CNS involvement \200 \200 \200 Asymmetrical neurological signs Cranial nerve palsy Altered mental status Spinal cord involvement \200 \200 Sensory level Loss of anal tone and sphincter re \202 ex Neuromuscular disease \200 \200 \200 Extremity weakness and wasting Hypotonia and hypore \202 exia Autonomic dysfunction 377 CHAPTER 22.9 ICU neuromuscular disorders Investigations Electrophysiological tests Comprehensive electrophysiological studies, inclu ding motor and sensory nerves conduction studies and needle EMG in upper and lower limbs, a re able to differentiate between CIP and CIM. However, electrophysiological tests do not pr edict duration of mechanical ventilation or length of ICU stay. \200 Use of corticosteroids should be restricted to condi- tions in which they have been proven to have a signi \201 - cant impact on morbidity and mortality. Neuromuscular blocking drug s should also be used only for selected indications, such as dif \201 cult to ventilate pa tients and intractable intracranial hypertension, and only when all other means have failed . If the clinical con- dition permits, daily interruption of neuromuscular block- ing drugs is recommended to reduce the risks associated with prolonged pharmacological denervation. Sedation protocols designed to minimize the use of seda- tives and analgesics decrease the duration of mechanical ventilation and possibly the incidence and severity of CINM. Strateg ies to mobilize patients with passive stretching or active exercise seem reasonable given t heir relative safety. Electrolyte disorders, including phosphate and magne- sium depletion, should be controlled throughout the entire critical care episode. Although not proven, ade quate nutrition seems a neces- sity to prevent catabolism and muscle wasting. IVIG might re duce the development of CINM, but more studies are required before this treatment can be re c- ommended. Nerve conduction studies \200 CIP is characterized by decreased CMAP and sen- sory nerve action potential with normal con duction velocity abnormalities may be detected as early as 48h after the onset of critical illness prolongation of CMAP suggests an associated myopathy EMG \200 CIM is diagnosed by abnormal EMG during voluntary contraction in conscious and cooperative patients Direct muscle stimulation (DMS) \200 differentiates between CIP and CIM in uncooperative patients stimulating and recording elec trodes are placed in the muscle distal to the end-plate zone in CIP there is a reduced or a bsent CMAP on motor nerve stimulation but a normal response with DMS in CIM the CMAP is red uced or absent after both motor nerve stimulation and DMS technically dif \201 cult Outcome \200 CINM is an independent predictor of prolonged mechanical ventilation and increased ICU mort ality and LOS. Complete functional recovery occurs in 70% of patients. Muscle wasting and weakness are common in survivors of critical illness, and some remain severely disabled. Mi ld disabilities persist in patients with seemingly good recovery. These include reduced or absent re \202 exes, glove and stocking sensory loss, muscle atrophy, dysasthe- sia and fo ot drop. Other electrophysiological tests \200 phrenic nerve conduction studies and diaphragmatic EMG may be indicated in patients who fai l to wean from mechanical ventilation Muscle biopsy \200 Not used routinely because it is invasive and the results are not immediately available Myo sin/actin ratio reduced in CIM Three types of histological changes are recognized \200\224 acute necrotizing, thick myosin \201 lament loss and \201 bre atrophy Allows diagnosis of other causes of muscle pathology \200 Further reading De Jonghe B, Sharshar T, Lefaucher JP, et al. Paresis acquired in the inten sive care unit: a prospective multicenter study. JAMA 2002; 288: 2859 \200\22367. Dhand UK. Clinical approach to the weak patient in the intensive care unit. Respir Care 2006; 51: 1024 \200\22340. Neuroimaging \200 Fletcher SN, Kennedy DD, Ghosh IR, et al. Persistent neuromuscu- lar and neurophysiologic a bnormalities in long-term survivors of prolonged critical illness. Crit Care Med 2003; 31: 1012 \200\2236. MRI of the spinal cord and brain to exclude cord com- pression and brainstem lesions Other \200 Latronico N, Peli E, Botteri M. Critical illness myopathy and neuropathy. Curr Opin Crit Care 2005; 11: 126 \200\22332. Serum CK \200\224variably raised but may be normal Latronico N, Shehu I, Seghelini E. Neuromuscular sequelae of Prevention and treatment There is no proven treatment for established CINM, and management focuses on prevention by avoidance of risk factors. \200 critical illness. Curr Opin Crit Care 2005; 11: 381 \200\22390. Schweickert W, Hall J. ICU-acquired weakness. Chest 2007; 131: 1541 \200\2239. Aggressive treatment of sepsis and MOF minimizes the risk of developing CINM, shortens its duration and reduces severity in established cases. The link between elevated blood glucose levels and CINM is well established. Tight glycaemic control with insulin infusion is asso ciated with a 50% reduction in the evolution of CIP and mortality bene \201 t in criticall y ill sur- gical patients. Tight glycaemic control in medical ICU patients results in a sma ller reduction in the incidence of CIP but signi \201 cant reductions in the duration of m echan- ical ventilation. 