The dengue epidemic is a well-known problem in the urban cities of Sri Lanka today. We can officially say that Sri Lanka is a malaria-free country today, but we have yet to curtail the spread and morbidity caused by the dengue virus. Mosquitos are enemy number one in all households and even though the SL government has done so much to try and limit the breeding of these mosquitos, the rainy monsoon seasons kind of screws this up.

As a medical/paediatric intern always remember that the rainy season = an increased number of dengue patients, so you should always suspect it in any child with fever and low platelets. I have had children come in shock with weak pulses and dropping blood pressures so never ever underestimate the severity of patients coming in with fever. It may be just a viral fever, but you need to rule out dengue fever first. I have had a patient with Down’s syndrome who only complained of a stomach ache which ended up being dengue hemorrhagic fever.

During my paediatric appointment, dengue was a real pain in the butt. It seemed that every time we discharged one recovered dengue patient, 2 more got admitted and that meant the possibility of hourly monitoring if the patient leaks (not fun if it’s a non-casualty night).

However, the one thing I learnt was the importance of monitoring and how to be an expert at fluid management. My consultant was relentless about monitoring, be it 4-6 hourly with simple dengue fever or hourly for those in the critical phase of dengue hemorrhagic fever (DHF). Even though it was super taxing (especially when it’s not your ward on casualty and you’re forced to do a night shift that requires hourly waking), I will forever be grateful to my consultant because it definitely improved my patient care and made me more vigilant as a practitioner.

The Sri Lankan Ministry of health has released guidelines for the management of dengue fever and dengue hemorrhagic fever in both adults and children which you should take a look at prior to going on to the ward. It’s not just for medical/paediatric interns, remember that acute abdomens in surgery can actually be dengue leakers (low platelets and white cell count on the full blood count is strongly suspicious!). The article below is based on the guideline for children with my experience added to it.

Signs and symptoms

Signs & symptoms of dengue. Those in red are warning signs of dengue hemorrhagic fever (rash meaning petechial rash and not the standard recover rash). * N + V – nausea and vomiting * RHC – Right hypochondriac pain

Dengue fever is fever for about 2 to 7 days associated with headache, retro-orbital pain, myalgia, arthralgia and rash.

There may be haemorrhagic manifestations such as mucosal bleeding, petechial rash and even GI bleeding. It is important that you document the time and date that the fever started as it is important to calculate the day into the illness. DHF in my experience has always occurred around day 3 and comes on when the fever just starts settling lasting for about 48 hours.

The patients experience abdominal pain (tender hepatomegaly) and plasma leakage so there may be reduced air entry (pleural effusions).

Investigations

The white cell count and platelet count will drop and this is seen in both DF and DHF. The platelets drop more severely and the haematocrit (PCV) increases as blood becomes more viscose in DHF.

Investigation charts – Easy to show platelets and white blood cell trends

Tourniquet test – This is used as a quick way to diagnose dengue, but it’s not specific. Apply a blood pressure cuff on the child and inflate it between the systolic and diastolic pressure. Wait 5 minutes and then after decuffing the BP cuff, wait one minutes and count the number of red spots that appear in the cubital fossa within a square inch. More than 10 petechiae is positive. The reason petechiae develop is due to the fragility of the blood capillaries.

If within the 1st 3 days of fever, the patient will be positive for the NS1 antigen (shed from the dengue virus. If after the 5th day of fever, the patient will be positive for IgM (acute infection) and/or IgG (second infection). In DHF, patients will be both IgM and IgG positive as DHF normally occurs when infected with the dengue virus for the 2nd time. For baseline purposes also do a CRP and liver function tests. A capillary blood PCV can be used to measure the haematocrit, but it is a real pain in the butt. You have to prick the child (like for a CBS) and fill up the capillary tube without any air bubbles. Once done stick it into clay to prevent more air bubbles. You then insert it in a centrifuge for 5 minutes and after that you out it in a reader and measure the top of the red component.

Admission criteria

• Patients with platelet counts <100,000 or if <150,000 but rapidly dropping and if more than 3 days with the following warning signs.

Copyrights – Sri Lanka MOH National Guidelines on management of DF & DHF in children and adolescents

DF Management

Dengue fever alone does not warrant admission, but the child should be reviewed daily with full blood counts just to ensure that the platelet count doesn’t drop below 150,000.

At home the parent should be advised to ensure that the child has bed rest and takes in adequate oral fluids such as ORS (jeevani), King coconut water, juices or soup, but no coloured drinks as if the child has haematuria you won’t be able to differentiate it.

Dengue 4-6 hourly monitoring chart

Panadol can be given 6 hourly with any antiemetics for nausea and vomiting (domperidone). Do not give any NSAIDS such as ibuprofen or any steroids as this can increase the risk of bleeding (already a bad idea in patients who are at an increased risk of bleeding, i.e. DHF).

When following up the patient, counts should be done daily or BD depending on your clinical judgement. If the child has any worsening of symptoms, refuses to eat/drink, has reduced urine output, bleeding tendencies, severe abdominal pain, signs of shock and behavioural changes, you need to admit the child ASAP.

If the child is admitted, then with simple dengue fever you should monitor the child every 4-6 hours (pulse rate, blood pressure, respiratory rate and CRFT). If any of these vitals are abnormal, the child may be going into DHF and hence require more intense monitoring. My consultant would ask us to do daily morning FBC and if unsure then check a PCV in the evening as well.

DHF Management

The only difference between DHF and DF is the critical/leaking phase that is seen in DHF. Almost every case of DHF that came into the ward lasted 48 hours and we were always able to calculate the peak time of leakage and the time the period should end based on the number of days of fever. The critical phase almost always starts as soon as the fever is settling, just when you think the patient is recovering.

