LITFL have an excellent summary of this topic.

Also, somewhere else on this site is a brief summary of the routes of enteral nutrition.

Advantages

  • Easy to insert
  • Least uncomfortable in the awake patient
  • The tubes are cheap
  • With a basic sump tube, one can aspirate the gastric contents and assess the residual volume, thereby keeping an eye on gastric emptying function

Disadvantages

  • Traumatic to the mucosa
  • sinusitis
  • pressure areas on the nares or upper lip
  • requires radiological confirmation of placement
  • easily dislodged by a delirious patient
  • may increase aspiration risk

Nasogastric route of insertion

Advantages
  • Easy to insert
  • Least uncomfortable in the awake patient
  • The tubes are cheap
  • With a basic sump tube, one can aspirate the gastric contents and assess the residual volume, thereby keeping an eye on gastric emptying function
Disadvantages
  • Traumatic to the mucosa: the coagulopathic patient will have a deluge of epistaxis.
  • In the long term, can cause sinusitis
  • In the long term, can cause pressure areas on the nares or upper lip
  • It requires radiological confirmation of placement
  • It is easily dislodged by a delirious patient
  • It may increase aspiration risk because the gastro-oesophageal sphincter is less competent when there is something constantly in it

Orogastric route of insertion

Advantages
  • Easy to insert (especially with direct laryngoscopy)
  • Fewer pressure are complications with long term use
  • Less traumatic to mucosa; its the route of choice for the patient with no platelets.
Disadvantages
  • The path of insertion is less direct than with the nasal insertion
  • Intolerably uncomfortable for the awake patient
  • May cause pressure areas on the lips
  • May interfere with oral hygiene care (in the sense that another tube in the mouth is something else to get in the nurses' way)

References

M Keymling Technical aspects of enteral nutrition Gut 1994; supplement 1: S77-S80

Ratzlaff, HARQLD C., JANE E. Heaslip, and E. S. Rothwell. "Factors affecting nasogastric tube insertion." Critical care medicine 12.1 (1984): 52-53.