TREATMENT OF INCREASED INTRACRANIAL PRESSURE IN NATURALLY TRAUMATIC BRAIN INJURY: COMPARISON BETWEEN MANNITOL AND HYPERTONIC SALINE: A PILOT STUDY

Increased intracranial pressure (ICP) is an important cause of secondary brain injury. Mannitol and Hypertonic Solutions of NaCl (HSS) are the gold standard to treat intracranial hypertension in case of traumatic brain injury (TBI). Aim of our study is to compare the effect of equimolar doses of Mannitol 18% and NaCl 3% solution in decreasing ICP in severe TBI. The study protocol was approved by the local Institutional Animal Care and Use Committee. This is prospective randomized study that involved stray animals admitted at the Veterinary Teaching Hospital between October 2010 and May 2015 with TBI and MGCS score ≤ 8 after hemodynamic stabilization. After extracranial therapy animals were anesthetized and Magnetic Resonance Imaging (MRI) was scheduled. Direct ICP was measured with Codman® Microsensor ® and cerebral perfusion pressure (CPP) was calculated . Data were measured at T1 and after 5-30-60-90-120 minutes (T2-T3-T4-T5-T6) after hyperosmolar therapy. CASE 1: 2-year-old, 4.2 kg male cat presented with MGCS 5. MRI showed signs of elevated ICP; suspected cerebellar hemorrhage, cerebellar herniation, secondary compression of the brain stem. T1: ICP 48 ± 2 mmHg and CPP 1±7 mmHg. The subject received NaCl 3%. T2: ICP and CPP unchanged. Fifteen minutes later brain herniation through the burr hole was observed; craniectomy was extended. T3: ICP 117±3 and CPP 15±8 mmHg. Because of deterioration of the patient's clinical condition, the cat was euthanized. CASE 2: 7 years old, 4.4 kg male adult cat with MGCS 8, with multiple lesions. MRI showed increased ICP, severe brain stem lesion, right hemisphere contusion, damage to the right extra cranial soft tissues. T1:ICP 27±3 mmHg; CPP 31±11 mmHg. Cat was treated with NaCl 3%. T2: ICP value 16±2 mmHg; CPP 46±7 mmHg. T3: ICP 14±1 mmHg; CPP 30±6 mmHg. T4: ICP 13±2 mmHg; CPP 81±13 mmHg. T5: ICP 13±2 mmHg; CPP 58±8 mmHg. T6: ICP 19±5 mmHg; CPP 63±15 mmHg. CASE 3: male mixed dog, of 8.4 kg, 6 years old with MGCS 7 with multiple lesions. MRI pointed out elevated ICP, severe impairment of the brain stem, right hemisphere contusion without mass effect and extra cranial soft tissues lesion. T1: ICP 21±1 mmHg, CPP 41±10 mmHg. The patient was treated with Mannitol 18%. T2: ICP value 17±2 mmHg; CPP 80±10 mmHg. T3: ICP 37±5 mmHg; CPP 54±2 mmHg. T4: ICP 34±4 mmHg; CPP 58±12 mmHg. T5: ICP 31±4 mmHg; CPP 89±4 mmHg. T6: ICP 32±3 mmHg; CPP 94±7 mmHg. To the author’s best knowledge, this is the first report comparing, in dogs and cats, MRI findings of raised ICP and direct ICP measurement. In this study MRI findings, suggested raising of ICP and localized the site and the extension of lesions. Elevated ICP were confirmed by direct measurements. Both Mannitol and NaCl 3% caused immediate decrease of ICP and rose in CPP compared with pre-treatment but ICP reduction was more prolonged after bolus with NaCl 3%. Further studies are required to better define the effects of these drugs on decreasing ICP in TBI patients. Francony G, Fauvage B, Falcon D, Canet C, Dilou H, Lavagne P. Equimolar doses of mannitol and hypertonic saline in the treatment of increased intracranial pressure. Crit Care Med 2008 36:795-800