ABSTRACT
As extracorporeal shock wave lithotripsy [ESWL] is carried out on an outpatient basis, it is crucial to choose an adequate analgesic with less adverse effects aiming to rapid post-ESWL discharge of patients. Propacetamol is a non opioid analgesic that seems to be suited to these goals because of its pharmacokinetics and pharmaco-dynamic characteristics. The safety and effectiveness of propacetamol use during ESWL in comparison to meperidine were evaluated in this study. Eighty patients with renal stones scheduled for ESWL procedure were randomly assigned to receive i.v. injection of either 2 gm propacetamol or 100 mg meperidine during ESWL without preoperative medications, according to a double-blinded protocol. Cardiorespiratory variables [respiratory rate, heart rate, mean arterial BP, peripheral O[2] saturation] were recorded before and every 5 min during ESWL and 15 min after the end of ESWL. During and after ESWL, patient arousal was assessed and nausea or vomiting were recorded. During ESWL an evaluation of effectiveness of pain management was done using 4 points scale: [0] No pain, [1] mild pain, [2] moderate pain, [3] severe pain. After ESWL the effectiveness of pain management was evaluated using 10-points visual analogue pain scale [VAS]. Gradual reduction of the mean blood pressure [MBP] was observed with meperidine use which became significant at 25 and 30 min after start of ESWL [p=0.003], while with propacetamol MBP was more stable. Also significant reduction of SpO[2] was observed with meperidine 10 min after the start of ESWL and even 15 min after the end of ESWL [p < 0.05], while it was insignificant with propacetamol. Respiratory upsets [short period of apnea with SpO[2] less than 90%], drowsiness, nausea and vomiting were observed with meperidine but not with propacetamol. Pain control during ESWL was not significantly different in both groups. The median value of pain scale was 0 [range 0 to 3] for group M and I [range 0 to 3] for group P [p = 0.25]. The mean value of VAS was [2.3 +/- 3.5] [range 0 to 10] for group M and [3.6 +/- 3.1] [range 0 to 8] for group P [p = 0.23]. Propacetamol is as effective as opioid-based analgesics yet it is safer and resulted in rapid discharge of patients following ESWL