Comparative evaluation of intraoperative use of normal saline, Ringer's lactate, and combination of normal saline and Ringer's lactate in neurosurgical patients - A preliminary randomized clinical trial.

BACKGROUND: Fluid management during intracranial surgery is an important concern. The type of fluid used can have biochemical and metabolic effects during intraoperative management. However, it is yet to be known whether biochemical and metabolic effects have an influence on the clinical outcome of a patient. OBJECTIVE: A prospective evaluation of the effects of normal saline (NS), Ringer's lactate (RL), and a combination of NS and RL on the biochemical, metabolic, and clinical outcomes in patients undergoing intracranial tumor surgery was carried out. MATERIALS AND METHODS: Ninety patients undergoing elective intracranial tumor surgery were randomized to receive NS, RL, or a combination of NS and RL. The biochemical and metabolic parameters were studied at different time points in the intraoperative and postoperative period. The hemodynamic parameters, brain relaxation score at the time of bone flap elevation, postoperative complications, and the duration of hospital stay were the clinical outcome variables of our study. RESULTS: The use of NS was associated with hyperchloremic metabolic acidosis and ionic hypocalcemia. RL caused significant hyponatremia and increase in serum lactate levels. The combination of NS and RL has least influence on biochemical and metabolic parameters. The effects of three fluids were similar on the hemodynamics, brain relaxation score, as well as on postoperative complications and the duration of postoperative hospital stay. CONCLUSION: There are variable effects of NS, RL, or its combination on the biochemical and metabolic parameters in patients undergoing intracranial tumor surgery. However, the clinical outcome of the patients remains similar.

Post-operative pulmonary complications in patients undergoing transoral odontoidectomy and posterior fixation for craniovertebral junction anomalies.

BACKGROUND: In patients with craniovertebral junction (CVJ) anomalies, the respiratory system is adversely affected in many ways. The sub-clinical manifestations may get aggravated in the postoperative period owing to anesthetic or surgical reasons. However, there is limited data on the incidence of postoperative pulmonary complications (PPCs) and associated risk factors in such patients, who undergo transoral odontoidectomy (TOO) and posterior fixation (PF) in the same sitting. MATERIALS AND METHODS: Five years data of 178 patients with CVJ anomaly who underwent TOO and PF in the same sitting were analyzed retrospectively. Preoperative status, intraoperative variables, and PPCs were recorded. Patients were divided into two groups depending on the presence or absence of PPCs. Bivariate analysis was done to find out association between various risk factors and PPCs. Multivariate analysis was done to detect relative contribution of the factors shown to be significant in bivariate analysis. P < 0.05 was considered as significant. RESULTS: The incidence of PPCs was found to be 15.7%. Factors significantly associated with PPCs were American Society of Anesthesiologists grade higher than II, preoperative lower cranial nerves palsy and respiratory involvement, duration of surgery, and intraoperative blood transfusion. In multivariate analysis, blood transfusion was found to be the sole contributing factor. The patients who developed PPCs had significantly prolonged stay in ICU and hospital. CONCLUSION: Patients with CVJ anomaly are at increased risk of developing PPCs. There is a strong association between intraoperative blood transfusion and PPCs. Patients with PPCs stay in the ICU and hospital for a longer period of time.

Effect of intraoperative dexmedetomidine on postoperative recovery profile of children undergoing surgery for spinal dysraphism.

BACKGROUND: Smooth recovery from anesthesia is desirable in children undergoing surgery for spinal dysraphism who are nursed in prone position during the postoperative period. Dexmedetomidine may be beneficial in these children owing to its sedative, anxiolytic, and opioid-sparing properties with minimal respiratory depression. METHODS: Thirty-six children with spinal dysraphism at lumbosacral area, aged 8 to 12 years, undergoing corrective surgery were randomized to receive either dexmedetomidine or volume-matched saline (placebo) after positioned prone until beginning of skin closure. Inspired concentration of sevoflurane was changed to keep the bispectral index score between 45 and 55. Perioperative hemodynamics, intraoperative fentanyl and sevoflurane consumption, and postoperative recovery profile and fentanyl consumption was observed by blinded observers. Postoperative pain, emergence agitation (EA), and discharge readiness from postanesthesia care unit was evaluated using the modified objective pain score, agitation Cole score, and modified Aldrete score, respectively. Fentanyl 0.5-1 µg/kg was administered for pain (objective pain score ≥4) or severe EA (agitation Cole score ≥4) lasting for >5 minutes. RESULTS: The 2 groups did not differ significantly with respect to demographics, duration of anesthesia, emergence, and extubation times. The intraoperative consumption of sevoflurane and fentanyl was significantly less in dexmedetomidine group (0.2±0.1 vs. 0.3±0.1 mL/min, P<0.0001 and 2.3±0.5 vs. 3.1±0.6 µg/kg, P=0.0001, respectively), along with a lower mean heart rate (P<0.001). The mean systolic blood pressure (P=0.98) and incidence of bradycardia and hypotension was comparable in between the 2 groups. Postoperatively, the children in dexmedetomidine group had significantly lower pain scores (P<0.0001), agitation scores (P<0.0001), and time to achieve full modified Aldrete score [0 (0 to 10) vs. 10 (0 to 20) min, P=0.001]. The postoperative consumption of fentanyl was significantly less in dexmedetomidine group [0 (0 to 1.04) vs. 0.88 (0 to 3) µg/kg, P=0.003], along with a longer time of first analgesic requirement [600 (5 to 2100) vs. 5 (5 to 185) min, P=0.0001]. The mean heart rate and systolic blood pressure were higher in placebo group (P<0.001), whereas no difference was observed in respiratory rate (P=0.73) and arterial oxygen saturation (P=0.36). The number of patients with postoperative nausea and vomiting was significantly lower in dexmedetomidine group [2 (11.1%) vs. 9 (50%), P=0.03]. CONCLUSIONS: Intraoperative use of dexmedetomidine in children undergoing spinal surgery results in a favorable recovery profile with reduced postoperative pain and EA, without adverse perioperative hemodynamic effects.

