Medical Emergencies
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Syncope (fainting) is the most common medical event in the dental setting, caused by decreased blood flow to the brain. Stress causes the release of increased amounts of catecholamines that causes a change in vascular resistance leading to blood pooling in the periphery. Prodromal symptoms can include lightheadedness, increased perspiration, pallor, blurred vision, nausea and vomiting, tachycardia, and a warm sensation. Late symptoms include yawning, tachypnea, cold hands and feet, visual disturbances, dilated pupils, hypotension, bradycardia, dizziness and loss of consciousness. If consciousness is not completely lost, it’s called presyncope. Treating patients in a supine position lowers the risk of syncope. Treatment includes administering 100% oxygen while the patient is in a supine position and managing the airway.
Orthostatic (postural) hypotension refers to a drop in blood pressure after sitting up or standing up. It occurs because of delayed or hindered reflexive constriction of the venous vessels in the lower body. Blood “pools” in the legs with less returning to the heart, reducing cardiac output. Predisposing factors for postural hypotension include certain medications (e.g. antihypertensives, tricyclic antidepressants, phenothiazines) age, prolonged treatment in a supine position, inadequate postural reflex (related to age), pregnancy, venous defects in the legs, and Addison’s Disease. Treatment includes moving pregnant patients from one side to the other, and bringing the chair up slowly/in stages.
Vasovagal syncope (neurocardiogenic syncope) is a loss of consciousness where triggering of an exaggerated autonomic response results in hypotension, bradycardia and peripheral vasodilation. Acute treatment of vasovagal and orthostatic syncope involves returning blood to the brain by positioning the person supine on the ground (or in the chair), with legs slightly elevated (Trendelenburg position), and monitoring vitals. Oxygen if necessary (not if they hyperventilate). Prevention consists of education and methods to avoid syncope (anxiety management and coping skills) or dealing with the underlying medical/pharmacological issue.
Malignant hyperthermia (MH) is a severe reaction to particular medications used during general anesthesia like suxamethonium chloride (suxamethonium/succinylcholine) and halothane. In susceptible individuals the medications cause the release of stored calcium in muscle cells resulting in contractions. This generates excessive heat and causes metabolic acidosis. Signs and symptoms include fever, muscular rigidity, tachycardia, hypercarbia, and hypoxia. MH is treated with dantrolene, rapid cooling and supportive measures.
Phlebitis describes venous inflammation that can occur after the insertion of a venous catheter. It is marked by pain/tenderness, induration, and erythema in the area of insertion. Treatment involves the elevating the affected limb, application of moist heat, and nonsteroidal anti-inflammatory medication (NSAIDs). Consider AB if an infection is suspected.
Airway obstruction can be a serious complication. It is more likely during certain procedures such as endodontics (rubber dam essential) and in patients with a diminished cough reflex (myasthenia gravis, muscular dystrophy). Larger objects can become trapped in the larynx, smaller objects may pass through the trachea and lodge in one of the bronchi (usually right). If the airway is partially obstructed the patient will forcefully cough, wheeze, appear distressed but is still able to breath. An obstruction with poor air flow will lead to weak, ineffective coughing, paradoxical respiration (abnormal chest movement), altered speech or the inability to talk, and possible cyanosis or lethargy.
If the airway becomes completely obstructed the patient will exhibit an inability to cough, speak or breath, with unconsciousness following shortly. Treatment involves encouraging the patient to clear the obstruction. Recline the patient and attempt to remove the object with forceps if visible. If a complete obstruction is suspected, initiate the Heimlich maneuver. If the patient or the dentist cannot clear the item, call EMS and provide basic life support. Atelectasis occurs when a foreign object obstructs airflow in the main stem bronchus causing the collapse of the affected lunch. Prolonged atelectasis can lead to pneumonia.
Laryngospasm refers to any foreign object coming into contact with the vocal cords or the area of the trachea below the vocal folds which can lead to forceful involuntary spasming of laryngeal musculature. Tonsillar suction and pharyngeal barriers can prevent laryngospasm. Minor spasms can be left to spontaneously correct, more severe spasms may need positive pressure oxygen or intravenous muscle relaxant (Succinylcholine) and reintubation. Cricothyroidotomy in the case of emergency. Laryngospasm has been associated with ketamine.