378 L THWAITES Tetanus Tetanus is a toxin-mediated disease caused by the bacte- rium Clostridium tetani resulting in: \200 \200 Special investigations should be ordered according to the clinical indications. In addition to routine blood tests, the following are helpful: \200 \200 Skeletal muscle rigidity and spasm Autonomic nervous system instability ABG CXR (aspiration is common) The disease is completely preventable by vaccination, and in recent years global vaccinatio n initiatives in infants and young women have begun to have an impact on the disease incide nce. Nevertheless, in the developing world, tetanus continues to be a common cause of morta lity and morbid- ity of neonates, children and young adults. In countries with well establi shed vaccination programs, the disease is rare and usually occurs in the elderly or cer- ta in \200\230high risk \200\231 groups such as IV drug users. In either setting, mortality f rom severe disease is high and good outcome is dependent on high quality care. Natural history Historically two periods have been used to characterize the progression of tetanus disease: \200 Incubation period: the asymptomatic period from infec- tion to the \201 rst symptom (typi cally 7 \200\22310 days). This can- not be calculated if no entry wound is found. Period of onset: the period from \201 rst symptom to \201 rst spasm (typically 24 \200\22372h). Shorter periods are associated with more rapidly progress- ing and severe disease. More acc urate prognosis can be calculated using speci \201 c prognostic scores. Tetanus gradually increases in severity over 1 or 2 weeks, with spasms reaching maximum intensity during the second week, and maximal autonomic disturbance during the second and third weeks. These gra dually improve, although muscle rigidity may persist for up to 6 weeks. A recurrence of spa sms or worsening of severity may sug- gest a persistent source of C. tetani infection. Etiology C. tetani is an anaerobic Gram-positive bacterium which produces a highly potent t oxin. Infection occurs after contamination of a wound with the bacterial spores. These are found throughout the environment, particu- larly in soil or human/animal feces. Wounds can be very minor abrasions, and in 25% of cases no wound is apparent by the time symptoms occ ur. Tetanus toxin prevents synaptic release of neurotransmitter from the presynaptic GABAer gic inhibitory interneurons, resulting in uncontrolled motor neuron activity and thus the c har- acteristic increased muscle tone and spasm. Similarly disinhibited autonomic (predomin antly sympathetic) nervous system activity is seen, producing cardiovascular instability. Differential diagnosis \200 Strichnine poisoning \200 Dystonic reactions to antidopamin ergic drugs \200 Surgical acute abdomen \200 Oropharyngeal infection \200 Hypocalcaem ia or meningoencephalitis in neonates Presentation The most common features from the history at presenta- tion are: \200 \200 \200 \200 \200 Management Airway management is paramount, but particular care must be taken to avoid provo king laryngeal spasm during laryngoscopy. If suf \201 cient experience is available, prima ry tracheostomy is recommended. Conventionally antitoxin is given SC, but recent studies an d a meta-analysis have indicated that intrathecal adminis- tration of human immunoglobulin reduces disease progres- sion and severity. Standard \201 rst-line drugs are IV benzodiaz epines (commonly diazepam or midazolam) and high doses are commonly required \200\224often >100mg/24h. In severe disease, neuro- muscular blocking agents are also necessary. Due to c ardi- ovascular instability, chose an agent without signi \201 cant cardiovascular effects . Magnesium sulfate can be used as an adjunct. It is also use- ful as it improves cardiovas cular instability. Target thera- peutic range of serum levels 2 \200\2234mmol/l. Cardiovasc ular instability is dif \201 cult to manage due to rapid \202 uctuations in peripheral r esistance. Agents with short half-lives are necessary, but heavy sedation and adequate spas m control are also of bene \201 t. Any source of infection should be carefully cleaned and debrided. Deep or internal sources of infection are associ- ated with worse prognosis. A f ull primary immunization course of DT (<7yrs old) or dT ( \211 7yrs) is required in all pat ients. Lockjaw Muscle stiffness Back pain Dif \201 culty swallowing