Peripheral Nerve Block

Alleviating pain in elective or emergency takes forefront in the present scenario because the adverse consequences of the same are widely known. Therefore adequate pain relief has become an integral component of the management of the patient by the anaesthetist, intensivist and pain physicians. Peripheral nerve blocks (PNB) are becoming immensely popular by virtue of easy identification by the use of ultrasound as well as minimal side effects related to the procedure. In addition, that US guided blocks reduce the mean effective anaesthetic concentration and volume (MEAC and MEAV) of the local anaesthetics is a well known fact. We hereby present two cases where a newer interfascial nerve block i.e.serratus anterior muscle (SAM) block was administered

An intercostal drain was inserted for hemothorax and exploratory laparotomy with splenectomy was performed as an emergency. The patient was transferred to intensive care unit in view of haemodynamic instability and blood loss. Mechanical ventilation was initiated with synchronised intermittent mode of mandatory ventilation (SIMV).Sedation and analgesia were provided with infusion of morphine (3 mg/hr) and midazolam (2mg/hr) as per the institutional protocol. Subsequently SAM block was administered in view of fractured ribs on left side using a using high-frequency (5–10 MHz) ultrasound probe and 20 ml of 0.5 % Ropivacaine was deposited between the neurofascial plane between Latissimus dorsi (LDm) and serratus anterior muscle (SAM) after negative aspiration at the level of fifth rib using a 25 G spinal needle. Subsequent to block, the hemodynamics of the patient improved and the need for sedation and analgesia reduced and was later on stopped as patient was completely pain free. Patient was weaned off and trachea was extubated next day. 24 hours post application of the block, the patient again started complaining of pain. Therefore SAM block was repeated in the same volume and concentration following which the static and dynamic VAS reduced to zero and patient was transferred to the ward next

In both the cases the SAM block was administered for entirely different indications. But the noteworthy observation in both the cases was the striking reduction in pain and total requirement of analgesia over 24 hours. There are sporadic case reports where an epidural catheter has been left in situ for continuous analgesia.3 In the present cases, in patient following MRM, patient was connected to IV PCA but patient did not take any additional top up. In patient in intensive care unit, the block had to be repeated after 24 hours in view of complaints of pain. This particular patient could probably have been benefitted with the placement of an epidural catheter. However 48 hours down the line the dynamic and static VAS were reduced and patient could be managed with NSAIDS.

Conclusion

SAM block can be utilized as a good alternative to provide analgesia to the lateral part of thorax. It can be used in perioperative, intensive care, emergency settings with good efficacy and helps in reducing pain as well morbidity of the patients in term of early weaning and early