ULTRASONOGRAPHY: Introduction, Principles, Indications, Advantages & Disadvantages

  • Sonography is a technique based on sound waves that acquires images in real time without the use of ionizing radiation.
  • The phenomenon perceived as sound is the result of periodic changes in the pressure of air against the ear-drum.
  • The periodicity of these changes ranges from 1500-20,000 Hz.
  • Ultrasound has a periodicity greater than 20 KHz, which is greater than the audible range (20Hz- 20 KHz).
  • Sonography comes from Latin word “sonus”- sound , Greek word “graphein”- write.
  • Sonography precisely means imaging with ultrasound.
  • Diagnostic Ultrasonography uses vibratory frequencies in range of 1- 20 MHz.

Principles

  • USG provides a non- invasive procedure of looking inside the human body.
  • Images are accomplished with pulse echo technique with the help of transducer.
  • Transducer: device that can convert one form of energy into another form.
  • Here electrical energy is converted into sonic energy.
  • Transducer is composed of thin piezoelectric crystal or material made up of a rea no. of dipoles arranged in a geometric pattern.
  • The electrical impulse generated by the scanner causes the dipoles in the crystal to realign themselves with the electric field and to change the crystal’s thickness suddenly. This abrupt change begins a series of vibrations that produce the sound waves that are transmitted into tissue being examined.
  • These echoes then return to transducer, where they are converted into electrical energy and then presented on the display of sonographic instruments. The ultrasound instruments processes the echo and present them as visible dots, which form the anatomic image on the display. The location of each dots correspond to the anatomic location of echo generating structure.
  • Gray scale image is achieved by different echo strength and echo arrival time is used to determine the depth of the structure that produced the echo.
  • Not all the ultrasound pulses are reflected back from any interface. Rather most of the original pulses continues to be reflected back from deeper interfaces.
  • If process is repeated, but with different starting points for each subsequent pulse, a cross sectional image of the anatomy is built up.

Coupling agents

  • Even a very thin layer of air between transducer and the skin surface reflects all the sound, preventing any penetration into the tissue, thus an aqueous gel is applied over the skin before application of transducer.
  • Coupling agents consists of: Carbomer 10 g, SDTA 0.25 g, Propylene glycol 75 g, Trolamine 12.5 g, Distilled water upto 500 g

Contrast Agents

  • Injected into the circulation to increase echogenicity
  • Contain micro-bubbles of gas
  • Produce stron echoes because  impedance of gas is different from that of suspended liquid (that enhance echogenicity from perfused tissues in gray scale sonography and Doppler ultrasound)

Main indications for USG in Head and Neck

  • Evaluation of neoplasm in the thyroid, parathyroid, salivary glands or lymph nodes; Stones in salivary glands or ducts; Sjogren syndrome, the vessels of the neck, including the carotid artery for atherosclerotic plaques.
  • To guide fine needle aspiration in the neck.
  • Evaluation of primary soft tissue tumors: Hemangiomas, Lymphagiomas, Cystic hygroma, Lipoma
  • Evaluation of infections of tongue, floor of mouth
  • Recent advances: 3D imaging to allow multi-planar reformatting, surface renderings (eg: fetal face) and color

Examination technique

Examination of

  • Thyroid glands
  • Vascular sheath
  • Floor of mouth
  • Tongue
  • Salivary gland
  • Tonsils
  • Then examination of lymph nodes

Advantages over conventional x-ray imaging

  • Sound waves are not ionizing radiation.
  • There are no known harmful effects on any tissues (at the energies and doses currently used in diagnostic ultrasound)
  • Images show good differentiation between different soft tissues and are very sensitive for detecting focal disease in salivary glands.
  • Technique is widely available and inexpensive.
  • Less/ low radiation
  • Relatively faster result is obtained.

Disadvantages

  • Limited use in head and neck region because sound waves are absorbed by bone.
  • Technique is operator dependent.
  • Images can be difficult to interpret for inexperienced operators because image resolution is often poor.
  • Real- time imaging means that the radiologist must be present during the investigation.
  • Ultrasonic waves of high intensity ultrasound generate cavitation.

Artifacts

1. Section thickness: results from beam width perpendicular to the scan plane.

  • Echoes are received that originate not only from center of beam but also from off center.
  • Third dimension volume is visible.

2.Reverberation (multiple reflection)

  • Can occur between transducer and strong reflector
  • Multiple echoes may be sufficiently strong to be detected and cause confusion on display.

3. Comet tail artifact

  • When the reflecting surfaces are closely spaced, they appear in a form of comet tail.
  • Irregularities of the surface of the lung may cause transient comet tail artifacts.

4. Refraction: one real structure is imaged as two artifactual objects.

5. Ghost artifact: In transverse scan, sound rays are refracted at the muscle or fat interfaces in such a way that smaller structures in abdomen or pelvis may be completely duplicated.

6. Mirror image artifact: Air filled lung, covered by visceral pleural, causes a highly reflective beam into the chest. Thus, sonography will produce pattern of bright echoes (mirror image) 

7. Gliding sign:

  • longitudinal image with transducer directly on the ribs appear as curving bright interfaces that cast dense acoustic shaws.
  • Lung surface moves with respiration, thus appear as gliding sign in sonography.

COPD (Chronic Obstructive Pulmonary Disease): Introduction, Clinical Features, Diagnosis & Management

Definition

COPD is defined as a common preventable and treatable disease that is characterized by persistent respiratory symptoms and airflow limitation that is due to airway and/or alveolar abnormalities usually by significant exposure to noxious particles/ gases.

