Pentylenetetrazol (PTZ) was injected into rats (30 or 35 mg/kg) and guinea pigs (40 or 45 mg/kg) daily or every second day. A progressive development of seizure activity after this treatment was observed. Doses ineffective after the first injection induced tonic seizures after 20 injections. Both kinds of treated animals immediately developed tonic seizures when PTZ was injected after a few months interruption for one time only. The results support the assumption that seizures induced by chronic injection of PTZ are similar to kindled seizures evoked by daily electrical stimulation and can be regarded as a model of epileptogenesis.

BACKGROUND: Myocardial injury after coronary artery bypass grafting (CABG) is defined as troponin concentrations >10 times 99th percentile upper reference limit (URL) according to the Fourth Universal Definition. However, troponin concentrations after non-CABG cardiac surgery which indicate greater-than-expected myocardial injury and increased risk for complications remain unclear. Our goal was to assess procedure-specific relationships between troponin T and a composite outcome of low cardiac output syndrome and in-hospital mortality in cardiac surgical patients. METHODS: Patients having cardiac surgery between January 2010 and December 2017 were categorized into 4 groups by procedure: (1) CABG; (2) mitral valve repair; (3) aortic valve repair/replacement (AVR); (4) mitral valve replacement (MVR) or CABG + valve surgeries. Exclusion criteria were elevated preoperative troponin T, preoperative kidney failure, circulatory arrest, or preoperative/planned mechanical circulatory support. Logistic regression was used to assess the association between troponin T and composite outcome, both overall and by procedure, including assessment of the interaction between procedure and troponin T on outcome. RESULTS: Among 10,253 patients, 37 (0.4%) died and 393 (3.8%) developed the primary outcome. Troponin T concentrations differed by procedure (P < .001). Compared to CABG, AVR had 0.53 (99.2% confidence interval [CI], 0.50-0.56; unadjusted P < .001) times lower troponin T concentrations, while MVR/CABG + valve were 1.54 (99.2% CI, 1.45-1.62, unadjusted P < .001) times higher. There were linear relationships between log 2 troponin T concentration and log odds mortality/low cardiac output syndrome. The (unadjusted) relationships were parallel for various types of surgery (interaction P = .59), but at different levels of the outcome. CONCLUSIONS: The relative increase in odds for mortality/low cardiac output syndrome per a similar increase in troponin T concentrations did not differ among cardiac surgical procedures, but the absolute troponin T concentrations did. Troponin concentrations should thus be interpreted in context of surgical procedure. (Anesth Analg 2022;134:1260-9) KEY POINTS• Question: Do postoperative troponin T concentrations differ by cardiac surgical procedure, and does the relationship between troponin T and postoperative outcomes also vary by procedure? • Findings: Troponin T concentrations after cardiac surgery were significantly different by procedure, though the association between troponin T concentrations and a composite of mortality and low cardiac output syndrome was not different. • Meaning: Postoperative troponin T concentration should be interpreted in the context of cardiac surgical procedure, though risk for mortality/low cardiac output syndrome increased to a similar extent with rising troponin T concentration across all procedures. GLOSSARYASA = American Society of Anesthesiologists; ASD = absolute standardized difference; AVR = aortic valve replacement/repair; BMI = body mass index; BUN = blood...

Lower extremity claudication is an extremely common symptom of peripheral vascular disease. Advancements in revascularization therapies often bring patients with this condition to the operating room, making this disease relevant for anesthesiologists. It is important to understand the comorbidities associated with this disease in order to assess the patient for readiness for the operating room. In addition, the dynamics of the procedure often necessitate certain intraoperative monitoring requirements. There is controversy regarding the best anesthetic management for these patients, whether it be general or neuraxial anesthesia. Finally, postoperative pitfalls and complications that can arise in the postoperative recovery area are discussed.

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Surgical resection of supratentorial brain tumors presents a unique set of challenges to the anesthesiologist. While symptoms from these lesions vary in presentation, increased intracranial pressure (ICP) is frequently part of the constellation and an important piece of anesthetic management. Along with maintenance of ICP, the goals of induction, maintenance, and emergence from these resections are to maintain cerebral blood flow (CBF) and cerebral metabolic rate and optimize neuroprotection. There is no single technique that is agreed upon in literature to encompass these goals, however a combination of IV anesthetics with low-dose volatile agents (0.5 MAC) is common in practice. Management of ICP is the hallmark of these cases since increased ICP may lead to ischemia, poor surgical visualization, and catastrophic herniation.