There may or may not be any h istory of injury. In neonates, the illness usually presents as dif \201 culty in feeding. Examination should look for \200 Trismus: if not apparent this can be precipitated using the spatula test \200\224where a pa tient with facial involve- ment will re \202 exly bite down on a spatula placed in the mou th) Risus sardonicus from facial muscle spasm (pathogno- monic) Muscle spasms, or abdominal rigidity (continuous) Check airway and respiratory compromise as laryngeal spasm is common and rapidly fatal if untreated Source of infection Heart rate, blood pressure, temperature \200\224also indica- tors of prognosis \200 \200 There is no diagnostic test to con \201 rm tetanus. In some cases C. tetani can be culture d from the wound, but in most the diagnosis is purely a clinical one principally based on t he presence of muscle rigidity and spasms. 379 CHAPTER 22.10 Tetanus Further reading: Farrar JJ, Yen LM, Cook T, et al. Tetanus. J Neurol Neurosurg Psychiatry tetanus antitoxin in the treatment of tetanus: a meta-analysis. Trop Med Int Health 2006; 1 1: 1075 \200\22381. Thwaites CL. Tetanus. Curr Anaesth Crit Care 2005; 16: 50 \200\2237. WHO. Tetanus vaccine. Wkly Epidemiol Rec 2006; 81: 198 \200\223208. 2000; 69: 292 \200\223301. Kabura L, Ilibagiza D, Menten J, et al. Intrathecal vs. intramuscular administration of hum an antitetanus immunoglobulin or equine 380 D TREACHER Botulism sporadic, generally involving small numbers of people who have eaten toxin-contaminated foo d. Although the inci- dence of foodborne and infant botulism has been constant over the pas t 30yrs, wound botulism, particularly in California, has increased markedly mainly amongst drug abusers injecting black tar heroin by IM or SC injection ( \200\231skin-popping \200 \231). Botulism is an acute, potentially life-threatening descending motor paralysis affecting pri marily cranial, respiratory and autonomic nerves caused by exotoxin released from the bacte rium Clostridium botulinum. It was \201 rst described in the early 19th century after an outbreak related to con- taminated sausages, and was named after the Latin for sau- sage, b otulus. Although a relatively rare cause of a proximal, neuroparalytic syndrome, it is impo rtant that clinicians rec- ognize the different patterns of clinical presentation since tim ely use of speci \201 c antitoxin therapy signi \201 cantly reduces mortality and morbidi ty. Foodborne botulism Symptoms Typically develop 12 \200\22348h after eating toxin-contaminate d food. The severity and rate of progression re \202 ects the toxin load, although individ ual susceptibility to the toxin varies considerably. Prodromal symptoms include nausea, vom iting, dry mouth and abdominal distension re \202 ecting autonomic nerve dysfunction, afte r which cranial and respi- ratory nerve dysfunction manifest as diplopia, dysphonia, dysart hria and dysphagia, dif \201 culty holding up the head and increasing respiratory distress . A symmetrical descending motor weakness follows initially affecting the trunk and proxima l limb muscles. Smooth muscle paralysis may lead to constipation and urinary retention. Sen sation is not affected. Bacteriology C. botulinum includes a number of genetically distinct Gram-positive, rod-shap ed, anaerobic, spore-forming bac- teria each of which produces antigenically speci \201 c neuro- toxins. The organisms are found worldwide and can be isolated from soil, vegetables, \201 sh and putrid foods. The spores are heat resistant and survive boiling water for se v- eral hours. The anaerobic, acidic conditions at 30 C asso- ciated with canning, smokin g and fermentation encourage germination of the spores, bacterial growth and toxin pro- duc tion. Examination Autonomic nerve involvement may be widespread result- ing in: \200 \200 \200 \200 \200 Toxins Of the eight toxins identi \201 ed, three (A, B, E) are particu- larly associated w ith human disease. The toxins are dena- tured at temperatures >80 C. Botulinum toxin is th e most potent bacterial toxin: 1g aerosolized is potentially capable of killing >1 million people. hypotension without compensatory tachycardia urinary retention abdominal distension with in testinal ileus dry mouth pupils 4 \200\2238mm with absent light and accommodation re \202 exes Mechanism of action The antigenically distinct toxins have a similar mechanism of action bu t vary in both species speci \201 city and severity of clinical manifestations produced. T oxin is absorbed across mucous membranes, spreads via the bloodstream and binds to a speci \201 c receptor at cholinergic transmitter sites. Once bound, the toxin enters the cytopla sm and irrevers- ibly blocks acetylcholine release from the presynaptic ter- minal, thereby blocking impulse transmission at neuromuscular junctions, autonomic ganglia and parasym- p athetic nerve