London, May 30 (IANS): Patients undergoing breast cancer surgery need less pain-killing medication post-surgery if they have anaesthesia that is free of opioid drugs, new research suggests.

While opioid drugs provide an excellent pain-killing (analgesia) effect throughout operations, they also have side effects, the researchers said. 

Post-operative complications, such as respiratory depression, post-operative nausea and vomiting, itching, difficulty going to the toilet and bowel obstruction are some examples of side effects.

The findings showed that patients in the non-opiate group require less pain-killers, but receive adequate pain relief. 

Patients require less analgesic 24 hours after a non-opiate anaesthesia than after an opiate anaesthesia.

"Non-opiate anaesthesia in breast cancer surgery might avoid several opiate-related side effects such as post-operative nausea and vomiting. It might also reduce cancer recurrence," said Sarah Saxena from Jules Bordet Institute in Belgium.

"However, it is too early to recommend non-opiate anaesthesia to all breast cancer patients," Saxena added.

In the study, pain-killer requirements were examined after patients received opiate anaesthesia and non-opiate anaesthesia. 

A randomised controlled trial was conducted, containing two groups each containing 33 breast cancer patients undergoing a mastectomy or lumpectomy. 

Both groups received intravenous paracetamol (1000mg/6h) and intravenous diclofenac (75 mg/12h). 

Patients received a PCA (patient-controlled analgesia) pump for breakthrough pain during the first 24 hours post-operatively.

The results were presented at Euroanaesthesia 2016 in London recently.