Infection control and prevention: see b p.32. Major incidents: see b p.38. Radiation incide nts: see b p.268. 211 DECONTAMINATION OF PATIENTS Decontamination of patients Decontamination after exposure to a chemical, biological, or ra diation hazard is intended to reduce the risks to the patient and to other people. Casualties should be decontaminated at the scene after a CBRN inci- dent, but some contamin ated patients are likely to arrive at EDs without warning. Many people will be worried abou t contamination, but not actually at risk. Patients injured by industrial incidents, road t raf \201 c collisions, bombs, or other incidents may also be contaminated. Even with advance planning it will be challenging to organize the ED, keep \200\230clean \200\231 areas clean, maintain order, and communicate between the \200\230decon \200\231 t eam (in PPE) and other ED staff. Equipment for decontamination \200 Scissors. Buckets. Sponges, soft brushes, wash cloths. Liquid soap. \200 Disposable towels. Disposable gowns and slippers. Blankets. \200 Pla stic bags (large for clothing, small for valuables). \200 ID labels and waterproof markin g pens (for patients and property bags). \200 Plastic bins with polythene liners (for use d decontamination equipment). \200 Warm or tepid water (hot water might increase chemical absorption). \200 0.9 % saline and drip sets for eye and wound irrigation. LA eye drops. Decontaminating non-ambulant patients \200 Keep contaminated patients outside the ED. \200 Clear, prepare, and secure the decontamination area. \200 Protect yourself with app ropriate PPE and use it properly. \200 Work in teams of 2 \200\2234 people. Look after ea ch other. \200 Tell the team what to look for and what to do. \200 In severe poisoning resuscitation, antidote administration, and decon- tamination may have to be done simultaneously. Tell casualties what you are doing. \200 Record patient \200\231s name and number on wris t band and property bags. \200 Remove or cut off clothing (which removes 80 \200\22390 % of contamination). Do not pull clothing off over the head. Fold clothing outside-in and put it in property bags. \200 Put valuables in a separate ba g. Wash glasses and keep with patient. \200 Clean face (protecting airway), open wounds, and sites for IV access, then from head to toes, front and back (log roll) including skin c reases. Rinse affected areas with soapy water (saline for wounds and eyes). \200 Wipe affected ar eas gently with a sponge to remove chemicals. \200 Rinse with clean water. \200 Dry pat ient. Cover in gown and blanket. Transfer to \200\230clean \200\231 trolley. \200 Move p atient to \200\230clean \200\231 area for further assessment and treatment. \200 Put con taminated equipment in appropriate containers. \200 Contain waste water if possible; if n ot, inform water/sewage agency. \200 Rest and rotate staff as needed. \200 Ensure staff are decontaminated before leaving the \200\230dirty \200\231 area. \200 Record names of staff involved in decontamination. \200 Warn staff of possible symptoms and check for si gns of poisoning. \200 Debrief staff and record events. 212 CHAPTER 4 Toxicology Plants, berries and mushrooms Plants and berries Many children eat plant leaves or brightly -colored berries, but serious poisoning from plants is very rare. Identify the plant if pos sible, using reference books 1 , 2 , 3 or the CD-ROM computer software Poisonous plants and fungi in Britain and Ireland ( b p.180). Advice on toxicity and any nec- essary treatment is available from Poisons Information Services. Many garden and house plants are non-toxic and no treatment is needed after ingestion. Serious poisoning from laburnum is very rare, with only one death recorded in the UK in 50 years. No treatment needs to be provided for children who eat laburnum seeds, except for th e very few with symptoms (nausea, salivation, vomiting, headache, rarely convulsions). Mushroom poisoning Serious poisoning from mushrooms or fungi is rare. Most deaths are due t o Amanita phalloides (death cap mushroom). Reference books 1 , 4 are useful, but identi \201 cation of mushrooms from the description or fragments available is often uncertain. Ad vice on toxicity and treatment is available from Poisons Information Services ( b p.181). M ushrooms found in gardens are unlikely to produce severe poisoning, but may cause vomiting and occasionally hallucinations, usually within 2hr of ingestion. Mushrooms which cause sym ptoms within 6hr are unlikely to be seriously toxic. Delayed toxicity occurs with Amanita p halloides and some other species, which grow throughout the UK. Amanita phalloides poisoning causes vomiting and profuse watery diarrhea after a latent per iod of 6 \200\22312hr, followed by hepatic and renal failure. The interval between ingestio n and the onset of symptoms is crucial in distin- guishing between non-serious and potentia lly fatal poisoning. Try to ascertain if: \200 More than one variety of mushroom was eaten (since poisonous an d edible mushrooms often grow together). Whether the mushrooms were cooked (since some toxins are inacti- vated by heat). Whether alcohol was taken (since disul \201 ram-like effects may occur with Coprinus species, ink cap mushrooms). For most toxic mushrooms only symptomatic treatment is required. Activated charcoal may d a bsorption if given within 1hr. Get expert advice immediately if Amanita poisoning is suspec ted ( b p.181). 