terminals. Cranial nerves are preferentially affected as toxin binds more rap idly to sites with rapid cycles of depolarization and repolarization. Sensory nerves and ad renergic synapses are not affected, and the toxin does not cross into the CSF. Recovery tak es up to 6 months and requires \200\230sprouting \200\231 of nerve terminals to form new m otor endplates. Cranial nerve involvement results in ophthalmoplegia, par- ticularly lateral rectus palsy, nystagmus, ptosis, dysarthria and dif \201 culty in swallowing, protruding the tongue or s hrugging the shoulders. Corneal and gag re \202 exes are pre- served and facial muscles ma y be spared. Phrenic nerve involvement and respiratory muscle weakness may occur early and develop rapidly. Limb involvement starts proximally and involves the arms \201 rst, produ cing a lower motor neuron \202 accid paralysis. Important normal \201 ndings are preser ved cortical function, intact sensation and absence of fever. Infant botulism Occurs in infants under 6 months, but there can be consid- erable variabili ty in the severity and presenting picture, presumably related to the extent of gut coloniza tion and subsequent toxin production and the individual host response. Classically related to eating contaminated raw honey, it generally starts with constipation progressing over 3 \200\22310 days to produce a \200\230 \202 oppy infant \200\231 who feeds poorly with a w eak cry and evidence of respiratory dis- tress. Cranial nerve involvement with new squint, ptosis and head and facial weakness predicts a more severe course and warrants close monito ring of ability to protect the airway and progressing respiratory muscle weakness. Most inf ants recover quite rapidly without requiring intubation or respiratory support, but the mor e severe cases may run a relapsing course and full recovery may take many months. Clinical presentation There are four clinical patterns of botulism determined by the route of exposure and site of toxin production: \200 Foodborne: eating food contaminated with t oxin \200 Infant: spores colonize GI tract with in vivo toxin pro- duction \200\224mainly in infants <6 months; rarely occurs in adults with a pre-existing GI disorder Wound: infec tion of deep wounds or abscesses with in vivo toxin production, particularly heroin addicts Inhalation: aerosolized toxin as could be used in a ter- rorist attack Epidemiology Traditionally infant botulism has been the most com- mon clinical presentation reported. Adult outbreaks are 381 CHAPTER 22.11 Botulism 5 Serum samples are frequently negative in infant botulism, Wound botulism Caused by colonization of wounds following trauma or associated with drug ab use using SC injection ( \200\230skin-popping \200\231) particularly with black tar heroin. In vivo toxin production occurs after about 10 days. There are usually no prodromal GI sym ptoms and there may be fever and a leucocytosis. and diagnosis relies on positive stool culture. Management Patients with dyspnoea or clinical signs of respiratory dis- tress (tachypnoea, use of accessory muscles) should be closely monitored with 6 hourly FVC, pulse oximetry and careful observation of bulbar function. Arterial blood gasses should be performed. A 70kg adult with FVC falling below 1.2l will have a weak cough, dif \201 culty clearing secretio ns, and progressive tachypnoea and respiratory distress. At this stage, the patient may req uire intubation and should be in a critical care area and kept nil by mouth so that urgent intubation can be safely performed as respiratory function may suddenly deteriorate. Respir atory failure is the main cause of death in botulism. There is no evidence that antibiotics are bene \201 cial in the early stages of foodborne botulism but may become appro- priate later if nosocomial infection, particularly pneumonia, develops. Benzylpenicillin or metro nidazole should be given to patients with wound botulism to cover other potential clostridi al infections. Avoid aminoglycoside anti- biotics which can potentiate the neuromuscular bl ockade. Drugs that reverse neuromuscular blockade are ineffective, although guanidine, whic h increases acetylcholine release, may have a role, but it remains experimental. Diagnosis Most clinicians will rarely see a case, making diagnosis dif- \201 cult particu larly the \201 rst case in an outbreak, since auto- nomic and cranial nerve signs may be missed in what is apparently a GI problem. Also \200\230skin-popping \200\231 drug abusers with wound botulism may be admitted with an overdose and be intubated before careful neuro logical examination can be performed. Botulism should always be considered in patients with a relevant history who develop cranial nerve abnormalities and a symmetrical descending pa raly- sis without sensory signs. Differential diagnosis Several other conditions have similar neurological