV/IO (Biphasic 120-200J) (Monophasic 360J) Resume CPR Immediately for 2 min No Yes Shockable? Shockable? Yes No CPR for 2 Min Epinephrine Repeat every 3-5 min Advanced Airway/capnography CPR for 2 Min *Treat Reversible Causes No Yes Shockable? Shockable? No Yes CPR for 2 Min Epinephrine *Amiodarone *Treat Reversible Causes CPR for 2 Min Epinephrine *Amiodarone *Treat Reversible Causes If pulse present begin post resuscitation *If pulse absent continue to arrow or end the cod e Avoid interruption in CPR, except to defibrillate. Push hard (>2 in [5 cm]) and fast (100/m in). Avoid excessive ventilation. Rotate compres- sions every 2 min. Consider capnography ( if PetCo 2 is <10 mm Hg, then improve CPR quality). Consider intra-arterial line (if diasto lic blood pres- sure [BP] is <20 mm Hg, then improve CPR quality). Return of pulse associat ed with sudden increase in PetCo 2 to >40 mm Hg and arterial waveform. (Consider the revers ible causes: 5H \200\231s; 5T \200\231s: Hypovolemia, Hypoxia, Hydrogen ion (acidosis), Hyp o-/Hyperkalemia, Hypothermia; Tension pneumothorax, Tamponade (Cardiac), Toxins, Thrombosis (car- diac, pulmonary). May replace first or second dose of epi with vasopres- sin 40 U IV /IO. From 2010 American Heart Association Guidelines for CPR and ECC. Circulation . 2010;122 (su ppl):729 \200\223767. 738 Headache Life-threatening considerations \212 \212 \212 Organ-threatening causes \212 N arrow angle glaucoma Temporal arteritis (elevated erythrocyte sedimentation rate [ESR], jaw \212 claudication, platelet count >400) Severe anemia e n i c i d e m y c n e g r e m E Meningitis Encephalopathy Intracranial bleed \212 Other potential causes \212 \212 \212 \212 \212 \212 Signs of meningismus? \212 \212 Decreased conscious level or localizing signs? \212 \212 \212 \212 \212 \212 Papilledema? \212 \212 \212 \212 Tension headache Migraine Cluster headache Post-traumatic Drugs (nitrates, calcium-channel blocker) Carbon monoxide poisoning or anoxia Meningitis (may not have fever or rash) Subarachnoid hemorrhage Encephalitis/meningitis Stroke Cerebral abscess Subarachnoid hemorrhage Tumor Subdural hema toma Tumor Severe hypertension Benign intracranial hypertension Any central nervous system (CNS) infection, if prolonged (e.g., >2 wks); e.g., tuberculosis (TB) meningitis Others \212 \212 \212 \212 Worrying headache features or \200\234red flags \200\235 \212 \212 \212 \212 \212 \212 \212 \212 \212 Two other vital questions: \212 \212 Paget \200\231s disease (elevated alk phos) Sinusitis Altitude sickness Cervical spondylosi s First headache or worst headache; Thunderclap headache; Unilateral headache and eye pain; U nilateral headache and ipsilateral symptoms; Cough-initiated headache; raised ICP/venous th rombosis Persisting headache scalp tenderness in those >50; Headache with fever or neck stiffness; Change in the pattern of \200\234usual headaches \200\235 Decreased level of co nsciousness consider subarachnoid hemorrhage consider subarachnoid hemorrhage cluster headache migraine, tumor, vascular temporal arteritis meningitis 739 Where have you been? (Malaria) Might you be pregnant? (Eclampsia; especially if proteinuria and elevated BP) Shortness of breath Wheezing? \212 Asthma \212 COPD \212 Heart failure \212 Anaphylaxis Stridor? (Upper airway obstruction) \212 \212 \212 \212 \212 Crackles? \212 \212 \212 \212 Chest clear? \212 \212 \212 \212 \212 \212 \212 Others \212 \212 Foreign body or tumor Acute epiglottitis Anaphylaxis Trauma (e.g., laryngeal fracture) Angi oedema Heart failure Pneumonia Bronchiectasis Fibrosis Pulmonary embolism (PE) Hyperventilation Metabolic acidosis (e.g., diabetic ketoacidosis [D KA]) Anemia Drugs (e.g., salicylates) Shock (may cause air hunger) Central causes Pneumothorax; pain, increased resonance Pleural effusion Chest pain: Differential diagnosis First exclude any potentially life-threatening causes by virtue of history, brief examination, and limited