Effect of Preanesthetic Fluid Loading on Postinduction Hypotension and Advanced Cardiac Parameters in Patients with Chronic Compressive Cervical Myelopathy: A Randomized Controlled Trial.

Purpose Hypotension during the early intraoperative phase is common and can lead to adverse perioperative outcomes. Fluid preloading is one of the methods to limit its occurrence. Patients with chronic compressive cervical myelopathy may have autonomic dysfunction, which can aggravate hemodynamic alterations during anesthesia. This study compared the occurrence of postinduction hypotension and changes in cardiac dynamic indices in patients with and without crystalloid preloading undergoing decompressive cervical spine surgery. Methods This randomized controlled trial was conducted over 15 months after obtaining patient consent, approval of the institute ethics committee, and trial registration. We compared preanesthetic fluid loading with Ringer's lactate (20 mL/kg over 30 minutes) with no preloading (2 mL/kg/h maintenance) in 60 consecutive patients undergoing cervical spine surgery. The ANSiscope was used to determine baseline cardiac autonomic function. Noninvasive cardiac output monitor was used to assess changes in heart rate, mean arterial pressure, cardiac index (CI), stroke volume variation (SVV), and total peripheral resistance index during study intervention, anesthetic induction, tracheal intubation, and change in position from supine to prone. Results The incidences of postinduction hypotension were 26.7% (8/30) and 86.7% (26/30) and the median doses of mephentermine used were 0 and 6 mg, respectively, in patients with and without fluid preloading (both p < 0.001). Preloading resulted in improvement in CI, reduction in SVV, and lesser vasopressor use. Conclusion Preloading reduced the occurrence of postinduction hypotension and vasopressor use, improved CI, and reduced SVV during the early intraoperative period. Registration number of Clinical Trial The trial was registered with Clinical Trial Registry of India (CTRI/2018/07/014970 on 19/07/2018).

Analgesia nociception index and hemodynamic changes during skull pin application for supratentorial craniotomies in patients receiving scalp block versus pin-site infiltration: A randomized controlled trial.

BACKGROUND: Noxious stimulation such as skull pin insertion for craniotomy elicits a significant hemodynamic response. Both regional analgesic techniques (pin-site infiltration [PSI] and scalp block [SB]), and systemic strategies (opioids, alpha-2 agonists, anesthetics, and beta-blockers) have shown to attenuate this response. Analgesia Nociception Index (ANI) provides objective information about the magnitude of nociception and adequacy of analgesia. This study compared ANI and hemodynamic changes in patients receiving local anesthetic SB versus PSI during skull pin application for craniotomy. MATERIALS AND METHODS: Sixty adult patients scheduled for elective supratentorial tumor surgery were randomly allocated to receive local anesthetic SB or PSI for skull pin insertion after the induction of anesthesia. Data regarding heart rate (HR), blood pressure (BP), and ANI were collected every minute for 5 min after the skull pin insertion beginning from the baseline. RESULTS: A significant difference was observed in ANI values between the SB (higher ANI) and the PSI groups during skull pin insertion, P < 0.001 and P = 0.003 for ANIi and ANIm, respectively. Similarly, a significant difference was seen in HR and BP both within and between the two groups during skull pin insertion (P < 0.001 for both). The magnitude and duration of change were smaller in the SB group compared with the PSI group for the parameters studied. A strong negative linear correlation was noted between ANI and hemodynamic parameters. CONCLUSIONS: The changes in HR, BP, and ANI were significantly less with local anesthetic SB compared with PSI during skull pin insertion in patients undergoing supratentorial craniotomy.

Effect of Atropine Premedication on Cardiac Autonomic Function During Electroconvulsive Therapy: A Randomized Crossover Study.

OBJECTIVES: Electroconvulsive therapy (ECT) results in significant cardiovascular changes. The acute cardiac autonomic changes during ECT remain unexplored. The primary objective of this study was to compare autonomic dysfunction with and without atropine premedication during ECT and secondarily to evaluate dysautonomia across psychiatric diagnoses before and after ECT. METHODS: In this crossover study, 41 psychiatric patients were monitored during 82 ECT sessions. Patients were randomized either to receive atropine or not to receive atropine during their second ECT session and were crossed over during their third session. Heart rate, blood pressure, and oxygen saturation were continuously monitored from stimulus application until 300 seconds after ECT. Demographic characteristics and ANSiscope indices derived pre- and post-ECT were collected. RESULTS: Autonomic dysfunction (%) before ECT was similar between atropine and no-atropine sessions (32.4 ± 15.7 vs 32.8 ± 16.7; 95% confidence interval, -7.6 to 6.7; P = 0.90) but increased significantly after ECT to 60.9 ± 16.3 and to 47.0 ± 17.3, respectively, and this difference was significant (95% confidence interval, 6.5-21.3; P < 0.001). There was no difference in the autonomic function across psychiatric diagnoses both before (P = 0.07) and after ECT (P = 0.12). CONCLUSIONS: Cardiac autonomic dysfunction worsens after ECT in patients with psychiatric illnesses and to a significantly greater extent with atropine premedication. The degree of dysautonomia is similar across various psychiatric diagnoses both before and after ECT. Atropine premedication during ECT should be restricted to select patients susceptible to bradyarrhythmia and could be avoided in others.

