Types of catheter

Types of catheter

Catheters can be classified based on their size (French scale), number of channels or composition (latex-coated or silicone) ( Figure 83.25 ). Size The French scale refers to the external diameter of the cathe ter, and 1Fr is 0.3 /uni00A0 mm in diameter. The standard catheter size for uncomplicated urethral catheterisation in women is 12Fr or 14Fr, and in men 16Fr. In patients with urethral stricture, a smaller size catheter should be consider ed. In cases of haema turia with ‘clot retention’, a 22Fr catheter is typically used to aid drainage of thick clots. Coudé tip catheters have a curved tip to allow easier passage past an enlarged prostate. Number of channels Single-channel catheters consist of a single drainage channel only and are used for CISC as these catheters do not require an Frederic Eugene Basil Foley , 1891–1966, urologist, Anker Hospital, St Paul, MN, USA. of two channels – a drainage channel and a channel for inflation of a balloon at the tip, which allows the catheter to be retained in the bladder. This is the standard catheter used for uncomplicated cases of urinary retention. The ‘three-way’ catheter has an additional channel for bladder irrigation and is used for patients with haematuria and ‘clot retention’ and following transurethral prostate or bladder surgery .

(a) (b) Figure 83.25 Types of urethral catheter. (a) Single-lumen catheter used for self-catheterisation; balloon retention mechanism; (c) a three-way catheter with an extra channel for irrigation;