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Vasopressors may be used if blood pressure does not improve with fluids. There is no evidence of substantial superiority of one vasopressor over another; however, using dopamine leads to an increased risk of arrythmia when compared with norepinephrine. Vasopressors have not been found to improve outcomes when used for hemorrhagic shock from trauma but may be of use in neurogenic shock. Activated protein C (Xigris) while once aggressively promoted for the management of septic shock has been found not to improve survival and is associated with a number of complications. Xigris was withdrawn from the market in 2011, and clinical trials were discontinued. The use of sodium bicarbonate is controversial as it has not been shown to improve outcomes. If used at all it should only be considered if the pH is less than 7.0.
Aggressive intravenous fluids are recommended in most types of shock (e.g. 1–2 liter normal saline bolus over 10 minutes or 20 ml/kg in a child) which is usually instituted as the person is being further evaluated. Which intravenous fluid is superior, colloids or crystalloids, remains undetermined. Thus as crystalloids are less expensive they are recommended. If the person remains in shock after initial resuscitation packed red blood cells should be administered to keep the hemoglobin greater than 100 g/l.
For those with haemorrhagic shock the current evidence supports limiting the use of fluids for penetrating thorax and abdominal injuries allowing mild hypotension to persist (known as permissive hypotension). Targets include a mean arterial pressure of 60 mmHg, a systolic blood pressure of 70–90 mmHg, or until their adequate mentation and peripheral pulses.
The main goals of treatment in distributive shock are to reverse the underlying cause and achieve hemodynamic stabilization. Immediate treatment involves fluid resuscitation and the use of vasoactive drugs, both vasopressors and inotropes. Hydrocortisone is used for patients whose hypotension does not respond to fluid resuscitation and vasopressors. Opening and keeping open the microcirculation is a consideration in the treatment of distributive shock, as a result limiting the use of vasopressors has been suggested. Control of inflammation, vascular function and coagulation to correct pathological differences in blood flow and microvascular shunting has been pointed to as a potentially important adjunct goal in the treatment of distributive shock.
Patients with septic shock are treated with antimicrobial drugs to treat the causative infection. Some sources of infection require surgical intervention including necrotizing fasciitis, cholangitis, abscess, intestinal ischemia, or infected medical devices.
Anaphylactic shock is treated with epinephrine.
Among the choices for vasopressors, norepinephrine is superior to dopamine in septic shock. Norepinephrine is the preferred vasopressor, while epinephrine may be added to norepinephrine when needed. Low-dose vasopressin also may be used as an addition to norepinephrine, but is not recommended as a first-line treatment. Dopamine may cause rapid heart rate and arrhythmias, and is only recommended in combination with norepinephrine in those with slow heart rate and low risk of arrhythmia. In the initial treatment of low blood pressure in septic shock, the goal of vasopressor treatment is a mean arterial pressure (MAP) of 65 mm Hg. In 2017, the FDA approved angiotensin II injection for intravenous infusion to increase blood pressure in adults with septic or other distributive shock.
Treatment guidelines call for the administration of broad-spectrum antibiotics within the first hour following recognition of septic shock. Prompt antimicrobial therapy is important, as risk of dying increases by approximately 10% for every hour of delay in receiving antibiotics. Time constraints do not allow the culture, identification, and testing for antibiotic sensitivity of the specific microorganism responsible for the infection. Therefore, combination antimicrobial therapy, which covers a wide range of potential causative organisms, is tied to better outcomes.
Septic shock is associated with significant mortality and is the leading non cardiac cause of death in intensive care units (ICUs).
Emergency oxygen should be immediately employed to increase the efficiency of the patient's remaining blood supply. This intervention can be life-saving.
The use of intravenous fluids (IVs) may help compensate for lost fluid volume, but IV fluids cannot carry oxygen in the way that blood can; however, blood substitutes are being developed which can. Infusion of colloid or crystalloid IV fluids will also dilute clotting factors within the blood, increasing the risk of bleeding. It is current best practice to allow permissive hypotension in patients suffering from hypovolemic shock, both to ensure clotting factors are not overly diluted and also to stop blood pressure being artificially raised to a point where it "blows off" clots that have formed.
