Measurement of Neutrophil Gelatinase-Associated Lipocalin (Ngal) Following Neuroradiological Procedure/s in Patients with Aneurysmal Subarachnoid Hemorrhage: A Preliminary Study.

Background: Radiocontrast administration during interventional neuroradiology (INR) procedures for aneurysmal subarachnoid haemorrhage (aSAH) can add to renal insult. Serum creatinine (sCr) is a conventional marker of acute kidney injury (AKI). Serum neutrophil gelatinase-associated lipocalin (sNGAL) is a novel marker which is increasingly used to predict renal injury in susceptible patients. Objectives: The primary aim of this study was to evaluate correlation between serum neutrophil gelatinase-associated lipocalin (NGAL) and sCr in aSAH patients undergoing therapeutic or diagnostic INR procedures. The secondary aim was to find the incidence of contrast-induced AKI and hemodynamic complications during the study period. Material and Methods: All consenting aSAH patients (18-60 years, Modified Hunt and Hess grade 1-4) posted for INR procedures during the study time were included. Patients with history of chronic renal disease, recent contrast exposure, or renal insufficiency were excluded. Blood samples for sCr and sNGAL were obtained preprocedure and then at 1, 6, 24, and 48 h after contrast administration. Hourly urine output was noted. AKI was defined by KDIGO guidelines. Statistical Analysis Used: Repeated measurement analysis of variance, Posthoc Bonferroni test and Pearson correlation coefficient test. Results: Fifty patients, mean age 47.34 ± 9.31 years, were enrolled for the study. Majority (48; 96%) were Hunt and Hess (H and H) grade I-III. The mean volume of contrast administered was 123.2 ± 53.08 mL. The mean sNGAL and sCr values at pre-op, 1, 6, 24, and 48 h were 124.99 ± 64.58, 148.40 ± 77.90, 147.33 ± 76.00, 125.49 ± 64.44, and 116.38 ± 61.79 ng/mL and 0.629 ± 0.23, 0.624 ± 0.22, 0.612 ± 0.21, 0.632 ± 0.19, and 0.577 ± 0.22 mg/dL, respectively. There was a correlation in sCr and sNGAL value (P < 0.001) at all study time points. However, no specific pattern was seen. No patient developed any AKI or hemodynamic complications in first 48 h. Conclusions: There is a correlation between serum NGAL and sCr at individual time points. NGAL may represent a sensitive early biomarker of renal impairment after INR Procedures. There was no incidence of AKI after contrast administration in aSAH patients without predisposing renal risk factors.

Perioperative anesthetic implications of epilepsy surgery: a retrospective analysis.

PURPOSE: Drug-resistant epilepsy (DRE) occurs in about 30 % of individuals with epilepsy. For seizure control, a wide range of surgical procedures are performed, depending on the underlying pathology. To address the anesthetic and perioperative concerns in these patients, we analyzed the data of persons with DRE who underwent epilepsy surgery at our institute. METHODS: A retrospective analysis of patients who underwent epilepsy surgery from 2005-2010 was performed. For data collection and analysis, patients were divided into three groups: Group I (temporal lobe epilepsy), Group II (extratemporal lobe epilepsy), and Group III (multilobar epilepsy and others). RESULTS: A total of 241 surgical procedures were performed on 235 persons with DRE. The procedures included temporal (149) and extratemporal (47) lobe resection, hemispherotomy (31), corpus callosotomy (5), vagus nerve stimulation (3), and implantation of invasive cerebral electrodes (6). General anesthesia was the more common anesthetic technique; awake craniotomy was performed in only five cases. Intraoperative neuromonitoring was used most frequently in Group II. Patients in Group III had the longest intraoperative course and the greatest blood loss. The overall incidence of postoperative mechanical ventilation was 17.84 %, with 53.84 % of patients in Group III alone. At one-year follow-up, a good outcome was seen in 78 % of temporal lobe resection, 55 % of extratemporal cortical resection, 82 % of hemispherotomy, and 80 % of corpus callosotomy procedures. CONCLUSIONS: Careful preoperative selection and meticulous perioperative management are the most significant factors for success of epilepsy surgery. Although temporal and extratemporal lobe surgeries have a fairly stable perioperative course, multilobar epilepsy requiring disconnective surgery poses a greater challenge.

Comparison of the effects of different anesthetic techniques on electrocorticography in patients undergoing epilepsy surgery - a bispectral index guided study.

