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The treatment of mesenteric ischemia depends on the cause, and can be medical or surgical. However, if bowel has become necrotic, the only treatment is surgical removal of the dead segments of bowel.
In non-occlusive mesenteric ischemia, where there is no blockage of the arteries supplying the bowel, the treatment is medical rather than surgical. People are admitted to the hospital for resuscitation with intravenous fluids, careful monitoring of laboratory tests, and optimization of their cardiovascular function. NG tube decompression and heparin anticoagulation may also be used to limit stress on the bowel and optimize perfusion, respectively.
Surgical revascularisation remains the treatment of choice for mesenteric ischaemia related to an occlusion of the vessels supplying the bowel, but thrombolytic medical treatment and vascular interventional radiological techniques have a growing role.
If the ischemia has progressed to the point that the affected intestinal segments are gangrenous, a bowel resection of those segments is called for. Often, obviously dead segments are removed at the first operation, and a second-look operation is planned to assess segments that are borderline that may be savable after revascularization.
Early treatment is essential to keep the affected limb viable. The treatment options include injection of an anticoagulant, thrombolysis, embolectomy, surgical revascularisation, or amputation. Anticoagulant therapy is initiated to prevent further enlargement of the thrombus. Continuous IV unfractionated heparin has been the traditional agent of choice.
If the condition of the ischemic limb is stabilized with anticoagulation, recently formed emboli may be treated with catheter-directed thrombolysis using intraarterial infusion of a thrombolytic agent (e.g., recombinant tissue plasminogen activator (tPA), streptokinase, or urokinase). A percutaneous catheter inserted into the femoral artery and threaded to the site of the clot is used to infuse the drug. Unlike anticoagulants, thrombolytic agents work directly to resolve the clot over a period of 24 to 48 hours.
Direct arteriotomy may be necessary to remove the clot. Surgical revascularization may be used in the setting of trauma (e.g., laceration of the artery). Amputation is reserved for cases where limb salvage is not possible. If the patient continues to have a risk of further embolization from some persistent source, such as chronic atrial fibrillation, treatment includes long-term oral anticoagulation to prevent further acute arterial ischemic episodes.
Decrease in body temperature reduces the aerobic metabolic rate of the affected cells, reducing the immediate effects of hypoxia. Reduction of body temperature also reduces the inflammation response and reperfusion injury. For frostbite injuries, limiting thawing and warming of tissues until warmer temperatures can be sustained may reduce reperfusion injury.
The prognosis depends on prompt diagnosis (less than 12–24 hours and before gangrene) and the underlying cause:
- venous thrombosis: 32% mortality
- arterial embolism: 54% mortality
- arterial thrombosis: 77% mortality
- non-occlusive ischemia: 73% mortality.
In the case of prompt diagnosis and therapy, acute mesenteric ischemia can be reversible.
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.
Most people with Takayasu’s arteritis respond to steroids such as prednisone. The usual starting dose is approximately 1 milligram per kilogram of body weight per day (for most people, this is approximately 60 milligrams a day). Because of the significant side effects of long-term high-dose prednisone use, the starting dose is tapered over several weeks to a dose which controls symptoms while limiting the side effects of steroids.
Promising results are achieved with mycophenolate and tocilizumab. If treatment is not kept to a high standard, long-term damage or death can occur.
For patients who do not respond to steroids may require revascularization, either via vascular bypass or angioplasty and stenting. Outcomes following revascularization vary depending on the severity of the underlying disease
The Infarct Combat Project (ICP) is an international nonprofit organization founded in 1998 to fight ischemic heart diseases through education and research.
Other medical treatments have been tried and include estrogen and progesterone therapy, Corticostreoids are effective, but are "limited by their side effects."
Secondary chronic intestinal pseudo-obstruction is managed by treating the underlying condition.
