Effects of Hyperthermia on Intracranial Pressure and Cerebral Autoregulation in Patients with an Acute Brain Injury.

Hyperthermia is a common detrimental condition in patients with an acute brain injury (ABI), which can worsen their prognosis and outcome. The aim of this study was to evaluate the effects of hyperthermia on intracranial pressure (ICP) and cerebral autoregulation (CA).Eight patients with ABI were studied. CA was assessed on the basis of the pressure reactivity index (PRx) coefficient. The ICP, cerebral perfusion pressure (CPP), and PRx were compared before and during development of hyperthermia. Hyperthermia was defined as an increase in cerebral temperature above 38.3 °C.Thirty-three episodes of hyperthermia were analyzed: 25 of these occurred on a background of initially normal ICP whereas 8 occurred on a background of initially elevated ICP, and 17 of the 33 episodes occurred on a background of initially intact autoregulation whereas 16 occurred on a background of initially impaired autoregulation.During hyperthermia, elevated ICP was found in 52% of instances where it was initially normal, and further progression of intracranial hypertension occurred in 100% of instances where ICP was initially elevated. The median ICP during hyperthermia was 24 [range quartiles 22-28] mmHg in instances where it was initially normal and 31 [quartiles 27-32] mmHg in instances where it was initially elevated (p < 0.01). The correlation coefficient between the brain temperature and ICP was 0.11 (p < 0.01). During hyperthermia, the number of episodes of ICP >20 mmHg increased by 41% in instances with intact autoregulation but ICP was above 20 mmHg and by 38% (p > 0.05) in instances with impaired autoregulation and ICP was 20 mmHg. The cerebral hyperthermia-associated increase in ICP was not associated with impaired autoregulation.

Intra-abdominal hypertension in patients with sellar region tumors.

BACKGROUND: Data on intra-abdominal hypertension [IAH] and secondary abdominal compartment syndrome [ACS] due to neurological insults are limited. METHODS: This was a prospective observational study conducted between January 2010 and January 2011 in the neurological ICU [NICU]. Forty-one consecutive patients with sellar region tumors [SRT] were enrolled into the study. If conservative therapy was ineffective in patients with ACS, thoracic epidural anesthesia [EA] was performed. Primary endpoint was defined as the efficacy of conservative treatment and EA in patients with IAH and ACS; secondary endpoint, the influence of IAH and ACS on outcomes. RESULTS: Of the 41 patients, 13 (31.7%) had normal intra-abdominal pressure and 28 (68.3%) developed IAH, of whom 9 (22%) had ACS (group II). On average, IAH developed on the second postoperative day, while ACS, between the third and the fifth day. Multiple organ dysfunction developed in 3 (23.1%) patients of group I and in 23 (82%) patients of group II (p = 0.0003). Ileus due to gastrointestinal dysmotility was present in 6 (46.2%) patients of group I and in all patients of group II (p = 0.0001). Significant risk factors for ileus were diencephalon dysfunction (whole group - in 33 patients (80.5%); group I - in 6 patients (46.2%); group II - in 27 patients (96.4%), p = 0.0002) and sepsis (whole group - in 8 patients (19.5%); group I - no cases; group II - in 8 patients (28.6%), p = 0.03). Conservative treatment was effective in the majority of patients (78.9%) with IAH and only in 3 (33%) patients with ACS. Thoracic EA was performed in four patients with ACS with success. Length of stay in the NICU was 6.5 ± 4.6 days in group I and 24.1 ± 25.7 (p = 0.02) days in group II. Five out of nine (55.6%) patients with ACS died. None of these patients received EA. All patients with EA had favorable outcomes. CONCLUSION: The development of IAH is common after SRT surgery. If conservative treatment is ineffective, EA can be considered in patients with secondary ACS. Further studies are warranted.