The goal of therapy for bradycardia or tachycardia is to rapidly identify and treat patients who are hemodynamically unstable or symptomatic due to the arrhythmia. Drugs or, when appropriate, pacing may be used to control unstable or symptomatic bradycardia. Cardioversion or drugs or both may be used to control unstable or symptomatic tachycardia. ACLS providers should closely monitor stable patients pending expert consultation and should be prepared to aggressively treat those with evidence of decompensation.

/pdf/part-8-adult-advanced-cardiovascular-life-support-2010-344vtppnij.pdf

Part 8: Adult Advanced Cardiovascular Life Support 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care

https://journal.chestnet.org/article/s0012-3692(12)60127-5/pdf

Perioperative Management of Antithrombotic Therapy: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

Evolution of Nervous Control from Primitive Organisms to Man A Symposium organized by the Section on Medical Sciences of the American Association for the Advancement of Science, and presented at the New York Meeting on December 29–30, 1956. Edited by Allan D. Bass. Pp. vii + 231. (Washington, D.C.: American Association for the Advancement of Science; London: Bailey Bros. and Swinfen, Ltd., 1959.) 52s.

The Central Nervous System

https://www.armv-paca.org/index.php/mediatheque-full/recommandations-1/mtev-1/accp-2008-1/145-the-perioperative-management-antithrombotic-pdf-1/file

The perioperative management of antithrombotic therapy: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition).

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Objectives. Low-dose aspirin given for secondary prevention of cardiovascular disease is frequently withdrawn prior to surgical or diagnostic procedures to reduce bleeding complications. This may expose patients to increased cardiovascular morbidity and mortality. Aim of the study was to review and quantify cardiovascular risks because of periprocedural aspirin withdrawal and bleeding risks with the continuation of aspirin.

Methods.  We screened MEDLINE (January 1970–October 2004) with additional manual cross-referencing for clinical studies, surveys on the opinions of doctors and guidelines.

Results.  Studies reporting the relative risk of acute cardiovascular events after aspirin withdrawal when compared with its continuation were not found. However, retrospective investigations revealed that aspirin withdrawal precedes up to 10.2% of acute cardiovascular syndromes. The time interval between discontinuation and acute cerebral events was 14.3 ± 11.3 days, 8.5 ± 3.6 days for acute coronary syndromes, and 25.8 ± 18.1 days for acute peripheral arterial syndromes (P < 0.02 versus acute coronary syndromes). On aspirin-related bleeding risks, we obtained 41 (12 observational retrospective, 19 observational prospective, 10 randomized) studies, reporting on 49 590 patients (14 981 on aspirin). Baseline frequency of bleeding complications varied between 0 (skin lesion excision, cataract surgery) and 75% (transrectal prostate biopsy). Whilst aspirin increased the rate of bleeding complications by factor 1.5 (median, interquartile range: 1.0–2.5), it did not lead to a higher level of the severity of bleeding complications (exception: intracranial surgery, and possibly transurethral prostatectomy). Surveys amongst doctors on the management of this problem demonstrate wide variations. Available guidelines are scarce and in part contradictory.

Conclusions.  Only if low-dose aspirin may cause bleeding risks with increased mortality or sequels comparable with the observed cardiovascular risks after aspirin withdrawal, it should be discontinued prior to an intended operation or procedure. Controlled clinical studies are urgently needed.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2796.2005.01477.x

Low-dose aspirin for secondary cardiovascular prevention - cardiovascular risks after its perioperative withdrawal versus bleeding risks with its continuation - review and meta-analysis.

H. VIERTIÖ-OJA, V. MAJA, M. SÄRKELÄ, P. TALJA, N. TENKANEN, H. TOLVANEN-LAAKSO, M. PALOHEIMO, A. VAKKURI, A. YLI-HANKALA and P. MERILÄINEN Datex-Ohmeda Division, Instrumentarium Corp., Helsinki, Department of Anesthesia, Eye and Ear Hospital, Helsinki University Hospital, Helsinki, Department of Anesthesia, Surgical Hospital, Helsinki University Hospital, Helsinki, Department of Anesthesia, Tampere University Hospital, and University of Tampere, Medical School, Tampere, and Instrumentarium Corp., Helsinki, Finland

/pdf/description-of-the-entropy-algorithm-as-applied-in-the-datex-dx0r80l6a9.pdf

Description of the Entropy algorithm as applied in the Datex-Ohmeda S/5 Entropy Module.