Related diagnosis include:

  • Chronic bronchitis and emphysema
  • Extrapulmonary manifestation include; impaired nutrition, weight loss, skeletal muscle dusfunction

Risk factors

  • Cigarette smoking
  • Biomass solid fuel
  • Occupational hazards: coal miners, cadmium, factory workers, gold miners
  • Outdoor and indoor air pollution
  • Low body weight
  • Repeated chest infection
  • Low socioeconomic status
  • Familial and genetic factors: alpha antitrypsin deficiency

Pathogenesis

Clinical features

  1. COPD should suspected in any patient over the age of 40 years who presents with symptoms of persistent cough and sputum production and/ or breathlessness.
  2. Depending upon presentation important DD include: Asthma, TB, Bronchiectasis, and Congestive cardiac failure (CCF)
  3. Symptoms
  • Cough with mucoid sputum
  • Chronic bronchitis
  • Breathlessness
  • Later stage; morning headache, weight loss

4. Physical Sign

Inspection

  • Pursed lip breathing
  • Central cyanosis
  • Use of accessory muscles: sternocleidomastoid scalene, trapezius
  • Tracheal descent during inspiration (tracheal tug)
  • Inward movement of lower ribs on inspiration (low flat diaphragm)

Palpation

  • Increased in AP diameter of chest (barrel chest)
  • Reduction in length of trachea palpable above the sternal notch
  • Flapping tremor and bounding pulse (due to hypercapnia)
  • Cardiac apex not palpable
  • Finger clubbing is not consistent with COPD and should alert the physician to potentially more serious pathology

Percussion

  • Chest hyper resonance on percussion
  • Loss of cardiac dullness on percussion

Auscultation

  • Decreased breath sound + wheeze
  • Heart sounds loudest in epigastrium
  • Crackles may accompany infection but if persistent raise the possibility to bronchiectasis.

Chronic Bronchitis Vs Emphysema

Investigations

  1. Chest x-ray: to identify the alternative diagnosis such as cardiac failure, other complication of smoking such as lung cancer and the presence of large bullae.
  2. Blood count: to exclude anaemia or document polycythaemia.
  3. Spirometry: The diagnosis of COPD is established when post bronchodilator FEV1 is less than 80% of the predicted valve and accompanied by FEV1/ FVC < 70%.
  4. Measurement of lung volume by Helium dilution technique.
  5. Exercise test
  6. Pulse oximetry may prompt referral for a domiciliary O2 assessment if less than 93%.
  7. CT Scan of Chest

Spirometric Classification of COPD: Severity based on post- bronchodilator FEV1

Differential Diagnosis of COPD

  • Chronic Asthma
  • Pulmonary TB
  • Bronchiectasis
  • Bronchopulmonary myositis
  • CCF

Management of COPD

1.Smoking Cessation

  • Education: 5A (Ask, Advice, Assess, Assist, Arrange) 4D (Deep breath, Drink, Distract, Delay)
  • Bupropion therapy
  • Nicotine Replacement Therapy: Nicotine gum, nasal spray, Transdermal patch

2.Avoid dusty and smoke laden atmosphere

3. Pulmonary Rehabilitation: treatment programmes that incorporate education and CV conditioning improves: -quality –dyspnea –exercise capacity -decrease hospitalization rate over period of 6-12 month

4. Bronchodilators

Short acting:

  • Beta agonist: Salbutamol (100-200 µg 6 hourly), Turbutaline
  • Anticholinergic: Ipratropium bromide (20-80 µg 6 hourly), for mild disease

Long acting:

  • Beta agonist: Salmeterol (50-100 µg Bd), Formeterol
  • Methylxanthine: Theophylline 150-300 mg BD, Doxophylline 400 mg
  • Anticholinergic: Tiotropium Bromide (20-80 µg 6 hourly): moderate to severe disease

Oral bronchodilator therapy may be contemplated in patient who cannot inhaled devices efficiently.

Adverse effects : tremor, tachycardia (for this give Beta agonist+ theophylline)

5. Corticosteroids

  • Inhaled corticosteroids(ICS) reduces the frequency and severity of excerbations.
  • Recommended in patient with severe disease FEV1 <50% who report two or more exacerbations requiring antibiotics or oral steroids per year.
  • Inhaled: Beclomethasone and budesonide- 200 µg/ BD, Fluticasone: 100 µg BD
  • Oral: Prednisolone- 30-40 mg/day, low dose prednisolone for long time 5-10 mg/day
  • Adverse effects: inhaled (Inhaled candidiasis, decreased bone density), oral (osteoporosis, weight gain, cataract, glucose intolerance, infections)

6. O2 Therapy: Supplemental O2- long term domiciliary O2 therapy (LTOT) (2L/min) reduces pulmonary hypertension. 15-16 hours/day at 2-4 L/min.

7. Surgical Intervention: Selected patient with COPD may benefit from surgical intervention:

  • Bullectomy
  • Lung volume reduction surgery (LVRS)
  • Lung transplantation

8. Other measures

  • Patient with COPD should be offered an annual influenza vaccination and as appropriate, pnuemoccal vaccination.
  • Obesity, poor nutrition, depression and social isolation should be identified and if possible improved.

Acute Exacerbation of COPD

  • Are characterized by increase in symptoms and deterioration in lung function and health status.
  • Patient of COPD requiring hospitalization or having at least 2 of 3 cardinal symptoms of COPD flare: like 1. Increase in dyspnea 2. Increase sputum production 3. Increase sputum purulence

Treatment

1. O2 Therapy: controlled O2 at 24% or 28% should be used with the aim of maintaining PaO2> 8 KPa (60 mm Hg) or (SaO2 > 90%) without worsening acidosis.

2. Bronchodilators

  • Nebulized short acting beta agonist + Anticholinergic should be used
  • Salbutamol- 5 mg/ 6 hourly + Ipratropium bromide 500 µg/ 6 hourly

3. Corticosteroids

  • IV: Hydrocortisone- 8 mg/ 6 hourly
  • Oral: prednisolone- 30-40 mg/ day

4. Broad spectrum antibiotics (for bacterial infections)

5. Ventilation Therapy

  • Non-invasive positive pressure ventilation
  • Invasive ventilation

Indications

  • Severe respiratory distress (respiratory failure)
  • Life threatening hypoxia or hypercapnia
  • Altered metal sensorium
  • Haemodynamic instability

6. Respiratory stimulant: Doxapram- 1.5-4 mg/ min as I.V infusion

Prognostic Criteria for COPD: BODE Index

  • B- BMI
  • O- Degree of airflow obstruction
  • D- Dyspnoea measurement
  • E- Exercise capacity

Complications of COPD

  • Secondary polycythemia
  • CO2 narcosis
  • Pneumothorax
  • Pulmonary HTN
  • Right Ventricular Failure (Cor Pulmonale)
  • Respiratory Failure
  • Pulmonary Bullae
  • Chest Infection

ORAL CANCER- Classification, Etiology, Clinical Features, Diagnosis and Its Management

  • Oral carcinoma is one of the most prevalent cancers.
  • Oral cancer is a disease of increasing age; approx. 95% of cases occur in people older than 40 years, with an average age at diagnosis of approx. 60 years.

