الفهرس 
1. HERITABLE CONNECTIVE TISSUE DISORDERSOnly 14 pages are availabe for public view
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Abstract
H
eritable connective tissue disorders are a group of diseases that affect the connective tissue and they are inherited in it’s nature. Heritable connective tissue disorders include Marfan syndrome, Ehler Danlos syndrome, osteogenesis imperfecta and congenital contractural arachnodactyly. As this group of diseases is inherited and genetic in its nature and they affect the connective tissue, they have a lot of similar clinical manifestations and have nearly the same way of management.
In Marfan syndrome, patients have disproportionately long limbs (span > height) and digits or reduced upper to lower segment ratio, pectus excavatum or carinatum, scoliosis, highly arched palate with dental crowding, ectopia lentis, dilatation of the aortic root with regurgitation, aortic aneurysm and/or dissection, skin striae and dural ectasia.
Congenital contractural arachnodactyly (C C A) is a rare autosomal dominant disease affecting multiple family members. Patients complain of inability to open the mouth (most likely due to masseteric fibrous bands and coronoid hyperplasia, which lead to molding deformities and developmental hypoplasia of the bones of mandible), flexion contractures of the fingers (apparent on dorsiflexion), with facial dysmorphism in the form of macrocephaly, facial asymmetry, downslanting palpebral fissures, micrognathia, long philtrum, low set ears, arachnodactyly, and chest wall deformities.
Ehler Danlos syndrome is characterized by easy bruising (typically the initial manifestation), bleeding from the gums following brushing of the teeth, or excessive bleeding after minor trauma are common presentations. It’s also charachterized by joint hyper mobility, skin hyper extensibility, general connective tissue fragility, delayed wound healing, atrophic scarring and cardiovascular manifestations ranging from no apparent lesion to arterial aneurysms, arterial rupture without aneurysm, varicose veins, aortic regurgitation, mitral valve prolapse and conduction disturbances. Floppy mitral valve syndrome and the combination of mitral and tricuspid insufficiency due to redundant chordae tendinae or valve cusps have been reported.
Osteogenesis imperfecta disease is charachterized by weak and brittle bone which is easily fractures with any minor trauma or vigorous movement. The patients also complain of dentinogenesis imperfecta, bone malformations, easy bruising, laxity of joints, gross delayed motor development, pulmonary problems and congenital heart diseases.
Anesthetic management of this group of disorders include preoperative assessment, indications of surgical intervention, preoperative medical history, preoperative labs and investigations and intraopertive anesthetic management including assessment of the airway, choice of anesthesia, positioning, management of intraoperative complications and also the postoperative managent and care of this patients including their monitoring in post anesthesia care unit (PACU) or in intensive care unit (ICU), fluid therapy, blood transfusion, pain control, nutrition and management of postoperative complications.
Many of heritable connective tissue disorders require a lot of operations and surgical interventions and the anesthesiologist should take care about the clinical symptoms and signs, laboratory findings and take a detailed history to make a meticulous preoperative assessment of these patients. The patient with a heritable disorder of connective tissue should be evaluated for a surgical procedure in three general areas: risk of general anesthesia, possibility or probability of the surgical procedure’s being successful and possibility or probability of the surgical procedure’s introducing new problems.
Preoperative assessment of patients with heritable connective tissue disorders begins with reviewing the clinical signs and symptoms of the diseases, knowing its complications and management. Anesthesiologist should anticipate airway and pulmonary problems (such as obstructive and restrictive lung diseases and pneumothorax). Cardiac problems are very common (especially aortic regurge and mitral valve prolapse) as well as aortic dissection. Intestinal manifestations (such as hernias, intestinal obstruction, megacolon and diverticula) and also musculoskeletal manifestations (as loose skin, hyperextensiblity and hypermobility of joints and soft, brittle bones) are also common.
