Cardiovascular manifestations of subarachnoid haemorrhage

Subarachnoid haemorrhage (SAH) is one of the devastating conditions, especially the aneurysmal bleed which has high mortality as well as morbidity. The mortality and morbidity caused by SAH have been recognised to be caused by both neurological and systemic causes. The alterations in systemic and other organ damage could cause death in up to 40% of SAH patients. Among the systemic manifestations, cardiovascular and respiratory complications increase hospitalisation and worsen the outcome. The main pathophysiological mechanism is the increased sympathetic activation causing myocardial necrosis. Various cardiovascular manifestations range from electrocardiogram changes to myocardial ischaemia, cardiac failure and arrhythmias. This review deals with the cardiac manifestations in SAH patients

Cerebral blood flow monitoring

Brain is a unique organ of the body that receives highest amount of cardiac output and totally depend on the blood supply for its survival and no reserve of blood flow making it vulnerable for ischaemia. Other important properties of cerebral circulation include autoregulation of blood flow, high oxygen extraction, and selective increase in blood flow to specific brain areas during various functional activities. It is important to understand that systemic and local factors affect the cerebral blood flow and the brain functions. Moreover the alterations in cerebral blood flow (acute or chronic) can be responsible for various symptoms as well as diseases pertaining to the brain. Hence it is important to measure the cerebral blood flow for the diagnostic as well as therapeutic purpose. This review focusses on the various techniques available for monitoring the cerebral blood flow

Correlation of systolic pressure variation, pulse pressure variation and stroke volume variation in different preload conditions following a single dose mannitol infusion in elective neurosurgical patients

Background: A Prospective observational study was designed assess the correlation between arterial pressure waveform derived indices and echocardiography derived stroke volume variation (SVV) at different preload conditions in patients undergoing elective craniotomies. Methods: Systolic pressure variation (SPV) and pulse pressure variation (PPV) were calculated from the arterial waveform. SVV was measured from transoesophageal echocardiography. After measuring baseline values for all three parameters, 1 g/kg of mannitol infusion (20%) was given over 15–20 min. Repeated measurements of SPV, PPV, SVV, urine output and peak airway pressure were done at the interval of 15, 30, 60, 90 and 120 min after stopping mannitol infusion. Pearson correlation coefficient (level of significance), and receiver operating characteristics curve were used for statistical analysis. Results: Significant correlation was present between SPV and SVV throughout the study. Significant correlation between SPV and PPV was present only at 90 min and 2 h after mannitol. The predictive effect of SPV and PPV in differentiating a volume loss ≥10 mL/kg was better than SVV. The best cut-off values for SPV, PPV and SVV were 12%, 9% and 20%, respectively. Conclusions: During mechanical ventilation with a tidal volume of 8 mL/kg, SPV correlated significantly with SVV at different preload conditions following mannitol infusion. PPV correlated poorly with SVV. SPV and PPV correlated only in the presence of hypovolaemia

A Rare Case of Drug Interaction Presenting as Perioperative Hyperthermia in a Patient Presenting for Neurosurgery

Perioperative hyperthermia has many differential diagnoses. This case report describes the rare causation of perioperative hyperthermia in a patient presenting for epilepsy surgery. The patient had two episodes of hyperthermia, initially post-anesthetic induction and later in the immediate post-operative period. The quest for the etiology sheds light on a rare drug interaction between topiramate, an antiepileptic drug, and glycopyrrolate causing intraoperative hyperthermia. However, the literature has not reported drug interaction between topiramate and glycopyrrolate resulting in perioperative hyperthermia. The combination of a glycopyrrolate-induced rise in temperature and oligohidrosis could have resulted in hyperthermia in our patient. Thus, it is prudent to avoid glycopyrrolate in the perioperative period when patients are on topiramate

Pediatric Microcuff Tube for Neurosurgical Procedures: A Boon or Bane?

Pediatric Microcuff endotracheal tubes have come into vogue in the last few years. It overcomes the problems faced with the uncuffed or conventional cuffed tubes used in the pediatric population. In addition, the more distal placement of the polyurethane cuffs in these tubes eliminates the risk of airway mucosal injury and hence postoperative stridor. This makes it an attractive option for neurosurgical patients where there is a high incidence of cranial nerve deficit, airway edema, and the requirement of prolonged postoperative ventilation. But due to this particular design, Murphy's eye is not incorporated in the tube, which can potentially hamper ventilation, especially when used for long duration surgery. With the help of our case report, we would like to warn the readers regarding this life-threatening complication that resulted in hypoxia in a 1-year-old child in the postoperative period