Introduction NIV for acute hypercapnic respiratory failure (AHRF) in COPD and restrictive lung disease has become widespread in the UK. Early institution of NIV in appropriate patients gives the best outcome.
Methods We retrospectively examined referral patterns to our tertiary 12 bedded NIV unit during a 12 month period from November 2012 to October 2013. Admission criteria to the unit is standardised and through the NIV consultant or senior nursing staff. Site of referral was noted and mortality rate was calculated.
Results 612 referrals were made to the dedicated NIV unit in the 12 months. 125 were elective admissions for setting up domiciliary NIV and were excluded from the mortality analysis as there was no mortality in this group. The overall mortality for the rest of the cohort was 15.2% of the remaining 487 patients acutely admitted to the unit. The source of referrals to the unit was varied and as shown in Figure 1. The mortality rate for admissions from the acute portals (A and E and the Acute Medical unit) were significantly lower (10.4%) than from the medical wards (23%). This reflects the fact that even with a well selected cohort the timing of the respiratory failure in the course of illness plays an important part in determining mortality. We know that uncorrected respiratory acidosis after 4 h of NIV is a strong determinant of mortality. The highest mortality (64.5%) was seen of referrals from the Frail elderly unit. This also shows that general constitution plays an important role in mortality.