May 26, 2009

Hirschsprung's Disease

One 7 months old female child presented with distension of abdomen and intermittent enterocolitis since birth. When I saw the child, she was weighing 4.3 kg which was far less than expected weight for her age. Her abdomen was distended with gas and I could see visible bowel loops. After doing per rectal examination, when I removed my finger, there was gush of liquid stool came with explosion.

This is typical of what it is called as Hirschsprung's disease. In this disease, there is problem in the innervation of part or whole large intestine or rarely extending small intestine. There is absence of ganglion cells in the affected part of intestine (Ganglion cells are required for proper peristalsis of intestine). The child presents with delayed passage of meconium, enterocolitis and distension of abdomen in the neonatal period while chronic constipation and distension of abdomen are presenting features in the older children.

Barium enema & full thickness rectal biopsy are the modalities of diagnosis. Treatment is decompression with colostomy and later pull through procedure or primary pull through procedure.

May 25, 2009

Meckel's Diverticulum

Introduction: Meckel's diverticulum is the diverticulum present on the antimesenteric border of terminal part of small intestine also called as ileum. It does not present in all individuals. It is a presistence of vitellointestinal duct in the abdomen.

There is unique 'The rule of two' i.e. Meckel's diverticulum is present in 2% of population, it is 2" long and it is 2 feet away from ileocaecal junction (junction where small intestine joins large intestine).

Clinical presentation:
1. Bleeding per rectum- profuse & painless bleeding
2. Intestinal obstruction- leadiing to vomiting, pain & abdominal distension
3. Infection- symtoms mimicking appendicitis

In majority of cases it is diagnosed at exploration when the child is being operated for appendicitis. When it presents as bleeding per rectum then Meckel's scan or RBC tagged scan is useful. Barium meal follow through can also sometimes diagnoses Meckel's Diverticulum.

Managment: Laparoscopic or open Meckel's diverticulectomy is the standard of care. In case of appendicectomy, it is worthwhile to trace aprroximately 2 feet of ileum from ileocaecal junction to rule out uncomplicated Meckel's diverticulum.

May 13, 2009

Diagnosis of Swine Flu

For diagnosis of swine influenza A infection, respiratory specimen would generally need to be collected within the first 4 to 5 days of illness (when an infected person is most likely to be shedding virus). However, some persons, especially children, may shed virus for 10 days or longer.

Sample Collection & Laboratory Diagnosis

· Preferred respiratory samples Nasal, Nasopharyngeal & throat swab

· Collection- on vaccine transport media

· Availability- with area & regional coordinator

· Storage of Samples : should be at 2-8⁰C until can be placed at -70⁰C.

· Transportation of Samples : dry ice in triple packaging. All samples should be labeled clearly and include patient’s complete information

· Laboratory biosafety measures should be followed for collections, storage, packaging and courier/ shipping of influenza samples.

· Available Laboratory tests:

- Rapid Antigen Tests: not as sensitive as other available tests.

- RT-PCR, Virus isolation, Virus Genome Sequencing, Four-fold rise in swine influenza A (H1N1) virus specific neutralizing antibodies

May 8, 2009

Laparoscopic Appendicectomy

First laparoscopic appendicectomy was performed by Dr Kurt Semm (A German gynecologist) & Dr Philippe Mouret (A French surgeon & gynecologist) in beginnings of1980's.

Laparoscopic instruments required for appendictomy:
1. Trocar & Cannula
2. Telscope
3. Grasping forceps
4. Dissector
5. Monopolar/ Bipolar cautery/ Harmonic scalpel
6. Clip applicator with clips
7. Endoloop introducer with endoloops
8. Suction cannula

Surgical procedure:
1. Hasson's/ open technique- umbilical port for camera
2. Suprapubic & Left side of abdomen in line with umbilical port for working instruments
3. Telescope introduced through umbilical port by Hasson's technique
4. CO2 insufflation done & pressure kept at 8-10 mm Hg
5. Working ports introduced
6. Appendix visualized in RIF by moving away all the small bowel loops
7. Trendelenberg's position with left tilt given
8. Appendix tip grasped & mesoappendix either cauterized & endoclips are put
9. Endoloops introduced at the base of appendix & appendix is cut in between the loops
10. Appendix removed through the umbilical port after checking haemostasis.

May 7, 2009

Swine Flu Vaccine

WHO: Questions and Answers related to Vaccines for the new Influenza A (H1N1)

From World Health Organization- May 2, 2009

Is an effective vaccine already available against the new Influenza A(H1N1) virus?