AIM: It is well known that general anesthetics suppress/alter electrocorticography (ECoG) activity. However there are no randomized studies available, comparing various anesthetic techniques as regards their effects on ECoG. METHODS: The following is a double blind, randomized cross over study to compare the effects of isoflurane and propofol with or without nitrous oxide on electrocorticographic activity in patients undergoing epilepsy surgery. 40 patients suffering from medically intractable epilepsy scheduled to undergo resective surgery under ECoG guidance under general anesthesia, (March 2008-December 2010) were enrolled. Patients received either isoflurane or propofol (with air/oxygen or nitrous oxide/oxygen) as maintenance agents as per randomization and ECoG was recorded and quantified as per a scoring system (range 1-5, where 5 is most abnormal). RESULTS: The mean ECoG score in isoflurane group and propofol with nitrous oxide was 3.0(1.2), 3.2(1.2) [p=0.7] and with air was 3.9(1.0) and 3.4(1.1) [p=0.1] respectively. In both isoflurane group and propofol group addition of nitrous oxide depressed the ECoG score (p ≤ 0.01, 0.5 respectively). The total duration of anesthesia, surgery, emergence time, extubation time, and hospital stay was comparable in two groups. CONCLUSION: In our study optimal ECoG recordings were possible with use of either isoflurane or propofol. Addition of nitrous oxide to either of the anesthetic regimens suppressed the ECoG score.

Comparative evaluation of percutaneous retrogasserian glycerol rhizolysis and radiofrequency thermocoagulation techniques in the management of trigeminal neuralgia.

BACKGROUND: Among the percutaneous procedures for the treatment of trigeminal neuralgia, percutaneous anhydrous glycerol rhizolysis (PRGR) and radiofrequency (RF) ablation of trigeminal neuralgia have stood the test of time. OBJECTIVE: A prospective study was conducted to compare PRGR and RF ablation techniques in patients with trigeminal neuralgia in terms of (1) efficacy of pain relief, (2) duration of pain relief and (3) side effects. METHODS: All patients presenting to our pain clinic for the first time for the treatment of trigeminal neuralgia were enrolled to receive either PRGR or RF ablation; the treatment was chosen by the patient. Demographic data, magnetic resonance imaging scan, relevant medical disease, amount of anhydrous glycerol, lesion temperature, and total duration of RF were noted. The presence or absence of cerebrospinal fluid egress, immediate pain relief, duration of pain-free period, need for repeat injection or additional peripheral nerve block, and recurrence of pain were also noted. The degree of pain relief was recorded every 3 months. Any complications during the procedure and side effects were also recorded. RESULTS: Seventy-nine patients underwent either PRGR (n = 40) or RF thermocoagulation (n = 39). A total of 23 patients (58.9%) in the PRGR group and 33 patients (84.6%) in the RF group experienced excellent pain relief. The mean duration of excellent pain relief in the PRGR and RF groups was comparable. By the end of the study period, 39.1% patients in the PRGR group and 51.5% patients in the RF group experienced recurrence of pain. CONCLUSION: Both PRGR and RF techniques can achieve acceptable pain relief with minimal side effects.

Stellate ganglion block for treatment of cerebral vasospasm in patients with aneurysmal subarachnoid hemorrhage - A preliminary study.

BACKGROUND: Stellate ganglion block improves cerebral perfusion by decreasing the cerebral vascular tone. Its effects on cerebral vasospasm to relieve neurological deficits have not been evaluated. This prospective observational study was carried out to evaluate the effect of stellate ganglion block on cerebral hemodynamics in patients with symptomatic cerebral vasospasm following aneurysmal subarachnoid hemorrhage. MATERIALS AND METHODS: Fifteen patients of either sex, aged 18-75 years, who underwent surgical clipping of aneurysm and developed refractory cerebral vasospasm were included. Stellate ganglion block was performed using 10 ml of bupivacaine 0.5% on the side with maximum cerebral blood flow velocity. Neurological status, cerebral blood flow velocity and pulsatility index were assessed before and 10 minutes, 30 minutes, 2 hours, 6 hours, 12 hours and 24 hours after stellate ganglion block. RESULTS: Improved Glasgow coma score was observed 30 minutes after stellate ganglion block. Neurological deficits reduced in 11 patients. Ipsilateral middle cerebral artery mean flow velocity decreased from 133.66 cm/sec before stellate ganglion block to 110.53 cm/sec at 6 hours (P<0.001) and 121.62 cm/sec at 24 hours (P<0.001) after stellate ganglion block. There was a decrease in ipsilateral anterior cerebral artery mean flow velocity after stellate ganglion block (P<0.001), which persisted for 12 hours. A decline in flow velocities was observed in contralateral middle cerebral artery (P=0.008) and anterior cerebral artery (P=0.041) for 12 hours. CONCLUSION: This study suggests stellate ganglion block to be an effective modality of treatment for refractory cerebral vasospasm after aneurysmal subarachnoid hemorrhage.