Anaesthesia for neurosurgical procedures in paediatric patients.

Recent advances in neurosurgery, neuromonitoring and neurointensive care have dramatically improved the outcome in patients affected by surgical lesions of central nervous system (CNS). Although most of these techniques were applied first in the adult population, paediatric patients present a set of inherent challenges because of their developing and maturing neurological and physiological status, apart from the CNS disease process. To provide optimal neuroanaesthesia care, the anaesthesiologist must have the knowledge of basic neurophysiology of developing brain and effects of various drugs on cerebral haemodynamics apart from the specialised training on paediatric neuroanaesthesia. This article highlights on the perioperative management of paediatric neurosurgical patients.

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.

Perioperative management of children with encephalocele: an institutional experience.

BACKGROUND: Encephaloceles are neural tube defects that are characterized by protrusion of the brain and meninges through a defect in the cranium. The inherent implications of pediatric anesthesia and difficult airway make surgical correction challenging for anesthesiologists METHODS: Available medical records of 118 children who underwent excision and repair of encephalocele over a period of 10 years were analyzed retrospectively. Data on associated anomalies, anesthetic management, perioperative complications, and outcome at discharge were reviewed. RESULTS: The average age of presentation was 1 year and 6 months. The most common site of lesion was the occiput (67%). Encephaloceles were giant (size of sac larger than the head) in 15.3% of children. Hydrocephalus was the most common complication (45.8%) and was predominantly associated in children with occipital encephaloceles (P=0.00). Difficult mask ventilation and intubation were encountered in 5.9% and 19.5% of children, respectively. In children with occipital encephalocele, the trachea was intubated commonly by direct laryngoscopy in the lateral position (47.5%). The average blood loss was 69.6±13.2 mL, and 56 children required transfusion, the average being 13.2±9.6 mL/kg. Intraoperative hemodynamic disturbances and respiratory complications were observed in 21.1% and 13.5% of children, respectively. The mean intensive care unit and hospital stay were 1.8±2.1 and 8.6±4.9 days, respectively. The stays were prolonged significantly whenever the children developed hydrocephalus, meningitis, and respiratory infection, predisposing to poor outcome. CONCLUSIONS: Difficult airway is not the only concern in children with encephalocele, but associated congenital malformations, hydrocephalus, large size of sac, and hemodynamic disturbances all require careful consideration.

A comparative evaluation of nitrous oxide-isoflurane vs isoflurane anesthesia in patients undergoing craniotomy for supratentorial tumors: A preliminary study.

BACKGROUND: Neuroanesthesiologists are a highly biased group; so far the use of nitrous oxide in their patient population is concerned. We hypothesized that any adverse consequence with use of nitrous oxide should affect the patient so as to prolong his/her stay in the hospital. The primary aim of this preliminary trial was to evaluate if avoidance of nitrous oxide could decrease the duration of Intensive Care Unit (ICU) and hospital stay after elective surgery for supratentorial tumors. PATIENTS AND METHODS: A total of 116 consecutive patients posted for elective craniotomy for various supratentorial tumors were enrolled between April 2008 and November 2009. Patients were randomly divided into Group I: Nitrous oxide - Isoflurane anesthesia (Nitrous oxide-based group) and Group II - Isoflurane anesthesia (Nitrous oxide-free group). Standard anesthesia protocol was followed for all the patients. Patients were assessed till discharge from hospital. RESULTS: The median duration of ICU stay in the nitrous group and the nitrous-free group was 1 (1 - 11 days) day and 1 (1 - 3 days) day respectively (P = 0.67), whereas the mean duration of hospital stay in the nitrous group was 4 (2 - 16) days and the nitrous free group was 3 (2 - 9) days (P = 0.06). The postoperative complications in the two groups were comparable. CONCLUSION: From this preliminary study with a low statistical power, it appears that avoidance of nitrous oxide in one's practice may not affect the outcome in the neurosurgical patients. Further large systemic trials are needed to address this issue.

Intensive care management of patients with acute intermittent porphyria: Clinical report of four cases and review of literature.

Acute intermittent porphyria (AIP), the most common and the most severe form of acute hepatic porphyria, is an autosomal dominant condition. It results from lower-than-normal levels (less than 50%) of porphobilinogen (PBG) deaminase. Patients may present commonly with gastrointestinal complaints and neuropsychiatric manifestations. Diagnosis may be confirmed with the presence of intermediary metabolites of haem synthesis, amino levulinic acid (ALA) and PBG in urine or with specific enzyme assays. Abdominal pain is the most common symptom (90%). Peripheral polyneuropathy, primarily motor with flaccid paresis of proximal musculature, with or without autonomic involvement, is characteristic. Respiratory failure necessitates ventilator and intensive care support. Avoidance of precipitating factors and the use of haem preparations and intravenous dextrose form the basis of management. Gabapentin and propofol, rather than the conventional antiepileptics appear to be the appropriate choice for seizure control. Here, we present intensive care management of four cases of AIP with varying clinical presentation.

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.