The platelet count drops below 100,000 (however this can also happen in simple dengue fever) and the haematocrit increases (>20%). A significant tell-tell sign is also abdominal pain and reduced air entry. FBC would be done twice a day and an additional haematocrit may be checked 6 hourly in-between.

A decubitus x-ray (the patient lies on their side to show even small amounts of fluid collections) or USS can show pleural effusions. USS can also show an oedematous gall bladder (another sure sign of DHF) and even ascites.

Children can quickly go into shock when in the critical phase and hence you should be on it with the fluid management because this is when patients can die. In order to accurately guide fluid management, the urine output needs to be monitored – so always insert a urinary catheter if you suspect the child is going to leak. In addition to the vitals monitored in simple dengue fever, the pulse pressure, urine output, warmth/coldness of peripheries and any bleeding evidence should be monitored hourly. If the patient is in shock then the patient may be needed to be monitored every 15 minutes.

Dengue critical phase hourly monitoring chart – below it shows the trend of as the plasma leakage peaks, the fluid requirement increases and this should decrease as the plasma leakage resolves. The dengue monitoring chart should therefore look like a pyramid.

Fluid management

With DHF it’s a careful balance of administering fluids to maintain perfusion, but not too much so as to prevent fluid overload. For this you need to calculate the maintenance + 5% fluid quota of the patient (depends on body weight) and this is administered over the 48 hour critical phase. This quota is an estimate of the appropriate amount of fluid required to prevent overloading and we largely stuck to this quota when managing dengue patients. The maximum weight that the quota is calculated for is 50kg!

The fluid can be given either with IV Saline or oral fluids and the guardian needs to be strictly told that there is only a certain limit to be given every hour and that they should not go over/under this limit. If the child is less than 6 months old, N/2 saline is given. In my experience, children are not willing to be woken up/hourly at night whilst sleeping to drink fluids so overnight I tended to put all the fluids IV and slowly change it back to oral in the morning. The monitoring chart fluid part should be dome shaped – i.e. the fluids required should increase and peak at the 24 hr mark of the critical phase. The fluid required should thereafter decrease and be minimum towards the end of the 48 hour period.

We would normally start fluids at 1ml/kg/hr and slowly increase/decrease it for the next hour depending on the vitals and urine output of the previous hour. The aim is to maintain the urine output at >0.5ml/kg/hr. If the UO is more than 1ml/kg/hr then you can decrease the fluid a bit, but don’t get too ahead of yourself. Dengue is a mind-boggling disease!

By the end of my paediatric appointment, I became a pro at balancing fluids and my consultant was happy that he could peacefully sleep at night. By the end of the 48 hour critical phase, the monitoring sheet should look like a pyramid where the fluids given increase as the leaking increases and then decreases towards the end of the leaking phase.

Dengue Shock Syndrome

The symptoms experienced are as for any type of shock – i.e. sweating, light-headedness, confusion and abdominal pain. Signs include tachycardia (the 1st sign but also may be appropriate due to the fever), hypotension, cold peripheries, prolonged CRFT and reduced urine output. Strongly suspect shock if the pulse pressure is <20mmHg.

This would require normal saline boluses in order to maintain the pressures (taken into the M+5% quota) – follow the algorithm below for management of patients in shock.

Copyrights – Sri Lanka MOH National Guidelines on management of DF & DHF in children and adolescents

When the patient is not responsive to the normal saline boluses, you may have to give colloid boluses (dextran 40) to a maximum of 3 boluses only within 24 hours. The colloids remain in the blood vessels for a longer period than normal saline. As the dextran molecules can interact with the blood, you need to send a blood sample for Group + DAT before administering colloids. I have only given this to one patient who came in with shock.

Dengue shock monitoring chart

Remember to check for acidosis, concealed bleeding (if HCT dropping, but the patient is in shock), calcium and sugar as these can make resuscitation refractory and require specific treatment. There is no place for fresh frozen plasma transfusion or IVIg or steroids in dengue! Platelet transfusions are not given.

In my experience you can say the critical phase is over mainly due to a sudden increase in the urine output, but also the vital signs come back to normal and the patient may develop the recovery (itchy) rash. Not all patients develop it though!

Signs of fluid overload include a puffy face/eyelids, abdomen distension and respiratory distress – with senior input you can give the patient a small dose of frusemide just to assist with getting rid of the excess fluid, but you need to carefully monitor the patient.

Recovery phase

It’s pretty easy to say when a child is in the recover phase – and I don’t mean just because of the itchy recovery rash (isles of white in a sea of red). The child’s appetite improves, the WBC count increases, followed by an increase in the platelet count, lots of urine passed and the vital signs stabilise.

After discharge from the hospital, the parents are advised to make the children rest for about 2 weeks. Dengue fever causes a lot of myalgia which persists even after recovery. We waited till the platelet count was >80,000 before discharge in addition to the general well being. This may vary between units and is not a fixed figure.

Additional notes

• Dengue is a notifiable disease so do not forget to send out the notification forms (see below).

  

  Dengue Notification form

• In addition to paracetamol, we also gave the patients oral/IV cefuroxime if in the leaking phase or if there is a fever spike after the fever has settled for >24 hours in order to prevent secondary bacterial infections.
• For the abdominal pain, the children were given IV ranitidine or O. omeprazole if tolerating orally. For nausea and vomiting, domperidone can be given.
• For the itching in the recovery phase, you can give the patient an antihistamine such as chlorpheniramine/loratadine and lactocalamine lotion.
• Patients should not die of dengue if there has been proper management and so if a patient does die of dengue there is an inquiry held and everybody including the doctor who first come in contact with the patient is required to give a statement.