ANAPHYLAXIS THE EXTREME HYPERSENSITIVITY!

A 5 year old female child was admitted in the ER with h/o wasp sting. She is drowsy and has facial and lip edema.She is also in respiratory distress with stridor. She has a rapid thready pulse with urticarial rashes all over the body. An attempt for endotracheal intubation under suxamethonium and sedation failed due to extensive edema of the tongue and oropharynx and the vocal cords were not visualised. Emergency airway access obtained by a classic LMA with positive pressure ventilation but desaturation persisted and the ENT surgeon was called in for emergency tracheostomy

Anaphylaxis is an acute, severe, potentially life threatening allergic reaction (type 1 hypersensitivity) characterised by severe bronchospasm, angio neurotic edema and cardiovascular collapse following repeated exposure to an allergen to which the individual is already sensitised. Anaphylaxis can be caused by a variety of allergens.  

SEPSIS ON THE GO.

Will you be careless about a lacerated sports injury or an unknown bite on your leg? Have you ever neglected a skin abrasion by a metal piece or thorn? Do insect bites need attention? Here is the story of a young labourer, a worker from a farm, who succumbed to death following sepsis due to an unattended injury/bite on his leg about which he was totally unaware.
This man was complaining of pain on his left hip and leg for two days.The left thigh appeared swollen with mild bluish discolouration on the anterolateral aspect.. He had no past history of any systemic illness and was in good health while joining the farm. Since 1 day he had low grade fever and there was progre ssive increase in difficulty of breathing. Examination showed tachypnea, dyspnea, Pulse: 122/mt, BP: 88/64 mm Hg, SPO2: 78% on room air, Pallor +, ABG: mild metabolic acidosis, Chest: b/l crepitations,CVS: tachycardia, CNS: alert and conscious, ABD: mild splenomegaly and abdominal wall edema, Swollen, warm and tender left leg with knee effusion and normal dorsalis pedis pulsation.A definite or identifiable mark of injury was not observed on the limb. A provisional diagnosis of cellulitis with septicemia or DVT with pulmonary embolism, was made. Patient was shifted to ICU for close observation of vitals and cardiorespiratory support. IV fluids started and  oxygen by mask applied, dopamine 10-15 mic/kg/mt and dobutamine 5-10 mic/kg/mt were on flow. Blood investigations were ordered.Fluid aspirated from thigh and knee was serosanguinous in nature and awaited culture reports. Empirical broad spectrum antibiotics were started.Doppler ultrasound ruled out DVT or limb ischemia due to thrombus.X ray of left femur was normal.ECG showed sinus tachycardia, and CXR was normal. CT chest, abdomen and limb were considered but deferred as contrast could not be given due to derranged RFT, hypotension and abnormal coagulation profile. The echo cardiogram revealed Dilated left ventricle and impaired systolic function with EF 40%, and global hypokinesia, consistent with myocarditis.Fresh blood transfusion and FFP commenced. The blood investigations now showed

Hb 12.9 gm/dl, Platelet 100 K/UL, Derranged coagulation, RBS 120 mg/dl,CRP ++, ESR 70mm/hr, WBC 16K/uL, Uric acid 417 micmol/Lt.,LDH 820 u/l, CK 9495u/l, Liver function  elevated bilirubin total and direct with high ALP and AST . RFT : creatinine 200 mic mol/ltr, Hypoalbuminemia, FDP 80 mic gram/ml, Urine Hemoglobin +++ and myoglobin + peripheral smear --> WBC more than 17% bands with toxic changes along with 10% atypical lymphocytes, Microcytic Hypochomic Anemia and Megakaryocytes

GUILLAIN-BARRE SYNDROME

Acute, frequently severe and fulminant, poly radiculopathy,which is auto immune in nature.Males and females equally affected. More frequent in adults than in children.Variants involving the cranial nerves, pure motor involvement etc are also found. In severe cases, muscle weakness may lead to respiratory failure,with auto nomic involvement and unstable hemodynamics, necessitating ventilatory management
Clinical Manifestations

• Rapidly evolving, progressive, ascending motor paralysis with or without sensory disturbance and with areflexia
• Lower cranial nerves are frequently involved and presented with difficulty in swallowing and maintaining airway
• Bulbar involvement is most frequently manifested as B/L facial paralysis
• Fever and other constitutional symptoms are usually absent
• Diminished DTR with absent proprioception. There may be marked sensory loss
• Bladder dysfunction is late and transient.
• Deep aching pain in muscles and back
• Difficulty in swallowing due to pharyngeal muscle weakness and impaired ventilation due to intercostal muscle paralysis in 30% of cases and they require ventilatory support
• Marked autonomic dysfunction leads to  Wide fluctuations in blood pressure – hypo / hyper tension, Sudden profuse diaphoresis,Peripheral vasoconstriction Resting tachycardia,Cardiac conduction abnormality, Orthostatic hypotension – severe, Thromboembolism due to immobilisation, & sudden death
• Metabolic derangements -Hyponatremia due to excessive ADH secretion

