Secondary outcomes
We measured the levels of pain experienced at rest (shoulder-tip and abdominal pain) at 3, 8, and 24 hours after surgery. We also estimated the level of abdominal pain felt with change of position at 24 hours after surgery. To account for the total pain experience, we calculated the sum of VAS scores given at any time point.
Post-operative analgesic treatment was also measured, both in recovery and post-operative ward.
We estimated the amount of pain treatment given during recovery in two different methods: First, we calculated the Morphine Milligram Equivalents (MME) given during recovery. The conversion factors for parenteral Morphine and Meperidine were 3 and 0.4 respectively18.
Also, we created an Analgesic index, such that a patient was scored according to the amount of analgesics given during recovery: one point for paracetamol treatment, 1 point for Dipyrone treatment,1 point for Meperidine treatment, 1 point for parenteral Morphine up to 2 mg, 2 points for 3-5 mg and 3 points for more than 5 mg.
Additionally, we recorded prescriptions for analgesics in general and particularly opiates (Tramadol Hydrochloride) at 3,8 and 24 hours post-surgery.