Elderly Narinder Rawal Hepatic failure Stephan Schug Renal insufficiency Stephan Schug Non-obstetric surgery during pregnancy Andreas Kopf Lactating patient Andreas Kopf Diabetes Esther Pogatzki-Zahn Cardiac patients Esther Pogatzki-Zahn Obesity Yigal Leykin Obstructive Sleep Apnoea Stephan Schug Opioid tolerant patients Babita Ghai, Saowarat Snidvongs, Vivek Mehta and Andreas Kopf