features to adult foodborne and wound botulism. These are listed below with key distinguishing features: \200 Miller \200\223Fisher syndrome \200\224a descending form of GBS. Limb weakness before respi ratory failure; prominent ataxia; sensory changes; raised CSF protein Myasthenia Gravis. Le ngthy history of fatiguable weak- ness, particularly in the evening; no autonomic features; normal pupillary responses. Lambert-Eaton Myasthenic Syndrome. Proximal leg weakness is an early sign; weakness improves with exer- cise; ptosis common but ophthalmoplegia and bulba r involvement are rare Tick paralysis. Complete ophthalmoplegia, check for presence of tick Brainstem CVA causing bulbar palsy Diphtheria. Presence of pharyngeal membrane; nasal disc harge; fever and foetor; paralysis occurs late. Paralytic rabies. History of animal bite; f ever; headache; local paraesthesiae; ascending asymmetrical paralysis starting in bitten li mb Poisoning. Atropine excess; organophosphate; hyper- magnesaemia; snake bites with neurot oxic venom (cobras, kraits, sea snake) Speci \201 c treatment Speci \201 c trivalent (A, B, E) equine antitoxin should be given to all adults as soon as a clinical diagnosis is made. Therapy should not be delayed until the bioassay results are availa- ble since this takes several days and the antitoxin is ine ffec- tive once the circulating toxin has bound to the cholinergic receptor. Studies have s hown reduced mortality and mor- bidity with the timely use of antitoxin. Anaphylaxis and se rum sickness can occur, and an intradermal test dose is recommended although most serum rea ctions will not be predicted by this test. Infants <1yr old and patients with evidence of a llergy to equine products should be given human derived antitoxin. \200 Key messages \200 Consider botulism in patients presenting with symmetri- cal descending \202 accid paralys is, cranial nerve palsies, autonomic dysfunction, and normal sensation. Obtain history of f ood exposure and drug abuse Give antitoxin as soon as diagnosis clinically suspected \200 Investigations 1 Mouse bioassay for toxin in patient \200\231s serum, urine, gas- tric aspi rate or in suspected food if available. Involves intraperitoneal injection of 0.5ml of samp le with and without trivalent antitoxin into mice. Mice not given the antitoxin develop bot ulism and die in 2 \200\2233 days. Toxin can be measured directly by ELISA, but only availa ble in spe- cialist centers. Further reading Arnon SS, Schechter R, Maslanka SE, et al. Human botulism immune globulin f or the treatment of infant botulism. N Engl J Med 2006; 354: 462-71S. Jin R, Rummel A, Biz T, et al. Botulinum toxin B recognizes its pro- tein receptor with hig h af \201 nity and speci \201 city. Nature 2006; 444: 1092 \200\22320. 2 Neurophysiological studies show reduced amplitude muscle action potentials that enhance a fter tetanic stimulation, and normal nerve conduction velocities. Post-tetanic exhaustion d oes not occur, and this is only found in botulism and hypomagnesaemia. Schreiner MS, Field E, Ruddy R. Infant botulism: a review of 12 years \200\231 experience. Pediatrics 1991; 87: 159 \200\22365. Werner SB, Passaro D, McGee J, et al. Wound botulism in California, 1951 \200\2231998: rece nt epidemic in heroin injectors. Clin Infect Dis 2000; 31: 1018 \200\22324. 3 Beware the use of the edrophonium (Tensilon) test to exclude MG as there are often false- positive results in patients with botulism 4 In wound botulism, samples should be sent for C. botuli- num culture and the wound/absces s should be thor- oughly debrided. 382 C COLLIN Neurorehabilitation Expert care in critical illness scenarios is producing more survivors. Investment in this c are must be matched by investment in rehabilitation and vocational services to return peopl e to optimal health states and full participa- tion in society. was associated with chronic long-term disability. 28% had severe disability with tetra- or paraplegia, and, although 68% recovered functional independence, many had persist- ing mixe d sensorimotor symptoms and signs with footdrop muscle atrophy, peripheral sensory loss and painful hyper- aesthesiae. Survivors of polytrauma or major complex sur- gery often have a critical illness picture superimposed on their primary pathology and are at increased risk of poor recovery. Additional problems of the patient soon to leave ICU that contribute to the overall picture of disability and dependence include the tracheostomy, catheters, drips and NG tubes or PEGs. Bowels may be incontinent, and sleep pattern is severely disrupted. Morbidity and mortality is poor The morbidity and mortality of individuals surviving >14 da ys ventilation was found in a study by Combes et al. to be poor, with only 197 survivors ou t of 347 achieving dis- charge from hospital. Of these, there were 99 long-term survivors w ho