Q 1 OUTLINE THE MANAGEMENT OF A 14 YR OLD GIRL WITH GUILLAIN BARRE SYNDROME ?
A 1 INTRODUCTION
1 Guillain-Barré syndrome (GBS) can be described as a collection of clinical syndromes that manifests as an acute inflammatory polyradiculoneuropathy with resultant weakness and diminished reflexes.
2 With poliomyelitis under control in developed countries, GBS is now the most important cause of acute flaccid paralysis.
3 Acute inflammatory demyelinating polyradiculoneuropathy (AIDP) is the most widely recognized form of GBS , but the variants known as acute motor axonal neuropathy (AMAN), acute motor-sensory axonal neuropathy (AMSAN), and Miller-Fisher syndrome also are well recognized.
4 Approximately one third of patients require admission to an intensive care unit (ICU), primarily because of respiratory failure.
5 After medical stabilization, patients can be treated on a general medical/neurologic floor, but continued vigilance remains important in preventing respiratory, cardiovascular, and other medical complications.
ETIOLOGY
1 C JEJUNI
2 CMV [ CYTOMEGALOVIRUS
3 EBV [ EPSTEIN BARR VIRUS ]
4 MYCOPLASMA PNEUMONIAE
5 VARICELLA ZOSTER VIRUS
6 HIV
7 INFLUENZA TYPE A AND B
8 BORRELIA
9 ZIKA VIURUS [ IN BRAZIL OUTBREAK ]
10 SECONDARY TO MENINGOCOCCAL CONJUGATE VACCINE
11 USE OF FLUOROQUINOLONES
Pathophysiology
1 GBS is a postinfectious, immune-mediated disease.
2 Cellular and humoral immune mechanisms probably play a role in its development.
3 Molecular mimicry - Immune responses directed against lipopolysaccharide antigens in the capsule of C jejuni result in antibodies that cross-react with ganglioside GM1 in myelin, resulting in immunologic damage to the peripheral nervous system
4 Macrophage-mediated, multifocal stripping of myelin
5 Pathologic findings in GBS include lymphocytic infiltration of spinal roots and peripheral nerves
6 This phenomenon results in defects in the propagation of electrical nerve impulses, with eventual absence or profound delay in conduction, causing flaccid paralysis.
7 A subgroup of patients may have a primary immune attack directly against nerve axons, with sparing of myelin.
Subtypes of Guillain-Barré syndrome
1 Several variants of GBS are recognized.
2 These disorders share similar patterns of evolution, symptom overlap, and probable immune-mediated pathogenesis. Recovery from them varies.
A ) Acute inflammatory demyelinating polyneuropathy
The acute inflammatory demyelinating polyneuropathy (AIDP) subtype is the most commonly identified form
It is generally preceded by a bacterial or viral infection.
Nearly 40% of patients with AIDP are seropositive for C jejuni.
B ) Acute motor axonal neuropathy
The acute motor axonal neuropathy (AMAN) subtype is a purely motor disorder that is more prevalent in pediatric age groups.
AMAN is generally characterized by rapidly progressive symmetrical weakness and ensuing respiratory failure.
Nearly 70-75% of patients with AMAN are seropositive for Campylobacter, with the majority of cases of AMAN being associated with preceding C jejuni diarrhea.
Patients typically have high titers of antibodies to gangliosides (ie, GM1, GD1a, GD1b). Inflammation of the spinal anterior roots may lead to disruption of the blood-CNS barrier.
Biopsies show wallerianlike degeneration without significant lymphocytic inflammation.
One third of patients with AMAN may actually be hyperreflexic.
Although the mechanism for this hyperreflexia is unclear, dysfunction of the inhibitory system via spinal interneurons may increase motor neuron excitability.
Hyperreflexia is significantly associated with the presence of anti-GM1 antibodies.
Acute motor-sensory axonal neuropathy
1 Acute motor-sensory axonal neuropathy (AMSAN) is a severe acute illness differing from AMAN in that it also affects sensory nerves and roots.
