Ultrasound guided subcostal TAP block for epigastric hernia repair: a case series
Introduction- Subcostal TAP block anaesthetises myocutaneous nerves supplying the anterior abdominal wall from T6 to T101. We present a case series of epigastric hernia repair under subcostal TAP block as a sole anaesthetic technique.
Methods- After IRB approval, we enrolled 10 ASA Grade I and II patients posted for elective epigastric hernia repair. The procedure was explained to patients and informed consent was obtained. Patients were premedicated with midazolam 1.5mg IV. Under aseptic precautions bilateral USG guided subcostal TAP block was given using 22G 100 mm needle and 15 ml 0.5% ropivacaine with 1µg/kg fentanyl was injected bilaterally. After 15 min, on confirmation of sensory block, surgery was started. Any discomfort while pulling of hernia content or pain during procedure was managed with intravenous bolus of 1µg/kg fentanyl at 5 minutes interval with a maximum of 3 boluses. Patient was given general anaesthesia if the pain persisted even after 3 boluses of fentanyl, and the case was considered as a block failure. Postoperative pain severity was measured using a Visual analogue scale (VAS), and paracetamol 15mg/kg IV was given whenever VAS score was more than 4. Duration of analgesia, PONV and surgeon’s satisfaction score were also recorded. Data were collected by an independent observer.
Results- Eight patients gave consent to participate in the study. Hemodynamic parameters remained stable throughout intraoperative period in all the patients. Block was successful in all the patients and none of the patients were given general anesthesia. Two patients required intraoperative fentanyl bolus. Surgical conditions were reported as excellent in two patients and satisfactory in rest of the patients. Postoperative median VAS score was below three in 75% of the patients and two patients required paracetamol supplementation in postoperative period at 6 hour and 12 hour respectively. Median duration of analgesia was 24 hours (range: 6-24 hours), after which patients were discharged home. None of the patient had PONV or any other complications.
DISCUSSION- Subcostal TAP block is generally a part of multimodal analgesia following various upper abdominal hepatobiliary and gastrointestinal surgeries2-4, and reports on its role as surgical anaesthesia are limited. In our case series, it was successfully used as a sole anaesthetic technique in a series of eight patients. The block resulted in good postoperative analgesia for 24 hours and side-effects of opioids were avoided. Though all the study patients were ASA status I or II, subcostal TAP block may be potentially advantageous in ASA 3 and 4 patients as reported by authors in case of high risk cardiac patient.5
Limitations: Inability to block visceral component of pain is a disadvantage of TAP block. Obese patients were not included as block was difficult to perform. Large hernia with intestinal content may require supplemental analgesic drugs. Placement of catheter and continuous infusion can prolong the analgesia. Since this is a small observational study, randomized comparative prospective trials may be conducted to prove its efficacy over LA infiltration or monitored anaesthesia care in such cases.
Conclusion: Subcostal TAP block can be an alternative to MAC or GA for epigastric hernia repair in view of good quality of analgesia and less requirement of narcotics.