No, but work is already underway to develop such a vaccine. Influenza vaccines generally contain a dead or weakened form of a circulating virus. The vaccine prepares the body’s immune system to defend against a true infection. For the vaccine to protect as well as possible, the virus in it should match the circulating “wild-type” virus relatively closely. Since this H1N1 virus is new, there is no vaccine currently available made with this particular virus. Making a completely new influenza vaccine can take five to six months.

What implications does the declaration of a pandemic have on influenza vaccine production?

Declaration by WHO of phase 6 of pandemic alert does not by itself automatically translate into a request for vaccine manufacturers to immediately stop production of seasonal influenza vaccine and to start production of a pandemic vaccine. Since seasonal influenza can also cause severe disease, WHO will take several important considerations such as the epidemiology and the severity of the disease when deciding when to formally make recommendations on this matter. In the meantime, WHO will continue to interact very closely with regulatory and other agencies and influenza vaccine manufacturers.

How important will Influenza A(H1N1) vaccines be for reducing pandemic disease?

Vaccines are one of the most valuable ways to protect people during influenza epidemics and pandemics. Other measures include anti-viral drugs, social distancing and personal hygiene.

Will currently available seasonal vaccine confer protection against Influenza A(H1N1)?

The best scientific evidence available today is incomplete but suggests that seasonal vaccines will confer little or no protection against Influenza A(H1N1).

What is WHO doing to facilitate production of Influenza A(H1N1) vaccines?

As soon as the first human cases of new Influenza A(H1N1) infection became known to WHO, the WHO Collaborating Center in Atlanta (The Centers for Disease Control and Prevention (CDC) in the United States of America) took immediate action and began the work to develop candidate vaccine viruses. WHO also initiated consultations with vaccine manufacturers worldwide to facilitate the availability of all necessary material to start production of Influenza A(H1N1) vaccine. In parallel, WHO is working with national regulatory authorities to ensure that the new Influenza A(H1N1) vaccine will meet all safety criteria and be made available as soon as possible.

Why is WHO not asking vaccine manufacturers to switch production from seasonal vaccine to a Influenza A(H1N1) vaccine yet?

WHO has not recommended stopping production of seasonal influenza vaccine because this seasonal influenza causes 3 million to 5 million cases of severe illness each year, and kills from 250,000 to 500,000 people. Continued immunization against seasonal influenza is therefore important. Moreover, stopping seasonal vaccine production immediately would not allow a pandemic vaccine to be made quicker. At this time, WHO is liaising closely with vaccine manufacturers so large-scale vaccine production can start as soon as indicated.

Is it possible that manufacturers produce both seasonal and pandemic vaccines at the same time?

There are several potential options which must be considered based on all available evidence.

What is the process for developing a pandemic vaccine? Has a vaccine strain been identified, and if so by whom?

A vaccine for the Influenza A(H1N1) virus will be produced using licensed influenza vaccine processes in which the vaccine viruses are grown either in eggs or cells. Candidate vaccine strains have been identified and prepared by the WHO Collaborating Center in Atlanta (The Centers for Disease Control and Prevention (CDC) in the United States of America)1. These strains have now been received by the other WHO Collaborating Centers which have also started preparation of vaccine candidate viruses. Once developed, these strains will be distributed to all interested manufacturers on request. Availability is anticipated by mid-May.

How quickly will Influenza A(H1N1) vaccines be available?

The first doses of Influenza A(H1N1) vaccine could be available in five to six months from identification of the pandemic strain. The regulatory approval will be conducted in parallel with the manufacturing process. Regulatory authorities have put into place expedited processes that do not compromise on the quality and safety of the vaccine. Delays in production could result from poor growth of the virus strain used to make the vaccine.

How would manufacturers be selected?

There are currently more than a dozen vaccine manufacturers with licenses to produce influenza vaccines. The vaccine strain will be available to each of them for vaccine production.

What is the global manufacturing capacity for a potential Influenza A(H1N1) pandemic vaccine?

While this cannot be assessed precisely since there is much uncertainty regarding the appropriate formulation for an effective and protective vaccine, a conservative estimate of global capacity is at least 1 to 2 billion doses per year.

How is production capacity for influenza vaccines distributed geographically?

More that 90% of the global capacity today is located in Europe and in North America. However, during the past five years, other regions have begun to acquire the technology to produce influenza vaccines. Six manufacturers in developing countries have done so with technical and financial support from WHO.