WHO Classification of oral cancer

Sites

Tongue, oropharynx floor of mouth (commonly), lips, gingiva, dorsum of tongue, palate

Risk factors

Six “S” mentioned in literature: Smoking, Spirits, Sharp tooth, Syphilis, Spicy food, Sepsis

1.Age and Gender

  • Increasing age- declining immune surveillance with age, longer exposure to potential carcinogens, time for accumulation of genetic changes
  • Men> Women

2.Genetic susceptibility

  • Family history of oral cancer
  • Head and neck cancer patient show as increased susceptibility to chromosome damage by mutagens.

3.Immune status: immunosuppressed individuals

4.Environmental factors: occupational i.e. fisherman and farmer-> longer working hours in sun.

5.Tobacco: Contains potent carcinogens i.e. Nitrosamines (Nicotine), polycyclic aromatic hydrocarbons, Nitrosodicthanolamine, nitrosoproline and polonium.

6.Alcohol

  • Increases permeability of oral mucosa
  • Dehydrates the mucosa
  • Immediate metabolite of ethanol-> readily damages cells
  • Minimizes detoxification of carcinogens

7.Betel (areca nut)

  • Betel quid chewing with or without added tobacco
  • Commonly involves the buccal mucosa
  • Substitutes- gutkha, pan, masala

8.Viruses

  • Epstein Barr Virus (EBV)
  • HSV
  • HSV-1, HSV-2
  • HPV-16, 18
  • HHV-4, 8

9.Nutritional factors: diet with low vitamin A, C, E, iron, selenium, folate and other trace element.

10.Other factors and oral hygiene

  • Poor oral hygiene
  • Faulty restoration
  • Ill-fitting denture
  • Sharp teeth cheek bites

Hallmarks of Carcinoma

Alteration in 6 normal physiologic process:

  1. Autonomy in growth signaling
  2. Evasion of apoptosis
  3. Unresponsiveness to growth inhibitory signaling
  4. Limitless replication
  5. Angiogenesis
  6. Invasion and metastasis

Clinical Features

Varied clinical presentative

  • Exophytic (mass forming, fungating, papillary)
  • Endophytic
  • Leukoplakia (white patch)
  • Erythroplakia (red patch)
  • Erythroleukoplakia (white and red patch)

Symptoms

  • Discomfort (common)
  • Mass/ lump/ swelling
  • Pain/ burning sensation (not usually)
  • Dysphagia
  • Voice change/ long term untreated disease
  • Halitosis
  • Odynophagia
  • Otalgia
  • Limited movement of tongue
  • Oral bleeding
  • Epistaxis
  • Loose teeth
  • Limited mouth opening
  • Ill-fitting denture
  • Anesthesia/ paresthesia
  • Paralysis

Signs of oral cancer

Early signs

  • Persistent red &/or white patch
  • Non healing ulcer
  • Progressive swelling or enlargement
  • Unusual surface changes
  • Sudden toot mobility without apparent cause
  • Unusual oral bleeding or epistaxis
  • Prolonged hoarseness of voice

Late signs

  • Indurated area
  • Paresthesia, dysesthesia of the tongue, or lips
  • Airway obstruction
  • Chronic earache
  • Trismus and dysphagia
  • Cervical lymphadenopathy
  • Persistent pain or referred pain
  • Altered vision
  • Epiphora

TNM Staging

Diagnosis and investigation

  1. History (Familial, Medical, Behavior(tobacco, smoking) history)
  2. Clinical examination
  3. Chair side screening
  • Vital staining/ Toluidine blue
  • Lugol’s Iodine
  • Chemiluminescence(vizilite)

4. Adjunctive clinical technique

  • Exfoliative cytology
  •  Brush biopsy
  • Punch biopsy
  • Scalpel biopsy
  • FNAC
  • Sentinal node biopsy and cytology\
  • Tissue- Autofluorescence (Velscope)
  • Photodynamic detection

5. Conventional imaging

  • Plain radiograph
  • OPG
  • Chest X-ray

6. Advance imaging

  • CT
  • Nuclear Scintiscanning
  • MRI (to access extent of soft tissue spread and recurrent tumors)
  • USG (imaging salivary gland masses, assessment of lymph mode)

7. Surgical biopsy (Excisional/ Incisional)

8. Blood Investigation (CBC, Hb, Blood grouping, cross matching, urea, electrolytes, LFT)- Immunological markers, Biochemical markers, Genetic marker

9. Saliva Investigation

treatment

Treatment depends upon

  • Size, site and location of primary tumor
  • Lymph node status
  • Presence of bone involvement
  • Ability to achieve bone margin
  • Preserve speech and swallowing function
  • Assessment of potential complication of therapy

1.Surgery

  • Clinically positive nodes
  • May be used as palliative
  • Aims at clearance of both primary lesion and involved regional lymphatics.
  • Extent of resection of the primary lesion depends upon the size and adjacent structures that may have been infiltrated.
  • Neck dissection (cervical lymphadenectomy). In this procedure, all lymph nodes are removed beginning from the lower border of mandible superiorly, to clavicular region inferiorly, and from the trapezius muscle posteriorly to midline anteriorly.
  • Commando surgery: a combined resection where in the primary tumor, affected lymphatics and involved adjacent structures are removed is referred to as commando surgery.
  • Microscopically frozen-section oriented histologic surgery (MOHS) technique: surgically resected specimens are immediately frozen and histologically analyzed to access for clear margins. The immediate assessment will aid in removing all tumor cells.

