Lessons Learned from a Hospital Evacuation during Tropical Storm Allison

When tropical storm Allison stalled over the City of Houston releasing massive rainfall on Friday evening, June 8, and Saturday, June 9, 2001, the hospitals comprising the mammoth “ Texas Medical Center” flooded out, causing a challenging predicament for hospital staff and patients. Dr. Cocanour and her physician colleagues at Memorial Hermann Hospital and University of Texas Health Sciences Center provided a case report of their experiences.*

Overview shot of Texas Medical Center. It is difficult to contain it in a single photo. Every angle looks different.
Source: http://www.mmrhouston.com/PhotoMedCtr.htm

Comparison of current size of Texas Medical Center with Chicago’s Loop and Cleveland Clinic.
Source: http://www.tmc.edu/masterplan/sld005.htm

The Texas Medical Center, Houston, is a consortium of health care organizations including 2 medical schools and 13 hospitals with more than 6041 licensed beds.** As a result of the flooding on June 8 and 9, Cocanour reports that “3 major hospitals closed to new patients, and 2 of these hospitals transferred their most critical patients to other institutions or other parts of their campus, and 1 hospital completely evacuated all patients, effectively shutting down more than 2000 hospitals beds and more than 500 intensive care unit (ICU) beds for the City of Houston. The storm also closed down 1 of only 2 level I trauma hospitals in Houston that serve more than 4 million people.” (pp. 1141-2)

Hospital disaster plans tend to focus on external events that create mass casualties, such as an earthquake or rioting, and less so on internal disaster events that require complete evacuation of a facility. Cocanour’s own hospitals, Memorial Hermann Hospital and Memorial Hermann Children’s Hospital ((MHH/MHCH), are located in the northeast corner of the Texas Medical Center (TMC). They have a combined bed capacity of 600, including 99 ICU beds, 84 level II and III neonatal ICU beds, and a level I trauma center. The hospitals are connected to office buildings and parking garages via underground tunnels and elevated walkways.

Memorial Hermann Hospital, Texas Medical Center, Houston. Source: http://obg.med.uth.tmc.edu/ images/Buildings/MemHermann2.jpg

Map of Memorial Hermann Hospital. Source: Christine Cocanour, Steven Allen, Janine Mazabob, John Sparks, Craig Fischer, Juanita Romas, Kevin Lally: “Lessons learned from the evacuation of an urban teaching hospital.” In Archives of Surgery, vol. 137, Oct. 2002, pp. 1141-1144

1. The Storm

Rain started falling hard at 6 p.m. Friday, June 8, 2001. Flood prevention systems developed after a 1976 tropical storm were in place and functioning. Rising water was first noted in TMC at around 11 p.m., according to Cocanour, who explained that Brays Bayou could not handle the water which was backing up into the streets (see SEMP Biot #215 at: http://www.semp.us/biots/biot_215.html). Electrical power supplied by Reliant Energy (an energy company based in Houston that provides electricity and natural gas to Houston, Dallas and much of the western US) failed at 1:40 a.m. and the hospital went to its gas-powered emergency generators. However, the electrical switchgear flooded in the basement at approximately 2 a.m. An internal hospital disaster was declared at 2:15 a.m. By 3:30 a.m., all power to the hospital was lost, according to Cocanour’s report.

2. The Hospitals

The two Hermann hospitals were designed to be 2 feet above the 100-year flood plain. This level, however, was breached by rising water of at least 2 feet, which crashed through exterior glass and entered the central core of the hospital. In addition, storm drains and manhole covers that were inside the hospital’s flood protection zone burst open by water in the storm sewers trying to find a place to go, thereby allowing “a tremendous amount of water to pour down the purchasing ramp and directly enter the hospital. Further water entered through pedestrian and utility tunnels, such as the one connecting the hospital with the Hermann Professional Office Building. “The water entered the lobby and emptied into the elevator shafts and stairwells, thus reaching the pedestrian tunnel. The floodwater accumulation between the Hermann Professional Office Building garage and basement forced open metal security doors, pouring water into the underground tunnels and allowing floodwater to enter the hospitals. This high pressure water destroyed the pathology laboratory and caused disbursement of medical waste and biohazardous material throughout the [hospital basements]. The tremendous water volume and pressure significantly damaged the lower 2 levels of MHH/MHCH.

As the water in the basements continued to rise, the hospital’s electrical switchgear and all other mechanical, electrical, and plumbing systems were submerged. “Although the emergency generators located on the second floor were above water and supplied with fuel, the flooding of the switchgear rendered the emergency generators unable to provide emergency power to the hospital. The hospital was then without electrical power, water, or telephone service.” (p.1143)

3. Patient Care Issues

Only one surgical procedure, which was completed safely, was in progress at the time of the switch to generator power. Cocanour explained that “[i]n the ICUs, many of the ventilators did not have batteries and patients receiving ventilatory assistance dependent on electrical power were manually ventilated using an ambu bag.” Neonates were kept warm with chemical perineum pads and skin-to-skin contact.