There is no cure for primary chronic intestinal pseudo-obstruction. It is important that nutrition and hydration is maintained, and pain relief is given. Drugs that increase the propulsive force of the intestines have been tried, as have different types of surgery.
Septic shock is associated with significant mortality and is the leading non cardiac cause of death in intensive care units (ICUs).
GAVE is treated commonly by means of an endoscope, including argon plasma coagulation and electrocautery. Since endoscopy with argon photocoagulation is "usually effective", surgery is "usually not required". Coagulation therapy is well-tolerated but "tends to induce oozing and bleeding." "Endoscopy with thermal ablation" is favored medical treatment because of its low side effects and low mortality, but is "rarely curative." Treatment of GAVE can be categorized into endoscopic, surgical and pharmacologic. Surgical treatment is definitive but it is rarely done nowadays with the variety of treatment options available. Some of the discussed modalities have been used in GAVE patients with another underlying disease rather than SSc; they are included as they may be tried in resistant SSc-GAVE patients. Symptomatic treatment includes iron supplementation and blood transfusion for cases with severe anemia, proton pump inhibitors may ameliorate the background chronic gastritis and minute erosions that commonly co-existed in biopsy reports.
Acute adrenal insufficiency is a medical emergency and needs to be treated with injectable hydrocortisone and fluid support.
Prucalopride, pyridostigmine, metoclopramide, cisapride, and erythromycin may be used, but they have not been shown to have great efficacy. In such cases, treatment is aimed at managing the complications. Linaclotide is a new drug that received approval from Food and Drug Administration in August 2012 and looks promising in the treatment of chronic intestinal pseudo-obstruction, gastroparesis and inertia coli.
Intestinal stasis, which may lead to bacterial overgrowth and subsequently, diarrhea or malabsorption, is treated with antibiotics.
Nutritional deficiencies are treated by encouraging patients to avoid food high in fat and fibre, which are harder to digest and increase abdominal distention and discomfort, and have small, frequent meals (5–6 per day), focusing on liquids and soft food. Reducing intake of poorly absorbed sugar alcohols may be of benefit. Referral to an accredited dietitian is recommended. If dietary changes are unsuccessful in meeting nutritional requirements and stemming weight loss, enteral nutrition is used. Many patients eventually require parenteral nutrition.
Total parenteral nutrition (TPN) is a form of long-term nutritional treatment needed for patients that have severe pseudoobstruction. After a period of no improvement of intestinal function or motility the decision to start TPN will be made, and the surgical procedure to add a long-term, more permanent IV to administer TPN will occur. Types of IV catheters to be placed will be a PICC line or central line which include mediports, Broviac, or Hickman lines depending on how long the physicians believe the patient will require TPN. Patients that are deemed TPN dependent will require constant checkups to monitor the catheter is working properly, check liver enzyme levels and look for signs of blood infections, as catheter blockage, liver damage, and infections of catheters are the main complications associated with long term TPN use and can result in sepsis and/or additional surgeries if not properly monitored. TPN nutritional feeds are given over a period of several hours to all day infusions, and are a mixture of all the vitamins, minerals, and calories similar to what one would get eating orally daily as well as any other specific nutritional needs the patient has at the moment. TPN format is typically changed depending on loss/gain of weight and bloodwork results, and is specially formulated to meet each individual patient's needs.
Use of octreotide has been described.
Cannabis has long been known to limit or prevent nausea and vomiting from a variety of causes. This has led to extensive investigations that have revealed an important role for cannabinoids and their receptors in the regulation of nausea and emesis. With the discovery of the endocannabinoid system, novel ways to regulate both nausea and vomiting have been discovered that involve the production of endogenous cannabinoids acting centrally. The plant cannabis has been used in clinics for centuries, and has been known to be beneficial in a variety of gastrointestinal diseases, such as emesis, diarrhea, inflammatory bowel disease and intestinal pain. Moreover, modulation of the endogenous cannabinoid system in the gastrointestinal tract may provide a useful therapeutic target for gastrointestinal disorders. While some GI disorders may be controlled by diet and pharmaceutical medications, others are poorly moderated by conventional treatments. Symptoms of GI disorders often include cramping, abdominal pain, inflammation of the lining of the large and/or small intestine, chronic diarrhea, rectal bleeding and weight loss. Patients with these disorders frequently report using cannabis therapeutically.