Indicated when:

  • Small and localized
  • Tumor involving bone
  • Side effect of surgery- low
  • Lack sensitivity to radiation
  • Recurrent lesion- previously received maximum dosage of radiation

Advantages of surgery: Complete tumor and lymph node excision

Disadvantages of surgery

  • Anesthesia risk
  • Surgical risk
  • Altered appearance
  • Reduced function
  • Complication: bleeding, Nerve injury

2.Radiation

  • Also known as, Radiation Therapy, is the treatment of cancer and other diseases with ionizing radiation.
  • Ionizing radiation deposits energy that injures or destroy cells in the area being treated (the target tissue) by damaging the genetic material(DNA) in the individual cells, making it impossible for them to continue to grow.
  • Used as: curative-> intent to cure-> radical radiotherapy, Palliative-> provide symptomatic relief from pain, bleeding, ulcerations, post surgical-> combined radiation- surgery
  • Hyperfractination of radiation: reduce chronic complication although acute complication is more severe (100-150 cGy delivered twice daily)
  • For epithelial malignancies, radiation protocol is 1.8- 2 Gy/week to total dose of 6000- 6500 cGy.
  • Biologic effects of radiation depends on: dose per fraction, number of fraction per day, total treatment time, total dose of radiation
  •   Radiation techniques: radiation may be administered to a localized lesion by using implant techniques (Brachytherapy) or to a region of the head and neck by using extended beam radiation.
  • Radiation sources: low kilovolt radiation-> for skin and lip lesions, cobalt 60-> linear accelerator of >_ 4 Mev, proton beam therapy
  • Types: IMRT-> Intensity Modulated Radio Therapy, IGRT-> Image Guided Radio Therapy

Brachy Therapy

  • Interstitial and Intracavitary implants are used to treat primary cancers in the head and neck.
  • Isotopes used include: Cesium, Iridium, Gold
  • Primary treatment modality for localized tumors in the anterior two thirds of the oral cavity, for boosted doses of radiation to a specific site, or for treatment following recurrence.
  • Advantages: less radiation exposure to other parts of body
  • Intersititial sources can be placed directly or preferably, after loaded into tubes or needles.

Advantages of Radiotherapy

  • No tissue or function loss
  • Good cosmetic outcome compared to surgery
  • Control of subclinical disease in regional nodes
  • Can simultaneously treat multiple primaries lesions

Disadvantages of Radiotherapy

  • Radiation complications: mucositis, radiation caries, osteoradionecrosis, xerostomia, loss of taste, salivary dysfunction, fungal infection, pain, difficult in speech and mastication

3.Chemotherapy

  • Chemotherapy is used as induction therapy before local therapies
  • It is adjunctive modality for other cancers
  • The objective of induction chemotherapy is to promote initial tumor reduction and to provide early treatment of micro metastases.
  • Chemotherapy of head and neck cancer, may result in temporary reduction in tumor size, but no increase in size.
  • Goal: to eradicate the rapidly growing cells of tumor or to modify their growth.
  • Chemotherapeutic agents affect the rapidly dividing cells of the target tumor and the lining epithelium, oral ecology and vascular inflammatory and healing responses of oral cavity.
  • Drugs used in oral cancer chemotherapy : Methotrexate, Bleomycin, Cisplatin, 5- Fluorouracil

Advantages of chemotherapy: Lesser invasive

Disadvantages of chemotherapy

  • Hair loss
  • Mouth sores
  • Loss of appetite
  • Nausea
  • Vomiting
  • Anemia
  • Diarrhoea
  • Low blood count
  • Mucositis
  • Ulceration of mucosa
  • Thrombocytopenia
  • Leukopenia

4.Targeted Therapy

  • EGFR antibody: Epidermal Growth Factor Receptor (EGFR) is a transmembrane tyrosine kinase receptor involved in proliferation and survival of cancer cells.
  • Examples: Cetuximab, Panitumumab, Erlotinib

5.Combined radiation and surgery

  • Radiotherapy has ability to eradicate well oxygenated tumor cells at the periphery of a tumor and to manage subclinical regional disease.
  • Surgery more readily manage tumor masses.
  • Combined therapy can result in improved survival in cases of advanced tumors and tumors that show aggressive biologic behavior.

6.Photodynamic Therapy

  • Photodynamic therapy is a treatment that uses a drug, called photosensitizer or photosensitizing agent, and a particular type of light.
  • When photosensitizers are exposed to specific wavelength of light, they produce a form of oxygen that kills near by cells.
  • Examples; porfimer sodium or photofrin

7.Gene therapy

  • Gene therapy is a way of treating or preventing diseases by altering the genetic instructions within an individual cells.
  • Gene therapy can involve replacing abnormal or absent genes with healthy ones that enable cells to produce useful proteins.
  • It can involve changing the way genes are regulated, so that under or overactive genes operate properly.

SYNCOPE & ITS MANAGEMENT

INTRODUCTION

  • Syncope is the sudden transient loss of consciousness(LOC) and postural tone due to decreased cerebral blood flow, with spontaneous recovery.
  • LOC occurs within 10 seconds of hypo perfusion of the reticular activating system in mid brain.

ETIOLOGY

1.Cardiac causes

2.Orthostatic Hypotension

3.Reflex (Neurally mediated) Syncope

SYNCOPE TRIGGERS

  • Micturation
  • Defecation
  • Glossopharyngeal neuralgia
  • Orthostatic
  • Venipuncture
  • Jacuzzi
  • Trumpet playing
  • Instrumentation
  • Deglutition
  • Cough
  • Post prandial
  • Valsalva maneuver
  • Sneezing
  • Diving
  • Weight lifting
  • Carotid sinus stimulation

PATHOGENESIS

Signs and symptoms

  • LOC with recovery
  • Lightheadedness
  • Dizziness
  • Palpitation, slow or rapid pulse
  • Pulse irregularity
  • Decreased BP
  • Darkening of vision
  • Ringing in ears
  • Symptoms of hyperventilation
  • Distal tingling
  • Nausea
  • Clamminess
  • Sweating
  • Incontinence of urine
  • Amnesia
  • Tongue biting