Hyperventilation is excessive ventilation in proportion to the body’s needs, often seen in patients presenting with acute anxiety. The increased rate of inspiration and expiration decrease the carbon dioxide in the blood causing respiratory alkalosis. Signs and symptoms include dizziness, lightheadedness, shortness of breath, chest pain, tachycardia, dry mouth, paresthesia in hands and feet, carpopedal spasm (spasm of the hands or feet), muscle pains and cramps, visual disturbances, confusion and possible unconsciousness. Treatment includes stopping the dental procedure, calming the patient, and basic CPR if necessary. Countering respiratory alkalosis can be done by having the patient rebreath expelled air (which has an increased carbon dioxide concentration) using a small paper bag (or similar). Oxygen is not indicated.
Asthma is characterized by airway inflammation and obstruction due to airway hyperresponsiveness. Attacks can either be classified as extrinsic asthma (allergic asthma) or intrinsic/idiosyncratic asthma, which is triggered by a non-allergic factor such as respiratory infection, physical exertion, emotional distress etc. Aspirin, non-steroidal antiinflammatory drugs (NSAIDs), barbiturates, narcotics, erythromycin and penicillin must be used with caution in asthma patients. Nitrous oxide is safe to use, and can improve the situation in patients with idiosyncratic asthma. Asthmatic patients often exhibit abnormally sensitive cough reflexes and increased secretions. Signs and symptoms of an asthmatic attack include chest pressure, a sense of suffocation and heightened anxiety (which may exacerbate), wheezing, chest distension, dyspnea, tachypnea, hypertension, tachycardia, confusion, cyanosis, and nasal flaring. Treatment includes termination of the dental procedure, placing the patient upright and trying to calm the patient. Perform basic life support and administer oxygen and a beta-2-adrenergic agonist (bronchodilator) like albuterol or terbutaline. Severe asthma attacks (formerly known as status asthmaticus) may require 0.5ml of 1:1000 epinephrine IM or SC. If several doses of the aerosolized bronchodilator fails, call EMS.
Angina pectoris is the medical term for chest pain caused by insufficient blood supply to the heart muscle, usually due to atherosclerotic plaques interrupting blood flow inside cardiac vessels. Angina may be precipitated by stress/anxiety. The sensation is usually described as suffocating, heavy, squeezIng pain or dull ache. Pain usually lasts for 1 to 15 minutes, and may radiate to the patient’s left or right arm, neck, lower jaw, palate or tongue. Stable angina only occurs with a common stimulus and is relieved with rest or nitroglycerin. Unstable angina can occur without warning or understandable stimulus. Treatment involves stopping the procedure, placing the patient in a comfortable semi upright position, and administering nitroglycerin tablet or spray, and waiting 2-3 minutes for the symptoms to resolve. If not, oxygen and another dose of nitroglycerin, and third after 2-3 minutes if they symptoms don’t resolve. If the pain still doesn’t relieve, call EMS & basic life support.
Myocardial infarct or heart attack may occur in any patient. Usually the patient presents with a predisposing medical condition such as coronary artery disease, angina pectoris, or hypertension. Compared to angina, the symptoms experienced are due to cardiac cellular death and necrosis. It is usually characterized by prolonged (more than 30 minutes) severe substernal pain that can radiate like angina. Nausea, vomiting, weakness, dizziness, palor, and patient distress is often noted. The heart rate may vary, from bradycardia to tachycardia. A myocardial infarct could lead to shock, heart failure and cardiac arrest. With cardiac arrest there would be an absence of carotid pulse, respiration, and blood pressure. Treatment includes terminating the procedure, placing the patient in a comfortable semi-supine position, and applying basic life support. Call for EMS. Administer oxygen and nitroglycerin and try to keep the patient calm. Oxygen, pain killers, give patients aspirin to help prevent further clotting. Transfer to a hospital.
