Evaluation of the Added Value of Metamizole to Standard Post-operative Treatment After Ambulant Surgery
Condition: Analgesia; Surgery; Recovery
Study type: Interventional

Summary: 
      The aim of this study is to investigate if the addition of metamizole to the standard
      post-operative treatment, i.e. paracetamol and ibuprofen, is superior in reducing
      post-operative pain on day 1 after ambulatory surgery compared to the standard post-operative
      treatment.

      Therefore, a mono-center, prospective, double-blind, randomized controlled superiority trail
      will be designed in order to investigate superiority of metamizole compared to the standard
      post-operative treatment in patients undergoing arthroscopic shoulder surgery.
    

Detailed description: 
      Ambulant surgery has been expanding substantially in the past decade, primarily because it is
      associated with lower costs and it is believed to be as safe as surgery in the in-patient
      setting. Moreover, it seems that early discharge can contribute to a faster recovery and a
      decreased incidence of hospital-associated complications. In view of the relative absence of
      major complications, post-operative pain and quality of recovery should be considered the
      principal endpoints after day surgery. The quality of recovery after different types of
      surgery is of major importance since the evaluation of recovery allows a discrimination
      between a normal and pathological health trajectory. A disadvantage in the ambulatory setting
      is related to the absence of postoperative surveillance by professionals. This implicates
      that the individual patient has to assess, without any support, if his/her quality of
      recovery is normal or not. There is limited information on procedure-specific quality of
      recovery after day surgery, however, different tools such as the 1-tem Global Surgical
      Recovery (GSR) index and the 5-dimensional European Quality of Life (EQ5D) questionnaires can
      be addressed.

      Particularly in the ambulant setting, good post-operative analgesia is challenging because
      patients have to control pain at home by themselves, in the absence of hospital staff.
      Moreover, there is a limit in the type of analgesia that is available (i.e. no strong
      opioids) as well as in the route of administration (i.e. no epidural, intravenous,
      subcutaneous or intramuscular route) at home. Nowadays a multimodal approach to control pain
      has been advocated in the ambulatory setting. This approach is based on a combination of
      paracetamol, non-steroidal anti-inflammatory drugs (NSAIDs) and, if necessary, weak opioids.
      A local and regional anesthesia also have been advocated in the ambulatory setting to relieve
      pain for 8 to 24 hours after surgery. Despite this multimodal pain therapy, the prevalence of
      outpatients suffering moderate to severe acute postoperative pain at home still remains high
      and varies from 9 to 40%. More specific, patients undergoing haemorrhoid surgery,
      arthroscopic shoulder and knee surgery, and inguinal hernia repair seem to be at highest risk
      to develop moderate to severe pain on the fourth postoperative day.

      Due to this relatively high prevalence and due to the fact that NSAIDs are not always
      sufficiently effective, can have numerous contraindications and therefore are not suitable in
      up to 25% of all patients; there is a need for an alternative pain therapy.

      Metamizole (dipyrone) is a non-opioid compound with strong analgesic, antipyretic and
      spasmolytic effects. The analgesic efficacy of intravenous or intramuscular metamizole for
      pain relief after inpatient surgery is well described. Recently, we showed in a prospective,
      double-blind, randomized controlled trial that the combination of paracetamol and metamizole
      is equally effective in treatment of acute post-operative pain at home after ambulatory
      surgery compared to paracetamol and ibuprofen. Moreover, patient satisfaction was equal in
      both groups, as well as the reported side effects.
    

Intervention name(s): Metamizole; Placebo oral tablet
Intervention type(s): Drug; Drug
Intervention description(s): Patients in the experimental group will be instructed to take metamizole 1000 mg orally three times a day for four days. All patients will be instructed to take ibuprofen 600 mg orally three times a day for four days and 1000 mg paracetamol orally four times a day during the entire study period.; Patients in the placebo group will be instructed to take a placebo orally three times a day for four days. All patients will be instructed to take ibuprofen 600 mg orally three times a day for four days and 1000 mg paracetamol orally four times a day during the entire study period.
Intervention MeSH terms: Dipyrone
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: This trial is designed as a mono-center, prospective, double-blind, randomized placebo controlled superiority trial comparing 2 groups of patients
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: ambulant surgery; post-operative medication; recovery