Early: feeling of warmness, pale color, heavy perspiration especially on forehead, sense of feeling bad, nausea, low BP, tachycardia, lightheadedness

Late: yawning, cold hands and feet, visual disturbance, bradycardia, loss of consciousness, pupillary dilation, fainting, low BP

History

  • Cardiac history, stroke, seizure
  • Occult blood loss (GI, Octopic)
  • Females: LMP, vaginal
  • Fluid loss: Nausea, vomiting, diarrhea
  • Past medical history
  • Medications

Differential diagnosis

  • Vasovagal
  • Orthostatic hypotension
  • Cardiac syncope
  • Micturition/ defecation syncope
  • Psychiatric
  • Stroke
  • Hypoglycemia
  • Seizure
  • Shock
  • Toxicologic (alcohol)
  • Medication effect (HTN)

Syncope Vs Seizure

Management OF sYNCOPE

Simple ways to prevent syncope

  • Don’t wave needle in front of patient
  • Administer LA in supine position
  • See that the clinic is not hot and humid
  • Check that the patient is not an empty stomach
  • Use mild sedatives if required

1.Before treatment

  • Stress reduction protocol
  • If necessary, give preoperative anxiolytic drugs.

2.Appearance of prodromal sign

  • Palpitation, sweating, nausea, warmness
  • Terminate all procedures
  • Position the patient in Trendelenburg position.
  • Administer O2 via facemask or nasal canula(if necessary)
  • Attempt to calm patient, cool towel on forehead.
  • Monitor vital sign.

3.Occurrence of episode of syncope

  • Terminate all dental treatment
  • Patient position (i.e. Trendelenburg position)
  • Check for breathing if;

Anxiety Reduction Protocol

1.Before Appointment

  • Hypnotic agent to promote sleep on night before surgery.
  • Sedative agent to decrease anxiety on morning of surgery.
  • Morning appointment so that reception room time is minimized.

2.During appointment

3.After surgery

  • Proper instruction for post-operative case.
  • Patient informed on expected post-surgical sequele.
  • Further reassurance
  • Effective analgesics
  • Patient informed on whom to be contacted if any problem arises
  • Telephone call on evening after surgery to see any problem arises.

SPLENOMEGALY: Causes, Characteristic & Investigations

The spleen may be enlarged due to:

  1. Involvement by lymphoproliferative disease
  2. Extramedullary hematopoiesis in myeloproliferative disease
  3. Enhanced reticulo- endothelial activity in autoimmune haemolysis
  4. Expansion of the lymphoid tissue in response to infections
  5. Vascular congestion as a result of portal hypertension

Causes of splenomegaly

A. Infective

  • Bacterial: Endocarditis, septicaemia, tuberculosis, brucellosis, salmonella
  • Viral: Hepatitis, Epstein Barr virus, CMV
  • Protozoal: Malaria, leishmaniasis, Trypanosomiasis
  • Fungal: Histoplasmosis

B. Congestive

  • Portal Hypertension: Cirrhosis, hepatic vein occlusion, portal vein thrombosis, stenosis or malformation of portal or splenic vein
  • Cardiac: chronic congestive cardiac failure, constrictive pericarditis

C. Inflammatory/ Granulomatous disorders

  • Felty’s syndrome in rheumatoid arthritis
  • SLE (Systemic Lupus Erythematosus)
  • Sarcoidosis

D. Hematological

  • Red cell disorders: megaloblastic anemia, haemoglobinopathies, hereditary spherocytosis, Haemoglobinopathies
  • Autoimmune hemolytic anemia
  • Myeloproliferative disorders: chronic myeloid leukemia, myelofibrosis, polycythemia rubra Vera
  • Neoplastic: leukemia- CML, lymphoma

E. Other malignancies: metastatic cancer- rare

F. Lysosomal storage disease: Gaucher’s disease, Niemann Pick disease

G. Miscellaneous: Cysts, Amyloid, Thyrotoxicosis

Hepatosplenomegaly is suggestive of lympho or myeloproliferative disease, liver disease or infiltration (e.g. with amyloid)

Associated lymphadenopathy is suggestive of lymphoproliferative disease.

Clinical Features

  • An enlarged spleen may cause: abdominal discomfort, accompanied by back pain and abdominal bloating due to stomach compression
  • Splenic infarction produces severe abdominal pain radiating to the left shoulder tip, associated with a splenic rub on auscultation.
  • Rarely, spontaneous or traumatic rupture and bleeding may occur.

Characteristics of the Spleen

  • Notch
  • Superficial
  • Dull to percussion
  • Cannot get examining hand between ribs and spleen
  • Moves well with respiration

Investigations

  • Imaging of the spleen by Ultrasound or CT will detect variations in density in the spleen.
  • Biopsy of enlarged abdominal or superficial lymph nodes
  • Chest X-ray: to detect mediastinal lymphadenopathy
  • CT of thorax: to detect mediastinal lymphadenopathy
  • CBC: Pancytopenia secondary to hypersplenism
  • Bone marrow Examination
  • Screening for infectious or liver disease
  • Splenectomy (rarely)

INFECTIVE ENDOCARDITIS: Introduction, Etiology, Clinical features, Diagnosis & Management

  • A microbial infection of the endocardial surface of heart.
  • Common sites: heart valves, but may occur at septal defect on chordae tendinae or in the mural endocardium
  • Males> females
  • May occur at any age, more commonly in elderly
  • Mortality: 20-30%

Causative Agents

A. Bacteria

  • Viridian group of streptococci (Streptococcus mitis, S. Sanguis)– common in URT and common cause of periodontal infection.
  • Other organisms S. faecalis, S. bovis, S. milleri
  • Staphylococcus aureus: common cause of acute endocarditis, others- S. pneumoniae, S. pyogens
  • Gram negative bacteria: HACEK group

H- Hemophilus, A- Actinobacillus, C- Cardiobacterium haminis, E- Eikanella, K- Kingella Kingae

B. Rickettsia: Coxiella brunetti (Q fever endocarditis)

C. Fungi: Candida, Aspergillus

Risk for Endocarditis

High risk

  • Prosthetic cardiac valve
  • Prior episodes of endocarditis
  • Complex congenital cardiac defect
  • Surgical systemic pulmonary shunts
  • I.V drug abuse
  • Intravascular catheters