investigations. Then consider other pote ntial causes. Immediately life-threatening \212 \212 \212 \212 \212 \212 Others \212 \212 \212 Acute MI Angina/acute coronary syndrome Aortic dissection Tension pneumothorax Pulmonary em bolism Esophageal rupture Pneumonia Empyema Chest wall pain: \212 \212 \212 \212 Pleurisy Gastroesophageal reflux Pericarditis Esophageal spasm Muscular Rib fractures Bony metastases Costochondritis \212 \212 \212 \212 740 \212 \212 \212 Herpes zoster Cervical spondylosis Intra-abdominal: \212 Cholecystitis \212 Peptic ulcera tion Pancreatitis \212 Sickle-cell crisis e n i c i d e m y c n e g r e m E \212 Although cardiac pain is usually described as a dull pressure or a substernal pressur e that radiates to jaw, neck, or arm, and is usually associated with exertion, not all card iac chest pain presents classically. It is worthwhile to consider obtaining CXR, ECG, CBC, comprehensive metabolic panel (CMP), and cardiac enzymes (including troponin) on all patien ts who are at risk. Cardiac chest pain can, and does at times, present atypically, so pleas e consider options such as short-stay units or observation units for low-risk patients. Car diac monitoring in appropriate inpatient units is indicated for higher risk patients. Discu ss options with the patient. Remember, just because the patient \200\231s chest wall is ten der to palpation doesn \200\231t mean the cause of the chest pain is musculoskeletal. Make sure you have excluded all potential life-threatening causes. Coma Definition Unarousable unresponsiveness. Causes Drugs, poisoning (e.g., carbon monoxide, alcohol, tricyclics) Hypoglycemia, hyperglycemia ( ketoacidotic, or hyper- Metabolic: osmolar coma) Hypoxia, CO2 narcosis (COPD) Sepsis Hypothermia Myxedema, Addisonian crisis Hepatic/uremic encephalopathy Trauma Infection meningitis; encephalitis, e.g., herpes Neurological: simplex \200\224give IV acyclovir if the slightest suspicion; tropical: Malaria (do thick f ilms), typhoid, rabies, trypanosomiasis Tumor: Cerebral/meningeal tumor Vascular, subdural/subarachnoid hemorrhage, stroke, hypertensive encephalopathy Epilepsy: Nonconvulsive status or postictal state Immediate management See Table 20.2. \212 Assess airway, breathing, and circulation. Consider intubation if GCS <8. Support the circu lation if required (i.e., IV fluids). Give O 2 and treat any seizures. Protect the cervical spine. \212Check blood glucose in all patients. Give 50 mL 50% dextrose IV (or 1 mg of glucagon i ntramuscularly if no IV) immediately if presumed hypoglycemia. IV thiamine if any suggestio n of Wernicke \200\231s encephalopathy (consider giv- ing glucose first). 741 \212 \212 IV naloxone for opiate intoxication (may also be given IM or via endo- tracheal [ET] tube); IV flumazenil for may be considered benzodiazepine intoxication if airway compromised and patient is not known to be chronically dependent on benzodiazepines. Caution must be exerci sed when administering flumazenil to a patient who has benzodiazepine dependency as it may precipitate seizures. Examination (see Table 20.3) \212 \212 Obtain full set, including rectal temperature. Vital signs are vital: Hematoma, laceration, bruising, cerebrospinal fluid (CSF)/ Signs of trauma: blood in nose or ears, fracture \200\234step \200\235 deformity of skull, subcutan eous emphysema, \200\234raccoon eyes \200\235 Stigmata of other illnesses: \212 \212Skin for needle marks, cyanosis, pallor, rashes, poor turgor \212 \212 \212 \212 Liver disease, alcoholism, diabetes, myxedema (alcohol, hepatic fetor, ketosis, uremia) Smell the breath Meningismus Heart/lung exam Abdomen/rectal exam melena Are there any foci of infection? Any features of meningitis?: but do not move neck unless cervical spine is cleared for murmurs, rubs, wheeze, consolidation, collapse for organomegaly, ascites, bruising, peritoneal signs, \212 \212 \212Note the absence of signs: E.g., no pin-point pupils in a known heroin add ict