stanford medicine


Take the tube

Special Report

Take the tube

Mass transit for lab samples

In a hospital the size of Stanford, where a quarter-mile’s distance might separate a tissue specimen from its destination lab, making good time means better medicine.

That’s why every day, 7,000 times a day, the hospital’s staff turns to pneumatic tubes — technology that was cutting edge when first introduced in the 19th century — for a transport network that the Internet and all the latest Silicon Valley wizardry still can’t match: A tubular system to transport a lab sample across the medical center in the blink of an eye.

In four miles of tubing laced behind walls from basement to rooftop, Stanford Hospital & Clinic’s pneumatic tube system shuttles foot-long containers carrying everything from blood to medication.

“Approximately 70 percent of the information on a patient’s chart is lab data,” says David Myrick, quality coordinator for the hospital’s clinical labs. “We conduct about 8 million tests a year, serving thousands of patients. We are going full blast, 24-7, at the highest level of testing. The tube system is part of a complex chain of events that ultimately give doctors the essential lab results they need to make decisions about our patients.”

The value of these pneumatic tube networks is not unique to Stanford — they are in use at hospitals nationwide — but SHC’s system, which also serves the adjacent Lucile Packard Children’s Hospital, is one of the largest in the country. Its architecture is a sophisticated design of switching points, waiting areas, sending and receiving points. It hosts 124 stations (every nursing unit has its own); 141 transfer units to prevent crashes; 99 inter-zone connectors to facilitate the most efficient routing, and 29 blowers, the heartbeat of the air-driven system. To help alert employees to the arrival of containers, the system has more than three dozen combinations of chiming tones.

Stanford hospital's chief engineer, Leander Robinson. Transfer units that direct the tubes to the various stations. Stanford hospital’s chief engineer, Leander Robinson, stands near the blowers that power the pneumatic tube system, four miles of tubing snaking behind the building’s walls. Bottom: transfer units that direct the tubes to the various stations.

Stanford’s leaders are planning a new hospital, which they project will be up and running by the end of the decade. When it opens, its tube system will be tied in to the old system to create what will likely be the largest pneumatic tube system in the world — approximately eight miles long and an additional 50 to 75 stations. It will have technology to enable six containers to be sent express within one transport zone. Now, just one at a time can be sent in that fashion. That multiple express capacity will be especially needed for the hospital’s transfusion service, which often sends blood and blood plasma when the need is urgent.

Such pneumatic tube systems date back to the early 19th century, when they drove the workings of postal services, department stores and other commercial businesses whose physical size demanded something faster than standard human pace. But those versions were usually designed to move paper. As computers and then the Internet made it possible to deliver data electronically without paper, tube systems lost their value for many industries.

But the technology endures — and thrives — in hospitals, thanks in part to more recent improvements in the delivery system. Originally, the tubes would arrive with a thud, a hard landing that could damage sensitive lab samples. Then in the late 1980s engineers figured out a way to control airflow to slow down the containers for a soft landing at their destination station.

At Stanford Hospital, before 1993, a team of about 20 people had the job of transporting the multitudes of tissue, medications and documents. However, the increasing size of the hospital, and the addition of two adjacent buildings, the Blake Wilbur Building and Packard Children’s Hospital, made the tube system option the most modern solution. “We like the human touch,” says chief of staff Bryan Bohman, MD, “but we don’t like the human foot speed.”

Depending on the diameter of a tube, cylinders can reach speeds of up to 25 feet per second, about 18 miles per hour, far faster than any human could ever manage.

It was also a question of best use of employee time, if, as often happened, a courier wasn’t available when a specimen needed to get to the lab. Having a nurse leave a patient’s bedside for a minutes-long run to the lab made no sense.

Reliable speed is crucial when the system carries blood products, some of which are temperature-sensitive and, by regulations, must be discarded if not properly maintained. The tube system, says lab operation services manager Gay Routh, “is vital, very vital. I don’t know what we’d do without the tube system, especially when it comes to tests like those that happen in surgery. When arterial blood gases are sent from the operating room, we need to return results in a very short period of time, so physicians know if they need to change settings on a monitor. Years ago, before the tubes, we would get a phone call and we’d have to send somebody. It definitely slowed our turnaround time.”

Lab assistant Napoleon Gacusana in Stanford Hospital's Pre-analytical department. Robinson holds an open cylinder that’s empty and ready for new cargo. Lab assistant Napoleon Gacusana in Stanford Hospital’s Pre-analytical department pulls out a freshly delivered blood sample. Bottom: Robinson holds an open cylinder that’s empty and ready for new cargo.

The hospital’s chief engineer, Leander Robinson, commands the system from a small basement office, where computer monitors light up every time someone puts a container in a chute, types in a numerical address and presses the “send” button. The screen displays a tiny icon that reflects the container’s travel through various switches and transfers, but it moves so quickly it’s actually hard to track its passage. Even during the heaviest flow through the system, between noon and 2 p.m., a container can cover the longest start-to-finish distance — 1,500 feet — in less than three minutes.

The system has a complete set of checks and balances, sensing where containers are needed and sending them. Some departments, such as the operating rooms, have dedicated lines that guarantee them a straight shot to the lab. “Blood products get first priority,” says Lee Chua, blood transfusion services manager.

The system does occasionally falter, but it is operative 98.8 percent of the time, Robinson says. And no cylinder has ever gotten stuck in a tube, he says.

Robinson has software that monitors the system, charting its use station by station and watching especially those times when someone sends a cylinder “stat” — the highest priority coding.

It’s also a work in constant progress; the hospital continues to evolve and locations can change. “The tube is everywhere,” Robinson says, “and the directories ever-changing.”

The system “is amazing,” says assistant patient care manager Pam Ponti, who sends and receives cylinders that affect surgical care. “I don’t know exactly how it knows where to go, I’m just happy that it does.”

Recently, the hospital’s tube system emerged as an object of interest to a newly formed group called Atlas Obscura. Dedicated to drawing attention to the world’s unusual sights, both natural and man-made, the group asked the hospital if it would participate in tours of these sights as part of the first Atlas Obscura Day, on March 20.

More than 3,000 people signed up to tour 80 locations in 20 countries. Many more people couldn’t be accommodated, including 45 who didn’t sign up fast enough to be among the lucky 13 to take the tour of Stanford Hospital’s now-famous tube system.


E-mail Sara Wykes

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