In a 2012 animal study, cannabichromene was shown to normalize gastrointestinal hypermotility without reducing the transit time. The study notes that this result is of potential clinical interest, as the only drugs available for intestinal dysmotility are often associated with constipation.
Differentiation of DIOS from constipation is generally performed by unit specializing in the treatment of cystic fibrosis. Adequate hydration and an aggressive regimen of laxatives are essential for treatment and prevention of DIOS. Osmotic laxatives such as polyethylene glycol are preferred. Individuals prone to DIOS tend to be at risk for repeated episodes and often require maintenance therapy with pancreatic enzyme replacement, hydration and laxatives (if the symptoms are also mild).
Oral contrast instillation into the colon/ileum under radiological control has been found to reduce the need for surgical intervention.
Adrenal crisis is triggered by physiological stress (such as trauma). Activities that have an elevated risk of trauma are best avoided. Treatment must be given within two hours of trauma and consequently it is advisable to carry injectable hydrocortisone in remote areas.
Endotoxemia is a serious complication of colic and warrants aggressive treatment. Endotoxin (lipopolysaccharide) is released from the cell wall of gram-negative bacteria when they die. Normally, endotoxin is prevented from entering systemic circulation by the barrier function of the intestinal mucosa, antibodies and enzymes which bind and neutralize it and, for the small amount that manages to enter the blood stream, removal by Kupffer cells in the liver. Endotoxemia occurs when there is an overgrowth and secondary die-off of gram negative bacteria, releasing mass quantities of endotoxin. This is especially common when the mucosal barrier is damaged, as with ischemia of the GI tract secondary to a strangulating lesion or displacement. Endotoxemia produces systemic effects such as cardiovascular shock, insulin resistance, and coagulation abnormalities.
Fluid support is essential to maintain blood pressure, often with the help of colloids or hypertonic saline. NSAIDs are commonly given to reduce systemic inflammation. However, they decrease the levels of certain prostaglandins that normally promote healing of the intestinal mucosa, which subsequently increases the amount of endotoxin absorbed. To counteract this, NSAIDs are sometimes administered with a lidocaine drip, which appears to reduce this particular negative effect. Flunixin may be used for this purpose at a dose lower than that used for analgesia, so can be safely given to a colicky horse without risking masking signs that the horse requires surgery. Other drugs that bind endotoxin, such as polymyxin B and Bio-Sponge, are also often used. Polymixin B prevents endotoxin from binding to inflammatory cells, but is potentially nephrotoxic, so should be used with caution in horses with azotemia, especially neonatal foals. Plasma may also be given with the intent of neutralizing endotoxin.
Laminitis is a major concern in horses suffering from endotoxemia. Ideally, prophylactic treatment should be provided to endotoxic horses, which includes the use of NSAIDs, DMSO, icing of the feet, and frog support. Horses are also sometimes administered heparin, which is thought to reduce the risk of laminitis by decreasing blood coagulability and thus blood clot formation in the capillaries of the foot.
Treatment is directed largely towards management of underlying cause:
- Replacement of nutrients, electrolytes and fluid may be necessary. In severe deficiency, hospital admission may be required for nutritional support and detailed advice from dietitians. Use of enteral nutrition by naso-gastric or other feeding tubes may be able to provide sufficient nutritional supplementation. Tube placement may also be done by percutaneous endoscopic gastrostomy, or surgical jejunostomy. In patients whose intestinal absorptive surface is severely limited from disease or surgery, long term total parenteral nutrition may be needed.