1 Cooper MR , Johnson AW , Dauncey EA ( 2003 ) Poisonous Plants and Fungi, An Illustrated G uide , 2 nd edn. TSO , London . 2 Dauncey EA ( 2010 ) Poisonous Plants: A Guide for Childcare Providers . Royal Botanic Gar dens , Kew . 3 Frohne D , Pf nder HJ ( 2004 ) Poisonous Plants , 2 nd edn. Manson Publishing Ltd , Lond on . 4 Bresinsky A , Besl H ( 1990 ). A Color Atlas of Poisonous Fungi . CRC Press , London . 213 BUTTON BATTERIES Button batteries Small children often swallow button or disc batteries intended for toys, w atches, hearing aids, and other electrical equipment. The larger batteries may become stuck in the esophagus, causing perforation or later stenosis. Most batteries that reach the sto mach pass through the gut without any problem. Corrosive damage could occur from electrical discharge, but toxicity from battery contents is rare. Mercury poisoning is very unlikely since mercuric oxide batteries are no longer sold. The Poisons Information Service may iden tify the type of battery involved from the reference number, if this is available on the pa cket or on a similar battery to that ingested. Management X-ray the chest and abdomen or use a metal detector to \201 nd the battery. A battery stuck in the esophagus should be removed immediately by endoscopy (which allows ins pection for oesophageal damage and so is preferable to a magnet or Foley catheter). An asymptomatic child with a battery in the stomach or bowel can be sent home with advice t o return if any symptoms develop. If the battery has not been passed after 2 or 3 days, and is causing concern use a metal detector or repeat X-ray to look for the battery. If it is still in the stomach (which is rare) consider removal by endoscopy to avoid any risk of per foration or absorption of battery contents. Batteries in the small or large bowel almost always pass spontaneously and should be left t o do so, unless they cause symptoms. If abdominal pain, vomiting, diarrhea or rectal bleedi ng occur an abdominal X-ray is needed to localize the battery, which may require removal by endoscopy or surgery. Batteries in the nose Button batteries lodged in the nose may cause corrosive burns and ble eding, sometimes with septal perforation after a few weeks. Liaise with an ENT specialist t o remove batteries from the nose as soon as possible. 214 CHAPTER 4 Toxicology Illicit drugs Many drugs are used illegally as stimulants or for mood-altering effects. Tox icity is often seen from heroin ( b p.188), cocaine, ecstasy, and related drugs. Street nam es for drugs vary and may be confusing. The Street Terms database ( http://www.whitehousedr ugpolicy.gov/streetterms ) and Toxbase ( b p.181) have lists of slang names about drugs. Il licit drugs vary in strength and are often mixed with other drugs or chem- icals, which may cause unexpected effects. Drugs may be smoked, sniffed ( \200\230snorted \200\231), swallo wed or injected. Injecting drug users are at increased risk of hepatitis ( b p.239), HIV ( b p.242), necrotizing fasciitis ( b p.234), botulism ( b p.237), anthrax ( b p.233) and end ocarditis ( b p.234). Ecstasy (MDMA) \200\230Ecstasy \200\231 (3,4-methylenedioxymetamphet amine, MDMA) is an amphetamine derivative used as an illegal stimulant drug. The name \200 \230ecstasy \200\231 is also used for benzylpiperazine (BZP), another illegal drug. \200 \230Liquid ecstasy \200\231 is GHB ( b p.215). MDMA is taken orally as tablets or powder, o ften at raves or parties. Some people who have previously tolerated the drug have idiosyn- cratic reactions, with severe toxicity from a single MDMA tablet. MDMA causes release of se rotonin, catecholamines and other hormones. Inappropriate ADH secretion, abnormal thirst, a nd excessive water intake may result in hyponatraemia and cerebral oedema, especially in wo men. Clinical features Euphoria, agitation, sweating, dilated pupils, ataxia, teeth grindin g, headache, tachycardia, hypertension. Severe poisoning can cause hyperpyrexia, muscle rig idity, rhabdomyolysis, convulsions, coma, cardiac arrhythmias, renal failure, hepatic failu re, cerebral hemorrhage, and DIC. Metabolic acidosis is common. Features of serotonin syndr ome may occur as may hypoglycaemia, severe hyponatraemia and hyperkalaemia. Treatment Consi