2 Patients are typically adults.
3 AMSAN often presents as rapid and severe motor and sensory dysfunction.
4 Marked muscle wasting is characteristic, and recovery is poorer than it is from electrophysiologically similar cases of AMAN.
5 As with AMAN, AMSAN is often associated with preceding C jejuni diarrhea.
6 Pathologic findings show severe axonal degeneration of motor and sensory nerve fibers with little demyelination.
Miller-Fisher syndrome
1 Miller-Fisher syndrome (MFS), which is observed in about 5% of all cases of GBS, classically presents as a triad of ataxia, areflexia, and ophthalmoplegia.
2 Acute onset of external ophthalmoplegia is a cardinal feature.
3 Ataxia tends to be out of proportion to the degree of sensory loss. Patients may also have mild limb weakness, ptosis, facial palsy, or bulbar palsy.
4 Patients have reduced or absent sensory nerve action potentials and absent tibial H reflex
5 Anti-GQ1b antibodies are prominent in MFS, and have a relatively high specificity and sensitivity for the disease.
6 Dense concentrations of GQ1b ganglioside are found in the oculomotor, trochlear, and abducens nerves
7 Patients with acute oropharyngeal palsy carry anti-GQ1b/GT1a IgG antibodies.
8 Recovery generally occurs within 1-3 months.
Acute panautonomic neuropathy
Acute panautonomic neuropathy, the rarest GBS variant, involves the sympathetic and parasympathetic nervous systems.
Patients have severe postural hypotension, bowel and bladder retention, anhidrosis, decreased salivation and lacrimation, and pupillary abnormalities.
Cardiovascular involvement is common, and dysrhythmias are a significant source of mortality.
Significant motor or sensory involvement is lacking.
Recovery is gradual and often incomplete.
Pure sensory GBS
A pure sensory variant of GBS has been described in the literature.
It is typified by a rapid onset of sensory loss, sensory ataxia, and areflexia in a symmetrical and widespread pattern.
Lumbar puncture studies show albuminocytologic dissociation in the CSF, and results from electromyography (EMG) show characteristic signs of a demyelinating process in the peripheral nerves.
The prognosis in pure GBS is generally good. Immunotherapies, such as plasma exchange and the administration of IVIGs, can be tried in patients with severe disease or slow recovery.
MANAGEMENT
1 Early recognition and treatment of GBS also may be important in the long-term prognosis, especially in the patient with poor clinical prognostic signs, such as older age, a rapidly progressing course, and antecedent diarrhea
IT INCLUDES -
1 ) Prehospital and Emergency Department Care
A ) requires careful attention to airway, breathing, and circulation (ABCs).
B ) Administration of oxygen and assisted ventilation may be indicated, along with establishment of intravenous access.
C ) Emergency medical services personnel should monitor for cardiac arrhythmias and transport expeditiously.
D ) In the emergency department (ED), continuation of ABCs, intravenous treatment, oxygen, and assisted ventilation may be indicated.
E ) Intubation should be performed on patients who develop any degree of respiratory failure.
Clinical indicators for intubation in the ED include the following:
Hypoxia
Rapidly declining respiratory function
Poor or weak cough
Suspected aspiration
Typically, intubation is indicated when the forced vital capacity (FVC) is less than 15 mL/kg.
Treatment is rarely needed for tachycardia. Atropine is recommended for symptomatic bradycardia.
Because of the lability of dysautonomia, hypertension is best treated with short-acting agents, such as a short-acting beta blocker or nitroprusside.
Hypotension from dysautonomia usually responds to intravenous fluids and supine positioning. Temporary pacing may be required for patients with second- and third-degree heart block.
2 ) ICU Treatment
Good supportive care is critical in the treatment of patients with GBS.
Admission to the ICU should be considered for all patients with labile dysautonomia, a forced vital capacity of less than 20 mL/kg, or severe bulbar palsy.
