A Review published Online First by The Lancet details the devastating health effects of earthquakes and the challenges posed by these natural disasters. The paper is by Dr Susan A Bartels, Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, and Harvard Humanitarian Initiative, Boston, MA and Dr Michael J Van Rooyen, Department of Emergency Medicine, Brigham and Women's Hospital, Boston, and Harvard Humanitarian Initiative, Boston, MA, USA.
The authors say: "Because earthquakes frequently affect populous urban areas with poor structural standards, they often result in high death rates and mass casualties with many traumatic injuries. These injuries are highly mechanical and often multisystem, requiring intensive curative medical and surgical care at a time when the local and regional medical response capacities have been at least partly disrupted. Many patients surviving blunt and penetrating trauma and crush injuries have subsequent complications that lead to additional morbidity and mortality."
In the past decade alone, earthquakes have caused more than 780 000 deaths, accounting for nearly 60% of all disaster-related mortality. The tsunami crisis of 2004 alone claimed more than 200 000 lives. Many of the most populous cities in the world are on fault lines, for example Los Angeles, Tokyo, New York, Delhi and Shanghai; as result, millions of people are exposed to earthquakes.
By destroying medical facilities, roads, and bridges, in addition to interrupting medical supply chains, earthquakes devastate local medical capacity and create a large, unmet need for complex surgical and medical care. Massive earthquakes can result in casualty rates ranging from 1% to 8% of the at-risk population. The reported ratios of death to injury vary, but across many studies seem to be about 1:3. Many victims die immediately. A second mortality peak occurs a few hours after the quake, as people with serious injuries such as liver or spleen lacerations, pelvic fractures, and subdural haematomas succumb. Then a third peak occurs in the days to weeks after the quake, as people with sepsis and multiorgan failure die. People with chronic diseases such as diabetes and heart conditions are put at increased risk of death, as access to vital medicines and care is cut off.
Between 2% and 15% of the population can suffer crush injuries, in which heavy loads crush some part of their body. This in turn can lead to kidney problems and failure, and amputation. Patients, even those with seemingly normal electrolyte levels, should undergo aggressive fluid resuscitation, but with fluids not containing potassium or calcium since high levels of these minerals can be present in people who have been crushed, raising the risk of death. Half of patients with crush syndrome develop kidney failure, and half of those need dialysis. Mortality for people with kidney failure in earthquake settings ranges from 14 to 48%.
Overall, the most common earthquake-related musculoskeletal injuries are lacerations (65%), fractures (22%), and soft-tissue contusions or sprains (6%). Earthquakes are estimated to result in crush injuries in 3% of people with the lower limbs most frequently affected (74%). Patients with crush injuries have a high incidence of sepsis, disseminated intravascular coagulation, adult respiratory distress syndrome, and death. Use of fasciotomy (cutting fibrous connective tissue to relieve internal pressure) is controversial due to risk of sepsis, as is amputation. Due to electrolyte and other imbalances caused by crushing, some doctors believe it is better to remove the crushed limb as soon as possible to save the patient. Others say that even severely crushed limbs can recover to full function.
Heart attacks rose by 35% in the week following the earthquake in Northridge, California, in 1994, and increases have been reported in other areas such as Taiwan. But in another earthquake in Loma Pietra, California (1989), no increase was reported. Following the Chinese earthquake of 2008, rates of arrhythmias increased sharply (between 6 and 9 times compared with two previous control periods). Following the Japanese earthquake of 1995, systolic blood pressure rose by 15-16 mm Hg and diastolic by 6-10 mm Hg for 2 weeks in elderly patients wearing ambulatory blood pressure monitoring devices.
Of course, once the initial earthquake response has subsided, many people can be displaced from their homes, raising other health emergencies. Overcrowding in makeshift shelters can lead to epidemics of infectious diseases. But the media often dramatically overestimates the role of dead bodies in such disease outbreaks. The only situation in which corpses have been documented to spread infections to the general population is during cholera outbreaks. Sepsis is common in earthquake disasters, and people with sepsis are two-and-a-half times more likely to die than those without it.
Mental health problems are also common following earthquakes. Depression can be highly prevalent (reports ranging from 6% to 72%). Following the Turkey earthquake of 1999, 17% of the population had suicidal thoughts. Post-traumatic stress disorder is also common. Fractures and fracture-dislocations are roughly equal in number (36% vs 33%). Of all spinal fractures, burst fractures are most common, with reported frequencies ranging from 49% to 55%. 30% of people affected by the earthquake in Taiwan in 1999 reportedly died from head injuries, and these injuries were the second most frequent type of trauma after lower-limb injuries in China in 2008.
Children are often at higher risk of injury and death during earthquakes than are adults. In fact, paediatric patients might be preponderant after major earthquakes: in Haiti, 53% of patients were younger than 20 years and 25% were younger than 5 years. Elderly individuals are also at higher risk than the general population, since they might be unable to react quickly and might be unable or unwilling to evacuate their homes. In most studies, they have higher mortality than younger individuals and are at risk of social isolation after natural disasters.
For Dr Susan A Bartels and Dr Michael J Van Rooyen, please contact Sasha Chriss at the Harvard Humanitarian Initiative. T) +1 617 384 8368 E) hhipress@gmail.com
Journal
The Lancet