Electric shock is also used as a medical therapy, under carefully controlled conditions:
- Electroconvulsive therapy or ECT is a psychiatric therapy for mental illness. The objective of the therapy is to induce a seizure for therapeutic effect. There is no conscious sensation of the electric shock because of the anesthesia used beforehand. Convulsive therapy was introduced in 1934 by Hungarian neuropsychiatrist Ladislas J. Meduna who, believing mistakenly that schizophrenia and epilepsy were antagonistic disorders, induced seizures first with camphor and then metrazol (cardiazol). The first patient was treated by Lucio Bini and Ugo Cerlettiin. ECT is generally administered three times a week for about 8-12 treatments.
- As a surgical tool for cutting or coagulation. An "Electrosurgical Unit" (or ESU) uses high currents (e.g. 10 amperes) at high frequency (e.g. 500 kHz) with various schemes of amplitude modulation to achieve the desired result - cut or coagulate - or both. These devices are safe when used correctly.
- As a treatment for fibrillation or irregular heart rhythms: see defibrillator and cardioversion.
- As a method of pain relief: see Transcutaneous Electrical Nerve Stimulator (more commonly referred to as a TENS unit).
- As an aversive punishment for conditioning of developmentally delayed individuals with severe behavioral problems. This controversial skin-shock method is employed only at the Judge Rotenberg Educational Center, a special needs school in Massachusetts.
- As a treatment for Hyperhidrosis with the device called iontophoresis
- As part of electrodiagnosis diagnostic tests including nerve conduction studies and electromyography.
- For genetic engineering and gene delivery using a non-viral vector system electroporation
Neurogenic shock is a distributive type of shock resulting in low blood pressure, occasionally with a slowed heart rate, that is attributed to the disruption of the autonomic pathways within the spinal cord. It can occur after damage to the central nervous system such as spinal cord injury. Low blood pressure occurs due to decreased systemic vascular resistance resulting in pooling of blood within the extremities lacking sympathetic tone. The slowed heart rate results from unopposed vagal activity and has been found to be exacerbated by hypoxia and endobronchial suction.
Neurogenic shock can be a potentially devastating complication, leading to organ dysfunction and death if not promptly recognized and treated. It is not to be confused with spinal shock, which is not circulatory in nature.
Fluid replacement is beneficial in hypovolemia of stage 2, and is necessary in stage 3 and 4. See also the discussion of shock and the importance of treating reversible shock while it can still be countered.
For a patient presenting with hypovolemic shock in hospital the following investigations would be carried out:
- Blood tests: U+Es/Chem7, full blood count, glucose, blood type and screen
- Central venous catheter or blood pressure
- Arterial line or arterial blood gases
- Urine output measurements (via urinary catheter)
- Blood pressure
- SpO2 Oxygen saturations
The following interventions would be carried out:
- IV access
- Oxygen as required
- Surgical repair at sites of hemorrhage
- Inotrope therapy (Dopamine, Noradrenaline) which increase the contractility of the heart muscle
- Fresh frozen plasma or whole blood
Vasopressors (like Norepinephrine, Dobutamine) should generally be avoided, as they may result in further tissue ischemia and don't correct the primary problem. Fluids are the preferred choice of therapy.
Depending on the type of cardiogenic shock, treatment involves infusion of fluids, or in shock refractory to fluids, inotropic medications. In case of an abnormal heart rhythm several anti-arrhythmic agents may be administered, e.g. adenosine.