Moderate risk

  • PDA, VSD, primum ASD
  • Co- aorta
  • Biscuspid aortic valves
  • Hypertrophy cardiomyopathy
  • Acquired valvular dysfunction
  •  MVP with mitral regurgitation

Clinical features

1. General symptoms

Acute (@ HW BASA)

  • High grade fever and chills
  • Weight loss
  • Back pain
  • Abdominal pain
  • Shortness of breath
  • Arthralgia

Subacute

  • Low grade fever
  • Anorexia
  • Weight loss
  • Fatigue
  • Arthralgia
  • Abdominal pain

2. Cardiac

  • Varying murmur (60% new or pre-existing murmur, 15-30 new or changes murmura)
  • Conduction disorders (10-20%)
  • Cardiac failure (40-50%)

3. CNS

  • Cerebral emboli (15%)
  • Convulsion
  • Coma
  • Hemiplegia

4. Eye

  • Subconjunctival hemorrhages (2-5%)
  • Roth’s spot (rare, <5%)

5. Hand and Toes

a. Osler’s nodes (5%)

  • More specific
  • Painful and erythematous nodules
  • Located on pulp of fingers and toes
  • More common in subacute IE

b. Loss of pulses

c. Digital clubbing (10%, long standing endocarditis only)

d. Splinter haemorrhage (10%)

  • Non specific
  • Non blanching
  • Linear reddish brown lesion found under the nail bed
  • Usually don’t extend the entire length of nail

e. Janeway lesions

  • More specific
  • Erythematous, blanching macules
  • Non painful
  • Located on palms and soles

f. Spleen : splenomegaly (30-40%, long standing endocarditis only)

g. Kidney: haematuria (60-70%)

h. Petechial rash (40-50%), may be transient: often located on extremities or mucus membranes

Diagnosis of Infective Endocarditis (Modified Duke Criteria)

Major Criteria

i. Positive blood culture

  • Typical organism from 2 cultures
  • Persistent positive blood cultures taken> 12 hours apart
  • Three or more positive cultures taken over> 1 hours

ii. Endocardial involvement

  • Positive echocardiographic finding of vegetations
  • New valvular regurgitation

Minor Criteria

  • Predisposing valvular or cardiac abnormality
  • Intravenous drug users
  • Pyrexia>_ 38 deg. Centigrade
  • Embolic phenomenon
  • Vasculitis phenomenon
  • Blood cultures suggestive, organism grown but not achieving major criteria
  • Suggestive echocardiographic findings

Definite Endocarditis: 2 major or 1 major and 3 minor or 5 minor

Possible Endocarditis: 1 major and 1 minor or 3 minor

Management of Infective Endocarditis

  1. Complete bed rest
  2. Removal of any source of infection e.g. tooth abscess
  3. Antimicrobial treatment
  4. Treatment of complication
  5. Monitoring of patient
  • Fever
  • murmur
  • ESR
  • C- reactive protein

6. Surgery

Indication for cardiac surgery

  • Heart failure due to valve damage
  • Failure of antibiotic therapy
  • Large vegetations on left sided heart valves with evidence on “high risk” of systemic emboli
  • Abscess formation

Antibiotic prophylaxis for Infective Endocarditishttps://wordpress.com/read/feeds/98369682/posts/2371583855

Antimicrobial treatment of common causative organism in Infective Endocarditis

MITRAL VALVE STENOSIS: Introduction, Clinical features & Management

Mitral stenosis is a valvular heart disease characterized by narrowing of the orifice of mitral valve of the heart.

Etiology

  • Rheumatic heart disease
  • Congenital

Pathophysiology

  • When the normal valve orifice of 5 cm3 reduced to 1 cm3 or less, severe mitral stenosis occurs.
  • In order to maintain normal cardiac output, left atrial pressure rises and ultimately hypertrophy and dilatation occurs.
  • Consequently, pulmonary venous, pulmonary arterial and right heart pressure rise.
  • Pulmonary hypertension may cause pulmonary edema and right ventricular hypertrophy, dilatation and failure.

Clinical features

Symptoms (@ BPH C2 OSF)

  • B- Breathlessness (Pulmonary congestion)
  • P- Palpitation (Atrial fibrillation)
  • H- Hemoptysis (pulmonary congestion, pulmonary embolism)
  • C- Cough (Pulmonary congestion)
  • C- Chest pain (Pulmonary hypertension)
  • O- Oedema, Ascites (Right heart failure)
  • S- Symptoms of thrombolic complication (e.g.: stroke, ischemic limb)
  • F- Failure (Low cardiac output)

Signs (@ AMA CR)

  • A- Atrial Fibrillation
  • M- Mitral facies
  • A- Auscultation (loud 1st heart sound-opening shaq, mid diastolic murmur)
  • C- Crepitation (pulmonary edema, effusion- raised pulmonary capillary pressure)
  • R- RV heave, loud P2 (Pulmonary hypertension)

Investigation

  1. ECG
  • Right ventricular hypertrophy: tall R waves in V1- V2
  • P mitrale or atrial fibrillation

2. Chest X-ray

  • Enlarged LA and appendage
  • Sign of pulmonary venous congestion

3. Echo

  • Thickened immobile cusps
  • Reduced valve area
  • Enlarged LA
  • Reduced rate of diastolic filling of LA

4. Doppler

  • Pressure gradient across mitral valve
  • Pulmonary artery pressure
  • Left ventricular function

5. Cardiac Catheterization

  • Coronary artery disease
  • Pulmonary artery pressure
  • Mitral stenosis and regurgitation

Complication (@ C (P3 A T2 I))

  • Congestive cardiac failure
  • Pulmonary edema
  • Pulmonary HTN
  • Pulmonary infarction
  • Atrial fibrillation
  • Thromboembolism- cerebral embolism
  • Tricuspid regurgitation
  • Infective endocarditis

Differential Diagnosis

  • Significant of mitral regurgitation
  • Severe AR
  • Tricuspid Stenosis
  • Atrial septal defects
  • Left atrial myxoma

