Effectiveness of Nebulized Dexmedetomidine for Treatment of Obstetric Post-Dural Puncture Headache
Condition: Post-Dural Puncture Headache
MeSH terms: Post-Dural Puncture Headache; Headache
Study type: Interventional

Summary: 
      Postdural puncture headache (PDPH) is a common complication, following neuraxial techniques.
      The obstetric population is particularly prone to PDPH. Therefore, treatment of PDPH is a key
      issue in obstetric anesthesia.

      Dexmedetomidine is a highly selective, centrally acting α2-adrenergic agonist with analgesic
      and anxiolytic effects. Moreover, it decreases cerebral blood flow (CBF) in humans and
      animals secondary to cerebrovascular vasoconstriction. It has been used via the intranasal
      and inhalational routes for many purposes including premedication, sedation and postoperative
      analgesia. Because of its desirable properties, we hypothesized that dexmedetomidine
      nebulization could be effective in the treatment of patients suffering from PDPH after
      caesarean section.
    

Detailed description: 
      Post-Dural puncture headache (PDPH) is a well-known common devastating complication of
      subarachnoid block. Despite the decreasing incidences of PDPH over the last years due to the
      advancement in the design and smaller size of spinal needles, PDPH remains to be a common
      complication in post-partum patients. Female gender, typically pregnant females, young age,
      low body mass index, dilutional anemia, and the preference of neuraxial anesthesia for
      Cesarean Section renders obstetric patients to be more exposed to PDPH. Consequently,
      treating this complication is of paramount importance in obstetric anesthesia.

      The cause of PDPH is not entirely known but there is a considerable evidence support the
      explanation of the low cerebrospinal fluid (CSF) pressure resulting from continuous CSF leak
      through the tear in meninges that exceeds the CSF production rate as a main cause of PDPH. As
      little as 10% CSF volume loss could induce PDPH from the traction on the pain sensitive
      intracranial structures in the upright position combined with reflex vasodilatation. Several
      treatment options have been proposed which are usually consisting of bed rest in supine
      position, fluid therapy, analgesics, sumatriptan and caffeine. Epidural blood patch remained
      the gold standard therapy but it is an invasive technique.

      Dexmedetomidine (Dex) is a highly selective centrally acting α2-adrenoreceptor agonist that
      produces cooperative sedation, anxiolysis, and analgesia with minimal respiratory depression.
      Moreover it was found to attenuate the stress and inflammatory response to anesthetic and
      surgical procedures. Stimulation of α2-receptors in substantia gelatinosa of the dorsal horn
      leads to suppression of nociceptive neurons firing and inhibition of substance-P release
      also, its stimulation in the locus coeruleus area which is known to be a significant
      nociceptive transmission modulator terminates pain signals transmission resulting in
      analgesia. Additionally, an existing literature supports that Dex decreases cerebral blood
      flow (CBF) in humans and animals secondary to cerebrovascular vasoconstriction. Thus, the use
      of Dex might be a useful adjunct in certain situations that require cerebral vasoconstriction
      together with analgesia such as PDPH. The present study will be undertaken to test this
      hypothesis.
    

Intervention name(s): Dexmedetomidine Nebulization; 0.9% Saline Nebulization
Intervention type(s): Drug; Other
Intervention description(s): ultrasonic nebulization of 1 µg/kg dexmedetomidine for PDPH treatment; nebulization of 4mL 0.9% saline
Intervention MeSH terms: Dexmedetomidine
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary purpose: Treatment