Dexmedetomidine anesthesia enhances spike generation during intra-operative electrocorticography: A promising adjunct for epilepsy surgery.

BACKGROUND: Anesthetic-induced suppression of cortical electrical activity is a major concern during epilepsy surgery. Dexmedetomidine (Dex) has been recently evaluated in a few small series for its effect on the electrocorticographic spikes intra-operatively. METHODS: In this prospective study, electrocorticogram (ECoG) was monitored during dexmedetomidine infusion in 34 patients (M:F=23:11, age=29.2 ± 10.9 years; duration of epilepsy=15.3 ± 8.9 years) undergoing anterior temporal lobe resection with amygdalo-hippocampectomy for drug-resistant mesial temporal lobe epilepsy (Right: 18, Left: 16). Anesthesia was induced with thiopental/propofol and maintained with oxygen-N2O-isoflurane. ECoG was recorded for 5 min after the end tidal MAC of N2O and isoflurane were decreased to zero; anesthesia was maintained with O2:Air=50:50, vecuronium and fentanyl. ECoG was recorded using a 4-contact strip electrode for: (a) 5 min prior to dexmedetomidine (PreDEX), (b) 5 min during dexmedetomidine infusion (DEX; 1 µg/kg) and (c) 5 min after stopping dexmedetomidine (PostDEX). RESULTS: The ECoG spikes were manually counted in all the channels. The mean spike rate in the 2 channels with maximum spikes (MAX CH A and MAX CH B) was normalized to a 3-min duration. RM-ANOVA and post hoc comparison of three phases were used to compare the spike rates. The mean spike rate during Dex phase was higher compared to preDEX (MAX CH B: p=0.007 and MAX CH A: p=0.079) and PostDEX (MAX CH B: p=0.17, MAX CH A: p=0.79) phases. The spike rate increased in 67.6% patients, while 11.8% patients showed ≤ 25% reduction and 20.6% patients showed >25% reduction in spike frequency. CONCLUSION: Dexmedetomidine is useful during intra-operative ECoG recording in epilepsy surgery as it enhances or does not alter spike rate in most of the cases, without any major adverse effects.

Successful anesthetic management for microsurgical excision of ruptured cerebellar arteriovenous malformation with trapped endovascular microcatheter.

Microsurgical excision and good anesthetic management of arteriovenous malformation (AVM) that ruptures during endovascular embolization can ensure good outcome despite per-procedural catastrophe. This case report illustrates the successful anesthetic management of microsurgical excision of ruptured AVM with entrapped microcatheter and highlights the role of the anesthesiologist in careful monitoring of the patient's hemodynamic status and communicating any changes to the radiology team to facilitate check angiography to diagnose the intracranial complication. This case highlights the need for anticipating and defining a catastrophe plan in advance of each interventional neuroradiology procedure as complications are rapid and require good multidisciplinary communication to ensure safe and successful outcomes.

Does hyperventilation improve operating condition during supratentorial craniotomy? A multicenter randomized crossover trial.

BACKGROUND: Hyperventilation has been an integral, but poorly validated part of neuroanesthetic practice. We conducted a two-period, crossover, randomized trial to evaluate surgeon-assessed brain bulk and measured intracranial pressure (ICP) in patients undergoing craniotomy for removal of supratentorial brain tumors during moderate hypocapnia or normocapnia. METHODS: Two-hundred and seventy-five adult patients with supratentorial brain tumors were randomized to one of two treatment sequences: hyperventilation (arterial carbon dioxide tension, PaCO2 = 25 +/- 2 mm Hg) followed by normoventilation (PaCO2 = 37 +/- 2 mm Hg) or normoventilation followed by hyperventilation. Ventilation and end-tidal CO2 tension were kept constant for 20 min. Patients were also randomly assigned to receive a propofol infusion or isoflurane anesthesia. At the end of each study period, subdural ICP was measured and the neurosurgeon, blinded to the treatment group, was asked to rate the brain bulk using a four-point scale. RESULTS: Using a generalized estimation equation model, we found that hyperventilation decreased the risk of increased brain bulk by 45%, P = 0.004, 95% confidence intervals 22% to 61%, and the number needed to treat was 8. The mean (+/-SD) ICP during hyperventilation, 12.3 +/- 8.1 mm Hg, was lower than that during normoventilation, 16.2 +/- 9.6 mm Hg, P < 0.001. Anesthetic regimen did not affect brain bulk assessment or ICP. CONCLUSIONS: In patients with supratentorial brain tumors, intraoperative hyperventilation improves surgeon-assessed brain bulk which was associated with a decrease in ICP.