PREGNANT PATIENT WITH DVT IN PAIN

24 year old second gravida with 9 weeks of pregnancy reports to the emergency department with 1 day history of pain left loin spreading to left lower limb.The patient gives history of contraceptive injections. On examination the left lower limb appeared swollen and tender. The homan's sign was positive.Femoral and Popleateal pulsations were felt but dorsalis pedis feebly felt compared to right leg. The limb was not pale or cold. A provisional diagnosis of DVT is made and a venous doppler was ordered which showed DVTof the left lower limb extending upto left ileofemoral vein.
Patient is admitted in icu, heparin infusion started 5000units iv and then 1000units/hr keeping the APTT level 1.5 to 2 times than normal.Monitoring of Spo2, ECG, NIBP and temperature commenced. Serial ABG s were performed to asses the respiratory status. Lower limb mesurements were taken frequently and observed for development of compartmental syndrome.Arterial doppler showed no arterial insufficiency and echocardiogram showed normal study. The CXR also was normal

Anesthetic referral was sent for pain relief.

Providing pain relief to this patient was a real challenge before the anaesthetist He has   to consider the following things before formulating the therapy

1) Patient is on thrombolytic therapy
2)Teratogenecity of anaesthetic agents
3)Effect of analgesic agents on uterine tone
4)Need of careful monitoring of the respiratory system as chance of pulmonary embolism is high.

NSAIDS including diclofenac sodium
Paracetamol
Paracetamol is considered to be safe and can be given intramuscular injection in case of
severe pain. But the efficacy is limited as continuous pain relief is not possible.The effects on maternal Liver like fatty liver or liver failure are of concern but are rare and occurs only on long term treatment.IV preparation is preferred as deep IM can cause hematoma formation as patient is on heparin

ANAESTHESIA IN DENTAL CHAIR

General anaesthesia in dentistry is seldom required and is reserved for patients who are intolerant to local anaesthesia, for example small children or for patients who are mentally disabled or agitated. Rarely for difficult dental extractions or  for dental releasing surgeries, General anaesthesia is administered to adults also. Still most of these cases can be managed under conscious sedation, supplemented with local anaesthesia or nerve blocks.

As a rule patients should be premedicated with atropine to reduce oral secretions and to reduce the occurrence of vasovagal syncope.(In children this may be administered at the dose of 0.02mg/kg IV following  induction and iv line placement) In a co operative child the IV cannula may be secured  after topical application of EMLA cream also. Intravenous induction with Propofol and lidocaine  may be condsidered for children above 3 yrs. A nasal mask or LMA may be used to protect the airway with additional pre op oral packing, particularly when nasal mask is used for delivering inhalational anaesthesia. Maintenance of anaesthesia is continued with oxygen, nitrous oxide with isoflurane allowing spontaneous ventilation. Alternatively inhalation induction with sevoflurane or halothane is preferred for children less than 3 yrs.The eyes should be protected. For maintenance, propofol or sevoflurane may be continued. Additional analgesia may be obtained by local nerve blocks by surgeon. If possible the child my be placed in the lateral position keeping the  head low with proper stabilisation of head and neck.Use of nitrous oxide may be reduced or stopped with concurrent administration of short acting analgesics like fentanyl, to prevent hypoxia,provide analgesia and to make available 100% oxygen. Post op analgesia can be achieved with paracetamol or diclofenac suppositories or with intramuscular opioids.

Another technique called inhalational sedation is used for adults who are unwilling for local anaesthesia. Here conscious sedation is given using iv anaesthetic agents followed by analgesia  supplemented with local anaesthetics once the sedative effect is established.Patients are given slow incremental doses of midazolam with oxygen and less than 50% nitrous oxide.A soft but weighted mask is put over the nostrils. It is essential that patient is conscious throughout the procedure and can control his airway. The patient should be able to communicate with the surgeon during the procedure. Mouth props are discouraged as they mask the patients inability to keep the mouth open, - an ominous sign of oversedation. Standard monitoring include  NIBP, ECG, Temperature probe  and Pulse Oximetry. Patient should be given 100 % oxygen following the procedure to avoid diffusion hypoxia and flumazenil should be available to reverse the residual effect of benzodiazepines effect,  if required.