Congestive heart failure (CHF) sees a combination of left and right ventricular failure, with evidence of both systemic and pulmonary congestion. The most common sign of left sided heart failure is pulmonary edema, whereas peripheral edema is the most common sign of right sided heart failure. CHF is a consequence of chronic obstructive lung disease, asthma, heart disease and hypertension. Acute pulmonary edema is a potentially life threatening condition due to the rapid accumulation of fluid into the alveolar spaces. Sign and symptoms include trouble breathing, pallor, sweating, edema visible in extremities, narrow pulse pressure, enlarged liver and spleen, left ventricular hypertrophy, weakness and fatigue, dyspnea and exertion, wheezing, and paroxysmal nocturnal dyspnea. A patient on digitalis may be prone to nausea and vomiting, and if on diuretics or vasodilators may be prone to orthostatic hypotension. Blood tinged sputum may be noted in acute pulmonary edema. Treatment includes stopping treatment, placing the patient in a comfortable semisupine position, and calling EMS. Initiate basic life support and administer oxygen. Nitroglycerin is given sublingually in the case of a myocardial infarct.
Angioedema refers to swelling of the tissue just under the skin or mucous membranes. It can be caused by an immediate Type I allergic reaction to an allergen, leading to edema of the face, tongue, pharyngeal tissues, abdomen, arms and legs. Other signs and symptoms include itching, burning, hives, dyspnea, exaggerated chest movements, stridor, and cyanosis. Angioedema is mediated by histamine or bradykinin release. In addition to basic life support, the dentist may need to use 0.5ml of 1:1000 epinephrine IM or SC. Administer oxygen. Intubation or cricothyroidotomy may be needed to protect the airways.
Seizures may appear suddenly, even in patients who are controlling the disorder with medications. Precipitating factors include flickering lights, fatigue, physical and emotional stress. Symptoms include an aura (warning of the onset of a seizure), convulsive movement of the extremities, excessive salivary flow, and loss of consciousness. Treatment includes placing the patient in a safe position where they cannot fall or hurt themselves, supine and on their side. Support the patient until the seizure subsides. If this hasn’t happened within 10 minutes call the EMS. Basic life support when the seizure subsides, oxygen if needed, monitoring vitals, letting the patient recover until vitals are close to normal. Examine the patient for traumatic injuries.
A cerebrovascular accident (CVA) or stroke is caused by a rupture of cranial blood vessels. Risk factors include hypertension, arteriosclerosis, aneurysm, infarctions, cerebral thrombosis, hemorrhage, or embolism. A transient ischemic attack (TIA) or temporary stroke usually lasts from 15 to 60 minutes and often precedes a stroke. TIAs is a strong risk factor for CVA. CVAs due to embolism have a sudden onset of symptoms, including a headache, nausea and
vomiting, chills and sweating, vertigo, loss of consciousness (very poor prognosis in CVA, 70-100% initial mortality rate), and neurological signs which can include paralysis on
one side of the body, difficulty breathing and swallowing, affected speech, loss of bladder and bowel control, and pupils that are unequal in size. Call EMS, administer oxygen, basic life support.
Hypoglycemia or Insulin Shock can occur as a result from an overdose of a hypoglycemic agent used to treat patients with diabetes. The faster the blood glucose level falls, the more symptomatic the patient. If a diabetic patient injecting insulin fails to maintain normal food intake, hypoglycemic symptoms can develop quickly, ultimately leading to a loss of consciousness. Ask your patient if they have eaten before their appointment. Consider giving them something if they have not. Early signs and symptoms include hunger, weakness, tachycardia, sweating, pallor, and paresthesia. This can then lead to incoherence, uncooperativeness, irritability, poor judgment and orientation. Finally hypoglycemia can lead to unconsciousness and convulsions. If a hypoglycemic event is noted early, administering oral carbohydrates (sugar, orange juice, candy bar etc.) should avoid a worsening condition. Otherwise call EMS, administer glucagon 1mg IM, 50ml of 50% dextrose IV.
