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Do non-steroidal anti-inflammatory drugs increase the risk of bleeding after tonsillectomy?
  1. S R Desikan, Registrar1,
  2. N G Meena2
  1. 1St Richard’s Hospital, Chichester, UK;
  2. 2SHO, East Surrey Hospital, Redhill, UK

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    You are a paediatric SHO covering the hospital wards. A 5 year old child has had tonsillectomy, and the nurse looking after this child says the child is in lots of pain. She has given paracetamol but the child is still crying in pain. You consider giving a non-steroidal anti-inflammatory drug (NSAID) but you know that these agents interfere with platelet function and are worried about increased risk of bleeding. You also consider giving morphine but you know that it may cause nausea and vomiting.

    Structured clinical question

    In children after tonsillectomy [patient] does the use of NSAIDs [intervention] compared with opiates [comparison] increase the risk of bleeding and decrease the risk of nausea or vomiting [outcome]?

    Search strategies and outcome


    Pubmed: search words—NSAIDs and tonsillectomy and bleeding.


    Search outcome: 47 hits (40 were relevant), two systematic reviews including all 25 good quality RCTs. Though both the reviews included adult patients, the majority of the patients in both the reviews were children. See table 3.

    Table 3

    NSAIDs and post-tonsillectomy bleeding


    Tonsillectomy is a commonly performed operation in children, and is done on an outpatient basis in many centres. It is associated with severe postoperative pain, nausea, and vomiting. Vomiting is among the most common reasons for unscheduled readmission after outpatient tonsillectomy. Two recent postal surveys conducted in the United Kingdom to evaluate pain treatment after tonsillectomy in children found that NSAIDs were used in 45–70% of patients. The incidence of post-tonsillectomy bleeding severe enough to require reoperation for haemostasis ranged from 1% to 5.5%.

    A well performed systemic review1 found perioperative NSAIDs increased the risk of reoperation (OR 2.33 and NNH of 60) but were equianalgesic to opiates, and the risk of emesis was significantly decreased (with NNT of 9). The balance is about two more reoperations against nine fewer cases of postoperative nausea and vomiting.

    Another systematic review with meta-analysis of randomised, double blind controlled trials of postoperative NSAID treatment looking primarily at the need for surgical electrocautery to stop bleeding found that 1 in every 29 patients treated with NSAIDs will need a reoperation. The authors suggested the use of NSAID therapy should be abandoned both at the hospital and at home.

    NSAIDs act by inhibiting cyclo-oxygenase (COX) and thereby reducing prostaglandin synthesis and inhibiting platelet aggregation. Two COX isoenzymes have recently been identified, the constitutive COX-1 isoform expressed in gastric mucosa and platelets and COX-2 isoform, which is upregulated during inflammation. However, selective COX-2 inhibitors do not inhibit platelet aggregation in vitro. Available studies of NSAID therapy for relieving pain related to tonsillectomy evaluated non-selective COX inhibitors. The way forward could be to investigate the use of COX-2 inhibitors which may provide similar pain relief without the risk of increased bleeding associated with non-selective COX inhibitors, and the use of local anaesthetic infiltration or dissection with high frequency ultrasound.


    • For every 100 patients undergoing tonsillectomy and treated with NSAIDs rather than opioids, two may need reoperation because of bleeding, but nine fewer will have postoperative nausea and vomiting.

    • Compared with opioids, NSAIDs seems to be equianalgesic following tonsillectomy.

    • Research into the use of cyclo-oxygenase type 2 inhibitors, which have minimal effects on platelet aggregation, is needed in children undergoing tonsillectomy.



    • Bob Phillips