4. Evacuation

By Saturday morning at 9 a.m., most of the roads into the TMC were impassable due to street flooding as deep as 5 feet. “The decision to being evacuating patients who were receiving ventilatory assistance was made at approximately 10:30 a.m. and the decision to completely evacuate all patients was made at approximately 2 p.m.” (p. 1143) Hospital administrators began contacting other hospitals to check for bed availability. The triage officer, the surgeon medical director of the shock trauma ICU, and a senior nursing director determined the order of evacuation of the patients. Where patients went and by what means was recorded manually “by obtaining a patient identification sticker from each patient as they departed.” (p. 1143) In some cases, nursing staff and equipment were sent with patients to hospitals that had available beds but insufficient staff and equipment. Some patients were transported by volunteers down 10 flights of stairs. Patients were secured to backboards for transit, including neonates who were strapped 5 to a board!

By 3 p.m. on June 10, 2001, the last patient was evacuated.

“Over a span of 31 hours, 169 patients were discharged from the hospital and 406 patients were successfully transferred by ground and air ambulance to 29 hospitals throughout southeast Texas. All 3 Life Flight helicopters were used along with helicopters from the Coast Guard and Texas National Army Reserve. Six patients died, but none of the deaths were attributed tot the conditions caused by the flooding. This was confirmed by the Harris County coroner.” (p. 1143)

Evacuation of patient at Memorial Hermann Hospital during tropical storm Allison 2001. Source: http://www.ringstones.com/znj/2001/Flood.htm

Flooded ramp at hospital.Source: http://www.med.uth.tmc.edu/construction/theflood.htm

5. Lessons Learned

Lesson 1: Flooding will occur on a flood plain. Don’t be surprised when it happens, especially when your hospital is built on a flood plain.

Lesson 2: Electrical power outages are not necessarily temporary. Don’t wait around for the electricity to come back on. Quickly assess the cause of the electrical outage and whether the power can be restored. If it cannot, begin evacuation.

Lesson 3: Appoint a triage officer to coordinate evacuation. This person must be knowledgeable about the hospital and patient care. A central command center is essential as communication between those triaging patients and those communicating with outside facilities.

Lesson 4: Normal communication avenues were lost when electric power was lost. Handheld radios and cellular telephones should be available in all units.

Lesson 5: Volunteers assisting in emergency hospital evacuations are better rested and more numerous at the beginning of the effort. Hospital officials should plan for strenuous tasks, such as the evacuation of patients on upper floors, to occur in the early stages of an evacuation.

Lesson 6: Have flashlights on all units available for all caregivers.

Lesson 7: Have battery-operated exit signs and stairwell lights to safely maneuver patients through stairwells.

Lesson 8: Maintain a paper record of all patients, their attending physician, accepting facility, and accepting physician (if available) as well as discharged patients. Because the information system was down and copy machines were unavailable, the patient’s medical record was sent with the patient to the accepting facility.

Lesson 9: Do not overwhelm any one accepting facility by sending multiple patients that arrive at the same time.

Lesson 10: Reassign staff as necessary to care for patients transferred to other facilities.

Lesson 11: Institute an equipment (e.g., ventilator) tracking system.

Lesson 12: Locate electrical panels high enough to avoid flood damage.

Lesson 13: Only services that are NOT critical to patient care should be located in lower levels of the hospital. The departments located in flooded areas at MHH/MCHC included the pathology laboratory (think autopsies), the clinical pharmacy, the cardiac catheterization laboratories, the gamma knife, physical therapy, and central supply services (!).

Editor’s Note: External, as well as internal, hospital disasters will become more common as local populations swell in size and built environments constructed in another age (the 1950s and 1960s) experience degrees of failure in the face of natural forces, such as hurricanes and earthquakes. Still, one becomes incredulous to learn that hospitals, known to be sitting in a flood plain, would place critical patient-care departments in the basement, as well as electrical switchgear controlling backup diesel gasoline-powered generators two floors above.

Sources:

*Christine Cocanour, Steven Allen, Janine Mazabob, John Sparkes, Craig Fischer, Juanita Romas, Kevin Lally: “Lessons learned from the evacuation of an urban teaching hospital.” In Archives of Surgery, vol. 137, Oct. 2002, pp. 1141-1144.

** For a list of Texas Medical Center members, go to www.tmc.edu.