1.1a MH Crisis Management: Dantrolene

Dantrolene Stocks:

The mhanz group recommends that a minimum of 24 (20mg) vials of dantrolene are held in any anaesthetising location where triggering anaesthesia is performed. Larger or remote hospitals should carry 36 vials.  This stock level represents 2-3 x 2.5mg/kg doses for an average sized adult and is a reasonable compromise between clinical need and economy.

Borrowing from other local hospitals

The mhanz group does not recommend reliance on dantrolene stocks from other hospitals for initial crisis management. Early and appropriate doses of dantrolene result in lowest morbidity and mortality. Dosing interval is every 10-15 minutes until signs of hypermetabolism are normalised.

Replenishing supplies after use

Each hospital should consider where additional dantrolene for acute management or replacement will be obtained (recurrence of an MH crisis occurs in up to 25% of patients during the first 24 hours).

Water for mixing Dantrolene:

It is extremely important that sterile water used for reconstituting dantrolene is not mistakenly infused into the patient during an MH crisis.  Suggestions to reduce the risk of this life-threatening error include:

• Use of 100ml water for injections plastic bottles
• Use of 250ml bags sterile water to visually distinguish from other safe IV fluid (available from B/Braun, it can be obtained via Biomed Code BPW001. (In New Zealand Ph 0800-833-133)
• Additional labelling of 1000ml bags of sterile water in the MH box
  • e.g.  “NOT for Intravenous infusion”

Dantrolene Mixing:

Mixing dantrolene can be time consuming and rapid administration is critical. As many as 36 vials may be required in the acute treatment of a large adult. Staff should practice mixing dantrolene with expired stock. The attached dantrolene task card demonstrates ONE method of reconstituting dantrolene. Newer stocks of Dantrolene may be easier to reconstitute due to a different freeze drying process. Newer stocks are identified by the “flip off” plastic top and Dantrium written in orange (the old stock has Dantrium written in blue).

As many staff as possible should be assigned to mixing dantrolene (hence three task cards). Ensure that ALL other tasks cards are assigned before giving out extra dantrolene cards to staff.

Vial Access Needle:

The BAXA ported “Two-fer drawing up needle” has been recommended for this purpose. It is a 16G short needle with a Huber point. It is available to order from St Ives Medical, PO Box 65-069 Mairangi Bay, Auckland 10, New Zealand, Phone or fax +64 (9) 479-6038. Another alternative is the B.Braun Micro Pin (product code MP2000).

Recommended Contents of an MH box:

A list of contents for a dedicated MH box is given in the attached document. Mobility is essential for the kit. A 50 L Esky/Chilly Bin on wheels is ideal.

Providing safe anaesthesia for a patient who has known or suspected MH susceptibility (1.5):

“Guidelines for managing the patient who is susceptible to malignant hyperthermia (MH)” is a set of recommendations from the mhanz group. Once an operating theatre and anaesthetic machine have been prepared according to instructions and non-triggering anaesthesia is instituted the patient should be treated like all “normal” patients. There is no clinical precedent to suggest that these patients are at risk of an MH crisis.

This document can be incorporated into operating theatre policy documents.