Monitoring
Patients managed at home or admitted to the hospital without warning signs should be monitored daily until they are out of the critical phase. These patients should have their vital signs checked every 2-3 hours, including temperature pattern. They should also be monitored for their volume of fluid intake and losses, urine output every 4-6 hours, warning signs, signs of plasma leakage and bleeding, hematocrit every 4-8 hours, and WBC and platelet counts.
Patients with shock should be monitored frequently until the critical period is over. Vital signs and peripheral perfusion should be checked every 15-30 minutes until the patient is out of shock, then every 1-2 hours. An indwelling arterial line may be placed for continuous and reproducible blood pressure measurements and regular blood sampling since in shock states, estimation of blood pressure using a cuff is usually inaccurate.
Patients with shock should also have their urine output checked hourly until the patient is stable and then 1-2 hourly. Hematocrit should be monitored before and after fluid boluses until the patient is out of shock and then 4-6 hourly. Changes in hematocrit must be interpreted together with the hemodynamic status, clinical response to fluid therapy, blood transfusion, and acid-base balance of the patient. Arterial and venous blood gases, lactate, total carbon dioxide or bicarbonate should be checked every 30 minutes to 1 hour until stable, then as needed. Blood glucose, renal profile, liver profile, and coagulation profile should be monitored if feasible before fluid resuscitation, then as required.
In general, patients given higher fluid infusion
rate should be monitored more frequently to avoid fluid overload while ensuring
sufficient volume replacement.
The signs of recovery among dengue patients include
stable vital signs, normal temperature, absence of bleeding, absence of
vomiting, return of appetite, good urine output (0.5 mL/kg/hour), stable
hematocrit, and convalescent confluent petechial rash.
Patients may be discharged from the hospital if there are visible
clinical improvement, absence of fever for 48 hours, return of appetite, good
urine output, stable hematocrit without intravenous fluids, rising trend of
platelet count, and no respiratory distress.
The following are the risk factors of patients with increased mortality:
- History of prior dengue infection
- Hypotension
- Narrow pulse pressure
- Significant bleeding
- Severe plasma leakage
- Dengue hemorrhagic fever grades III and IV
- Prolonged shock
- Respiratory, liver, or renal failure
Complications
Hemorrhagic Complications
The risk of bleeding is increased in patients with one of the
following: Hypotension, narrow pulse pressure, hepatomegaly, platelet count of
<50,000/mm3, WBC count of <5000/mm3, or ALT >3x
the normal value.
Patient with bleeding that remains stable with intravenous fluid
replacement is considered to have minor bleeding. Patients who have prolonged
shock, hypotensive shock, renal or liver failure and/or severe metabolic
acidosis, pre-existing peptic ulcer disease, trauma, or are given NSAIDs or on
anticoagulant therapy are at high risk for major bleeding.
Patients with severe bleeding are those with unstable hemodynamic
status with severe overt bleeding or low hematocrit level even after fluid
resuscitation, refractory shock that did not improve with consecutive fluid
replacement of 40-60 mL/kg, hypotensive shock with low or normal baseline
hematocrit level, or those with worsening metabolic acidosis particularly those
with severe abdominal tenderness and distension. Major bleeding usually comes
from gastrointestinal tract. Those with hemolytic disorder are at risk of acute
hemolysis with hemoglobinuria and need blood transfusion.
Fluid Overload
Fluid overload is a common cause of acute respiratory distress and
failure in severe dengue. It is usually secondary to excessive or rapid IV fluids, wrong use of crystalloid solutions, incorrect use of large volumes of intravenous
fluids in patients with unrecognized severe bleeding, inappropriate transfusion
of fresh-frozen plasma or platelet concentrates and cryoprecipitates,
continuation of intravenous fluids even after plasma leakage has resolved, or
presence of comorbid conditions like congenital or ischemic heart disease,
chronic lung, and renal disease.
Patients usually present with fast or difficulty in breathing,
chest wall in-drawing, wheezing, large pleural effusions, tense ascites,
increased jugular venous pressure, pulmonary edema, or irreversible shock. Chest
X-ray, ECG, arterial blood gases, echocardiogram, and
cardiac enzymes may be done. Patients should be given oxygen and intravenous
fluids should either be discontinued or decreased depending on the phase of the
disease and the patient’s hemodynamic status.
Other Complications
Other complications of dengue include hyper- or
hypoglycemia, electrolyte and acid-base imbalances, and co-infections and
nosocomial infections.