Cerebral autoregulation and CO2 reactivity before and after elective supratentorial tumor resection.

BACKGROUND: The effect of surgical decompression of tumor on autoregulation and CO2 reactivity is not known. We examined the effect of elective tumor resection on cerebral autoregulation and CO2 reactivity. METHODS: Patients with supratentorial tumors undergoing elective craniotomy for tumor resection under standard anesthesia underwent cerebral autoregulation and CO2 reactivity testing immediately before and between 6 and 24 hours after surgery. Transient hyperemic response of the middle cerebral artery after the release of 10 second compression of the ipsilateral common carotid artery was used to calculate the transient hyperemic response ratio (THRR). THRR>1.1 defined the normal autoregulation. Voluntary hyperventilation was titrated to reduce the ETCO2 by 10 mm Hg below baseline and CO2 reactivity was calculated. RESULTS: Thirty-five patients (26 male and 9 female) were studied. Overall, cerebral autoregulation was intact before and after tumor resection for the cohort (THRR 1.27+/-0.10 and 1.30+/-0.12, P=0.11). However, cerebral autoregulation was impaired preoperatively in 7 (20%) patients and remained impaired in all 7 patients after tumor resection. Larger tumor size (P=0.002), and midline shift more than 5 mm (P<0.001) were associated with impaired cerebral autoregulation. Twenty-eight (80%) patients who had intact preoperative cerebral autoregulation maintained autoregulation postoperatively. CO2 reactivity was within normal limits before and after surgery in all patients and did not change between the 2 periods (3.41+/-0.46/mm Hg and 3.60+/-0.63%/mm Hg, P=0.07). CONCLUSION: Preoperative cerebral autoregulation was impaired in a significant number of patients with large supratentorial tumor size and midline shift more than 5 mm and was associated with postoperative impaired cerebral autoregulation during the first 24 hours after the surgery.

Effects of phenytoin therapy on bispectral index and haemodynamic changes following induction and tracheal intubation.

SUMMARY: Laryngoscopy and tracheal intubation (LTI) increase blood pressure and heart rate (HR). Intensity of these changes is influenced by the anaesthetic depth assessed by the bispectral index (BIS). We determined the effect of phenytoin on anaesthetic depth and its influence on haemodynamics following LTI. Fifty patients of ASA grades I and II on oral phenytoin 200 to 300mg per day for more than one week were compared with 48 control patients. Standard anaesthesia technique was followed. BIS, non invasive mean blood pressure (MBP) and HR were recorded 30, 60, 90 and 120 sec after LTI. Phenytoin group needed lesser thiopentone for induction, 5 mg (1.1) vs. 4.3 mg (0.7) [p=0.036]. BIS was significantly lower in the phenytoin group vs. the control 30, 60, 90 and 120 sec after LTI [43.1 (16.0) vs. 48.9 (14.9), p=0.068, 56.3 (16.7) vs. 64.3 (14.4), p=0.013, 59.8 (15.8) vs. 67.5 (12.1), p=0.008, 62.6 (14) vs. 68.9 (11.2), p=0.017, and 64.2 (11.3) vs. 69 (11.7), p=0.033], respectively. MBP was also lower in the phenytoin group 30, 60, 90 and 120 sec after LTI [112.8 mmHg (13.8), vs. 117.9 mmHg (18) p=0.013, 108.6 (12.8) vs. 117.5 (16) p=0.003, 106.1 mmHg (14.1) vs. 113.2 mmHg (14.9), p=0.017, 101.8 mmHg (13.8) vs. 109.5 mmHg (14.1), p=0.007], respectively. HR was lower in phenytoin group at 30 sec. (p=0.027), 60 sec (p=0.219), and again at 120 sec (p=0.022). Oral phenytoin therapy for over a week results in greater anaesthetic depth as observed using BIS, which also attenuated haemodynamic response of LTI.

Planning for early emergence in neurosurgical patients: a randomized prospective trial of low-dose anesthetics.