Any patients exhibiting clinical signs of respiratory compromise to any degree also should be admitted to an ICU.
Because most deaths related to GBS are associated with complications of ventilatory failure and autonomic dysfunction, many patients need to be monitored closely in ICUs by physicians experienced in acute neuromuscular paralysis and its accompanying complications
3 ) Competent intensive care includes the following features:
A ) Respiratory therapy
B ) Cardiac monitoring
C ) Safe nutritional supplementation
D ) Monitoring for infectious complications (eg, pneumonia, urinary tract infections, septicemia)
RESPIRATORY THERAPY
1 Approximately one third of patients with GBS require ventilatory support.
2 Monitoring for respiratory failure, bulbar weakness, and difficulties with swallowing help to anticipate complications.
3 Proper positioning of the patient to optimize lung expansion and secretion management for airway clearance is required to minimize respiratory complications.
4 Serial assessment of ventilatory status is needed, including measurements of vital capacity and pulse oximetric monitoring.
5 Respiratory assistance should be considered when the expiratory vital capacity decreases to less than 18 mL/kg or when a decrease in oxygen saturation is noted (arterial PO2 < 70 mm Hg).
6 Tracheotomy may be required in a patient with prolonged respiratory failure, especially if mechanical ventilation is required for more than 2 weeks.
Cardiac monitoring
1 Close monitoring of heart rate, blood pressure, and cardiac arrhythmias allows early detection of life-threatening situations.
2 Critically ill patients require continuous telemetry and close medical supervision in an ICU setting.
3 Antihypertensives and vasoactive drugs should be used with caution in patients with autonomic instability.
4 Hemodynamic changes related to autonomic dysfunction are usually transitory, and patients rarely require long-term medications to treat blood pressure or cardiac problems.
Nutrition
1 Enteral or parenteral feedings are required for patients on mechanical ventilation to ensure that adequate caloric needs are met when the metabolic demand is high.
2 Even patients who are off the ventilator may require nutritional support if dysphagia is severe.
3 Precautions against dysphagia and dietary manipulations should be used to prevent aspiration and subsequent pneumonias in patients at risk
.Prevention of infection
The risk of sepsis and infection can be decreased by the use of minimal sedation, frequent physiotherapy, and mechanical ventilation with positive end-expiratory pressure where appropriate.
Transfer may be appropriate if a facility does not have the proper resources to care for patients who require prolonged intubation or prolonged intensive care.
4 ) Prevention of thromboses, pressure sores, and contractures
1 Subcutaneous unfractionated or low ̶ molecular-weight heparin (LMWH) and thromboguards are often used in the treatment of immobile patients to prevent lower-extremity deep venous thrombosis (DVT) and consequent pulmonary embolism (PE).
2 Prevention of pressure sores and contractures entails careful positioning, frequent postural changes, and daily range-of-motion (ROM) exercises.
5 ) Bowel and bladder management
1 Although bowel and bladder dysfunction is generally transitory, management of these functions is needed to prevent other complications.
2 Initial management should be directed toward safe evacuation and the prevention of overdistention.
3 Monitoring for secondary infections, such as urinary tract infection, also is an area of concern.
4 Nephropathy has been reported in pediatric patients.
5 ) Mental status management
Hospitalized patients with GBS may experience mental status changes, including hallucinations, delusions, vivid dreams, and sleep abnormalities.
These occurrences are thought to be associated with autonomic dysfunction and are more frequent in patients with severe symptoms. Such problems resolve as the patient recovers.
Psychiatric and psychological problems such as depression and anxiety are likely to occur.
Education, counseling, and medications are necessary to manage these problems and help the patient adjust and improve from their profound disability.
6 ) USE OF PHYSIOTHERAPY
1 The goals of the therapy programs are to reduce functional deficits and to target impairments and disabilities resulting from GBS.
2 daily ROM exercises and proper positioning to prevent muscle shortening and joint contractures.