der activated charcoal ( b p.185) if <1hr since ingestion. Observe asymptomatic patients fo r at least 4hr. Monitor ECG, pulse, BP and temperature. Record ECG, check U&E, creatinine, glucose, LFTs and CK. Test urine for blood. In severe cases, check ABG and coagulation. Supportively treat airway, breathing, and circulation. Get expert advice ( b p.181) and ICU help in severe poisoning. Rapid sequence intubation may be needed because of trismus and \201 ts: use rocuronium, rather than succinylcholine which may cause hyperkalaemia. Contro l agitation with oral or IV diazepam or lorazepam: large doses may be needed. For severe hy pertension, give IV diazepam and GTN. Avoid B -blockers, which may cause unopposed -adren ergic stimulation with i BP and d coronary blood \202 ow. Do not treat single short \201 ts, but give diazepam or lorazepam for repeated or prolonged \201 ts. Correct metabo lic acidosis (possibly with sodium bicarbonate), checking ABG and U&E. Treat hyperkalaemia ( b p.162). Treat mild hyponatraemia by \202 uid restriction. IV saline may be needed for severe hyponatraemia: rapid correction of chronic hyponatraemia can cause brain injury (ce ntral pontine myelinolysis), but this is less likely with acute hyponatraemia caused by MDM A. Cool as for heat stroke ( b p.264) if hyperpyrexial. If rectal T > 40 C, consider dan trolene 1mg/kg IV (up to 10mg/kg in 24hr). See also serotonin syndrome \200\224 b p.216. 215 ILLICIT DRUGS Amphetamine These sympathomimetic stimulants can be swallowed, snorted, smoked or injected. Body packers may suffer severe poisoning. Toxic features are euphoria, agitation, psychosi s, sweating, dilated pupils, tachycardia, hyper- tension, vomiting, abdominal pain, \201 ts, hyperpyrexia and metabolic acidosis. Severe poisoning may cause stroke, MI, rhabdomyoly sis, renal failure and DIC. Cardiac arrest can occur in violent agitated patients who need physical restraint. Treat amphetamine poisoning as for MDMA ( b p.214). Mephedrone, methedrone, M-cat Synthetic cathinone compounds, sold as \200\230plant food \200\231 (now illegal in the UK), are snorted or swallowed as stimulants. Toxic effects are similar to amphetamines: agitation, sweating, tachycardia, palpitations, hypertension. Som e have nausea, hallucinations, \201 ts, muscle spasms, nausea, peripheral vasoconstrictio n and myocardial ischaemia. Nasal irritation and epistaxis may occur after snorting these d rugs. Treat as for MDMA/amphetamines. Cocaine Cocaine base ( \200\230crack \200\231) is usually smoked. Cocaine salt ( \200\230co ke \200\231) is snorted, eaten or injected. Body packers may be poisoned if pack- ages leak . Toxic effects (due to catecholamines, serotonin and amino acid stimulation and sodium cha nnel blockade) are euphoria, agitation, delirium, ataxia, dilated pupils, sweating, vomitin g, \201 ts, tachycardia, arrhythmias and hypertension. Chest pain may be due to myocardia l ischaemia or MI (from i catecholamines, i O 2 demand, coronary vaso- spasm and thrombosis ), aortic dissection or pneumothorax. Cerebral hemorrhage, hyperpyrexia, rhabdomyolysis, re nal failure, gut ischaemia and serotonin syndrome may occur. Cocaine is a local anesthetic, so hot air from smoking crack can cause airway burns. Treat as for MDMA ( b p.214). Give d iazepam for agitation (5 \200\22310mg IV, repeated at 5min intervals if needed, sometimes u p to 100mg). Treat chest pain with diazepam, GTN, O 2 and aspirin. GTN, calcium blockers an d phentolamine may d BP and i coronary blood \202 ow. Avoid B -blockers, which may cause paradoxical hypertension and i coronary vasoconstriction. If ECG suggests acute MI, conside r angioplasty or thrombolysis. Gammahydroxybutyrate (GHB, GBH, \200\230liquid ecstasy \200\231) GHB is used illegally as a body-building agent and psychedelic drug. It is ingested or injected. Intoxication may ca use vomiting, diarrhea, drowsi- ness, confusion, ataxia, and agitation. Severe poisoning re sults in coma, respiratory depression, \201 ts, bradycardia, and hypotension. Treatment C onsider activated charcoal ( b p.185) if <1hr since ingestion. Observe for at least 4hr and monitor pulse rate, BP and breathing. Provide supportive treatment as needed. Control agit ation and convulsions with diazepam. Naloxone may reverse some effects of GHB. LSD (lysergic acid diethylamide) Causes visual hallucinations, agitation, excitement, tachy cardia and dilated pupils. Hypertension and pyrexia may occur. Paranoid delusions may requi re sedation. Massive overdose of LSD is rare, but may cause coma, respiratory arrest and co agulation disturbances. Treat supportively. 