On the evening of July 30, 1945, a U.S. battleship traveling from Guam to the Philippines was spotted in the Philippine Sea by a Japanese submarine crew. Six torpedoes sped across the black water with devastating effect.
Three hundred sailors died immediately as the stricken ship sank. Another 900 men were left floating in an oil slick in the shark-infested Pacific Ocean for four days.1
The events that led to the sinking represent a classic tale of systems failures. They ring familiar to any physician who has closely examined modern medical error.
The communication breakdown that prevented the ship’s captain from being aware of submarine activity on the same route four days before is no different than communication breakdowns in complex hospital systems. The bureaucratic decision by a remote administrator to withhold the safety measure of an escort to prevent such an attack on the grounds that it “lacked necessity” likely resonates with physicians who have struggled with getting authorization for care.
Why did those sailors remain in the water four days before rescue? Despite being only a two-hour flight from the nearest base, they were not recovered—or even missed—for what must have seemed an endless amount of time.
In the end, slightly more than 300 men were alive when they were spotted by a plane that happened to fly past. The rest succumbed to dehydration, exposure, and sharks. The failure of the Navy to rescue the sailors offers lessons to the clinician trying to improve transitions of care more than a half a century later.
The Feedback Loop
Hospital discharge is a complex process initiated by physician orders on charts, prescription pads, and patient instructions. Most often, the things we assume will be done out of our direct view are carried out satisfactorily. However, any hospitalist can easily recount stories of tests or follow-up that didn’t happen as ordered. Patients who fall through the cracks at discharge—like the stranded sailors of the USS Indianapolis—are, in part, the story of a simple omitted step: the feedback loop.
A feedback loop occurs when the results or consequences of an action are returned as an input loop to the initiating step in order to modify subsequent actions. This fundamental engineering concept can keep complex systems on course. The feedback loop allows the lack of completion of a portion of a process to be recognized—and corrective measures taken—before additional harm occurs.
In Guam, the island base from which the USS Indianapolis departed, the marker indicating the ship on the plotting board was removed when the ship left. Later, the Philippine port of Leyte failed to note that the ship didn’t arrive. Policy at the time was that all ships that left port were presumed to have arrived at their destination unless a call indicating trouble was received. The junior officer who noticed that the ship hadn’t arrived assumed there had been an order to divert to an alternate port. The Navy had no feedback mechanism to communicate between the two ports and raise an alarm when a ship did not arrive. In fact, a Navy directive discouraged communicating the arrival of combat ships as a matter of military secrecy. As a result, no rescue mission was launched—and the sharks began to arrive.