Positive inotropic agents (such as dobutamine or milrinone), which enhance the heart's pumping capabilities, are used to improve the contractility and correct the low blood pressure. Should that not suffice an intra-aortic balloon pump (which reduces workload for the heart, and improves perfusion of the coronary arteries) or a left ventricular assist device (which augments the pump-function of the heart) can be considered. Finally, as a last resort, if the person is stable enough and otherwise qualifies, heart transplantation, or if not eligible an artificial heart, can be placed. These invasive measures are important tools- more than 50% of patients who do not die immediately due to cardiac arrest from a lethal abnormal heart rhythm and live to reach the hospital (who have usually suffered a severe acute myocardial infarction, which in itself still has a relatively high mortality rate), die within the first 24 hours. The mortality rate for those still living at time of admission who suffer complications (among others, cardiac arrest or further abnormal heart rhythms, heart failure, cardiac tamponade, a ruptured or dissecting aneurysm, or another heart attack) from cardiogenic shock is even worse around 85%, especially without drastic measures such as ventricular assist devices or transplantation.
Cardiogenic shock may be treated with intravenous dobutamine, which acts on β receptors of the heart leading to increased contractility and heart rate.
Neurogenic shock can result from severe central nervous system damage (brain injury, cervical or high thoracic spinal cord). In more simple terms: the trauma causes a sudden loss of background sympathetic stimulation to the blood vessels. This causes them to relax (vasodilation) resulting in a sudden decrease in blood pressure (secondary to a decrease in peripheral vascular resistance).
Neurogenic shock results from damage to the spinal cord above the level of the 6th thoracic vertebra. It is found in about half of people who suffer spinal cord injury within the first 24 hours, and usually doesn't go away for one to three weeks.
The severity of this disease frequently warrants hospitalization. Admission to the intensive care unit is often necessary for supportive care (for aggressive fluid management, ventilation, renal replacement therapy and inotropic support), particularly in the case of multiple organ failure. The source of infection should be removed or drained if possible: abscesses and collections should be drained. Anyone wearing a tampon at the onset of symptoms should remove it immediately. Outcomes are poorer in patients who do not have the source of infection removed.
Antibiotic treatment should cover both "S. pyogenes" and "S. aureus". This may include a combination of cephalosporins, penicillins or vancomycin. The addition of clindamycin or gentamicin reduces toxin production and mortality.
Not required for physiologic sinus tachycardia. Underlying causes are treated if present.
Acute myocardial infarction. Sinus tachycardia can present in more than a third of the patients with AMI but this usually decreases over time. Patients with sustained sinus tachycardia reflects a larger infarct that are more anterior with prominent left ventricular dysfunction, associated with high mortality and morbidity. Tachycardia in the presence of AMI can reduce coronary blood flow and increase myocardial oxygen demand, aggravating the situation. Beta blockers can be used to slow the rate, but most patients are usually already treated with beta blockers as a routine regimen for AMI.
Practically, many studies showed that there is no need for any treatment.
IST and POTS. Beta blockers are useful if the cause is sympathetic overactivity. If the cause is due to decreased vagal activity, it is usually hard to treat and one may consider radiofrequency catheter ablation.
With proper treatment, people usually recover in two to three weeks. The condition can, however, be fatal within hours.
Initial treatment given will usually be supportive in nature, for example administration of oxygen, and monitoring. There is little care that can be provided pre-hospital other than general treatment for shock. Some teams have performed an emergency thoracotomy to release clotting in the pericardium caused by a penetrating chest injury.
Prompt diagnosis and treatment is the key to survival with tamponade. Some pre-hospital providers will have facilities to provide pericardiocentesis, which can be life-saving. If the patient has already suffered a cardiac arrest, pericardiocentesis alone cannot ensure survival, and so rapid evacuation to a hospital is usually the more appropriate course of action.
