Vital Signs Baby Valve

WLMD ID: apof
Vital Signs Pop-off Valve (Pediatric)       

A growing awareness of the possible health risks to hospital personnel from daily, repeated exposure to anesthetics led to the National Institute for Occupational Safety and Health to recommend measures that would limit such exposure. Their publication in 1977 encouraged the development of many new gas scavenging devices. Built into the breathing circuit of an anesthesia apparatus, a gas scavenger collects most of the waste gases for later disposal. Vital Signs, Inc., a medical equipment manufacturer based in New Jersey, marketed its Gasovac Scavenging System in the 1970s and 1980s. One component of the Gasovac was the pressure relief valve shown here, also called a pop-off valve.

Scavengers are often part of a machine that is equipped with a rebreathing circuit that routes the patient's exhaled air through a carbon dioxide absorber. Young children are especially sensitive to carbon dioxide, so for these patients, nonrebreathing circuits are sometimes used. In 1954, five nonrebreathing circuits were analyzed by British physicist William Wellesley Mapleson, PhD, DSc, FRCA (Hon.) (born 1926). These became known as Mapleson Systems "A" through "E".  The Vital Signs "baby" pop-off valve was part of a scavenger made for use with the nonrebreathing circuits called Mapleson A and Mapleson D.

Catalog Record: Vital Signs Baby Valve Vital Signs Valve (pediatric)

Access Key: apof

Accession No.: 2016-03-28-1 C

Title: [Baby Pop-off Valve without fresh gas inlet / Vital Signs].

Corporate Author: Vital Signs, Inc.

Title variation: Alt Title
Title: Vital Signs pressure relief valve.

Title variation: Alt Title
Title: Vital Signs valve 6140 without fresh gas inlet.

Title variation: Alt Title
Title: Mapleson A pop-off valve.

Title variation: Alt Title
Title: Mapleson D pop-off valve.

Physical Description: 1 valve : metals (aluminum?), plastics ; 5.5 x 5.25 x 4.25 cm.

Subject: Pressure Relief Valves.
Subject: Gas Scavengers.
Subject: Anesthesia, Inhalation – instrumentation.
Subject: Air Pollution, Indoor – prevention & control.

Note Type: General
Notes: The only pertinent manufacturer’s publications found by the cataloger are dated from 1978 to 1980. The first year in the date range is based on the year that the National Institute for Occupational Safety and Health published its first recommendations for limiting exposure to anesthetics. The second year in the date range is based on the donor’s statement that he used it in the 1980s and 1990s.

Described with the hose barb connector/exhaust at right angle to inline connector and the 15mm male tapered connector to the left and control knob fully extended.

Note Type: Citation
Notes: Azar I. Anesthetic gas spillage and scavenging. International Anesthesiology Clinics. Winter, 1981;19(4):1-37.

Note Type: Citation
Notes: Dorsch JA, Dorsch SE. Controlling trace gas levels. Understanding Anesthesia Equipment: Construction, Care and Complications. 3rd ed. Baltimore: Williams & Wilkins; 1994:289-300.

Note Type: Citation
Notes: Dorsch JA, Dorsch SE Understanding Anesthesia Equipment: Construction, Care and Complications. Baltimore: Williams & Wilkins, 1975:159-173.

Note Type: Citation
Notes: Geraci CL. Operating room pollution: governmental perspectives and guidelines. Anesth Analg.
November-December, 1977;56(6):775-777.

Note Type: Citation
Notes: Mapleson WW. The elimination of rebreathing in various semi-closed anaesthetic systems. Br J Anaesth. September, 1954;26(5):323-332.

Note Type: Citation
Notes: National Institute for Occupational Safety and Health. Occupational exposure to waste anesthetic gases and vapors: criteria for a recommended standard. Cincinnati, Ohio : U.S. Department of Health, Education, and Welfare, Public Health Service, Center for Disease Control, National Institute for Occupational Safety and Health, Robert A. Taft Laboratories, March, 1977.

Note Type: Citation
Notes: OSHA Directorate of Technical Support and Emergency Management. Anesthetic gases: guidelines for workplace exposures. Occupational Safety & Health Administration website. https://www.osha.gov/dts/osta/anestheticgases/#A. Published July 20, 1999. Revised May 18, 2000. Accessed April 7, 2017.

