Ch 19 Bandages and drains

Question 1

What is Laplace’s law in regards to bandages

Answer 1

The pressure applied under each point under a bandage is proportional to (NxT)/(RxW)

Question 2

bandage layers

functions of primary?

Answer 2

Primary, secondary and tertiary

Functions of primary layer
o Final barrier between wound and external contaminants
o Absorbing or transferring exudate to secondary layer
o Maintaining a moist wound environment that supports selective autolytic debridement, granulation, epithelization, and or contraction

Question 3

Sites at risk for tourniquet effect

ischemic injuries can occur within 24-48 hours

Answer 3

Just proximal to digits, carpi, and tarsi

Additional padding placed to increase diameter of these narrow sites helps restore gradual proximally directed pressure gradient

Question 4

What is the normal closing pressure of arterioles to the skin and to the underlying muscle?

Answer 4

Skin 30mmHg
Muscle 50mmHg

Question 5

List the three main methods of pressure relief in bandages

Answer 5

Doughnuts
Windows
Splints

Question 6

List five techniques for anchouring bandages?

Answer 6

Stirrups
Tape strip overlays
Torso straps
Figures-of-8
Incorporating hair

Question 7

List three benefits of drains

open passive and closed active suction

Answer 7

Remove accumulations of serum and blood that provide a media for bacteria

Pressure relief (pressure can compromise perfusion and cause pain)

Evacuation of inflammatory mediators, bacteria, necrotic tissue and foreign material

Question 8

What are the two main types of reservoirs on active drains?

Answer 8

Compressible
Rigid

Question 9

What is the recommended negative pressure generated in human drains?

Answer 9

25-74mmHg for delicate tissue
75-250mmHg for heavier exudate or large areas
200-400mmHg to encourage active adhesion

Question 10

What pressures can be generated by a grenade bulb using various methods of compression?

Answer 10

170mmHg when rolled from apex to base
110 when compressed with 2 hands
84 when compressed with 1 hand

Question 11

What is the decision to remove a drain based on?

Increased drain presence increase risk of ascending infection

Answer 11

The quantity and quality of the fluid and ongoing drain function
> become increasingly serosanguineous
> health of cells seen on serial cytology
> quantity of fluid should steadily decrease until a plateau

One study found significant lower incidence of seroma formation in SQ wounds when the drain was removed when the productions was below 0.2mh/kg/hr

drain is foreign material and thus itself induces fluid production

Question 12

i. Should not exit in incision because
1. Entry point for bacteria
2. Increases risk of infection and dehiscence
3. Increases herniation risk
4. Drainage along incision line (penrose)
ii. Cover with absorbable material

Question 13

In vitro studies of active suction drains revealed that compressible reservoirs lose suction rapidly as they fill to 20% to 30% capacityand more gradually with further filling, with some units losing all suction before they are ful

Question 14

Clinical use and complications of
percutaneous cystostomy pigtail
catheters in 25 cats
Nurra 2022

Answer 14

Retrospective, 25 cats

40% developed pigtail catheter complications including dislodgement, urine leakage, urinary tract infection and bladder rupture. The majority of complications were easily resolved and did not require surgical intervention

Conclusions and relevance The results suggest that percutaneous pigtail catheter placement can facilitate
urine diversion in both the emergency setting and in the long-term management of urine retention without many complications

Question 15

On the nature of canine aural haematoma and its treatment with continuous vacuum drainage

Answer 15

Nine of the 10 dogs were successfully treated without recurrence at 6 months postoperatively and with excellent cosmetic results. In one case, infection required early drain removal and delayed healing was associated with wrinkling of the pinna

Question 16

Evacuated blood collection tubes fall within the negative pressure
range of previously reported CSSD rigid reservoir systems

Question 17

Evaluation of Jackson-Pratt Thoracostomy Drains
Compared with Traditional Trocar Type and
Guidewire-Inserted Thoracostomy Drains
Sherman 2020

Answer 17

restrospective study, 65 canine and feline
JP (n ¼ 31), TRO (n ¼ 25),
There were no differences in the number of major complications when comparing all three drains
individually (P ¼ .350). JP drains and GW drains can be considered as an alternative to traditional TRO thoracostomy

complications of drains 7-22%

Question 18

For the present study, use of a syringe of ≥ 20 mL and application of 1 mL of negative suction volume resulted in in vitro pressures much more negative than the currently recommended pressure of –14.71 mm Hg for continuous suction. Additional in vitro or cadaveric studies are needed. (Am J Vet Res 2019;80:625–630)

Answer 18

Influence of 4 drain configurations on fluid dispersal
and retrieval in an instillation model
Miriam Bates

Negative pressure wound therapy with
instillation reduced wound bioburden in terms of colonyforming
units

Question 19

Evaluation of complications and long-term outcomes associated with 101 dogs and cats discharged with and without subcutaneous active closed-suction drains (2014–2022)
Hui Yu Lu 2023

Answer 19

retrospectively, 101, There were 77 animals in Group D and 24 animals in Group ND

There is a higher risk of complications associated with discharging an animal from hospital (37%) with a subcutaneous closed suction drain than removing it prior to discharge (4%). These complications, however, were primarily minor and easily managed. Discharging an otherwise stable animal to home with a subcutaneous closed suction drain may be feasible to decrease duration of hospitalization, cost to the owner, and stress for the animal.