had impaired quality of life compared with a matched general population. There has been scant atten- tion given to rehabilitation aspects and long-term functional outcome of peopl e with critical illness polyneuropathy. In 2004, Van der Schaaf reported a small prospectiv e study in which he found that most survivors of CIN had restric- tions of functional abili ties, reduced quality of life, auton- omy and participation, and he recommended prolonged r ehabilitation treatment to improve functional outcome, participation and social integration . Rehabilitation starts in ICU The human form soon resembles a banana shape if left paralyzed , lying supine on a yielding pressure-relieving mattress with loss of lumbar lordosis, and development of hip, shoulder and ankle contractures. Pressure sores may be avoided, but at a structural cost with much soft tissue shortening. 1 Maintain passive range of movement at all joints This includes neck and back in addition to the usually Rehabilitation improves outcome Evidence of the bene \201 ts of a rehabilitation program i s growing. The most severely affected will not get back home without an intensive in-patien t program in a specialist facility. There are stringent efforts being made now to col- lect data to con \201 rm the bene \201 t of a range of rehabilitation interventions. Jones et al. reported the effectiveness of a 6 week self-help rehabilitation manual in an RCT, and Elliott et al. have set up an RCT of an 8 week individualized physi- cal and psychological program for survivors of critical illness. targeted upper and lower limb joints. 2 How? Active hands-on therapy, supplemented by a postural regime including side and prone lying, and splinting to protect very vulnerable joints, e.g. ankles. 3 Maintain baroreceptor sensitivity This is not easy but a periodic head-up posture and til t- tabling helps with this and neck and trunk mobilization. Risks in severe acquired brain injury These include early and severe generalized spasticity . Enthusiastic early treatment for this may prevent severe disabling contracture developmen t. Multi-disciplinary man- agement of severe spasticity includes the following: \200 \200 \200 \200 \200 Critical illness impairments \200 Immobility: this causes muscle and tendon structure changes within 7 days, producing soft t issue shortening and contractures, reduces bone density, compromises skin integrity and pre disposes to further complications including DVT, PE and respiratory infection Lung damage i ncluding pulmonary \201 brosis due to pro- longed ventilation, ARDS and PE, may reduce de livery of oxygen to re-covering nerve cells. Critical illness polyneuropathy and myopathy. Hypoxic, ischaemic or embolic damage to brain or spinal cord, causing the typical and easil y recognized features of stroke, paraplegia, or tetraplegia, and the less obvious cognitive , memory and dysexecutive states, often a fea- ture of watershed infarcts and severe hypote nsive and hypoxic episodes. Vascular insults can also produce cauda equina syndrome, radicu lopathies and peripheral nerve lesions. Multi-organ failure. Emotional and behavioral chang es, sometimes linked to subtle cognitive changes, but can be part of a disabling post criti cal illness stress disorder. IM botulinum toxin injections Oral antispasticity medication Stretching physiotherapy Splin ting regime Antispasticity postural regime \200 Access to neurorehabilitation expertise at this stage is vital. A severe catabolic state wi th major weight loss, muscle wasting and mobilization of calcium from the skeleton is anoth er particular complication of severe polytrauma with brain or spinal cord injury. Catabolis m and immobility combined with muscle or joint trauma predispose oste- oporosis, nephrolith iasis and heterotopic ossification (HO). Prevention of these complications may not always b e possible. Up to 80% of individuals with brain injury caus- ing impaired consciousness for at least 1 month will have HO compared with 10 \200\22320% with briefer loss of conscious- ness but requiring hospitalization and rehabilitation. The treatments for catabolic state and early HO include providing calori \201 c needs + 1000 kcal, following a physio- therap y regime, and use of antiin \202 ammatory drugs. Late HO requires ongoing physiotherapy su pplemented rarely by orthopedic interventions in the most severe cases. \200 Can you spot it early? In the ICU some patients are unexpectedly dif \201 cult to wean off ventilation, and this is the early clue to look for neurological impairment and neuromuscu lar breathing dif \201 culties. Latronica et al. reviewed the impact of CIN and CIP, and f ound it delayed weaning by 2 \200\2237 times and 383 CHAPTER 22.12 Neurorehabilitation Communication and emotional needs Communication needs should be addressed as soon as the pa tient is conscious in