216 CHAPTER 4 Toxicology Serotonin syndrome Background The clinical picture of serotonin syndrome is increasingly re cognized amongst those taking selective serotonin reuptake inhibitors (SSRIs). The syndrome can occur in patients who have taken therapeutic doses of SSRIs, and this is especially li kely if they have recently started on the medication or if it is taken in combination with other drugs which increase production, availability or release of serotonin (eg cocaine, MD MA, amphetamines) or reduce metabolism (eg MAOIs). Serotonin syndrome can also occur after an acute overdose. Numerous drugs have been implicated \200\224 in addition to those menti oned above, they include: tricyclic antidepressants, venlafaxine, tramadol, pethidine, bupr enorphine, St John \200\231s wort, olanzapine and lithium. Clinical features Altered mental status Confusion, hallucinations, and agitation may occur, with drowsiness and reduced conscious level in severe cases. Neuromuscular features Rigidity, shivering/tremor, teeth grinding, ataxia, and hyper-re \202 exia (especially affecting the lower limbs) may occur. Autonomic effects These include tachycardia, hypertension (or hypotension), \202 ushing, diarrhea, vomiting and hyperthermia. Severe cases can result in \201 ts, rhabdomyolysis, renal failure and coagulopathy. Differential diagnosis This includes neuroleptic malignant syndrome, malignant hyperthermia , severe infection (eg encephalitis), other direct effects of drug overdose or withdrawal. Investigations Check U&E, glucose, LFTs, CK, FBC, urinalysis, ABG, ECG CXR. Treatment Provide supportive measures and obtain expert advice (see b p.181). Agitation, hy perthermia, myoclonic jerking and \201 ts may bene \201 t from diazepam therapy. Treat r habdomyolyis with IV \202 uids and urine alkalinization. Cyproheptadine (dose 4 \200\2238mg orally) is a serotonin receptor antagonist. Although dat a are lacking, there is a good theoretical basis for its use in serotonin syndrome. 217 BODY PACKERS Body packers Body packers try to smuggle drugs such as cocaine or heroin by ingesting multi ple packages of drugs wrapped in condoms or latex. Packages may also be hidden in the rectu m or vagina (individuals who do this are some- times referred to as \200\230 body pushers \200\231 ). Serious or even fatal poisoning may occur if any packages leak and the drugs ar e absorbed. Risk factors Risk factors for complications occurring when an individual has concealed drug s include: \200 Vomiting, abdominal pain, abnormal vital signs. \200 Clinical evidence of poisoning. \200 Home made or improvised packaging. \200 Large size and/or large numb er of packets. \200 Delayed passage of the packets (beyond 48hr). \200 Fragments of pac kets in the stool. \200 Poisoning in a cotransporter. \200 Previous abdominal surgery ( i risk of obstruction due to adhesions). \200 Concomitant drug use (especially constipat ing agents). Management Suspected body packers need careful assessment and observation. Check for rectal and vaginal packages if the patient consents: get senior advice if there is any problem or uncertainty about consent. Try to determine the drug involved, and the number of packages and type of packaging used. Observe for at least 8hr for toxic effects, monitoring heart ra te, BP, ECG and SpO 2 . Urine toxicology screening may detect heroin or cocaine. Give activ ated charcoal ( b p.185). Consider a naloxone infusion ( b p.188) for heroin body packers. Abdominal CT or X-ray may show packets of drugs, which can be removed by whole bowel irriga tion ( b p.185). Surgery may be needed for bowel obstruction or to remove leaking packages. Avoid endoscopic removal which may damage packaging and increase drug leakage. Advice is a vailable from Poisons Information Centers ( b p.181). Body stuffers This term is sometimes applied to individuals who swallow drugs imme- diately prior to being apprehended by the police. The quantity of drugs ingested in this way may b e less than by body packers or pushers. However, any packaging is likely to be much less ro bust than that used by body packers or pushers, thereby increasing the risk of the packages leaking. This page intentionally left blank 219 Chapter 5 Infectious diseases Incubation periods Noti \201 able infectious diseases Childhood infectious diseases Mening itis Gastroenteritis/food poisoning Fish poisoning Infestations Tuberculosis Anthrax Strept ococcal infections Staphylococcal infections Tetanus Gas gangrene Botulism Sexually transmi tted diseases Hepatitis Leptospirosis (Weil \200\231s disease) Herpes virus infections Infe ctious mononucleosis (glandular fever) Human immunode \201 ciency virus (HIV) Presentation of HIV +ve patients Imported infectious diseases Malaria Typhoid and paratyphoid (enteric fever) Dengue Poliomyelitis Rabies Viral haemorrhagic fevers Severe acute respiratory syndr ome In \202 uenza pandemics, avian \202 u, and swine \202 u 220 221 222 224 226 229 230 232 233 234 235 236 237 237 238 239 239 240 241 242 244 246 247 248 248 249 249 250 251 252 220 CHAPTER 5 Infectious diseases