When to think of  intubation?

• Difficult access as in impacted tooth, macroglossia, short neck
• Excessive uncontrolled bleeding
• maxillofacial or major dental surgery
• Mentally handicapped
• Obstruction of nasal passages, large adenoids where nasal mask is not effective

If adenoid hypertrophy is not suspected, nasal intubation following suxamethonium can be considered.

Problems in dental chair

• Reduced venous return, so more severe reaction to a vasovagal attack due to pain
• Increased chance of air embolism in sitting position
• Unprotected airway ie shared airway between surgeon and anaesthetist
• Aspiration of blood or mucus can cause  laryngospasm,
• Adrenaline in local anaesthetic can cause arrhythmias in presence of halothane
• Higher incidence of  arrhythmias due to stimulation of 5 th cranial nerve
• Nasal bleeding if nasal airway is used to deliver the anaesthetic
• Fainting due to cerebral hypoxia or cardiac arrest may be unrecognised
• Difficulty in initiating CPCR once cardiac arrest occurs
• Foreign body obstruction of the airway by needles or dentures,necessitating removal by bronchoscopy
• Uncontrolled and profuse bleeding into the airway in patients not screened for coagulopathies especially in out patients
• Higher incidence of infective endocarditis
• Anaphylaxis, to local anaesthetics or other drugs
• Malignant hyperpyrexia if halothane is used
• Difficulty in administering post op analgesia

MUSCLE RELAXANTS IN THE ICU.

Muscle relaxants are used in icu to facilitate mechanical ventilation of  the critically ill patients.The drugs commonly used  are pancuronium, vecuronium, atra curium, cisatra curium, and rocuronium.  Muscle relaxants are essential in the management of tetanus, status epilepticus, to provide hyper ventilation in head injury, or after  precise surgical intervention like tracheal anastomosis and vascular anastomosis.These agents are also used to reduce oxygen consumption or to reduce work of breathing in COPD and ARDS(where inflation pressures are high) patients.

Apart from the beneficial effects  the complications of these agents are also of concern and are investigated. These can be classified as  complications due to short term use and long term use

Short term use   

• Side effects atracurium causing histamine release or hyperkalemia due to suxamethonium
• Inadequate analgesia or sedation as these components are under estimated when relaxants are used

Long term use

• Immobility : DVT decubitus ulcers, peripheral nerve injuries.
• Inability to cough:  retained secretions,  atelectasis and infection
• Persistent paralysis on stoppage of the drugs "Critical Illness Neuropathy and Critical Illness Myopathy", Steroid induced myopathy.
• CNS effects of drugs eg: laudanosine causing convulsions

The end result of these complications  are failure to wean from mechanical ventilator, other ventilator associated complications,  residual weakness for life, and health care costs.

H1N1 AND HAND HYGIENE

There is a raising concern and anxiety about the spread of H1N1 influenza among people and health care personnel, as the number of reported cases are on the hike. Eventhough the mode of transmission is by droplet spread, transmission through conta minated hands are also considered to be significant. Along with personal protection devices like N-95 mask, goggles, apron, and gloves the importance of hand hygiene is also stressed, as prevention is the major goal for the control of spread. Several studies conducted on this issue have proved that practise of safe and appropriate hand hygiene is an important public health initiative to reduce pandemic H1N1 influenza transmission.

The commercially available hand sanitisers are alcohol based with the addition of various antiseptics and emollients.They are available both in liquid form and gel form. The advantages of alcohol based sanitisers are.

• Instant in action , effective in less than 15 seconds
• Reliable, almost 99% of pathogens including viruses are killed(actiton on spores doubtful)
• Easy to use as it immediately dries up and hand washing is not necessary
• leaves less stain than other agents

Since the liquid form of alcohol can cause skin irritation and allergy in some individuals, the gel form is recommended for routine cleansing. The major ingredients of gel based sanitisers are 70%v/w denatured alcohol(ethanol),1.45%v/v glycerol, carbomer, emollients, and moisturisers.Other preparations contain alcohol 70% and 4% w/v chlorhexidine, with vitamin E or moisturisers

Research by (Ref), Grayson ML, Melvani S, Druce J, Barr IG, Ballard SA, Johnson PD, Mastorakos T, Birch C., Infectious Diseases Department, Austin Health, Heidelberg, Victoria 3084, Australia, showed that hand hygiene with soap and water or alcohol-based hand rub is highly effective in reducing influenza A virus on human hands, although washing with soap and water is the most effective intervention.