ICU. Those with a tracheostomy will need aids provided early to facil itate asking questions and permitting communication with those around them. It also allows early assessment of cognitive and emotional status, which will in \202 uence outcome. If t here is evidence of signi \201 - cant communication impairment, a speech and language ther apist should be involved and will usefully spend time with both the patient and their relat ives. knowledge of expected outcome, and by the patient and family, who have a better understandi ng of the contextual factors, the home and vocational environment. Fatigue, pain and graded therapy Initial attempts to work with the patient fresh out of ICU often stall, with problems with pain, low blood pressure, fatigue, balance disorders, comp ounded by loss of diurnal sleep \200\223wake pattern and emotional reactions to the illness . There is a constant \201 ne tuning initially as the therapist and patient begin to work out a program that both can stick to. Certain pieces of equipment such as graded power- as sisted pedals (e.g. MotoMed) are invaluable. Fatigue and pain remain the great limiters of recovery, and are associ- ated with learned dependency, chronic fatigue states and secondar y gain. That is why it is so important to have access to active rehabilitation early after the illness to pre- vent negative behavioral traits prevailing. Self-help pro- grammes must include graded exercises, goal setting and regular review. Leaving ICU All patients with severe critical illness, a neuromyopathy, focal neurology of brain or spinal cord, obvious neurocog- nitive and psychological impairments should be cons idered for referral to a specialist neurorehabilitation facility as early as possible. It c an be dif \201 cult to meet the needs of such patients on general medical wards where ther e may be little therapy and no equipment. Being discharged on to a general ward with a seve re CIN, or a new paraplegia, can be distressing and depressing after the ICU experience. Th e patient is no longer the center of attention, has to compete for staff time to receive ba sic care, feels aban- doned, and may be highly dependent and frightened. Their relatives ar e often similarly worried and initially take on the ICU staff role by camping out on the wa rd. It is helpful if relatives can meet members of the rehabilitation team early rather tha n late, and visit the unit, which may not be in the same hospital. Cognitive problems affect outcome Failure to motivate a self-directed recovery program is o ften due to unrecognized cognitive problems, slowed information processing, short-term memo ry impairment and reduced new learning and executive skills. These prob- lems reduce insigh t, intitiative, attention and concentration. Psychology input to the patient and the team c an support new learning strategies recovery and adaptation. The talking therapies There are many. Cognitive behavioral treatment (CBT), Person-centered therapy (CPT), solution-focused brief therapy (SFBT), rewind theory and others all have th eir advocates. Counseling treatments encourage adjustment using a spectrum of methods that span re \202 ective through to directive techniques. Most are based on frequent ses- sions , identifying negative patterns of behavior and desired changes. Anxiety or depressive illn ess may also respond well to short-term pharmacological therapy. How to do it Moving into rehabilitation should give the patient the opportunity to work on impairments, reduce disability and develop a discharge plan. It is a simple problem-solving process, and depends on team work and clarity of thinking. The key qualities of successful rehabilitation team mem- bers are good communication skills, expertise and \202 exibil- ity. Each patient has a personalized rehabilitation plan which includes: 1 Meeting ongoing surgical and medical needs 2 Assessing and observing cognition, communication skills Novel home-based therapies In the future, traditional therapist-based services may be suppl emented by virtual environments, teletherapy, porta- ble robotic devices employing errorles s learning systems and positive feedback. These methods are unlikely to be superior, but ca n enrich and vary the exercise environment and allow the patient greater control and applic ation. and emotional state 3 Assessing physical impairments and functional de \201 cits 4 Appraisal of the social sit uation, home environment and potential for later return to work Knowledge of these permits the development of a rehabili- tation program and discharge plan which should include 1 Expected outcome \200\224managing expectations 2 Identi \201 catio n of discharge destination 3 Expected date of discharge 4 Advice on work and driving 5 Refe rral on to community resources. This should be according to need but is often modi \201 ed by availability. Further