Ultrasound Blocks for the Anterior Abdominal Wall

68 | Ultrasound Blocks for the Anterior Abdominal Wall
patient satisfaction compared with unmonitored anesthesia
(Song 2000). Finally, the traditional use of monitored anesthesia
care with propofol and opioids or spinal and general anesthesia
may have negatively influenced its diffusion (Callesen 2001,
Toivonen 2004).
A documented problem of the IFB/LIA is that it may require
supplementary local anesthetic and sedation with moderate to
high doses of benzodiazepines, requiring the attendance of an
anesthesiologist (Ding 1995). IFB/LIA and IIB have not been
evaluated in overweight and obese patients, where larger local
anesthetic volumes are needed, although they are reported to be
safe especially if the mixture is diluted. Moreover, a higher
intensity of intra- and postoperative pain and a higher incidence
of complications have been reported in obese patients (Nielsen
2005, Reid 2009).
Some authors state that IFB/LIA of triple block performed
before surgery is more time consuming, requires larger volume
of the local anesthetic solution, does not always result in
satisfactory anesthesia because of the blind nature of the
procedure, and accidental needle puncture of the inguinal
nerves may result in prolonged postoperative pain or
neuropathic pain within their innervation field (Amid 1994).
However, actual anesthesia block techniques offer selective
nerve block achievement with low volumes of local anesthetic,
direct visualization if ultrasounds are used, optimal pain control,
fast recovery and discharge of patients and low analgesic
requirements. A randomized study in children undergoing groin
surgery performed to compare postoperative analgesia with IIB
performed either percutaneously by the anesthesiologist before
surgery or by the surgeon under intraoperative direct vision,
revealed no statistical difference in pain scores between the
groups (Trotter 1995).