Another Kind of Circulatory System

In the depths of the hospital, through doors that often go unnoticed by most employees, is a transportation system that plays a huge role in modern health care. The passengers are not people, although some are samples of people – blood samples, that is, secured in a “carrier” and on their way to the hospital lab. The carriers – cylindrical cartridges with a secure latch on each end — race all over the hospital through pneumatic tubes hidden deep behind the walls. Unit nurses can send samples to the lab for testing, or receive blood products and medications to administer to their patients.

Pneumatic tube systems have been used in communications, banking, health care and industry since the mid-1800s to move small things from one place to another much faster than a human could travel — even faster than a car. Digital communication has taken over the conveyance of messages, but when it comes to transporting an actual object across a hospital campus, the pneumatic tube still reigns supreme.

The pneumatic tube system at University of Maryland Medical Center (UMMC) is one of the most complex in existence, according to Pevco, the company that designed and installed it some 20 years ago at UMMC’s University Campus, and has updated and expanded it through the years  The last big upgrade was 2011, when UMMC added two additional miles of pipe, interchange rooms, 25 new pieces of equipment and 10 additional zones.

Before this system was installed, the hospital staff included couriers hired specifically to “run” blood products, lab samples, and pharmaceuticals. They were fast, but no match for the tube system once it was installed. It takes 15 minutes to walk from the two furthest points in the hospital, but only five minutes for a carrier in the tube system.

A pneumatic delivery system transports containers through tube networks using air pressure. The nerve center of the system is a computer that takes up so little space it only requires a small closet. When a nurse or lab technician enters a destination into one of the 99 stations throughout the hospital, the computer selects the quickest available route, waits until the route is clear, then uses vacuum to pull the carrier out of the station into the pipes.

The “whoosh” sound a carrier makes heading down a clear passageway is music to the ear of Richie Stever, CHFM, LEED AP, director of operations and maintenance at UMMC.

“The system is designed like a roadway system,” Stever said. “When the pipe  — think of it as a highway —  is clear, the carrier is lifted from the station with a motor that creates suction, and then it travels through the pipe until it reaches a diverter – like a highway interchange — switches roads, and then is moved with pressure via a motor until it reaches its final destination.”

There are 5.5 miles of pipe throughout the complex, with the average time for deliveries being less than five minutes. To create that kind of power, the tube system is backed by 22 blower motors that push and pull air through the pipes.  There are 22 zones the items can travel through, and 103 diverters. Diverters are used to make bridges from station to station. The diverter is placed at an intersecting point and changes the carrier’s path to a different tube. There are three interchange rooms in the system where the diverters are used to change the direction of the carriers.

The carriers are numbered cylindrical cartridges equipped with two latches on each end as well as foam padding to protect the contents during their trip – sometimes miles at a time.  There are 99 carrier stations throughout the hospital building, with seven in the Central Pharmacy, eight in the North Core Laboratory, seven in the South Core Laboratory, three in the Blood Bank and one at each nurses’ station.

When a carrier comes through to the station, a tone will sound to let those nearby know that a specimen or blood product has just come in. Those 99 stations generate more than 5,000 transactions per day at a speed of around 500 feet per second.

As with any complex machine, things can go wrong, but built-in features kick in to fix them. If a blower is off-line because of mechanical or electrical failure, another blower within the system can do the job. If a cartridge opens up en route and spills the contents, technicians use measurements to figure out where the spill or clog is  before deploying a special “squeegee” — more like a large sponge — that is as big as the inside of the tubes. The squeegee is sent through the tubes multiple times to clean up the spill.

“Twenty years ago, when we installed the first part of the tube system, we never imagined we would be able to send a thousand carriers in a day,” said Scott Kruelle, system operator for the tube system. “Now, we send more than 5,000 carriers a day.”

More Reflections From Haiti: “I Fear for the Patients”

By Anthony Amoroso, M.D.
Assistant Professor of Medicine

Editor’s Note: Dr. Amoroso was part of the first University of Maryland team to go to Haiti to provide medical care to earthquake survivors. The following is an excerpt of an e-mail he sent to his wife the day before leaving Haiti. Read Dr. Amoroso’s first Haiti blog post.

I’m going to try to get out tomorrow. A bit torn, patients have gotten word of our departure and getting a bit upset. Every day we make some improvements and it becomes a bit addictive. We worked late tonight doing what we can to make transition to incoming group. There are about 5 people staying on and another 10-15 coming tomorrow. We know every patient in the hospital and have a medical and surgical records on all of them. We only have a few backlog cases waiting the new team.

We leave with 5 functioning operating rooms, an organized stock room, almost automated lab, an admissions and discharge system, medical records, ambulatory appointment system, 6-bed trauma bay for wound care and fractures, community triage teams, some capacity for patient transport, beginnings of sanitation with port-a-pots finally arriving and medical waste and sharps disposal. We continue to struggle for beds, linens, crutches, flys, lack of misquito nets, human waste disposal and basic hygiene like toothpaste, soap, and shampoo.

From a medical standpoint the nature of the injuries — fractured legs, very large wounds, bone infections, kidney failure from crush, paralysis, dead limbs, and amputations — makes for long-term complicated problems.

My biggest frustration and anger lies in the entrenched backward and uncaring health system that permeates the hospital despite the fact that it is destroyed. It’s a real feat that it is running, and this only through the force of several external personalities. As these people leave I fear for the patients and know the volunteers will walk away frustrated.

The bigger picture remains far from over. There are hundreds of thousand homeless people living in squalid improvised camps throughout the city and region. Dysentery is picking up, and we saw the first cases of hepatitis A today. A cholera outbreak is easily feasible and would be devastating. How on earth the cleanup will commence and even come close to succeeding remains a mystery to me.

I’ve hit my wall, fatigued, with muscle and back pain. Chronic dehydration. Now with mouth sores. I have no more socks, underwear, or food. I guess it’s time to go home. It’s been an incredible experience. I’ll be back to see how this turns out.

Reflections From Haiti: “I Felt Invisible”

By Anthony Amoroso, M.D.
Assistant Professor of Medicine

Editor’s Note: Dr. Amoroso was part of the first University of Maryland team to go to Haiti to provide medical care to earthquake survivors.  Below are his reflections, written while en route back to Baltimore. Read Dr. Amoroso’s second Haiti blog post

I’m now in Boston awaiting my connection to BWI, my extraction provided by a UN cargo plan. I’m sitting here watching the Rachael Ray Show … the altered sense of reality is intense.

Watching CNN with the horrific pictures of bodies and destruction compelled us all to do something. I am grateful for Dr. [Robert] Redfield, Dr.  [Thomas]  Scalea and all the others for giving me the opportunity to put away the TV remote and help.

I had been to Haiti 5 other times. I knew things would be difficult, but words and a few photos from a moving car cannot capture the utter destruction, impromptu camps, dust, smells and filth. There are certainly thousands upon thousands of people entombed in the rubble and still thousands suffering from untreated wounds and fractures. And I fear the next wave of misery from unsanitary living conditions is around the corner.

For the first time in Haiti I felt invisible, and I was stuck by the fact that people were getting back to the daily hard work necessary to survive in Port-au-Prince.

The Haitian people are hard as nails, but I simply cannot image any rosy future for Port-au-Prince. The international response, though large, is perplexing, and I think the poverty, destruction, and trauma is a staggering challenge.

I believe we did something meaningful. I believe we made a indelible connection not only to the patients but the staff and students of the hospital. I am proud to have been part of the Maryland team — tough, focused, careful and caring and never self important or touristic. I am thankful for the vision, professionalism, respect and humor of the “team.”

The terms “block crush injury” will be with me for life.