You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Disease", "Chemical"].

Please return the output as a JSON object of the format: {"Chemical" : ["Naloxone", ...], "Disease" : ["Hypotensive", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

Reduction of pain during induction with target-controlled propofol and remifentanil. BACKGROUND: Pain on injection of propofol is unpleasant. We hypothesized that propofol infusion pain might be prevented by infusing remifentanil before starting the propofol infusion in a clinical setting where target-controlled infusions (TCI) of both drugs were used. A prospective, randomized, double-blind, placebo-controlled trial was performed to determine the effect-site concentration (Ce) of remifentanil to prevent the pain without producing complications. METHODS: A total of 128 patients undergoing general surgery were randomly allocated to receive normal saline (control) or remifentanil to a target Ce of 2 ng ml(-1) (R2), 4 ng ml(-1) (R4), or 6 ng ml(-1) (R6) administered via TCI. After the target Ce was achieved, the infusion of propofol was started. Remifentanil-related complications were assessed during the remifentanil infusion, and pain caused by propofol was evaluated using a four-point scale during the propofol infusion. RESULTS: The incidence of pain was significantly lower in Groups R4 and R6 than in the control and R2 groups (12/32 and 6/31 vs 26/31 and 25/32, respectively, P<0.001). Pain was less severe in Groups R4 and R6 than in the control and R2 groups (P<0.001). However, both incidence and severity of pain were not different between Groups R4 and R6. No significant complications were observed during the study. CONCLUSIONS: During induction of anaesthesia with TCI of propofol and remifentanil, a significant reduction in propofol infusion pain was achieved without significant complications by prior administration of remifentanil at a target Ce of 4 ng ml(-1).
{"Chemical": ["remifentanil", "Remifentanil", "propofol"], "Disease": ["pain", "Pain"]}