Background Inadequate analgesia during general anaesthesia may present as undesirable haemodynamic responses. No objective measures of the adequacy of analgesia exist. We aimed at developing a simple numerical measure of the level of surgical stress in an anaesthetized patient. Methods Sixty and 12 female patients were included in the development and validation data sets, respectively. All patients had elective surgery with propofol–remifentanil target controlled anaesthesia. Finger photoplethysmography and electrocardiography waveforms were recorded throughout anaesthesia and various waveform parameters were extracted off-line. Total surgical stress (TSS) for a patient was estimated based on stimulus intensity and remifentanil concentration. The surgical stress index (SSI) was developed to correlate with the TSS estimate in the development data set. The performance of SSI was validated within the validation data set during and before surgery, especially at skin incision and during changes of the predicted remifentanil effect-site concentration. Results SSI was computed as a combination of normalized heart beat interval (HBInorm) and plethysmographic pulse wave amplitude (PPGAnorm): SSI=100–(0.7*PPGAnorm+0.3*HBInorm). SSI increased at skin incision and stayed higher during surgery than before surgery; SSI responded to remifentanil concentration changes and was higher at the lower concentrations of remifentanil. Conclusions SSI reacts to surgical nociceptive stimuli and analgesic drug concentration changes during propofol–remifentanil anaesthesia. Further validation studies of SSI are needed to elucidate its usefulness during other anaesthetic and surgical conditions.

Assessment of surgical stress during general anaesthesia

The clinical diagnostic signs for detecting inadvertent oesophageal intubation may all be misleading. We therefore tested the practice of recording exhaled carbon dioxide during the intubation procedure as an additional measure for detection of accidental oesophageal intubation. Twenty patients were intubated simultaneously into the trachea and oesophagus and the carbon dioxide concentration was continuously recorded from both sources. Manual ventilation of the lungs always resulted in a typical CO2 curve pattern. Ventilation by mask prior to the intubation obviously resulted in some filling the stomach by exhaled gas in 9 of the 20 patients. In these cases some CO2 could be detected during oesophageal ventilation. As the oesophageal CO2 concentrations were very low initially, compared to the tracheal recordings, and carbon dioxide completely disappeared after a few ventilations into the oesophagus, distinguishing between the tracheal and oesophageal capnography tracings was easy.

Capnography for detection of accidental oesophageal intubation.

Transcranial magnetic motor evoked potentials (tcMMEP) were used to assess the functional integrity of the descending motor pathways. The tcMMEP, recorded bilaterally from anterior tibialis muscles, were evoked by an electric current induced in the motor cortex by a high-intensity transient magnetic field applied to the scalp surface. Potentials were recorded from ten of 12 volunteer subjects and preoperatively in 11 of 11 scoliotic patients. Group mean latency in the volunteers (32.0 +/- 2.1 msec) did not differ from that of the scoliotics (28.6 +/- 5.0 msec), but values in the latter group were more variable. During nitrous oxide-narcotic anesthesia, tcMMEP with reproducible latencies were obtained in 9 of 11 (82%) cases. A small, but statistically significant, increase in latency occurred during anesthesia. Compared with preoperative values (523 +/- 490 microV), individual tcMMEP amplitudes were significantly decreased intraoperatively (163 +/- 153 microV). Although the absolute amplitudes varied widely, the minimum recorded value was over 20 microV. Thus, intraoperative tcMMEP waveforms were readily discriminable from background electrical noise. These results demonstrate the technical feasibility of intraoperative tcMMEP monitoring. Combined somatosensory evoked potential and tcMMEP monitoring may provide a more complete picture of spinal cord function, intraoperatively.

Transcranial magnetic motor evoked potentials (tcMMEP) for functional monitoring of motor pathways during scoliosis surgery.

Patients undergoing intraocular surgery are elderly and may have disease or be receiving medication which increases the risk of haemorrhage. We interviewed 1383 consecutive patients scheduled for eye surgery requiring retrobulbar/peribulbar block about their use of non- steroidal anti-inflammatory drugs, oral steroids and warfarin. A history of diabetes mellitus and globe axial length was noted. Medial peribulbar and inferolateral retrobulbar blocks were performed by three specialists and six doctors in training. The ensuing haemorrhages were graded as follows: 1=spot ecchymosis; 2=lid ecchymosis involving half of the lid surface area or less; 3=lid ecchymosis all around the eye, no increase in intraocular pressure; 4=retrobulbar haemorrhage with increased intraocular pressure. Acetylsalicylic acid was taken by 482 (35%) patients, non-steroidal anti-inflammatory drugs by 260 (19%) and warfarin by 76 (5.5%). Lid haemorrhages (grades 1–3) were observed in 55 patients (4.0%); in 33 of these patients the haemorrhages were spotlike (grade 1). No grade 4 haemorrhages occurred. The preoperative use of acetylsalicylic acid, non-steroidal anti-inflammatory drugs or warfarin, whether or not they had been discontinued, did not predispose to haemorrhage associated with retrobulbar/peribulbar block.

Markku Paloheimo

Papers

Description of the Entropy algorithm as applied in the Datex-Ohmeda S/5 Entropy Module.

Assessment of surgical stress during general anaesthesia

Capnography for detection of accidental oesophageal intubation.

Transcranial magnetic motor evoked potentials (tcMMEP) for functional monitoring of motor pathways during scoliosis surgery.

Haemorrhage and risk factors associated with retrobulbar/peribulbar block: a prospective study in 1383 patients