Incubation periods Incubation period usually <1 week Staphylococcal enteritis Salmonella enteritis Bacillary dysentery ( Shigella ) Botulism Cho lera Dengue Diphtheria Gas gangrene Legionnaires \200\231 disease Meningococcaemia Scarlet fever Yellow fever 1 \200\2236 hours 6 \200\22348 hours (usually 12 \200\22324 hours) 1 \200\2237 days (usuall y 1 \200\2233 days) 12 \200\22396 hours (usually 18 \200\22336 hours) 12 hours \200\2236 da ys (usually 1 \200\2233 days) 4 \200\2237 days 2 \200\2235 days 6 hours \200\2234 days 2 \200\22310 days (usually 7 days) 1 \200\2237 days (usually 3 days) 1 \200\2234 days 3 \200 \2236 days Incubation period usually 1 \200\2233 weeks Brucellosis Chickenpox Lassa fever Leptospirosis Malaria (falciparum) Malaria (vivax, malar iae, ovale) Measles Mumps Pertussis (whooping cough) Poliomyelitis Rubella Tetanus Typhoid Typhus 7 \200\22321 days (occasionally some months) 10 \200\22320 days (usually about 14 days) 6 \200\22321 days 2 \200\22326 days (usually 7 \200\22312 days) 7 \200\22314 days (occasional ly longer) 12 \200\22340 days (occasionally > 1 year) 10 \200\22318 days (rash usually 14 \200\22318 days) 14 \200\22318 days 5 \200\22314 days (usually 7 \200\22310 days) 3 \200 \22321 days (usually 7 \200\22310 days) 14 \200\22321 days 1 day \200\2233 months (usually 4 \200\22314 days) 3 \200\22360 days (usually 7 \200\22314 days) 7 \200\22314 days Incubation period usually > 3 weeks Amoebiasis Hepatitis A Hepatitis B, hepatitis C HIV Infectious mononucleosis Rabies Syphili s 2 weeks \200\223many months 2 \200\2236 weeks (usually 4 weeks) 6 weeks \200\2236 months 2 weeks \200\2233 months (anti-HIV appears) 4 \200\2237 weeks 4 days \200\2232 years (usually 3 \200\22312 weeks) 10 days \200\22310 weeks (usually 3 weeks) Duration of infectivity of infectious diseases Chickenpox Hepatitis A Measles Mumps Pertussis 3 days before rash until last vesicle crusts 2 weeks before until 1 week after jaundice sta rts 4 days before rash until 5 days after rash appears 3 days before to 1 week after saliva ry swelling 3 days before to 3 weeks after start of symptoms (5 days if on appropriate anti biotic) 1 week before to 1 week after onset of rash 10 \200\22321 days from onset of rash ( 1 day if on penicillin) Rubella Scarlet fever 221 NOTIFIABLE INFECTIOUS DISEASES Noti \201 able infectious diseases In Britain certain infectious diseases are \200\230not i \201 able \200\231. A doctor who knows or suspects that a patient has one of these disea ses is obliged to notify the local Health Protection department. Use the special noti \201 cation form if available. Telephone the consultant in Communicable Disease Control if inve stigation or control of an outbreak may be needed. HIV and AIDS are not noti \201 able diseases, but may be reported in strict con \201 denc e in the same way. Noti \201 able infectious diseases in Britain (ND) Anthrax Botulism Brucellosis Cholera Di phtheria Encephalitis (acute) * Erysipelas * * Food poisoning * Haemolytic uraemic syndrome (HUS) Haemophilus in \202 uenzae type b (Hib) * * Infectious bloody diarrhea ( E. coli O1 57 infection * * ) Infectious hepatitis (acute) * Invasive group A streptococcal disease an d scarlet fever * Legionnaires \200\231 disease * Leprosy * Malaria * Measles Meningitis (a cute) * Meningococcal septicaemia * /meningococcal disease * * Mumps Necrotizing fasciitis * * Paratyphoid Pertussis (whooping cough) Plague Poliomyelitis Rabies Rubella Severe acute respiratory syndrome (SARS) Smallpox Tetanus Tuberculosis Tularaemia * * Typhoid Typhus * Viral haemorrhagic fever (VHF) West Nile fever * * Yellow fever Noti \201 able only in England and Wales. ** Noti \201 able only in Scotland. 222 CHAPTER 5 Infectious diseases Childhood infectious diseases Children at risk Unimmunized children are at risk of infectio ns which would be prevented by the standard immunization schedule. Always ask about vaccina tion status in any febrile, unwell child. The common infectious diseases of child- hood can be very serious in children with immune de \201 ciency or those on immunosuppressant drug s . Refer such children for specialist advice if they develop an infectious disease or have been in contact with one. Children with cystic \201 brosis can become very ill with meas les, whooping cough or chickenpox \200\224 refer these also. Neonates rarely develop the c ommon exanthems of childhood, but require referral if these occur. Chickenpox can be partic ularly serious in this age group. Measles ND A virus infection spread by airborne droplets. Incubation period =10 \200\22318 days. Infectious from just before the onset of symptoms un til 5 days after the rash appears. Initial features (lasting 83 days) are fever, malaise, c oryza, conjunctivitis and cough. Koplik \200\231s spots (small white spots like grains of s alt) appear inside the cheeks. 