To investigate whether an oral nutritional supplement of a mixture of arginine, glutamine and HMB for a maximum period of four weeks is more beneficial than the standard dietary approach to the healing of pressure ulcers, and to examine whether the use of it can reduce admissions and length of hospitalizations for these patients.

All patients would be assessed by a dietitian to ensure them receiving nutritional support of at least 30 kcal/kg/day and of at least 1.2 g/kg/day of protein regardless of feeding method. During the study period, vitamin C and zinc supplement would not be given. Nutritional supplement other than that provided by the dietitian to meet the energy and protein requirement would not be given. The pressure ulcers would be cared according to the "Basic nursing standards for patient care: Wound dressing - Version 5" published by the Hospital Authority Head Office.

The treatment group would also be given 2 Sackets of a mixture of arginine, glutamine and HMB (ABOUND) every day for a maximum period of 4 weeks, either orally or via enteral feeding.

Inclusion Criteria:

1. Inpatients of medical and geriatric wards of OLMH and WTSH
2. Aged 18 and older with stage III - IV lesions
3. Patients fed orally or through feeding tubes were included

Exclusion Criteria:

1. Patients with history of using the nutritional supplement (ABOUND) in previous three months
2. Patients with cellulitis, wounds with purulent discharge or osteomyelitis or sepsis
3. Patients requiring protein restriction
4. Patients with poorly controlled diabetes mellitus (latest HbA1C > 8.5) (healing process may be affected
5. Patients under palliative care