Rationale and study design for an Individualized PeriopeRative Open lung VEntilatory approach in Emergency Abdominal Laparotomy/scopy: study protocol for a prospective international randomized controlled trial

BACKGROUND

Postoperative pulmonary complications (PPC) are the most frequent postoperative complications, with an estimated prevalence in elective surgery ranging from 20% in observational cohort studies to 40% in randomized clinical trials. However, the prevalence of PPCs in patients undergoing emergency abdominal surgery is not well defined. Lung-protective ventilation aims to minimize ventilator-induced lung injury and reduce PPCs. The open lung approach (OLA), which combines recruitment manoeuvres (RM) and positive end-expiratory pressure (PEEP) titration, aims to minimize areas of atelectasis and the development of PPCs; however, there is no conclusive evidence in the literature that OLA can prevent PPCs. The purpose of this study is to compare an individualized perioperative OLA with conventional standardized lung-protective ventilation in patients undergoing emergency abdominal surgery with clinical signs of intraoperative lung collapse.

METHODS

Randomized international clinical trial to compare an individualized perioperative OLA (RM plus individualized PEEP and individualized postoperative respiratory support) with conventional lung-protective ventilation (standard PEEP of 5 cmH2O and conventional postoperative oxygen therapy) in patients undergoing emergency abdominal surgery with clinical signs of lung collapse. Patients will be randomised to open-label parallel groups. The primary outcome is any severe PPC during the first 7 postoperative days, including: acute respiratory failure, pneumothorax, weaning failure, acute respiratory distress syndrome, and pulmonary infection. The estimated sample size is 732 patients (366 per group). The final sample size will be readjusted during the interim analysis.

DISCUSSION

The Individualized Perioperative Open-lung Ventilatory Strategy in emergency abdominal laparotomy (iPROVE-EAL) is the first multicentre, randomized, controlled trial to investigate whether an individualized perioperative approach prevents PPCs in patients undergoing emergency surgery.

An Early Pleistocene hominin mandible from Atapuerca-TD6, Spain

We present a mandible recovered in 2003 from the Aurora Stratum of the TD6 level of the Gran Dolina site (Sierra de Atapuerca, northern Spain). The specimen, catalogued as ATD6-96, adds to the hominin sample recovered from this site in 1994-1996, and assigned to Homo antecessor. ATD6-96 is the left half of a gracile mandible belonging to a probably female adult individual with premolars and molars in place. This mandible shows a primitive structural pattern shared with all African and Asian Homo species. However, it is small and exhibits a remarkable gracility, a trait shared only with the Early and Middle Pleistocene Chinese hominins. Furthermore, none of the mandibular features considered apomorphic in the European Middle and Early Upper Pleistocene hominin lineage are present in ATD6-96. This evidence reinforces the taxonomic identity of H. antecessor and is consistent with the hypothesis of a close relationship between this species and Homo sapiens.

Short human occupations in the Middle Palaeolithic level I of the Abric Romani rock-shelter (Capellades, Barcelona, Spain)

This paper presents a multidisciplinary study on the size of the occupied surfaces, provisioning strategies and behaviour planning at the Romani rock-shelter, using the Middle Palaeolithic record of the level i. This level is dated around 46.000 BP through U/Th ages. A behavioural interpretation is proposed, which emphasises the activities and the systemic value of the archaeological artefacts and structures. Occupation patterns are identified on the basis of the accumulations formed by human activities. These archaeological accumulations, consisting of artefacts and hearths, are easily defined visually as spatial units. The relationships between these accumulations, established by means of refitted remains, indicate that differences can be established between: 1) small and medium-sized occupation surfaces; 2) restricted and diversified provisioning strategies. This variability suggests that different modes of occupation are represented in the same archaeological level. The human activities reveal the generalization of fire technology. In almost all sizes of the occupation surfaces, the exploitation of vegetal resources near the Abric Romani marks the threshold of the restricted provisioning strategy. Limited use and fragmented knapping activities are recorded in the lithic assemblage. Faunal remains show differential transport. The exploitation of lithic, faunal and vegetal resources characterizes the diversified provisioning strategy. The small occupation surfaces and restricted provisioning strategies suggest short settlements in the Abric Romani. This shorter occupation model complements the longer diversified provisioning strategy recorded in both small and medium-sized occupied surfaces. The selection of precise elements for transport and the possible deferred consumption in the diversified provision strategy suggest an individual supply. In this respect, Neanderthal occupations in the Romani rock-shelter show a direct relation to: 1) hunting strategic resources; 2) high, linear mobility.