Addisonian crisis (adrenal crisis) is an endocrinologic emergency caused by an acute deficiency of the adrenal hormone cortisol. Primary adrenal insufficiency (Addison Disease) is characterized by low cortisol and high ACTH resulting from adrenal gland destruction. Secondary adrenal insufficiency is characterized by low cortisol and low ACTH caused by defective pituitary gland or hypothalamic function (usually pituitary adenoma). Tertiary adrenal insufficiency is due to a decrease in corticotropin releasing hormone (CRH) secretion caused by suppression from long-term exogenous steroid use (the most common cause). Addisonian crisis is a serious and potentially fatal medical emergency.
Early symptoms include hypoglycemia, fatigue, weakness, nausea, vomiting, diarrhea, abdominal and back pain, dizziness, and hypotension. Adrenal crisis can lead to syncope, cardiovascular collapse, metabolic encephalopathy, and shock. Prevention is key. A thorough medical history should gather information regarding the dose, duration, frequency and route of administration of glucocorticosteroids. Minor oral surgical procedures (uncomplicated extractions) should not increase stress levels enough to precipitate an adrenal crisis. However, major surgical procedures may require steroid supplementation (two to four fold increase in the regular dose). Treatment should include cessation of the dental procedure, placing the patient in supine position, provide basic life support, administer oxygen, administer 50-100mg of hydrocortisone IV, and contact EMS. Hypoglycemia can be countered with 50-100ml of 50% dextrose.
Oxygen is the most important drug used in a medical emergency. The primary airway hazard for an unconscious patient is their own tongue
SHOCK
When there is insufficient blood flow to the tissues of the body a patient may experience failure of the circulatory systems to perfuse vital organs, termed shock. In general shock is characterized by increased vascular resistance (pale, cool skin), hypotension, tachycardia, tachypnea, an adrenergic response (anxiety, vomiting and diarrhea, diaphoresis), myocardial ischemia, mental status changes, and increases thirst. There are 3 stages of shock.
- Compensatory stage – the body compensates for the inability to perfuse tissues with increased heart rate and increases peripheral resistance.
- Progressive metabolic acidosis – compensation cannot keep up.
- Irreversible (refractory) stage – organ damage occurs. Catastrophic failure.
Hypovolemic shock is the most common occurring when there is not enough circulatory volume (inadequate left ventricular filling), most often because of severe blood loss (trauma). In children vomiting and diarrhea is the most common reason. Burns and excess urine production due to diabetic ketoacidosis and diabetes insipidus can also cause fluid loss leading to hypovolemic shock.
Cardiogenic shock is caused by the heart failing to pump enough blood around the body, most commonly due to an acute myocardial infarct. Increased jugular venous pressure causes jugular vein distention and an abnormal heart rhythm. Obstructive shock is caused by an obstruction in the circulatory system. Fluid accumulating in the pericardium (pericardial effusion), air or fluid trapped in the pleural cavity (tension pneumothorax), or a blockage in the lungs hindering blood returning to the heart (pulmonary embolism) can cause obstructive shock.
Septic shock is caused by a severe infection, usually mediated by endotoxins released from lysed gram-negative bacteria. The overwhelming infection causes vasodilation leading to hypotension. Activation of the coagulation pathways can lead to disseminated intravascular coagulation. Neurogenic shock is caused by injury to the CNS that interrupts circulation.
Anaphylactic shock is caused by a severe type I allergic response, most commonly caused by aspirin and penicillin. The release of histamine causes potentially life threatening widespread vasodilation, leading to hypotension and increased capillary permeability. Signs and symptoms include itching of soft palate, nausea, vomiting, substernal pressure, urticaria and pruritus, laryngeal edema, hypotension, cardiac arrhythmias and even loss of consciousness. Treatment includes stopping dental treatment, basic life support, and calling EMS. 0.5ml of 1:1000 epinephrine IM or SC, oxygen, monitor vitals.
