METHODS
This single center, prospective randomized observer blind study was
conducted in Health Sciences University Ankara City Hospital between
01/03/20 - 01/08/20, after receiving approval from Institutional Ethics
Committee (dated 13/02/20 and numbered E1-20-315) and registered on
ClinicalTrials.gov (ID: NCT04474873).
Sixty volunteer patients of both gender, aged 18-65, in the American
Society of Anesthesiologists Physical Status Classification (ASA) I-II
risk group who were scheluded to undergo PCNL were included in the
study. Three patients were excluded because of returning to open
surgery.
Exclusion criteria were ASA> II, patients with
comorbidities (cardiac, respiratory, hepatic, renal, neurologic,
psychiatric), pregnancy, morbid obesity, and also patient’s refusal to
participate in the study .
After creating 2 sets of 30 unique numbers from 1 to 60 for each group
using an internet-based program (www.randomize.org), the patients were
randomly allocated to control or ESPB group.
General anesthesia protocol was same between groups. 1.5-2 mg/kg
propofol, 0.5 to 1mcg/kg fentanyl and 0.6 mg/kg rocuronium were used
for induction and patients were intubated. General anesthesia were
maintained with the end-tidal sevoflurane concentration of 2% and
0,2-0.5 µg/kg/min remifentanil. Mechanical ventilation was performed
with the tidal volume of 6-8 ml/kg, respiratory rate of 12 breaths/min,
exhalation : inhalation = 1:2, and oxygen flow rate of 2.0 L/min during
operation. Sugammadex 2mg/kg were used for reversal.
In control group there is no intervention and pain management was
continued with intravenous rescue tramadol analgesia. In ESPB group the
block was performed with USG (Toshiba Diagnostic Ultrasound System,
GM-55402A00E, Japan, 8 mHz linear probe) before general anesthesia
induction. The patients were placed in the prone position and after skin
cleaning, ESPB was performed at the T11 level using the in-plane
technique. Before the procedure, 3 mL of 2% lidocaine was applied
locally to the patient’s skin. A 21G 100 mm insulated needle 15 (Vygon
echoplex, France) was inserted in the cranial-caudal direction until it
made contact with the T11 transverse protrusion in the in-plane
approach. Hydrodissection was applied with 15 ml saline solution. Then a
total of 15mL 0.5% bupivacaine was injected as a local anesthetic. The
location of the needle tip was confirmed by removing the erector spina
muscle from the bone shadow of the transverse process and observing the
distribution of local anesthetic in both cranial and caudal directions
(Figure 1).
Analgesic effect was evaluated by pinprick test including T10, T11, T12
nerve distribution segments (Figure 2). A successful ESPB must contain
all three segments, otherwise the block was considered unsuccessful and
planned to remove from the study.
In both groups, how to use the peak flowmeter (ExpiRite Peak Flow
Meter®) was explained to the patients during the preoperative interview
and at the postoperative 0th, 6th and 24th hours, the patients were
asked to breathe as deeply as they could, and then to breathe into the
flowmeter as effectively and rapidly as they could. It was explained to
the patients that they should grasp the peak flowmeter with their lips
in a sitting position in the bed and blow it in one breath, and that
they should not put their tongue on the end of the device during
blowing15. Measurements were made three times for each
visit and the highest value was recorded.
In both groups, 1gr of intravenous paracetamol was administered
intraoperatively and at the 8th and 16th hour postoperatively..
Postoperative pain and agitation was evaluated using VAS, Dynamic VAS at
0, 6 and 24 hours and the Riker sedation-agitation scale at 0th Hours
after surgery. Peak expiratory flow rate(PEFR) and SPO2were measured in preoperative examination and at the 0th, 6th, 24th
hours postoperatively. In the postoperative period, intravenous tramadol
(100mg) was administered as a rescue analgesic when VAS ≥ 4. Time and
number of the rescue analgesic administrations, number of the nausea and
vomiting, mobilization and oral intake time and length of hospital stay
were recorded and analyzed in both groups. Duration of surgery,
diameter, number and location of the renal Stones were also recorded.
In all patients, the time from stopping sevoflurane inhalation to the
awakening was called the awakening time and was recorded. The Riker
sedation-agitation scale was used to determine the anxiety level of the
patients in the wake-up service. Postoperative pain was evaluated using
VAS and Dynamic VAS (pain with deep breathing and cough-DVAS) at 0, 6
and 24 hours after surgery. For VAS and DVAS, two end descriptions were
written on both ends of a 100 mm line, and patients were asked to
indicate where their condition was appropriate by drawing a line or by
putting a dot or mark on this line. Pain due to Foley catheter
application was also evaluated. The evaluations was done by a blinded
observer independent of the study. Patient and surgeon satisfaction in
both groups was evaluated as ”1. very satisfied, 2. satisfied, 3.
dissatisfied, 4. very dissatisfied” with the four-option Likert
measurement system.