Following the" NO FEAR, FIGHT INFLUENZA" campaign, instant hand sanitisers are made available everywhere, including supermarkets,restaurants, clinics, schools, factories etc.One danger of alcohol based sanitisers is that they are flammable and can cause burns.It happened in one hospital where the hospital cleaner used hand wash gel after cleaning the toilets and immediately lighted up a cigarette, holding up his hands to protect the flame from the wind, and his hands burst into flames.Anoher incidence reported from a birthday party where the children were playing with a sanitiser spray and their dress caught fire from candles. So it is advised that after sanitiser use one should make sure that the hands are dry before lighting gas stove,cigarettes or candles and when handling fire or dealing with any job which produces spark for example welding works.

Agents that reduce skin microflora are called antiseptics, whereas agents that reduce microflora on non living objects are called disinfectants. Antibiotic creams or dettol(chlorhexidine) are considered antiseptics, while glutaraldehyde (cidex) or floor cleaners like lysol(phenol based) are categorised as disinfectants. The efficacy of disinfectants or antiseptics are determined by Rideal Walker coefficient and is obtained by dividing the figure indicating the degree of dilution of the disinfectant that kills a microorganism in a given time by that indicating the degree of dilution of phenol that kills the organism in the same space of time under similar conditions.
Ref: Clin Infect Dis. 2009 Feb 1;48(3):285-91.
Watch a video on H1N1

AIRWAY MANAGEMENT IN A PATIENT WITH HUGE THYROID

Airway management of a patient with a huge thyroid swelling is a real challenge to the anaesthetist. The anaesthetic concerns and  the  management of airway are discussed here.

60 year old female patient is admitted to the A&E department with history of neck swelling and stridor. She is a known case of medullary carcinoma thyroid with lymph node metastases.

The patient assumed a sitting position as stridor exacerbated on lying supine and looks distressed .She was oriented conscious and responding to comm ands.  Examination of the chest revealed b/l basal creps and oxygen saturation was 88% with oxygen mask. ABG showed resp acidosis with hypoxemia.The pulse rate was regular and ECG was normal.The thyroid swelling was huge and completely occupying the anterior neck with the trachea not at all palpable at any point and with evidence of possible retrosternal extension.Oxygen by mask administered and patient postioned sitting, leaned forward.

Investigations done:

• Routine hemogram
• CXR showed severe narrowing and deviation of the trachea to the right side, by compression from the mass

• CT scan showed narrowed tracheal orifice(the black round hole) with compression of the esophagus and nodular metastases

Additional investigations (may be deferred here as this patient requires emergency airway access)

• Pulmonary function tests may show a restrictive defect with high FEV1/FVC ratio
• Carotid angiogram to assess the vessels

Anaesthetic problems anticipated

1) Induction or any anaesthetic intervention should be done with the patient in sitting position, as supine position further compromises airway.

2)Emergency tracheostomy, minintracheostomy or retrograde tracheostomy cannot be
performed here due to tumour extension.

3)Distorted airway anatomy makes intubation impossible even with fiber optic bronchoscopy.

4)Ventilation through Fastrach may not be adequate and may not be effective due to tracheal compression, if intubation through Fastrach fails.

5)Airway blocks like trans tracheal or superior laryngeal nerve blocks cannot be performed.

6) Tracheostomy malfunction may occur post operatively due to  tracheal collapse because of  tracheomalacia.


The  ideal management in this case would be a fiberoptic trial of intubation through the nasal or oral route, in the sitting position with topical airway anaesthesia, followed by palliative debulking of the tumor and then tracheostomy.

• Lignocaine jelly or gargle may be used to anaesthetise the posterior tongue
• Glossopharyngeal nerve block can be performed intra orally by injecting local anaesthetic into the base of the palatoglossal fold.
• Nasal passages may be anaesthetised by lignocaine jelly using swabs or catheter.
• Excellent anaesthesia of the larynx and trachea can be achieved with topical aerosolised lignocaine.
• Intravenous sedation can be given with midazolam or fentanyl in titrated doses during the procedure, if patient is uncomfortable.
• A smaler sized re inforced tube is preferred for intubation

The other suggested techniques are awake intubation through a fastrach,intubation
following rigid fiber optic bronchoscopy and inhalation induction using sevoflurane in the sitting postition followed either by blind intubation or fiberoptic aided intubation.



Anaesthetist should be vigilant, careful and well prepared while dealing with neck masses compromising airway. Management should done in operation theatre set up with all available equipments ready to tackle the difficult situation. The ENT and General surgeon also should be available to deal with emergency.

Thanx to Dr.Santhosh Kumar Sathiarajan, Radiologist,  Ibri hospital, Muscat.

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