surgical preparation

Question 1

Cotton muslin has ___ threads per square inch, and pima cotton with tightly twisted fibers woven into ___ threads per square inch.

Answer 1

140; 270
The cotton muslin is not a good barrier. It instantly allows passage of bacteria when wet (termed strikethrough), and dry penetration of bacteria may also occur because its pore size is 50 to 100 µm, which is large enough to allow bacteria (5 to 12 µm) to pass through. On the other hand, pima cotton has a weave tight enough to prevent penetration by skin squames, but it readily allows penetration of bacteria when wet.

Question 2

T/F: Cotton muslin is a good barrier when wet.

Answer 2

False; The cotton muslin is not a good barrier. It instantly allows passage of bacteria when wet (termed strikethrough), and dry penetration of bacteria may also occur because its pore size is 50 to 100 µm, which is large enough to allow bacteria (5 to 12 µm) to pass through.

Question 3

T/F: Pima cotton is a good barrier when wet.

Answer 3

False; Pima cotton has a weave tight enough to prevent penetration by skin squames, but it readily allows penetration of bacteria when wet. A chemical treatment process, Quarpel, makes cotton fabric water resistant by providing a fluorochemical finish in combination with pyridinium or a melamine hydrophobe. This process renders pima cotton an effective barrier for up to 75 washings.

Question 4

When large volumes of liquids are expected in the surgery (e.g., in colic and arthroscopic surgery), _________ __________ materials should be the material of choice for barrier drapes.

Answer 4

nonwoven disposable

Question 5

T/F: Air within the operating room should be under low negative pressure.

Answer 5

False; Air within the operating room should be under low positive pressure, so that when the doors open, air flows out of the room rather than into it.

Question 6

A minimum of __ air exchanges per hour is recommended if the air is recirculated, and __ air changes per hour if the air is exhausted to the outside.

Answer 6

25; 15

Question 7

T/F: Chlorhexidine diacetate is effective against a broad range of microorganisms and viruses (bactericidal, fungicidal, tuberculocidal, virus inactivating); and excellent residual effect. It also penetrates deep into the stratum corneum of the skin, where it forms a defensive barrier against organisms that emerge with perspiration.

Answer 7

False; Sterillium is effective against a broad range of microorganisms and viruses (bactericidal, fungicidal, tuberculocidal, virus inactivating); and excellent residual effect. It also penetrates deep into the stratum corneum of the skin, where it forms a defensive barrier against organisms that emerge with perspiration.

Question 8

T/F: Rubbing the hands with an antiseptic is significantly more effective than scrubbing with brushes.

Answer 8

True; Hand rubbing with 0.2% chlorhexidine and 83% ethanol (Hibisoft) suppressed the number of bacteria and prolonged sterilization for more than 3 hours.