Acute Caremiddle twist
An 84-year-old woman is on the ward on the evening of the first day after hemiarthroplasty for a fractured neck of femur. She has a morphine patient-controlled analgesia device and nasal oxygen at 2 L/min. She is comfortable, fully oriented and reading her newspaper. Her respiratory rate is 14 per minute and the oximeter reads 97 per cent; her observations have not changed since the operation. The night nurse asks which observation will warn her earliest if the morphine begins to depress this woman's breathing. Which one of the following should you nominate?