- Pancreatic enzymes are supplemented orally in pancreatic insufficiency.
- Dietary modification is important in some conditions:
- Gluten-free diet in coeliac disease.
- Lactose avoidance in lactose intolerance.
- Antibiotic therapy to treat Small Bowel Bacterial overgrowth.
- Cholestyramine or other bile acid sequestrants will help reducing diarrhoea in bile acid malabsorption.
If this is not the case, the patient is generally administered a proton pump inhibitor (e.g. omeprazole), given blood transfusions (if the level of hemoglobin is extremely low, that is less than 8.0 g/dL or 4.5–5.0 mmol/L), and kept NPO, which stands for "nil per os" (Latin for "nothing by mouth", or no eating or drinking) until endoscopy can be arranged. Adequate venous access (large-bore cannulas or a central venous catheter) is generally obtained in case the patient suffers a further bleed and becomes unstable.
In addition to fluid support, impactions are often treated with intestinal lubricants and laxatives to help move the obstruction along. Mineral oil is the most commonly used lubricant for large colon impactions, and is administered via nasogastric tube, up to 4 liters once or twice daily. It helps coat the intestine, but is not very effective for severe impactions or sand colic since it may simply bypass the obstruction. Mineral oil has the added benefit of crudely measuring GI transit time, a process which normally takes around 18 hours, since it is obvious when it is passed. The detergent dioctyl sodium sulfosuccinate (DDS) is also commonly given in oral fluids. It is more effective in softening an impaction than mineral oil, and helps stimulate intestinal motility, but can inhibit fluid absorption from the intestine and is potentially toxic so is only given in small amounts, two separate times 48 hours apart. Epsom salts are also useful for impactions, since they act both as an osmotic agent, to increase fluid in the GI tract, and as a laxative, but do run the risk of dehydration and diarrhea. Strong laxatives are not recommended for treating impactions.
Prostacyclin (prostaglandin I) is commonly considered the most effective treatment for PAH. Epoprostenol (synthetic prostacyclin) is given via continuous infusion that requires a semi-permanent central venous catheter. This delivery system can cause sepsis and thrombosis. Prostacyclin is unstable, and therefore has to be kept on ice during administration. Since it has a half-life of 3 to 5 minutes, the infusion has to be continuous, and interruption can be fatal. Other prostanoids have therefore been developed. Treprostinil can be given intravenously or subcutaneously, but the subcutaneous form can be very painful. An increased risk of sepsis with intravenous Remodulin has been reported by the CDC. Iloprost is also used in Europe intravenously and has a longer half life. Iloprost was the only inhaled form of prostacyclin approved for use in the US and Europe, until the inhaled form of treprostinil was approved by the FDA in July 2009.
In a "hemodynamically significant" case of hematemesis, that is hypovolemic shock, resuscitation is an immediate priority to prevent cardiac arrest. Fluids and/or blood is administered, preferably by large bore intravenous cannula, and the patient is prepared for emergency endoscopy, which is typically done in theatres. Surgical opinion is usually sought in case the source of bleeding cannot be identified endoscopically, and laparotomy is necessary.
Securing the airway is a top priority in hematemesis patients, especially those with a disturbed conscious level (hepatic encephalopathy in esophageal varices patient.) A cuffed endotracheal tube could be a life saving choice.
The dual (ET and ET) endothelin receptor antagonist bosentan was approved in 2001. Sitaxentan (Thelin) was approved for use in Canada, Australia, and the European Union, but not in the United States. In 2010, Pfizer withdrew Thelin worldwide because of fatal liver complications. A similar drug, ambrisentan is marketed as Letairis in the U.S. by Gilead Sciences.