Initial management in hospital is by pericardiocentesis. This involves the insertion of a needle through the skin and into the pericardium and aspirating fluid under ultrasound guidance preferably. This can be done laterally through the intercostal spaces, usually the fifth, or as a subxiphoid approach. A left parasternal approach begins 3 to 5 cm left of the sternum to avoid the left internal mammary artery, in the 5th intercostal space. Often, a cannula is left in place during resuscitation following initial drainage so that the procedure can be performed again if the need arises. If facilities are available, an emergency pericardial window may be performed instead, during which the pericardium is cut open to allow fluid to drain. Following stabilization of the patient, surgery is provided to seal the source of the bleed and mend the pericardium.
In people following heart surgery the nurses monitor the amount of chest tube drainage. If the drainage volume drops off, and the blood pressure goes down, this can suggest tamponade due to chest tube clogging. In that case, the patient is taken back to the operating room for an emergency reoperation.
If aggressive treatment is offered immediately and no complications arise (shock, AMI or arrhythmia, heart failure, aneurysm, carditis, embolism, or rupture), or they are dealt with quickly and fully contained, then adequate survival is still a distinct possibility.
Blocking agents of the adrenoceptors alpha 1/alpha 2 are typically used to treat the effects of the vasoconstriction associated with vascular claudication. Cilostazol (trade name: Pletal) is FDA approved for intermittent claudication. It is contraindicated in patients with heart failure, and improvement of symptoms may not be evident for two to three weeks.
Neurogenic claudication can be treated surgically with spinal decompression.
If the person has been sufficiently fluid resuscitated but the mean arterial pressure is not greater than 65 mmHg, vasopressors are recommended. Norepinephrine (noradrenaline) is recommended as the initial choice. If a single vasopressor is not enough to raise the blood pressure, epinephrine (adrenaline) or vasopressin may be added. Dopamine is typically not recommended. Dobutamine may be used if heart function is poor or blood flow is insufficient despite sufficient fluid volumes and blood pressure.
Exercise can improve symptoms, as can revascularization. Both together may be better than one intervention of its own.
Pharmacological options exist, as well. Medicines that control lipid profile, diabetes, and hypertension may increase blood flow to the affected muscles and allow for increased activity levels. Angiotensin converting enzyme inhibitors, beta-blockers, antiplatelet agents (aspirin and clopidogrel), naftidrofuryl, pentoxifylline, and cilostazol (selective PDE3 inhibitor) are used for the treatment of intermittent claudication. However, medications will not remove the blockages from the body. Instead, they simply improve blood flow to the affected area.
Catheter-based intervention is also an option. Atherectomy, stenting, and angioplasty to remove or push aside the arterial blockages are the most common procedures for catheter-based intervention. These procedures can be performed by interventional radiologists, interventional cardiologists, vascular surgeons, and thoracic surgeons, among others.
Surgery is the last resort; vascular surgeons can perform either endarterectomies on arterial blockages or perform an arterial bypass. However, open surgery poses a host of risks not present with catheter-based interventions.
Initial care in the hospital, as in the prehospital setting, aims to ensure adequate airway, breathing, cardiovascular function, and spinal immobilization. Imaging of the spine to ascertain presence of SCI may need to wait if emergency surgery is needed to stabilize a life-threatening injury. Acute SCI merits treatment in an intensive care unit, especially injuries to the cervival spinal cord. Patients with SCI need repeated neurological assessments and treatment by neurosurgeons.
If the systolic blood pressure falls below 90 mmHg within days of the injury, blood supply to the spinal cord may be reduced, resulting in further damage. Thus it is important to maintain the blood pressure using a central venous catheter, intravenous fluids, and vasopressors, and to treat cases of shock. Mean arterial blood pressure is measured and kept at 85 to 90 mmHg for seven days after injury. The treatment for shock from blood loss (hypovolemic shock) is different from that for neurogenic shock, and could harm people with the latter type, so it is necessary to determine why someone is in shock. However it is also possible for both causes to exist at the same time. Another important aspect of care is prevention of hypoxia (insufficient oxygen in the bloodstream), which could deprive the spinal cord of much-needed oxygen. People with cervical injuries may experience a dangerously slowed heart rate; treatment to speed it up include atropine and electrical cardiac pacing.