Management

  1. Medical treatment for patient with minor symptoms
  • No exertion
  • Anticoagulant; Aspirin, to reduce risk of systemic embolism
  • Diuretics: to control pulmonary congestion
  • Digoxin: 0.125- 0.25 mg/dl in atrial fibrillation
  • Antibiotics for prophylaxis against IE

2. Definitive treatment

a. Mitral Ballon Valvuloplasty : Treatment of choice if following criteria is fulfilled:

  • Significant symptoms
  • Isolated mitral stenosis
  • No mitral regurgitation
  • Mobile, non- calcified valve/ sub-valve apparatus on echo
  • Left atrium free of thrombus

b. Mitral Valvotomy: closed or open mitral valvotomy (commisurotomy), if facilites or expertise for valvuloplasty are not available.

c. Mitral Valve Replacement (MVR): Necessary if there is mitral regurgitation, rigid and calcified valve.

Criteria for mitral valvuloplasty

  • Significant symptoms
  • Isolated mitral stenosis
  • No mitral regurgitation
  • Non calcified valve
  • Mobile
  • Left atrium free of thrombus

CONE BEAM COMPUTED TOMOGRAPHY (CBCT)

  • CBCT imaging is the most significant technologic advances in maxillofacial imaging since the introduction of panoramic radiograph.
  • It was initially developed commercially for an angiography.
  • It uses a divergent cone shaped or pyramidal shaped source of ionizing radiation and two dimensional area detector fixed on a rotating gantry, to provide multiple sequential transmission images that are integrated directly, forming volumetric information.

Princilples

  • All CT scanners consists of an x-ray source and detector mounted on a rotating gantry.
  • During rotation of the gantry, the x-ray source produces radiation, while the receptor records the residual x-rays after attenuation by the patient’s tissues.
  • These recordings constitute the “raw data” that is reconstructed by a computer algorithm to generate cross- sectional images.
  • The basic component of the gray-scale images in the picture element(pixel) values.
  • CBCT imaging is performed using a rotating platform or gantry carrying an x-ray source and detector.
  • A divergent cone-shaped or pyramidal source of radiation is directed through the region of interest (ROI), the residual attenuated radiation beam is projected onto an area x-ray detector on opposite side.
  • The x-ray source and detector rotate around a rotation center, fixed within the center of ROL. This rotational center becomes the center of the final acquired image volume.
  • During the rotation, multiples sequential planar projection images are obtained while the x-ray source and detector move through an arc of 180 to 360 deg.
  • These single projection images constitute the raw primary data and are individually referred to as basis, frame or raw images.
  • There are usually several hundred two-dimensional basis images from which the image volume is calculated and constructed.
  • The complete series of images is referred to as the projection data. The softwares including algorithms are applied to these projection data to generate a volumetric data set that can be used to provide primary reconstruction images in three orthogonal planes (axial, sagittal and coronal).

Indication/ application

  1. Implant site assessment: CBCT provides cross sectional images of the alveolar bone height, width, and angulation and accurately depicts vital structures i.e. Inferior alveolar dental nerve canal in mandibular or sinus in maxilla.
  2. Endodontics
  • Identifications of potential accessory canals in teeth with suspected complex morphology
  • Identification of root canal system anomalies and determination of root curvature
  • Diagnosis of pathosis of non-endodontic origin.
  • Intraoperative or post-operative assessment of endodontic treatment complications
  • Diagnosis and management of dentoalveolar trauma
  • Localization and differentiation of external from internal root resorption or invasive cervical resorption.

3. Orthodontic and three dimensional cephalometry

  • Used in diagnosis, assessment and analysis of maxillofacial orthodontic and orthopedic anomalies
  • Facilitates surgical exposure and planning of subsequent movement
  • Assessment of palatal morphologic features and dimensions, tooth inclination and torque, characterization of alveolar bone for orthodontic mini-implant placement, available alveolar bone width for buccolingual movement of teeth.

4. Adequate visualization of TMJ, Pharyngeal airway space and soft tissue relationship

5. Three dimensional cephalometry include demonstrating and characterizing asymmetry and anteroposterior, vertical and transverse dentoskeletal discrepancies, incorporating soft tissue integument and potential for assessment of growth and development.

6. Mandibular 3rd molar position- relationship of inferior alveolar canal (IAC) to the roots of mandibular 3rd molar teeth, to minimize the likelihood of nerve damage.

7. Temporomandibular Joint

  • Provides multiplanar and potentially three dimensional images of the condyle and surrounding structures to facilitate analysis and diagnosis of the bone morphology features and joint space and function.
  • Imaging can depict the features of degenerative joint disease, developmental anomalies of the condyle, ankylosis and rheumatoid arthritis.

8. Maxillofacial pathosis

  • Assessment of condition such as impacted canines, supernumerary teeth, fractured or split teeth, periapical lesions, periodontal diseases.
  • Bening calcification (tonsilloliths, lymph nodes, salivary gland stones)
  • Trauma
  • Assessment of extent and degree of involvement of benign odontogenic and non- odontogenic condition.

Advantages

  • Lower radiation dose than CT (Conventional)
  • Lower time, space and cost than CT (Conventional)
  • Greater hard time definition than medical CT
  • Multiplanar reformation
  • 3D volume rendering
  • Better images with good spatial resolution

Disadvantages

  • Higher radiation than 2D imaging
  • Artifacts and scatters
  • Less soft tissue discrimination than medial CT
  • Motion artifacts due to increased scan time
  • Scan volume insufficiency
  • Poor contrast resolution, thus soft tissue can’t be viewed
  • Image noise is determental

Image artifacts

An artifact is any distortion or error in the image that is unrelated to the subject being studied.

  1. Inherent artifacts:
  • causes- projection geometry, reduced trajectory rotational arcs, image reconstruction

a. Scatter: Scatter results from x-ray photons that are diffracted from their original path after interactions with matter. Causes streak artifacts similar to artifacts of beam hardening.

b. Partial volume averaging: occurs when selected voxel size of the scan is larger than the size of the object being imaged.

c. Cone beam effect

  • Occurs especially in the peripheral portions of the scan volume
  • Because of the divergence of x-ray beam as it rotates around the patient in a horizontal plane, structures at the top or bottom of the image field are exposed only when the x-ray source is on opposite side of patient.
  • Result : image distortion, streaking artifacts, greater peripheral noise
  • Minimized by incorporation by manufacturers of various forms of cone beam reconstruction.