All patients should be investigated carefully. Cardiological consultation is important. Echocardiograghy is helpful for diagnosis of complications and assessment of cardiac function. And electrocardiogram for diagnosis of dysrhythmias and conduction abnormalities which is very common in these disorders. Angiograghy and catheter data should be done if needed. Patients might be taking beta blockers, angiotensin receptor blockers (ARB) for blood pressure control to minimize shear forces and wall stress in the aorta, diuretics (history of heart failure), and anticoagulants (if he or she had valve or aortic root replacement in the past). Beta blockers should be continued perioperatively. Patients with heritable connective tissue disorders are more vulnerable to infective endocarditis and should receive antibiotic prophylaxis for that.
Chest consultation as well as chest x ray, arterial blood gases and pulmonary function test are important as these patients frequently have kyphosis, scoliosis and chest abnormalities (as pectus carinatum and pectus excavatum). Full hematological and biochemical investigations and coagulation profile are also very important.
Assessment of the airway (by the standard and approved methods such as mallampati classification of the airway, thyromental distance, neck mobility and extension and mouth opening) is very important as many of these patients are considred as cases of difficult intubation. Anesthesiologist should anticipate it and put a plan for airway management in such patients.
After putting a plan for anesthesia, the anesthesiologist should start monitoring of the patient by the standard monitoring (such as non invasive blood pressure, pulse oximetry, electrocardiogram and capnograghy). Other monitors are put according to the general condition of the patient and type of surgery. In most situations, the anesthesiologist may need more monitoring with invasive blood pressure, transesophageal echocardiograghy, and central venous pressue monitoring. These patients require a lot of cardiothoracic surgeries such as sugery for correction of aortic regurge or for aortic dissection.
According to the type of surgery and according to the general condition of the patient. Anesthesia whether general or regional (including intrathecal, epidural and also peripheral nerve blocks) is selected.
For obstetric anesthesia, instrumented vaginal delivery can be safely performed in patients with heritable connective tissue disorders who have no cardiovascular involvement or stable minimal aortic dilatation (<4 cm). Epidural analgesia is strongly recommended to minimize stress associated with labor pain. Both regional and general anesthesia has been used successfully in parturients undergoing cesarean delivery. Neuraxial anesthesia may pose technical challenges due to kyphoscoliosis. The standard dose of local anesthetic required for the spinal anesthesia might be inadequate due to the presence of dural ectasia.
Positioning is one of the important issues in the intraoperative management as a lot of complications can occur in such patients due to improper positioning. Padding should be used to reduce shear forces and external tissue pressure. The eye should be protected as direct force to the eyeball increases the risk of retinal detachment and globe rupture, especially in kyphoscoliotic patients and brittle cornea syndromes with increased ocular fragility, and in pathological myopia. Adhesive tapes and wound dressing for fixation of devices should be easily removable or avoided if possible because of the risk of severe skin damage; the history should specifically address this issue.
The goal of postoperative care is to ensure that patients have good outcomes after surgical procedures. A good outcome includes recovery without complications and adequate pain management.
Postoperative monitoring should aim at adequate control of blood pressure, heart rate, early detection of any postopaerative dysrhythmias, early dealing with it and proper management of the volume status of the patient.
Calculation of optimum fluid is also an important issue. Careful fluid management is required postoperatively with hourly urine assessment and replacement of ongoing losses. Ileus is inevitable but can be minimized by avoiding nitrous oxide and utilizing a multi-modal analgesic regime and assessment for the need of blood transfusion or any of blood products according to the status of the patient.
Effective postoperative pain control is an essential component of the care of such surgical patients. Inadequate pain control, apart from being inhumane, may result in increased morbidity or mortality. Evidence suggests that surgery suppresses the immune system in a degree proportionate to the invasiveness of the surgery. Good analgesia can reduce this deleterious effect.
While most patients will progress to oral nutrition after surgery and require little or no intervention, major surgery or postoperative complications can delay the prescription of an oral diet. In such patients, nutritional requirements are often increased to support wound healing and hyper metabolism associated with surgical recovery.
Postoperative nausea and vomiting may be with the patient from the start or it may be a complications of positioning or of the anesthetic procedure itself. It needs special considerations for management and care especially in cases of aortic regurge, mitral valve prolapse, aortic dissection, scoliosis and also A discharge protocols for these patients are very important and it should be based on the clinical data and recovery from anesthesia.