reading Combes A, CostaMA, Troillet JL, et al. Morbidity, mortality and qual- ity o f life outcomes of patients requiring 14 days of mechanical ventilation. Crit Care Med 2003 ; 315: 1373 \200\22381. Elliott D, McKinley S, Alison JA, et al. Study protocol: home based physical rehabilitation for surviviors of a critical illness. Crit Care 2006; 10: R90. Jones C, Skirrow P, Grif \201 ths RD, et al. Rehabilitation after critical illness: a rand omized controlled trial. Crit Care Med 2003; 31: 2456 \200\22361. Goal planning This is the key to active, outcome-driven rehabilitation and can be used to b ridge the gap between hospital and home, with the patient being an active driver of the pro cess, and on discharge taking full responsibility to set goals to achieve continuing recove ry after discharge. \200\230SMART \200\231 goals (Speci \201 c, Measurable, Appropriate, Relevant, Timely) are informed by experienced staff who have a reasonable Latronica N, Shehu I, Seghelini E. Neuromuscular sequela of critical illness polyneuropathy. Curr Opin Crit Care 2005; 11: 381 \200\22390. Van der Schaaf M, Beelen A, de Vos R. Functional outcome in patients with critical illness polyneuropathy Disabil Rehabil 2004; 26: 1189 \200\22397. 384 A COHEN Hyperthermias through its effect on intracellular calcium metabolism. This switches off heat production i n conditions such as malignant hyperthermia. Cooling will be inhibited by drugs that advers ely affect normal heat loss mechanisms such as anticholinergic agents which inhibit sweatin g. Under normal circumstances, body temperature is closely controlled around a set point close to 37 C by balancing heat production and loss. Pyrexia can be a complicating factor in cr itical illness or a reason for admission to inten- sive care in its own right. The term hyp erthermia is often used interchangeably with hyperpyrexia but can more accurately be de \201 ned: Hyperpyrexia describes a situation in which the set point for temperature is rais ed, e.g. by infection. Hyperthermia is an elevation of body temperature due to an inability of control systems to function. This results from an imbalance between factors making the body hot and those allowing it to cool. Physical methods of cooling Simple methods of cooling rely on enhancing normal heat loss. E vaporative losses can be encouraged using a fan and sponging the skin. Direct cooling of th e skin can be achieved by using cold packs, but these may cause skin damage and will be ine ffective if they cause vasoconstriction. Specially designed cooling blankets based on cold water or air circu- lation are safe and more effective. Irrigation of various body cavities with cold \202 uid has been described, most commonly the bladder and stomach. Physiological effects of pyrexia Cardiovascular A high central temperature is associated wi th tachycardia, elevated cardiac output, low SVR and hypotension. This picture is seen when a patient in early sepsis is initially \202 uid resuscitated; failure to resuscitate ade quately would result in the same patient being peripherally cold and clammy. Extracorporeal cooling Special systems are available, but the majority of ICUs can rapidly deploy equipment they already have. Venovenous dia \201 ltration in its various guises is a common form of RRT. Usually these systems are heated in an attempt to prevent heat loss. Some patients with marked pyrexia may bene \201 t from connection to an extracorporeal cir cuit of this nature even when not in renal failure. Metabolic Tissue oxygen demand is increased in association with a rise in metabolic rate. P art of the effect on tissue oxygena- tion will be offset by a right shift in the oxyhaemogl obin dissociation curve, increasing availability of oxygen. Purpose-built cooling systems The desire actively to cool cardiac arrest patients has resul ted in the availability of a number of specially designed cooling systems. One of these is based on the use of an intravascular catheter with a specially designed cuff through which cool water is circulated. Alternative designs include tents that surround the patient payin g special attention to cooling of the neck region. A common characteristic of these systems is incorporation of sophisticated monitoring and control features. Immunological Temperature-sensitive pathogens are compromised by a rise in body temperature , while leucocyte activity is enhanced, thus promoting response to infection. Pyrexia complicating critical illness The most likely cause of pyrexia in a critically ill patient is response to sepsis. Temperature is regulated in the hypoth- alamus. Cytokine rel ease during sepsis results in activation of the arachidonic acid pathway and stimulation of heat production via PGE2. Some of the effects of pyrexia may confer a survival bene \201 t, but there comes a time when bene \201 ts are offset by disadvantages.