Healthcare inspectors were forced to help elderly patients whose buzzers were not being answered by staff.

Investigators visited four NHS Lothian hospitals in late 2015 and early 2016 after a complaint highlighted a series of issues about the care of older people.

The team from Healthcare Improvement Scotland (HIS) said regular use of temporary staff, high levels of sickness absence and recruitment problems are putting pressure on the health board.

During a visit to Edinburgh's Ferryfield House, which specialises in dementia care, inspectors had to respond to buzzers twice after staff left patients waiting for between five and ten minutes.

They said three elderly wards they visited were "noisy with buzzers ringing frequently for lengthy periods" due to "delays in staff responding". However, they highlighted that they heard no buzzers at Astley Ainslie Hospital because staff "proactively anticipated patient needs".

In their report released on Wednesday, the watchdog noted: "Across the other facilities, we saw a lack of staff presence in the ward areas and we saw instances where some patients waited over 5 minutes until their buzzer was answered.

"For example, in the frail elderly ward in Ferryfield House, we intervened on two separate occasions to assist patients who were calling for assistance and had waited 5-10 minutes."

Inspectors also said there were problems with record-keeping and asked NHS Lothian to address the issue.

Following their visits to Astley Ainslie Hospital, Ferryfield House, Findlay House and Ellen's Glen House, they concluded: "The NHS across Scotland is facing a number of challenges, due to an ageing population, particularly in areas providing care to patients with complex care needs.

"These pressures are evident in hospital-based complex clinical care (HBCCC) services in NHS Lothian.

"Since February 2015, NHS Lothian has invested over £1.13m in nursing staffing, but the use of temporary staff, levels of sickness absence and difficulties in recruiting show pressures on the system. A number of initiatives have been recently introduced to help address these pressures.

"Patients and families provided positive feedback but identified some areas for improvement. Many of their comments reflect challenges due to staffing pressures.

"NHS Lothian is putting in place the building blocks to allow its strategic vision for the HBCCC service to be implemented and is working with partners to develop a comprehensive operational plan."