Note Type: Citation
Notes: Vital Signs. The pollution solution. East Rutherford, New Jersey: Vital Signs, Inc., 1980. In: Vital Signs company file. Located at: Wood Library-Museum of Anesthesiology, Schaumburg, Illinois.

Note Type: Citation
Notes: Vital Signs. The gasovac scavenging system. Little Ferry, New Jersey: Vital Signs, Inc., ca. 1978. In: Vital Signs company file. Located at: Wood Library-Museum of Anesthesiology, Schaumburg, Illinois.

Note Type: Citation
Notes: Vital Signs. If you are using this… add this. East Rutherford, New Jersey: Vital Signs, Inc., 1980. In: Vital Signs company file. Located at: Wood Library-Museum of Anesthesiology, Schaumburg, Illinois.

Note Type: Physical Description
Notes: One scavenging pop-off valve; The valve is made of metal [anodized aluminum?]; At the top of the valve is a control knob, colored blue [blue anodized aluminum?]; The knob turns 360 degrees on its base; Below the control knob is a hose barb connection referred to as the ‘valve exhaust’; This valve exhaust can rotate 360 degrees and connects to a part called by the manufacturer as the ‘safety interface’ (all these parts being components); Below the valve exhaust is an inline adapter with standard 15 millimeter taper connections (one end is male with an exterior diameter of 15 millimeters and the other end is female with an interior diameter of 15 millimeters); The top of the knob is labeled: “OPEN [new line] MAX. [new line] PRESSURE [new line] 60 [new line] cm H20” with an arrow indicating the direction to turn the knob open; The front side of the body of the inline adapter is labeled: “WARNING [new line] CONNECT TO [new line] SAFETY [new line] INTERFACE [new line] VITAL SIGNS”; The bottom of the inline adapter is stamped with a number: “0772”.

Note Type: Reproduction
Notes: Photographed by Mr. Steve Donisch, November 15, 2016.

Note Type: Acquisition
Notes: Gift of Quentin A. Fisher, M.D. F.A.A.P.

Note Type: Historical
Notes: According to the manufacturer’s publications and product literature, the baby pop-off valve is to be placed within the pediatric breathing circuit and connected to a safety interface to prevent unwanted positive and negative pressure. The pop-off valve is one component of a larger system, referred to as the Vital Signs Gasovac scavenging system. In this system excess gas from the pediatric circuit are exhaled through to the pop-off valve and routed to the Gasovac safety interface. The valve exhaust is connected to the safety interface via flexible tubing. Product literature depicts this valve in use within the Mapleson A and Mapleson D systems.

Physicist William Wellesley Mapleson (born 1926) began his career at what is now the Cardiff University School of Medicine in 1952. One of Dr. Mapleson’s first assignments was to find a way to eliminate the patient’s rebreathing of his own exhaled carbon dioxide. To do so, Dr. Mapleson studied the five breathing circuits that had been identified by Sir Ivan Whiteside Magill (1888-1986).

Magill’s circuits consisted of five different configurations of equipment. All of the circuits included an anesthesia mask, one or more hoses, and an expiratory valve; four of the five circuits also featured a rebreathing bag. Mapleson called Magill’s five circuits “Systems” A through E, and published his analysis of them in September, 1954. This work received widespread attention, and the systems he described quickly became known as “Mapleson A” through “Mapleson E”.

The configuration now called “Mapleson A” consists of a corrugated tube with a mask at one end and a reservoir bag at the opposite end. An expiratory valve is attached near the mask, and a second smaller tube attached close to the bag. The smaller tube carries the fresh gas supply from the anesthesia machine. The larger tube carries the patient’s exhaled breath to the reservoir bag. When the bag is full, it is vented out through the valve. The configuration now called “Mapleson D” reverses the proximity of the valve to the mask and the second hose to the bag. When the bag is full, it is vented out through the valve at some distance from the mask. Dr. Mapleson concluded that system D came closest to the elimination of rebreathing.

Gas scavenging systems such as the Gasovac were implemented due to concerns over excessive levels of waste anesthetic gases in the operating room affecting medical personnel. In 1977 NIOSH (National Institute for Occupational Safety and Health) recommended limiting exposure to any halogenated anesthetic.

Note Type: Exhibition
Notes: Selected for the WLM website.