Several classes of antihypertensive agents are recommended, with the choice depending on the cause of the hypertensive crisis, the severity of the elevation in blood pressure, and the usual blood pressure of the person before the hypertensive crisis. In most cases, the administration of intravenous sodium nitroprusside injection which has an almost immediate antihypertensive effect, is suitable (but in many cases not readily available). Besides, nitroprusside runs a risk of cyanide poisoning. Other intravenous agents like nitroglycerine, nicardipine, labetalol, fenoldopam or phentolamine can also be used, but all have a delayed onset of action (by several minutes) compared to sodium nitroprusside.
In addition, non-pharmacological treatment could be considered in cases of resistant malignant hypertension due to end stage kidney failure, such as surgical nephrectomy, laparoscopic nephrectomy, and renal artery embolization in cases of anesthesia risk.
It is also important that the blood pressure is lowered smoothly, not too abruptly. The initial goal in hypertensive emergencies is to reduce the pressure by no more than 25% (within minutes to 1 or 2 hours), and then toward a level of 160/100 mm Hg within a total of 2–6 hours. Excessive reduction in blood pressure can precipitate coronary, cerebral, or renal ischemia and, possibly, infarction.
The diagnosis of a hypertensive emergency is not based solely on an absolute level of blood pressure, but also on the typical blood pressure level of the patient before the hypertensive crisis occurs. Individuals with a history of chronic hypertension may not tolerate a "normal" 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.
SMA syndrome can present in acute, acquired form (e.g. abruptly emerging within an inpatient stay following scoliosis surgery) as well as chronic form (i.e. developing throughout the course of a lifetime and advancing due to environmental triggers, life changes, or other illnesses). According to a number of recent sources, at least 70% of cases can typically be treated with medical treatment, while the rest require surgical treatment.
Medical treatment is attempted first in many cases. In some cases, emergency surgery is necessary upon presentation. A six-week trial of medical treatment is recommended in pediatric cases. The goal of medical treatment for SMA Syndrome is resolution of underlying conditions and weight gain. Medical treatment may involve nasogastric tube placement for duodenal and gastric decompression, mobilization into the prone or left lateral decubitus position, the reversal or removal of the precipitating factor with proper nutrition and replacement of fluid and electrolytes, either by surgically inserted jejunal feeding tube, nasogastric intubation, or peripherally inserted central catheter (PICC line) administering total parenteral nutrition (TPN). Pro-motility agents such as metoclopramide may also be beneficial. Symptoms may improve after restoration of weight, except when reversed peristalsis persists, or if regained fat refuses to accumulate within the mesenteric angle. Most patients seem to benefit from nutritional support with hyperalimentation irrespective of disease history.
If medical treatment fails, or is not feasible due to severe illness, surgical intervention is required. The most common operation for SMA syndrome, duodenojejunostomy, was first proposed in 1907 by Bloodgood. Performed as either an open surgery or laparoscopically, duodenojejunostomy involves the creation of an anastomosis between the duodenum and the jejunum, bypassing the compression caused by the AA and the SMA. Less common surgical treatments for SMA syndrome include Roux-en-Y duodenojejunostomy, gastrojejunostomy, anterior transposition of the third portion of the duodenum, intestinal derotation, division of the ligament of Treitz (Strong's operation), and transposition of the SMA. Both transposition of the SMA and lysis of the duodenal suspensory muscle have the advantage that they do not involve the creation of an intestinal anastomosis.
The possible persistence of symptoms after surgical bypass can be traced to the remaining prominence of reversed peristalsis in contrast to direct peristalsis, although the precipitating factor (the duodenal compression) has been bypassed or relieved. Reversed peristalsis has been shown to respond to duodenal circular drainage—a complex and invasive open surgical procedure originally implemented and performed in China.
In some cases, SMA Syndrome may occur alongside a serious, life-threatening condition such as cancer or AIDS. Even in these cases, though, treatment of the SMA Syndrome can lead to a reduction in symptoms and an increased quality of life.
Prevention focuses on improving sanitation of water and food sources.
Treatment focuses on addressing the central components of intestinal inflammation, bacterial overgrowth and nutritional supplementation.