Swelling can cause further damage to the spinal cord by reducing the blood supply and causing ischemia, which can give rise to an ischemic cascade with a release of toxins that damages neurons. Thus treatment is often geared toward limiting this secondary injury. People are sometimes treated with drugs to reduce swelling. The corticosteroid drug methylprednisolone is commonly used within eight hours of the injury, but its use is controversial because of side effects. Studies have shown high dose methylprednisolone may improve outcomes if given within 6 hours of injury. However, the improvement shown by clinical trials has been inconclusive, and comes at the cost of increased risk of serious infection or sepsis, gastrointestinal bleeding, and pneumonia. Thus organizations that set clinical guidelines have increasingly stopped recommending methylprednisolone in the treatment of acute SCI.
Surgery may be necessary, e.g. to relieve excess pressure on the cord, to stabilize the spine, or to put vertebrae back in their proper place. In cases involving instability or compression, failing to operate can lead to worsening of the condition. Surgery is also necessary when something is pressing on the cord, such as bone fragments, blood, material from ligaments or intervertebral discs, or a lodged object from a penetrating injury. Although the ideal timing of surgery is still debated, studies have found that earlier surgical intervention (within 24 hours of injury) is associated with better outcomes. Sometimes a patient has too many other injuries to be a surgical candidate this early. Surgery is controversial because it has potential complications (such as infection), so in cases where it is not clearly needed (e.g. the cord is being compressed), doctors must decide whether to perform surgery based on aspects of the patient's condition and their own beliefs about its risks and benefits.
In cases where a more conservative approach is chosen, bed rest, cervical collars, immobilizing devices, and optionally traction are used. Surgeons may opt to put traction on the spine to remove pressure from the spinal cord by putting dislocated vertebrae back into alignment, but herniation of intervertebral disks may prevent this technique from relieving pressure. "Gardner-Wells tongs" are one tool used to exert spinal traction to reduce a fracture or dislocation and to immobilize the affected areas.
General anaesthesia is recommended for people with sepsis who require surgical procedures to remove the infective source. Inhalational and intravenous anaesthetics are used. Requirements for anaesthetics may be reduced. Inhalational anaesthetics can reduce the level of proinflammatory cytokines, altering leukocyte adhesion and proliferation, inducing apoptosis (cell death) of the lymphocytes, possibly with a toxic effect on mitochondrial function. Although etomidate has a minimal effect on the cardiovascular system, it is often not recommended as a medication to help with intubation in this situation due to concerns it may lead to poor adrenal function and an increased risk of death. The small amount of evidence there is, however, has not found a change in the risk of death with etomidate.
It is recommended that the head of the bed be raised if possible to improve ventilation. Paralytic agents should be avoided unless ARDS is suspected.
Surgical approaches have also been used successfully in TOS. Microsurgery can be used approaching the area from above the collar bone (supraclavicular) followed by neurolysis of the brachial plexus, removal of the scalene muscle (scalenectomy), and the release of the underlying (subclavicular) blood vessels. This approach avoids the use of resection, and has been found to be an effective treatment. In cases where the first rib (or a fibrous band extending from the first rib) is compressing a vein, artery, or the nerve bundle, part of the first rib and any compressive fibrous tissue, can be removed in a first rib resection surgical procedure; scalene muscles may also need to be removed (scalenectomy). This allows increased blood flow and the reduction of nerve compression. In some cases there may be a rudimentary rib or a cervical rib that can be causing the compression, which can be removed using the same technique.
Physical therapy is often used before and after the operation to improve recovery time and outcomes. Potential complications include pneumothorax, infection, loss of sensation, motor problems, subclavian vessel damage, and, as in all surgeries, a very small risk of permanent serious injury or death.
Evidence for the treatment of thoracic outlet syndrome as of 2014 is poor.
Surgical shock is the shock to the circulation resulting from surgery. It is commonly due to a loss of blood which results in insufficient blood volume.