1 \200\2232 days later a red maculopapular rash starts behin d the ears, and spreads to the face and down the body. Treatment is symptomatic unless there are complications (eg otitis media or bacterial pneum onia). Febrile convulsions may occur. Encephalitis is rare, but can be fatal. Hospital admi ssion is rarely needed unless the child is very ill or has pre-existing disease. In the tro pics many malnourished children die from measles, but in the UK the mortality is very low. Mumps ND Mumps is a virus infection spread by saliva and respiratory droplets. Infectivity is greatest at the onset of symptoms, but many sub-clinical cases also spread infection. Incubation period = 14 \200\22318 days. Typical features are fever with pain and swelling in one or both parotid glands. Aseptic me ningitis may occur. Orchitis affects 10 \200\22315 % of post- pubertal males, but rarely ca uses sterility. The pain of orchitis may be relieved by analgesia and a short course of ste roids. Orchitis is uncommon before puberty, so consider torsion of the testis if a child pr esents with testicular pain and swelling ( b p.700). 223 CHILDHOOD INFECTIOUS DISEASES Rubella (German measles) ND Rubella is usually a mild disease, but infection during pregnan cy may cause severe congenital disorders, particularly eye defects, heart defects and deafn ess. Guidance on the management of, and exposure to, rubella in pregnancy is available from the Health Protection Agency based in London ( www.hpa.org.uk/infections ). The virus is s pread mainly by the airborne route, with an incubation period of 2 \200\2233 weeks and infe ctivity from 1 week before symptoms until 1 week after the rash appears. A macular rash occ urs on the face and trunk, with mild fever, occipital lymphadenopathy and sometimes transie nt arthralgia. Rare complications are encephalitis and thrombocytopenia. Treatment is generally symptomatic. The clinical diagnosis of rubella is unreliable: simila r rashes may occur with enterovirus and parvovirus infections. If there is concern about ru bella infection in pregnancy take blood for viral antibody levels and arrange urgent follow -up by the GP or obstetrician. Whooping cough see b p.684. 224 CHAPTER 5 Infectious diseases Meningitis Causative organisms Meningitis may be bacterial , viral, or occasionally fungal . Bacterial causes of meningitis include meningococci, pneumococci, Haemophilus in \202 ue nzae, Listeria , and tuberculosis (TB). Other bacteria may also cause meningitis in neonate s, the elderly, and immunosuppressed patients. Clinical features of bacterial meningitis Some patients with meningitis have the classic fe atures of headache, neck stiffness, photophobia, fever and drowsiness. However, the clinica l diagnosis of meningitis may be very dif \201 cult in early cases. Neonates may present w ith anorexia, apnoea, or \201 ts. Meningitis may start as a \200\230 \202 u-like \200 \231 illness, especially in the immunosuppressed or elderly. Consider meningitis in any feb rile patient with headache, neurological signs, neck stiffness, or d conscious level. Menin gococcal meningitis ND is caused by Neisseria meningitidis . It can result in septicaemia, coma, and death within a few hours of the \201 rst symptoms. Skin rashes occur in 50 % of patients, often starting as a maculopapular rash before the characteristic petechial rash develops. There may be DIC and adrenal hemorrhage (Waterhouse \200\223Friderichsen). Mening ococcal septicaemia ( b p.666) may occur without meningitis. Management Resuscitate if necessary, give oxygen and obtain venous access. Start antibiotics immediately (without waiting for investigations) if the patient is shocke d or deteriorating or there is any suspicion of meningococcal infection (especially a petec hial or purpuric rash): give IV ceftriaxone or cefotaxime (adult 2g; child 80mg/kg). Chlora mphenicol is an alternative if there is a history of anaphylaxis to cephalosporins (see BNF ). In adults > 55 years add ampicillin 2g qds to cover Listeria . Give vancomycin rifam picin if penicillin-resistant pneumococcal infection is suspected. Give IV dexamethasone (0 .15mg/kg, max 10mg, qds for 4 days) starting with or just before the \201 rst dose of ant ibiotics, especially if pneu- mococcal meningitis is suspected. Initial investigations are FBC, U&E, glucose, clotting screen, ABG, CRP, blood cultures, ED TA sample for PCR, and clotted blood for serology. LP is needed if meningitis is suspected, unless there is a coagulopathy or i ICP: do CT scan if there is suspicion of i ICP (confus ion/coma, hypertension, bradycardia or papilloedema) or focal neurological signs. Provide supportive treatment including: \200 IV \202 uids. \200 Pressure area care. \200 Monitor conscious level, T , BP, ECG, SpO 2 , and \202 uid balance. Get expert h elp promptly and organize ICU care. For the latest advice and algorithms see www.meningitis.org and www.nice.org.uk/guidance/CG 102/quickrefguide For meningitis and LP in children see b p.666. 