BACKGROUND: For early detection of a cerebral complication, rapid awakening from anesthesia is essential after craniotomy. Systemic hypertension is a major drawback associated with fast tracking, which may predispose to formation of intracranial hematoma. Although various drugs have been widely evaluated, there are limited data with regards to use of anesthetics to blunt emergence hypertension. We hypothesized that use of low-dose anesthetics during craniotomy closure facilitates early emergence with a decrease in hemodynamic consequences. METHODS: Three emergent techniques were evaluated in 150 normotensive adult patients operated for supratentorial tumors under standard isoflurane anesthesia. At the time of dural closure, the patients were randomized to receive low-dose propofol (3 mg.kg(-1).h(-1)), fentanyl (1.5 microg.kg(-1).h(-1)) or isoflurane (end-tidal concentration of 0.2%) until the beginning of skin closure. Nitrous oxide was discontinued after head dressing. RESULTS: Median time to emergence was 6 min with propofol, 4 min with fentanyl, and 5 min with isoflurane (P=0.008). More patients had hypertension in the pre-extubation compared with extubation or postextubation phase (P=0.009). Comparing the three groups, fewer patients required esmolol with fentanyl use overall, and in the pre-extubation phase (P=0.01). Significant midline shift in the preoperative cerebral imaging scans was found to be an independent risk factor for emergence hypertension. CONCLUSIONS: Pain during surgical closure may be an important cause of sympathetic stimulation leading to emergence hypertension. The use of low-doses of fentanyl during craniotomy closure is more advantageous than propofol or isoflurane for early emergence in neurosurgical patients and is the most effective technique for preventing early postoperative hypertension.

Rupture of intracranial aneurysm after partial clipping due to aspiration drainage system--a case report.

In neurosurgical practice, extradural or subgaleal drains are commonly placed and connected to a vacuum system. Several reports have described severe bradycardia or arterial hypotension, or both, after connection of negative suction pressure to the extradural or epicranial drains following craniotomy. We encountered an unusual complication with the use of the vacuum drain after an elective aneurysmal clipping surgery. Our case is an iatrogenic intracranial hypotension leading to a clinically significant and potentially fatal complication.

Is phenytoin administration safe in a hypothermic child?

A male neonate with a Chiari malformation and a leaking myelomeningocoele underwent ventriculoperitoneal shunt insertion followed by repair of myelomeningocoele. During anaesthesia and surgery, he inadvertently became moderately hypothermic. Intravenous phenytoin was administered during the later part of the surgery for seizure prophylaxis. Following phenytoin administration, the patient developed acute severe bradycardia, refractory to atropine and adrenaline. The cardiac depressant actions of phenytoin and hypothermia can be additive. Administration of phenytoin in the presence of hypothermia may lead to an adverse cardiac event in children. As phenytoin is a commonly used drug, clinicians need to be aware of this interaction.

Transient cardiac asystole in transsphenoidal pituitary surgery: a case report.

Unlike other cardiac arrhythmia, asystole during neurosurgical procedures is not reported in the literature. We describe such a case during transsphenoidal pituitary surgery in a patient who was not having any history of associated cardiac problems. Its possible cause in relation to the perioperative sequence of events has been discussed.

Effect of cerebrospinal fluid return on success rate of percutaneous retrogasserian glycerol rhizotomy.

BACKGROUND AND OBJECTIVE: Trigeminal neuralgia is a painful syndrome, which has been commonly treated with percutaneous retrogasserian glycerol rhizotomy (PRGR). This study was performed to evaluate the effect of cerebrospinal fluid (CSF) return on the success rate of PRGR. METHODS: In this retrospective, nonrandomized, observational case series, 100 cases underwent 140 PRGRs under fluoroscopic guidance and were followed up for 6 to 36 months. The results were compared in the presence or absence of CSF return before PRGR. RESULTS: The PRGR was successful in 115 procedures (82.1%). CSF return was present in 84 procedures (60%) and, among these, 76 PRGRs (90.5%) produced pain relief. More than 1 year of pain relief without medications was present in 60 of 84 procedures (71.4%). CSF return before PRGR was absent in 56 procedures (40%) and success resulted in 39 procedures (69.6%). Pain relief for more than 1 year without medications was present in 19 procedures (33.9%). The success rate and duration of pain relief was greater in the presence of CSF return compared with absence of CSF return (P < .005). The incidence of complications such as facial dysesthesia (40%), corneal anesthesia (2.8%), herpes simplex (3.5%), and nonbacterial meningitis (0.7%) was not significantly different in 2 groups ( P > .05). CONCLUSION: The presence of CSF is an important factor in determining the success rate and duration of pain relief of PRGR.