Pain prevalence, assessment and treatment
The prevalence of acute pain in the population surviving this natural disaster was similar as that reported in pre-hospital settings  or EDs .
Figures of pain prevalence after earthquakes or natural disasters can be hardly compared due to the large number of variables including population size, city structure, and magnitude of the disaster . Our findings are on line with the report of the 2005 earthquake in Pakistan where up to 29% of the victims experienced some level of pain associated with trauma [23, 24]. In rescue conditions acute pain may range from severe pain (es. chest pain) associated with internistic diseases to algic syndromes where pain is the disease, as a distinct nosological entity. Thus, the double characteristic of pain, in itself  or comorbid event in multiple organic and psychiatric disorders , makes this issue of growing interest in catastrophe medicine .
Time-course of prevalence indicates that pain syndromes had the highest value in the first, second and fifth week. Similarly, pain syndromes with different characteristics, namely acute or chronic relapsed, had a biphasic time-course. During the first 15 days after the earthquake most of the acute pain syndromes were caused by traumatic events (fractures, lacerated-contused or incised wounds, joint distortion or dislocation), as a direct or indirect consequence of buildings collapse and nocturnal escape. During week five, pain prevalence increased because of work accidents during rebuilding and removal of rubble from the seismic areas. During week 3 and 4, the prevalence of traumatic cases decreased, but a relapsing of benign arthro-osteo muscular pain and immune reaction diseases, such as postherpetic neuralgia, fibromyalgia, rheumatoid arthritis and trigeminal neuralgia was documented.
The second group of pain syndromes was related to multiple causes, including psychosocial factors; among these causes stressful life conditions, such as living in tents, atmospheric agents, wide range of temperatures, small uncomfortable beds, hard physical work, daily life in emergency centers and unmet personal needs should be considered.
Adverse conditions are known to make the body more susceptible to pathologies, to activate neuroendocrine responses (adaptive, physiological and behavioral) and elicit adaptation processes specific for each person (allostasis) . Pain can be identified as a persistent chronic condition with an emotional impact, becoming in itself a stressing event. Thus, the relationship between stress and pain after a natural disaster is self-perpetuating .
This vicious circle may be interrupted by effective painkilling drugs, that prevent chronic pain, particularly in cases of post-traumatic pain, when an aggressive attitude in the administration of strong opioids and ketamine, should be recommended. Two painful conditions with double presentation, acute and relapsed, the primary headache and the low back pain, were pathologies with a considerable prevalence and severity, having a multi-factorial pathogenesis compared to other pain conditions [30, 31].
We also observed a higher threshold of pain, particularly in young people tirelessly rescuing the persons buried under rubble during the first few hours following the earthquake. On the other hand, we also reported a reduced threshold of pain, secondary to positive modulators, such as ancestral fear of death, deprivation of sleep, of food and intimacy, mourning, loss of house and social relationships. The influence of mood and mind status on pain perception has been documented by several studies , and so it has been demonstrated that antidepressant treatment may have a positive effect on pain . Psycho-cognitive and behavioral disorders reported in the present observational study have been constantly supported by a psychologist in AMPs.
These concepts are essential for understanding analgesic methods during natural disasters.
Severe pain has been reported in more than half of patients; unfortunately, this condition was often underestimated in the management of extrahospital emergency centers . The use of the v-NRS score as a vital parameter allowed us to have an objective evaluation of the problem . Pain scales are helpful for emergency practitioners engaged in disaster medicine after the 2009 earthquake in L’Aquila, as they represent an excellent clinical tool for the evaluation, treatment and follow-up of the patients .
In the present study, the most common drugs used for pain treatment included paracetamol, non- steroid antinflammatory drugs and weak opioids administrated in monotherapy in several cases. Pharmacological associations have been frequently used; the synergic mechanism of drugs combination obtained an adequate pain control and minimized individual doses and side effects. The rationale of our approach was to increase the therapeutic plan and drugs combination according to the type and pain intensity; this approach also supplied for the lack of opioid analgesics.
In front of a consistent prevalence of severe pain, strong opioids have been used only in small proportion of cases as monotherapy, in a smaller sample of patients they have been associated with adjuvants and/or NSAIDs; from these figures the need for an increased availability of narcotics drugs during a natural disaster is evident.
Efficacy of pain treatment was documented by a 4 points decrease of v-NRS score, immediately after treatment and at the second assessment. Efficacy and tolerability of drugs was substantially similar among the various therapeutic specialties, either in mono- or multiple-therapy. The high safety and efficacy profile of our simplified pharmacological protocols is probably related to the choice of drugs based on the assessment of pain intensity by v-NRS scale and clinical characteristics of painful conditions .
Another therapeutic strategy that we have adopted was assigning prophylactic drugs for the eventual side effects onset that resulted in absence of these events, as happens in the usual schemes adopted in our pain clinical practice.
Shortage of opioids during natural disasters did not only occur in our region, but has been documented in other areas after an earthquake ; this aspect is of major concern for the global community. Insufficient administration of strong opioids may depend on difficulties in finding, storing, prescribing and dispensing these drugs. Shortage of painkilling drugs, either opioids and non-opioids, in the first hours after the earthquake was related to difficulties in internal transports and transfer of drugs from and to the hospital pharmacy, which was seriously damaged. Also for these reasons, different forms of pain have been under treated and scarcely controlled, especially in the long-term. In such a disastrous condition, it was important that suffering people deprived from basic healthcare services (including laboratory and x-ray examinations) could at least be treated with major painkilling drugs, including strong opioids.