Doctor workflow in the DDAVP-HTS protocol

NDH ICU DDAVP-HTS Protocol for Severe Hypotonic Hyponatraemia (Dr version)
Step 1	Check inclusion (Severe hypotonic hyponatraemic patient) and exclusion criteria (heart / renal / liver failure / neurosurg patient) before starting the protocol and estimate BW by Dr Insert Foley catheter to save urine x Osm/Na/K and monitor urine output Q1H Check blood for CBC RLFT CaPO4 CE clotting ABG Osmolarity TFT Cortisol Desmopressin (DDAVP) 2 microgram IV STAT (must be given before start of 3% HTS infusion) Start 3% HTS infusion (45mL 23.4% NaCl make up to 500mL NaCl 0.9%, if unavailable, 50ml 5.85% NaCl make up to 100ml NaCl 0.9% for continuous IV infusion), initial rate according to BW: BW < 50 kg à start at 10 mL/hr BW 50 to 70 kg à start at 15 mL/hr BW > 70 kg à start at 25 mL/hr Confirm by Dr 1) Q6H serum Na rise (typically aim ↑ 1-3 mmol/L every 6 hours) 2) Maximum acceptable upper limit of serum Na within 24 hours (normally 8-10 mmol/L/day) 3) Review 3% HTS infusion if rate >35 mL/hr by default
Step 2	Monitor serum Na/K & urine Osm/Na/K Q6H at a fixed schedule (6 am à 12 noon à 6 pm à 12 am) Continue Desmopressin (DDAVP) 1 microgram IV Q4H Nurse would inform Dr if high urine output > 150 mL/hr while on DDAVP Inform senior consultant if persistent polyuria (>300ml/hr) for 2 hours If Na rise within target (e.g. Na 115 when target is 113-115) à continue current treatment in Step 2 If Na rise out of target (e.g. Na 116 when target is 113-115) à nurse would inform Dr as described below:
	↓ Na rise too slow ( Na rise < target )	↑ Na rise too fast ( Na rise > target )
	If Na rise = 0 (Na remains the same as the previous result) Inform Dr to increase 3% HTS infusion by 5 mL/hr If Na rise < 0 (Na drops below the previous result) Inform Dr for review and further management Recheck serum Na/K more frequently as directed by Dr	Inform Dr to consider the following actions Give D5 bolus (e.g. 250 mL over 30 minutes) Withhold 3% HTS infusion during D5 bolus Resume 3% HTS afterwards unless ordered by Dr Recheck serum Na/K more frequently as directed by Dr Dr is responsible for reviewing the result ± follow-up actions
Step 3	The treatment plan and prescriptions must be reviewed daily by Dr during morning round Input Daily Goal - Na target: Na rise Q6H, Na target at 6am, U/O target, blood taking order Stop DDAVP and 3% HTS infusion when serum Na > 125 mmol/L or as directed by Dr when stable

Version 02 – April 2023 (Prepared by NDH ICU Hyponatraemia Working Group)