The global rate of cesarean section is increasing despite the World Health organization's recommendation rate of cesarean section(1, 2). According to a WHO report, more than 18 million cesarean sections are performed every year(1).
Approximately, 80–90% of cesarean sections are performed with spinal anesthesia which is relatively safe as compared to general anesthesia which is accompanied by a difficult airway and risk of aspiration(3–6). However, post-dural puncture Headache is one of the commonest complications of the neuraxial block associated with penetration of dura matter and continuous flow of cerebrospinal fluid (7–14).
The International Headache Society (IHS) defines PDPH as ‘‘Headache occurring within 5 days of a lumbar puncture caused by cerebrospinal fluid (CSF) leakage through the dural puncture. It worsens 15 minutes of standing or sitting and improves after 15 minutes of lying down. It is usually accompanied by neck stiffness and/or subjective hearing symptoms, nausea and vomiting, photophobia. It recovers spontaneously within one week, or after sealing of the leak with an autologous epidural lumbar patch within 48 hrs. There is no fever, leukocytosis, and neurologic deficit(15).”
Ninety percent of postural puncture headaches will occur within three days of dural puncture whereas sixty-six percent of the headache may happen within 48hrs of the procedure and rarely, the headache will develop between five to fourteen days after the procedure. However, some reports showed cases of post-dural puncture within 20 minutes of dural puncture and 19 months after dural puncture which were successfully managed with Epidural Blood Patch(9).
The exact mechanism of PDPH is still unknown but symptoms are generally attributed to excessive loss of CSF from the dural puncture site which results in reduced CSF pressure(12).
The lowered CSF pressure reduces the cushioning effect provided by the CSF to the brain and results in traction on intracranial pain-sensitive structures such as meningeal vessels, upper cervical and cranial nerves. The release of adenosine consequent to the sudden drop in CSF volume is also thought to cause vasodilatation of intracranial vessels and post-dural puncture headache(4).
Different factors of post-dural puncture have been mentioned in the literature among which needle size and volume of cerebrospinal fluid (CSF) lost were the independent predictors of severity of PDPH after spinal anesthesia, diagnostic lumbar puncture, or accidental dural puncture during epidural procedures(4, 7–12, 14, 16–24). The incidence of post-dural puncture headache is more likely in adults whose ages are between 30–50 years as compared to older age greater than 50 and children younger than 13 years old.
The lower weight is found to be strongly associated with the higher incidence of PDPH and cumulating evidence showed an inverse relationship between BMI and PDPH suggesting that heavier patients, in general, have higher intra-abdominal pressure, which in turn raises intra-epidural pressure and prevents cerebrospinal fluid from leaking when ADP occurs(4, 25).
Different studies showed that smokers had a considerably reduced rate of PDPH in comparison with non-smokers suggesting an inhibitory effect of tobacco smoking on PDPH that may be associated with the stimulation role of nicotine in dopamine neurotransmission(4, 15, 26).
Though pregnancy is a risk factor for PDPH due to the young age, female, sometimes sitting position, pregnancy-associated depression and anxiety, and the special popularity of regional anesthesia in this population, a meta-analysis showed that pregnancy itself does not increase the risk of PDPH. However, PDPH is associated with fatigue, sleep deprivation, and night work that lead to a higher incidence of ADP in clinical personnel when performing epidural analgesia(4).
Evidence showed that the prevalence of post-dural puncture headache in Ethiopia after spinal anesthesia was very high ranges from 38.7–42.6%(18, 23). While other studies conducted in Sub-Saharan Africa showed that the prevalence of PDPH varied from 15 to 27.5% which was strongly correlated with needle type and size (17, 27–31).
The incidence of PDPH with a randomized clinical trial conducted in Egypt on ninety obstetric patients in three groups receiving single-shot spinal anesthesia, continuous spinal anesthesia with epidural Cather and single-shot spinal with prophylactic 5ml normal saline and 10 ml normal saline before removal of the catheter after twenty-four hours was 10%, 16.6%, and 10% respectively(32).
A systemic review conducted in the United Kingdom revealed that the incidence of post-dural puncture headache after spinal anesthesia varied from 1.5%-11%. Whereas, 50% of patients developed post-dural puncture headache after accidental dural penetration with 16–18 gauges epidural needle(21).
The Cochrane database for systemic reviews identified incidence of post-dural puncture headache as 10% after spinal anesthesia, 36% after diagnostic lumbar puncture, and 81% after accidental dural puncture(9).
PDPH is getting worse with movement which leads to different undesirable consequences including delayed mother-to-child bonding, delayed breastfeeding, prolonged hospitalization, deep venous thrombosis, and thromboembolism incidents, delayed oral intake, and increase health care system cost(33).
An epidural blood patch is the known gold standard management PDPH for years when conservative management failed to be effective despite inconclusive evidence as depicted with recent systemic reviews and meta-analysis(34, 35).
Different systemic reviews and meta-analyses and randomized controlled trials revealed that conservative management for PDPH including bed rest, oral fluid intake, simple oral analgesics, and caffeine failed to show significant benefit and was associated with undesirable side effects(11, 21, 34, 36–38).
A systemic review and meta-analysis by Apfel et al identified inconclusive evidence from one study with subgroup analysis. However, the quality of the included study for subgroup analysis had a small sample size, no randomization, no allocation concealment, no blinding, and proper controlling of confounders were not considered as a result both the original RCT and the systemic review recommends further RCT with high power and proper randomization(34).
A randomized clinical trial conducted to investigate the preventive benefits of intrathecal normal saline revealed a statistically significant difference in the severity and prevalence of PDPH between the groups. However, this RCT failed to assess adverse effects associated with administration of normal saline including inadequate sensory and motor block, and high spinal block and they recommend further RCT with large sample size and possible adverse effects(39).
Despite recent advancements in neuraxial techniques and different clinical and epidemiological researches on the treatment and prevention of post-dural puncture headache, the incidence of PDPH is very high and further randomized trials are in demand on its prevention approaches. Therefore, this study aimed to investigate the efficacy and safety of prophylactic intrathecal normal saline for the prevention of PDPH after spinal anesthesia during cesarean delivery