BLEEDING DISORDERS
Hemophillia is a sex-linked recessive blood clotting disorder caused by reduced/defective coagulation factor. Males are affected and females are carriers. Hemophilia A is the most common, caused by a factor VIII deficiency. Hemophilia B (Christmas disease) is caused by a factor IX deficiency. Hemophilia C (Rosenthal syndrome) is not sex-linked and less severe, caused by a factor XI deficiency, and linked to the Ashkenazi Jews. A patient with hemophilia will exhibit prolonged partial thromboplastin time (PTT), but normal prothrombin time (PT), thrombin time, platelet count and normal bleeding time. No treatment is required with cases of mild hemophilia, but more severe cases will require replacing defective clotting factors.
Von Willebrand disease is an inherited autosomal dominant (both sexes) bleeding disorder caused by defective von Willebrand factor (VWF), resulting in failure of platelet plug formation. It also affects several breeds of dogs. Patients will exhibit prolonged partial thromboplastin time (PTT) and prolonged bleeding time, but normal platelet count, thrombin time (TT) and prothrombin time (PT).
Thrombocytopenia is characterized by a low platelet count. A normal human platelet count ranges from 150,000 to 450,000 platelets per microliter of blood. Usually there are no symptoms though patients can suffer from nosebleeds, bleeding gums, heavy menstruation, bruising (from small pinpoint petechiae, to purplish ecchymosis, to extensive hematomas), or bleeding under the skin or mucous membranes. Many conditions can cause thrombocytopenia including dehydration, Vit B12 or folic acid deficiency, liver failure, sepsis and leukemia. Abnormal platelet numbers can be due to reduced productions in the bone marrow, increased trapping of platelets in the spleen, or faster than normal destruction of platelets.
An autoimmune disorder called Idiopathic (immune) thrombocytopenic purpura (ITP) sees antibodies created against the patient’s own platelets. Signs and symptoms include splenomegaly, and bleeding from the skin and mucous membranes. Thrombotic thrombocytopenic purpura (TTP) is characterized by blood clots forming in small vessels throughout the body causing severe thrombocytopenia, anemia, and often kidney, heart and brain dysfunction. Known triggers can include infections, medications, autoimmune disease (lupus), and pregnancy. In half the cases there is no known trigger. Be mindful of postoperative hemorrhage, and also consider the patient may be on long term steroid therapy (adrenal insufficiency).
To avoid problems, tests are conducted to measure the patient’s clotting mechanisms. Normal prothrombin time (PT) is usually less than 11 seconds, preferably between 5 and 7 seconds. Partial thromboplastin time (PTT) detects coagulation defects of the intrinsic pathway (e.g hemophilia). Normal value is between 25 and 36 seconds. Bleeding time should be under 9 minutes. The value developed to normalize the prothrombin time (PT) is called the international normalized ratio (INR). It is a ratio of the prothrombin time of the patient to the normal prothrombin time (11 to 13.5 seconds). A value of 2 means double the PT, a value of 3 means triple. The recommended therapeutic ranges for standard oral anticoagulant therapy varies for the treatment, but usually lies between 2 and 3.5. Patients with INR over 3.5 should be treated with caution.
In the past patients stopped anticoagulant therapy before operations, but this is no longer recommended. The patient’s INR should be stabilized and the patient treated within safe ranges using proper protocols. Modern anticoagulant therapy no longer requires frequent INR monitoring.
CARDIOPULMONARY RESUSCITATION
The guidelines related to CPR changes frequently. To see up to date information see the American Heart Association’s guidelines. The most important factor determining survival is the time between cardiac arrest and the attachment of a defibrillator device.
Commonly used are the DRS ABCD of CPR
- Danger – ensure the are is safe for yourself and others
- Response – try and get a response from the victim
- Send for help – call emergency services or ask another person to make the call
- Airway – A head tilt and jaw thrust is used to examine the airway. Spinal manipulation is avoided if a spinal injury is suspected. The airway is checked for obstructions.
- Breathing – Look, listen and feel for breathing, if not breathing normally, provide rescue breaths. A bag valve mask can be used, 10-12 breaths per minute.
- Circulation/CPR – check for a pulse (though this isn’t always recommended), if absent start compressions at 100 compressions per minute, at a 30:2 ratio.
- Defibrillation – apply a defibrillator if available and follow the verbal instructions.