225 MENINGITIS Prophylaxis of meningococcal infection While intubating a patient with suspected meningococ cal infection wear a suitable mask (eg FFP3) and a face shield to reduce the risk of infect ion. Meningococcal infection is spread by droplets from the nose of an infected carrier, who may be well. Notify the consultant in Communicable Disease Control ( b p.221) immediately abou t any suspected meningococcal infection and obtain advice about antibiotic prophylaxis. Pro phylactic antibiotics (rifampicin, cipro \202 oxacin or ceftriaxone) are needed for the pa tient \200\231s family and close contacts. Hospital and ambulance staff do not need prophyl axis unless they have given mouth to mouth ventilation or intubated the patient without usi ng protective equipment. Rifampicin is given 12 hourly for 2 days (5mg/kg for child aged <1 year; 10mg/kg at 1 \200 \22312 years; 600mg at age > 12 years. It makes the urine orange or brown, discolors soft c ontact lenses, and d effectiveness of OCP for 8 4 weeks (see BNF ) \200\224 give appropria te warnings and record this in the notes. Cipro \202 oxacin is given as a single oral dose of 500mg (adults), 250mg (child 5 \200 \22312 years) or 125mg (child 2 \200\2235 years), although it is not licensed for chemoprop hylaxis of meningitis. Ceftriaxone is given as a single IM dose of 250mg (adults and children > 12 years) or 125mg (children <12 years). Tell contacts of meningococcal patients to report to a doctor at once if they develop sympt oms. TB meningitis Often gradual onset, with malaise, anorexia, vomiting, headache and even- tua lly signs of meningitis. Cranial nerve palsies, spastic paraplegia and coma can occur. Meni ngitis may be part of miliary TB ( b p.232), which may be apparent on chest X-ray. Ophthalm oscopy may show choroidal tubercles and papilloedema, which is found more commonly than in other forms of meningitis. Refer for specialist investigation and treatment. Viral meningitis Viral causes of meningitis include coxsackie, mumps, and echoviruses. Vira l meningitis produces similar clinical features to bacterial infection, but the illness is often less severe. The initial management is the same as for suspected bacterial meningitis . Refer for admission and investigation. Fungal meningitis Fungal meningitis is usually part of disseminated infection in immuno- su ppressed patients, (eg those with AIDS ( b p.242), lymphoma, or on steroid therapy). Crypto coccus neoformans is the commonest organism. Symptoms usually develop slowly, as with TB me ningitis. There may be papilloedema and focal neurological signs. Admit for specialist inve stiga- tion and treatment. 226 CHAPTER 5 Infectious diseases Gastroenteritis/food poisoning ND : 1 Diarrhea is the usual presenting symptom of gastroent eritis, but it may also occur in many other conditions as diverse as otitis media, appendic itis and ulcerative colitis. Antibiotics often cause diarrhea. Constipation may present as diarrhea if there is over \202 ow around an obstructing stool. A rectal tumor may present similarly. A baby \200\231s parents may seek advice about diarrhea when in fact the stools are normal. Breast-fed babies almost always have loose stools, which may be yellow or green and very f requent, often after every feed. However, gastroenteritis is very rare in fully breast-fed babies. In children aged > 6 months, normal stool frequency ranges from 1 stool on alternat e days to 3 stools daily. Diarrhea and vomiting may be caused by many types of bacteria and viruses, and also by some toxins and poisons. Many episodes of gastroenteritis result from contaminated food, usuall y meat, milk or egg products, which have been cooked inadequately or left in warm condition s. The speci \201 c cause is often not identi \201 ed. Some infections are spread by feca l contamination of water (eg cryptosporidiosis from sheep feces). Rotavirus infection (comm on in children) may be transmitted by the respiratory route. Severe illness with bloody dia rrhea, haemolysis and renal failure may result from infection with verocytotoxin producing E. coli (VTEC O157). Stool microscopy and culture are unnecessary in most cases of gastro- enteritis, but obtain them if the patient has been abroad, is severely ill, has prolonged symptoms, comes from a n institution or works as a food-handler. Food poisoning is a noti \201 able disease ( b p .221). Immediate noti \201 cation by telephone is mandatory if an outbreak is suspected. T he food eaten, symptoms and incubation period may suggest the organism or toxin involved (s ee Table 5.1). Carbon monoxide poisoning ( b p.208) may cause malaise and vomiting in sever al members of a family and be misdiagnosed as food poisoning. History Record the duration of symptoms and the frequency and description of stools and vom it. Document other symptoms (eg abdominal pain, fever), food and \202 uid ingested and dr ugs taken. Enquire about affected contacts, foreign travel and occupation (especially relev ant if a food-handler). Examination Look for abdominal tenderness, fever and other signs of infection. Record the p atient \200\231s weight and compare this with any previous records. Assess the degree of de hydration \200\224 this is traditionally classi \201 ed as mild (<5 % ), moderate (5 \200 \22310 % ), or severe ( > 10 % ), as outlined opposite. 