What will be the storage requirements for Influenza A(H1N1) vaccine?

The vaccine should be stored under refrigerated conditions at between 2°C and 8°C.

It has been impossible so far to develop vaccines for major killers such as HIV and malaria. How sure are we that there will not be scientific or other hurdles in developing an effective Influenza A(H1N1) vaccine?

Typically, development of influenza vaccines has not posed a problem. Influenza vaccines have been used in humans for many years and are known to be immunogenic and effective. Each year seasonal influenza vaccines with varying composition are produced for the northern and southern hemisphere influenza seasons. Vaccine manufacturers will employ a number of different technologies to develop their vaccines. They will take advantage, notably, of novel approaches that were developed over the past years for H5N1 avian influenza vaccines. One key unknown is yield of vaccine virus production, since some strains grow better than others and the behavior of the new Influenza A(H1N1) strain in manufacturers’ systems is not yet known. New recombinant technologies are under development, but have not yet been approved for use.

Will Influenza A(H1N1) vaccines be effective in all population groups?

There are not data on this but there also is no reason to expect that they would not, given current information.

Will the Influenza A(H1N1) vaccine be safe?

Licensed vaccines are held to a very high standard of safety. All possible precautions will be taken to ensure safety and new Influenza A(H1N1) vaccines.

How can a repeat of the 1976 swine flu vaccine complications (Guillain-Barré syndrome) experienced in the United States of America be avoided?

Guillain-Barré syndrome is an acute disorder of the nervous system. It is observed following a variety of infections, including influenza. Studies suggest that regular seasonal influenza vaccines could be associated with an increased risk of Guillain-Barré syndrome on the order of one to two cases per million vaccinated persons. During the 1976 influenza vaccination campaign, this risk increased to around 10 cases per million vaccinated persons which led to the withdrawal of the vaccine.

Pandemic vaccines will be manufactured according to established standards. However, they are new products so there is an inherent risk that they will cause slightly differently reactions in humans. Close monitoring and investigation of all serious adverse events following administration of vaccine is essential. The systems for monitoring safety are an integral part of the strategies for the implementation of the new pandemic influenza vaccines. Quality control for the production of influenza vaccines has improved substantially since the 1970s.

Will it be possible to deliver new Influenza A(H1N1) vaccine simultaneously with other vaccines?

Inactivated influenza vaccine can be given at the same time as other injectable vaccines, but the vaccines should be administered at different injection sites.

If the virus causes a mild pandemic in the warmer months and changes into something much more severe in, say, 6 months, will vaccines being developed now be effective?

It is too early to be able to predict changes in the Influenza A(H1N1) virus as it continues to circulate in humans or how similar a mutated virus might be to the current virus. Careful surveillance for changes in the Influenza A(H1N1) virus is ongoing. This close and constant monitoring will support a quick response should important changes in the virus be detected.

Will there be enough Influenza A(H1N1) vaccine for everyone?

The estimated time to make enough vaccine to vaccinate the world's population against pandemic influenza will not be known until vaccine manufacturers will have been able to determine how much active ingredient (antigen) is needed to make one dose of effective Influenza A(H1N1) vaccine.

In the past two years, influenza vaccine production capacity has increased sharply due to expansion of production facilities as well as advances in research, including the discovery and use of adjuvants. Adjuvants are substances added to a vaccine to make it more effective, thus conserving the active ingredient (antigen).

What is WHO's perspective on fairness and equity for vaccine availability?

The WHO Director-General has called for international solidarity in the response to the current situation. WHO regards the goal of ensuring fair and equitable access by all countries to response measures to be among the highest priorities. WHO is working very closely with partners including the vaccine manufacturing industry on this.

Who is likely to receive priority for vaccination with a future pandemic vaccine?

This decision is made by national authorities. As guidance, WHO will be tracking the evolution of the pandemic in real-time and making its findings public. As information becomes available, it may be possible to better define high-risk groups and to target vaccination for those groups, thus ensuring that limited supplies are used to greatest effect.

Will WHO be conducting mass Influenza A(H1N1) vaccination campaigns?

No. National authorities will implement vaccination campaigns according to their national pandemic preparedness plans. WHO is exploring whether the vaccine can be packaged, for example, in multi-dose vials, to facilitate the rapid and efficient vaccination of large numbers of people.

Developing countries are very experienced in administering population-wide vaccination campaigns during public health emergencies caused by infectious diseases, including diseases like epidemic meningitis and yellow fever, as well as for polio eradication and measles control programmes.