2. Procedure related artifacts

  • Under sampling of object lead too noiser image
  • Reduced data sample leads to misrgistration, sharp edges and noiser images.
  • Scanner related artifacts appear as circular or ring streaks
  • Misalignment of x-ray source to detector creates a double contour artifacts similar to that created by patient motion.
  • Repeated use of CBCT equipment over time may result in slight configuration changes.

3. Introduced artifacts

a. Beam Hardening : when an X-ray beam passes through an object  lower energy poton are absorbed in preference to higher energy photons.

  • Cupping artifact: distortion of metallic structures as a result of differential absorption.
  • Extinction or missing value artifact: Streaks and dark bands, which when present between two dense objects.

4. Patient motion artifacts

  • Patient motion can cause mis-registration of data, which appears as double contours in reconstructed image.
  • Problem can be minimized by restraining the head and using as short a scan time as possible.
  • Motion Artifact

RADIONUCLIDES

INTRODUCTION

  • Radionuclide imaging (a form of functional imaging) provides a means of assessing such physiologic changes.
  • Radionuclide is a diagnostic modality in which radio-pharmaceuticals are used to get images.
  • Nuclear medicine examinations are commonly used to assign function of the brain, thyroid, heart, lungs, and gastrointestinal system as well as for diagnosis and follow-up of metastatic disease, bone tumors and infection.
  • Radionuclide imaging uses radioactive atoms or molecules that emits gamma (y) rays.
  • Radio-pharmaceuticals are administered intravenously in the body and they reach the affected bone and bind with pathological lesion by tagging with the tissue resulting in the release of gamma rays by the disintegration of radioactive substances.
  • This gamma rays are detected by gamma camera, forms planar images showing the locations of radionuclides in the body.
  • This image is recorded as scintigraphy.
  • SPECT and PET imaging are advanced nuclear medicine techniques that form tomographic views.

Principles

Widely used radionuclides are

  • 99m Tc (Technetium): t1/2- 6 hours, mimics Iodine distribution when given i.v – for brain tumors, thyroid gland, skeletal system, respiratory system diagnostics — bound to Methylene diphosphate (MDP) mu
  • 131 I (Iodine): t1/2 – 804 days, for iodine metabolism, liver, kidney function.
  • 67 Ga (Gallium): for infection like Osteomyelitis
  • 74 Se (Selenium)
  • 51 Cr: t1/2- 277 days, In hematology
  • 198 Au: t1/2- 2.697 days
  • 111 In: for liver, brain diagnosis

Gamma emitting Isotopes

  • Iodine (131 I)
  • Gallium (67 Ga)
  • Selenium (74 Se)

Target (Critical) Organs

  • Target organ is organ in which radio-pharmaceuticals are maximally accumulated and which is exposed by excessive radiation.
  • Mostly it is organ we want to examine.
  • Be safely regulations, there are 3 groups of target/ organs due to decreasing / radio sensitivity.
  1. Group: whole body, genitals, bone marrow, small intestine mucosa
  2. Group: muscles, thyroid, fat, liver, kidneys, spleen, GI tract, Lungs, lens
  3. Group: Skin, bones

Indications

  • Assessment of site and extent of bone metastases
  • Investigation of salivary gland function particularly in Sjogren’s syndrome.
  • Evaluation of bone grafts
  • Assessment of continued growth in condylar hypoplasia
  • Investigation in thyroid function
  • Brain scans and assessment of a breakdown of blood brain barrier

ContraindicATION

  • Pregnancy
  • Allergic reaction
  • Previous surgical, radiologic procedure
  • Prior medications

Advantages

  • Target tissue function is investigated
  • All similar target tissue can be examined during on investigation
  • Computer analysis and enhancements of results are available.

Disadvantages

  • Poor image resolution
  • High radiation dose
  • Image are not disease specific
  • Difficult to localize exact anatomical site of source of emission
  • Not easily available

Why Technetium (99m Tc- Pertechnetate)?

  • Single 141 ev gamma emissions which are ideal
  • Short half life: 6.5 hours
  • Radially attached to  variety of different substances that are concentrated in different organ.’
  • Safe
  • Easily produced, as and when required, on site.

Imaging Devices

  • Planar nuclear imaging
  • Single photon emission computed tomography
  • Position emission tomography
  • Fusion imaging

Antibiotic Prophylaxis for Infective Endocarditis

Guidelines for Antibiotic Prophylaxis

High risk category

  • Prosthetic cardiac valves
  • Previous bacterial endocarditis
  • Complex cyanotic congenital diseases
  • Surgically constructed systemic pulmonary shunts or condults

Moderate risk category

  • Most other congenital cardiac malformation
  • Acquired valvular dysfunction e. RHD
  • Mitral valve prolapse

Negligible risk category

  • Isolated secundum atrial septal defect
  • Surgical repair of ASD or patent ductus arteriosus
  • Previous coronary bypass graft surgery
  • MVP without valvular regurgitation
  • Physiologic, functional or innocent heart murmur
  • Previous Kawasaki disease
  • Previous rheumatic fever
  • Cardiac pacemaker and implanted defibrillators

Dental procedures in which antibiotic prophylaxis is recommended

  • Dental extraction
  • Periodontal procedure
  • Dental implant placement
  • Endodontic (root canal) instrumentation or surgery only beyond the apex
  • Subgingival placement of antibiotic fibers or strips
  • Intra ligamentary local anesthetic injections
  • Oral prophylaxis where bleeding is anticipated.

Endocarditis prophylaxis not recommended for

  • Restorative procedure
  • Local anesthetic injections (Non- ligamentary)
  • Intracanal endodontic treatment
  • Placement of rubbber dams
  • Taking of oral impressions
  • Fluoride treatments
  • Taking of oral radiographs
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