227 GASTROENTERITIS/FOOD POISONINGND: 1 Clinical evidence of mild dehydration (<5%) \200 Thirst. \200 d urinary output (in a ba by <4 wet nappies in 24hr). \200 Dry mouth. Clinical evidence of moderate dehydration (5 \200\22310%) \200 Sunken fontanelle in infants. \200 Sunken eyes. \200 Tachypnoea due to metabolic acidosis. \200 Tachycardia. Clinical evidence of severe dehydration (>10%) \200 d skin turgor on pinching the skin. \200 Drowsiness/irritability. Table 5.1 Food poisoning characteristics Symptoms * Cause Incubation Food Staph. aureus 1 \200\2236 hours Meat, milk D, V, P, shock Bacillus cereus 1 \200\22316 hours Rice D, V, P Salmonella 6 \200\22348 hours Meat, eggs D, V, P Escherichia coli 1 \200\2232 days Any food D, V, P E. coli VTEC 0157 1 \200\2232 days Meat, milk D, V, P Campylobacter 1 \200\2233 days Meat, milk Fever, P, D Shigella 1 \200\2233 days Any food Bloody D, V, fever Vibrio parahaem 2 \200\2233 days Seafood Watery D Cholera 12hr \200\2236 days Water, seafood D (watery), shock Rotavirus 1 \200\2237 days D, V, fever, cough Botulism 12 \200\22396 hours Preserved food V, paralysis <1 hour Fish Flushing, headache, D, V, P ( b p.229) Histamine \201 sh poisoning (scombrotoxin) D, V, P, paraesthesiae, muscle weakness ( b p.229) Fish from tropical coral reef Ciguatera \201 sh poisoning 1 \200\2236 hours (rarely 30 hours) Paralytic shell \201 sh poisoning 30 min \200\223 10 hours Shell \201 sh Dizziness, paraesthesiae, weakness, respiratory failure ( b p.229) Chemicals <2 hours Food, water Various Mushrooms <24 hours Mushrooms D, V, P, hallucinations ( b p.212) D = diarrhea, V = vomiting, P = abdominal pain. 228 CHAPTER 5 Infectious diseases Gastroenteritis/food poisoning ND : 2 Treatment Most cases are self-limiting, but careful a ttention is needed to ensure adequate \202 uid replacement and also to prevent cross-infe ction ( b p.32). Hospital treatment is needed if the patient looks seriously ill, dehydrati on is > 5 % , there is a high fever or the family are unlikely to cope with the patient at home. Babies aged <3 months may be dif \201 cult to assess and can deteriorate rapidly \200\224 refer for admission. Severely dehydrated ( > 10 % ) children need immediate IV \202 uids, initially 0.9 % saline (10 \200\22320mL/kg over 5min, repeated as necessary). Oral rehydration therapy (ORT) is effective in most patients with gastro- enteritis (<5 % d ehydration). Standard ORT products (eg Dioralyte ) contain glucose, sodium, potassium, c hloride and citrate (details in BNF ). Glucose is important to enhance absorption of sodium and water. Usual dose of ORT: infant 1 \200\2231 times usual feed volume. child 200mL after each loose stool. adults 20 0 \200\223400mL after each loose stool. Extra ORT can be given if the patient is still thirsty. Frequent small sips are usually tol erated better than a large drink. Check that the patient (or parent/carer) can understand t he instructions supplied with the ORT sachets or effervescent tablets and can measure the n ecessary amounts of clean water. Recommence normal feeds and diet after 24hr (or earlier if diarrhea has settled or the patient is hungry). Give further ORT if the diarrhea continues . A child with acute diarrhea requires daily review (usually by the GP), but should be seen earlier if he becomes more ill (especially if drowsy or pyrexial), or if vomiting and/or d iarrhea worsens. Home-made salt and sugar mixtures may be dangerously inaccurate for ORT, b ut if nothing else is available, one could use salt 2.5mL (half a 5mL spoonful) and sugar 2 0mL (4 \227 5mL spoonfuls) in 1 pint (500mL) of cooled boiled water. Drugs other than ORT are rarely needed in gastroenteritis. In adults an anti-emetic (prochl orperazine 12.5mg IM or 3mg buccal) may be helpful, but in children prochlorperazine often causes troublesome side effects. However, oral ondansetron (0.1 \200\2230.15mg/kg, max 8mg) reduces vomiting and the need for IV \202 uids and admission. Prolonged vomiting require s investigation and hospital admission. Anti-diarrhoeal drugs (eg kaolin, codeine phosphate, loperamide) are contraindicated in chi ldren and rarely needed in adults: they may aggravate nausea and vomiting and occasionally cause ileus.