The heterogeneity in the literature may be explained by looking at inconsistent variables and lack of controlled studies. Nagpal et al. explored a different measure, cerebral hypoxia, because they noted that cerebral ischemia could occur despite normal ICP and CPP. The patient in their case study had elevated ICP to 38, but was able to bring down the threshold to the accepted 20 mm Hg with mannitol, although the cerebral oxygenation as noted by the PbtO₂ was deficient [9]. Although Bloomfield hypothesized that JVD and cerebral congestion were the cause of the elevated ICP, Nagpal, and Migletti postulate that the lung function is also critical [7–9]. Nagpal notes that DL may have a beneficial effect on ICP, but more so on PbtO₂ (cerebral oxygenation) by improving pulmonary gas exchange and blood pressure [9]. Migletti noted that DL reduces the positive pressure applied to the diaphragm, and this may shift the compliance curve of the lung. Improved compliance may allow improved buffering of volume and pressure changes from all compartments [8].

Efforts to decrease ACS with nonoperative measures to avoid decompressive laparotomy have been disappointing [11, 12]. Migletti found that paracentesis alone does not change the ICP significantly [8]. Continuous negative applied pressure (CNAP) to the abdominal wall failed to lower ICP in the absence of IAH. With IAH, there was improvement [11, 12].

In an effort to standardize the management of the patient with refractory ICP, Scalea et al. used their extensive experience to create an algorithm for management related to the multiple compartment syndrome [1, 4] (Fig. 16.1). The emphasis is on conventional management of initial elevated ICP as its primary management. Initial conventional interventions include maintaining and establishing airway, breathing and circulation. Achievement and maintenance of optimal physiology is used to prevent secondary injury. First tier recommendations (Table 16.2) should be continued until ineffective, then second tier, then consideration for heroic measures. Each of these measures should be checked and reinforced if there are deviations from the recommended management. Emphasis was placed on timing of interventions and continuing to reverse the process provoking the increased intracranial pressure. They emphasize awareness that many interventions may initially worsen the ICP. For example, fluid therapy to improve the mean arterial pressure (MAP) may lead to third space accumulation, worsening ICP and IAH.