Critically discuss the nursing assessment and the nursing management (including any preventative measures) of these two complications.

John a 28 year old accountant presented to an emergency department with a two day history of lower abdominal pain. The abdominal pain started at the umbilicus and radiated to the right iliac fossa over the past 24 hours. The surgical registrar has assessed John and notes that John has a fever tachycardia rebound tenderness to the right iliac fossa and muscle guarding. Johns vital signs are as follows:
Vitals:
T 38.7 C
HR 110 bpm
BP 100/60 mmHg
RR 22 bths/min
SpO2 97% room air
The surgical registrar diagnoses John with an acute appendicitis and decides to perform an open appendectomy. Surgery occurs and there is a safe surgical outcome. After one hour in recovery John is transferred to a surgical ward. The potential post-operative complications for John include the following:
Venous thromboembolism
Pain
Critically discuss the nursing assessment and the nursing management (including any preventative measures) of these two complications. In your discussion draw upon and critique research evidence to identify current best practice.