3 Active muscle strengthening can then be slowly introduced and may include isometric, isotonic, isokinetic, or progressive resistive exercises. Mobility skills, such as bed mobility, transfers, and ambulation, are targeted functions.
4 Patients should be monitored for hemodynamic instability and cardiac arrhythmias, especially upon initiation of the rehabilitation program.
5 The intensity of the exercise program also should be monitored, because overworking the muscles may, paradoxically, lead to increased weakness.
7 ) ROLE OF OCCUPATIONAL AND RECREATIONAL THERAPY
1 Occupational therapy professionals should be involved early in the rehabilitation program to promote upper body strengthening, ROM, and activities that aid functional self care.
2 Restorative and compensatory strategies can be used to promote functional improvements.
3 Energy conservation techniques and work simplification also may be helpful, especially if the patient demonstrates poor strength and endurance.
4 Participation in recreational therapy assists in the patient’s adjustment to disability and improves integration into the community.
5 Recreational activities, either new or adapted, can be used to promote the growth, development, and independence of a long-term hospital patient.
8 ) Speech Therapy
1 Speech therapy is aimed at promoting speech and safe swallowing skills for patients who have significant oropharyngeal weakness with resultant dysphagia and dysarthria.
2 In ventilator-dependent patients, alternative communication strategies also may need to be implemented.
3 Once weaned from the ventilator, patients with tracheostomies can learn voicing strategies and can eventually be weaned from the tracheostomy tube.
4 Cognitive screening also can be performed conjointly with neuropsychology to assess for deficits, since cognitive problems have been reported in some patients with GBS, especially those who have had an extended ICU stay
9 Immunotherapy
1 ) Plasma exchange carried out over a 10-day period may aid in removing autoantibodies, immune complexes, and cytotoxic constituents from serum and has been shown to decrease recovery time by 50%.
2 ) In well-controlled clinical trials, the efficacy of IVIGs in GBS patients has been shown to equal that of plasma exchange
3 ) IVIG treatment is easier to implement and potentially safer than plasma exchange, and the use of IVIGs versus plasma exchange may be a choice of availability and convenience
4 ) Additionally, IVIG is the preferential treatment in hemodynamically unstable patients and in those unable to ambulate independently
5 ) Some evidence suggests that in select patients who do not respond initially to IVIG, a second dose may be beneficial.
6 ) try plasma exchange first, and if this does not provide patient improvement then they go to IVIG. Theoretically, if IVIG is given first, then the plasma exchange will be removing the IVIG, which was just given days earlier
10 ) Corticosteroids
1 ) Corticosteroids are ineffective as monotherapy.
2 ) According to moderate-quality evidence, corticosteroids given alone do not significantly hasten recovery from GBS or affect the long-term outcome.
Methylprednisolone
Substantial evidence shows that intravenous methylprednisolone alone produces neither significant benefit nor harm. In combination with IVIG, intravenous methylprednisolone may hasten recovery but does not significantly affect long-term outcome.
11 ) Analgesia
1 ) Pain medications may be required in inpatient and outpatient settings. A tiered pharmacologic approach that starts with nonsteroidal anti-inflammatory drugs (NSAIDs) or acetaminophen, with narcotic agents added as needed, is usually recommended.
2 ) Narcotics should be used judiciously because patients may already be at risk for ileus.
3 ) Most patients do not require narcotic analgesics after the first couple of months of illness.
4 ) Adjunct medications for pain, such as tricyclic antidepressants and certain anticonvulsants, may be beneficial for dysesthetic-type pains.
5 ) Nonpharmacologic pain relief therapies include frequent passive limb movements, gentle massage, and frequent position changes.
6 ) Desensitization techniques can be used to improve the patient’s tolerance for activities.
7 ) Modalities such as transcutaneous electrical nerve stimulation (TENS) and heat may prove beneficial in the management of myalgia.
8 ) Education and psychological counseling can decrease the amount of suffering associated with this pain and disability