Evaluation of Cerebral Perfusion Pressure, Cerebral Blood Flow, and Cerebral Oxygenation at Different Head of Bed Positions Using Transcranial Doppler and Near-Infrared Spectroscopy in Postoperative Neurosurgical Patients.

OBJECTIVES: Nursing postoperative neurosurgical patients with head of bed (HOB) elevation beyond 30° might be desired at times to prevent pulmonary complications. Due to the paucity of studies determining the effect of HOB beyond 30° on cerebral perfusion pressure (CPP), cerebral blood flow (CBF), and regional cerebral oxygenation (rSO2), this study was designed. METHODS: A total of 40 patients following elective neurosurgery for supratentorial tumors were studied in the neurosurgical intensive care unit three hours following admission. They were assessed for CBF velocities of middle cerebral arteries on either side using transcranial color Doppler (TCCD), rSO2 using near-infrared spectroscopy (NIRS), and mean arterial pressure measured at tragus level at various HOB positions. The estimated cerebral perfusion pressure (CPPe) was calculated from TCCD parameters, and the estimated intracranial pressure (ICPe) was then derived. Their variations at different HOB positions were noted. RESULTS: TCCD parameters such as peak systolic velocity (PSV) and mean flow velocity (MFV) did not significantly vary upon elevating HOB from 0° to 30° but reduced significantly when HOB was further elevated to 60° (p < 0.05). ICPe reduced significantly with a change of HOB positions from 0° to 60° (p < 0.001), and a significant reduction in CPPe was noticed when HOB was elevated to 60° (67.2 ± 10.1 mmHg vs. 74.7 ± 11.2 mmHg at 0°). However, none of these HOB positions affected rSO2 values. CONCLUSION: Postoperative nursing with positions up to 60° HOB can be tried in indicated patients following elective neurosurgery when complemented with CBF velocity and rSO2 monitoring and in whom CPP-guided therapy is not preferred.

Role of multimodal monitoring in the management of patients undergoing complex intracranial bypass procedures - A case series and literature review.

Patients undergoing complex intracranial neurovascular procedures continue to have a high mortality rate. Individualised goal-directed cerebral resuscitation employing multimodality neuromonitoring may impact these patients' treatment and prognosis. Advanced monitoring methods aid in the early identification of secondary brain insults and serve as endpoints for goal-directed therapy in the perioperative period. Unfortunately, there is a paucity of literature exploring the impact of multimodality monitoring and its outcome in these patients. We aim to present this case series wherein the patients had a favourable outcome post-intracranial complex bypass procedure, owing to goal-directed management guided by multimodality monitoring in the perioperative period.

Near-Infrared Spectroscopy-Guided Hyperventilation for Transient Intracranial Pressure Control during Anesthesia Induction in a Patient with Impending Uncal Herniation.

Near-infrared spectroscopy (NIRS) is known to determine the adequacy of regional cerebral oxygen supply. NIRS values during anesthetic induction depends upon various factors such as anesthetic agents, inspired oxygen fraction, blood carbon dioxide levels and systemic blood pressure. Also high intracranial pressure (ICP) can lead to reduced NIRS values, secondary to increased cerebral vascular resistance induced decrease in cerebral blood flow. However optimal hyperventilation instituted as a bridge to definitive ICP management is difficult to ascertain as hypocapnia due to poorly titrated hyperventilation can potentially worsen ICP. Here we describe a novel application of NIRS-guided hyperventilation during anesthesia induction in a brain tumor patient with raised ICP features and impending uncal herniation as suggested by computed tomography (CT) scan, with ipsilateral baseline reduced NIRS values. These ipsilateral NIRS values further reduced significantly during anesthesia induction even before profound bradycardia occurred, which promptly improved to baseline following hyperventilation.

Anesthetic Management of Hashimoto's Encephalopathy Presenting for Spine Surgery.

Hashimoto's encephalopathy (HE) is a rare neuroendocrine disorder, and there are no reports regarding anesthetic implications in a patient diagnosed with HE. These patients can have a plethora of systemic manifestations involving cardiovascular, respiratory, renal, gastrointestinal, hematologic, and central nervous systems. Once diagnosed, meticulous preoperative assessment is essential to rule out systemic involvement and to reduce the perioperative morbidity. Perioperative steroid therapy, neuromonitoring in the perioperative period, opioid free analgesia, and avoidance of nephrotoxic drugs are of paramount importance in the management of such patients. Awareness of the clinical condition and extreme vigilance can detect relapses in the perioperative period. Thus, a meticulous preoperative assessment, balanced anesthesia, perioperative neuromonitoring, and steroid therapy are essential to reduce the perioperative morbidity.

A Mysterious Case of Spontaneous Cervical Epidural Hematoma and Bilateral Primary Spontaneous Pneumothorax Caused by a Rare Etiology.

Spontaneous spinal epidural hematoma (SSEH) is a rare disorder that can present as an acute onset of pain and radicular symptoms that mimic disc herniation. Primary spontaneous pneumothorax (PSP) can be defined as the presence of air in the pleural space without apparent underlying lung disease or trauma. We describe a rare case of SSEH in the cervical spine (C5-7) presenting with a novel association, a bilateral PSP, which has never been documented before. Both SSEH and spontaneous pneumothorax, though rare, can be associated with vasculopathy and our patient had signs of vasculopathy of intracranial vessels and pulmonary vasculature. Vasculopathy also needs to be considered while evaluating a case of PSP without emphysema-like changes (ELC) and if diagnosed as the cause, pleurodesis could be considered as a part of the management to avoid the sequel of recurrent pneumothorax and prolonged ICU stay in this subset of patients. HOW TO CITE THIS ARTICLE: Thakkar K, Ajayan N, Unnikrishnan P, Sethuraman M, Hrishi AP. A Mysterious Case of Spontaneous Cervical Epidural Hematoma and Bilateral Primary Spontaneous Pneumothorax Caused by a Rare Etiology. Indian Journal of Critical Care Medicine, January 2019;23(1):51-53.