How feasible will it be to immunize large numbers of people in developing countries against a pandemic virus?

Developing countries have considerable strategic and practical experience in delivering vaccines in mass campaigns. The main issue is not feasibility, but how to ensure timely access to adequate quantities of vaccine.

What is the estimated global number of doses of seasonal vaccine used annually?

The current annual demand is for less than 500 million doses per year.

Will seasonal influenza vaccine continue to be available?

At this time there is no recommendation to stop production of seasonal influenza vaccine.

1National Institute for Biological Standards and Control (UK), Food and Drug Administration/Center for Biologics Evaluation and Research (USA), New York Medical College (USA), Victorian Infectious Diseases Research Laboratory (Australia)

May 6, 2009

How to investigate a suspected c/o Neuroblastoma

Neuroblastoma arises from adrenal medulla in majority of cases, however it may arise from any organ having neural crest cells.

Hematological & Biochemical tests:
Complete blood count
Biochemistry including serum LDH & serum ferritin

Diagnostic & Prognostic tests:
CT Scan of primary region
Urinary VMA (Vanillyl mandelic acid) and HMV (Homovanillic acid)
MIBG (131I-meta-iodobenzyl guanidine) scan
Tru-cut needle biopsy of the tumor
N-myc amplification
DNA index

Metastatic Work-up
Chest X-Ray
Bone marrow aspiration & Biopsy
MRI spine ( If neurological symptoms)
Bone scan

May 4, 2009

Inhaled Foreign Body

( CT chest with virtual bronchoscopy showing cut off in
left main bronchus with left lung collapse & shift of mediastinum)

Inhalation of foreign body (FB) is the commonest cause of acute respiratory distress in children. 'Peanuts' is the commonest FB to be inhaled. It is important that these type of objects are kept away from children< 5 yrs. The other FBs are metal pins, vegetative FB, plastic objects, seeds, pen tops etc.

Presentation: The child presents with acute onset of respiratory distress started with coughing, choking & may lead to cynosis & respiratory arrest. There may be h/o inhalation of FB if parents or relatives are around the child. This is an emergency situation.

Management: The child needs to be resuscitated first. If the child cant breath or make a sound, invert the child & give 3/4 forceful back slaps. The child may cough out FB. But if the child can breath or make a sound then this procedure should not be done as it may dislodge FB & increase the obstruction. The child needs to be shifted to the hospital as early as possible. X-ray of chest will show FB ( if it is radio opaque), portion of lung or whole lung may look overinflated, there may be collapse of lung & mediastinal shift. CT chest with virtual bronchoscopy will exactly locate radiolucent FB & help in uncertain cases. Bronchosopy & removal of FB is the definitive management.

May 3, 2009

Pneumothorax in children

Pneumothorax in children may be because of one of the following causes

1. Hyaline membrane disease
2. Positive pressure ventilation
3. Obstructive respiratory disease
4. Trauma to the chest wall or oesophagus
5. Staphylococcal pneumonia
6. Cystic fibrosis
7. Diaphragmatic hernia
8. Tracheotomy
9. Spontaneous

A small pneumothorax may be without any symptoms & may be spontaneously absorbed. Tension pneumothorax with respiratory distress, lung collapse & mediastinal shift is a surgical emergency and needs an immediate intervention as it is life threatening condition. Emergency needle aspiration (through the second intercostal space) or intercostal chest drainage is the life saving procedure which can immediately bring back the patient to normal.

May 2, 2009

Causes of scrotal swelling in children

Causes of scrotal swelling in children:

1. Inguinoscrotal hernia
2. Congenital hydrocele
3. Acute epididymo-orchitis
4. Testicular torsion
5. Obsructed hernia
6. Testicular tumor
7. Lymphoma of testis
8. Haematocele
10. Cellulitis of scrotum
11. Scrotal abscess

Out of these, Testicular torsion & obstructed inguinoscrotal hernia are surgical emergencies. In case of congenital hydrocele, there is possibility of spontaneous resolution till 1 year of age. Inguinoscrotal hernia & testicular tumor are surgical semiemergencies while lymphoma is an oncological emergency. In case of acute epididymo-orchitis, one should rule out testicular torsion & then start on antibiotics. Similarly cellulitis, trauma & haematocele can be treated conservatively. The child who progressed to scrotal abscess (rare) will need incision & drainage (again a surgical emergency).