Dexmedetomidine elevates the lethal dose threshold of bupivacaine in rats: A dosing study.

Dexmedetomidine (DMED), an alpha-2 adrenoreceptor agonist, has been widely used in regional anesthesia procedures. However, the effect of DMED on local anesthetic cardiotoxicity has not been well delineated. This study consisted of two experiments. In experiment A, 42 Sprague-Dawley (SD) rats were randomly divided into 6 groups (n = 7), each group was pretreated with DMED 0 µg kg-1 (D0 group), 1 µg kg-1 (D1 group), 3 µg kg-1 (D3 group), 6 µg kg-1 (D6 group), 12 µg kg-1 (D12 group), and 24 µg kg-1 (D24 group), administered through the right femoral vein. In experiment B, 20 SD rats were randomly divided into 4 groups (n = 5), such as control group, DMED group, yohimbine (YOH) group, and DMED + YOH group. Each subgroup in experiment B was also pretreated similarly as in experiment A. After pretreatment of rats as described above (in experiments A and B), bupivacaine 2.5 mg kg-1 min-1 was infused to induce cardiac arrest. In experiment A, the lethal dose threshold of bupivacaine and plasma bupivacaine concentration in D3 and D6 group were higher than the other groups. In experiment B, there was no interaction between DMED and YOH in lethal dose threshold, arrhythmia time, plasma concentration of bupivacaine, and myocardial content of bupivacaine. DMED doses of 3-6 µg kg-1 elevated the lethal dose threshold of bupivacaine without involvement of the alpha-2 adrenoceptors.

Training and accrediting international surgeons.

BACKGROUND: Formal international medical programmes (IMPs) represent an evolution away from traditional medical volunteerism, and are based on the foundation of bidirectional exchange of knowledge, experience and organizational expertise. The intent is to develop multidirectional collaborations and local capacity that is resilient in the face of limited resources. Training and accreditation of surgeons continues to be a challenge to IMPs, including the need for mutual recognition of competencies and professional certification. METHODS: MEDLINE, Embase and Google Scholar™ were searched using the following terms, alone and in combination: 'credentialing', 'education', 'global surgery', 'international medicine', 'international surgery' and 'training'. Secondary references cited by original sources were also included. The authors, all members of the American College of Academic International Medicine group, agreed advice on training and accreditation of international surgeons. RESULTS AND CONCLUSION: The following are key elements of training and accrediting international surgeons: basic framework built upon a bidirectional approach; consideration of both high-income and low- and middle-income country perspectives; sourcing funding from current sources based on existing IMPs and networks of IMPs; emphasis on predetermined cultural competencies and a common set of core surgical skills; a decentralized global system for verification and mutual recognition of medical training and certification. The global medical system of the future will require the assurance of high standards for surgical education, training and accreditation.

Clinician-performed ultrasound in hemodynamic and cardiac assessment: a synopsis of current indications and limitations.

Accurate hemodynamic and intravascular volume status assessment is essential in the diagnostic and therapeutic management of critically ill patients. Over the last two decades, a number of technological advances were translated into a variety of minimally invasive or non-invasive hemodynamic monitoring modalities. Despite the promise of less invasive technologies, the quality, reliability, reproducibility, and generalizability of resultant hemodynamic and intravascular volume status data have been lacking. Since its formal introduction, ultrasound technology has provided the medical community with a more standardized, higher quality, broadly applicable, and reproducible method of accomplishing the above-mentioned objectives. With the advent of portable, hand-carried devices, the importance of sonography in hemodynamic and volume status assessment became clear. From basic venous collapsibility and global cardiac assessment to more complex tasks such as the assessment of cardiac flow and tissue Doppler signals, the number of real-life indications for sonology continues to increase. This review will provide an outline of the essential ultrasound applications in hemodynamic and volume status assessment, focusing on evidence-based uses and indications.

Pre-injury neuro-psychiatric medication use, alone or in combination with cardiac medications, may affect outcomes in trauma patients.

BACKGROUND: Recent review of older (≥45-years-old) patients admitted to our trauma center showed that more than one-third were using neuro-psychiatric medications (NPMs) prior to their injury-related admission. Previously published data suggests that use of NPMs may increase patients' risk and severity of injury. We sought to examine the impact of pre-injury NPM use on older trauma patients' morbidity and mortality. MATERIALS AND METHODS: Retrospective record review included medication regimen characteristics and NPM use (antidepressants-AD, antipsychotics-AP, anxiolytics-AA). Hospital morbidity, mortality, and 90-day survival were examined. Comparisons included regimens involving NPMs, further focusing on their interactions with various cardiac medications (beta blocker - BB; angiotensin-converting enzyme inhibitor/angiotensin receptor blocker - ACE/ARB; calcium channel blocker - CCB). RESULTS: 712 patient records were reviewed (399 males, mean age 63.5 years, median ISS 8). 245 patients were taking at least 1 NPM: AD (158), AP (35), or AA (108) before injury. There was no effect of NPM monotherapy on hospital mortality. Patients taking ≥3 NPMs had significantly lower 90-day survival compared to patients taking ≤2 NPMs (81% for 3 or more NPMs, 95% for no NPMs, and 89% 1-2 NPMs, P < 0.01). Several AD-cardiac medication (CM) combinations were associated with increased mortality compared to monotherapy with either agent (BB-AD 14.7% mortality versus 7.0% for AD monotherapy or 4.8% BB monotherapy, P < 0.05). Combinations of ACE/ARB-AA were associated with increased mortality compared to ACE/ARB monotherapy (11.5% vs 4.9, P = 0.04). Finally, ACE/ARB-AD co-administration had higher mortality than ACE/ARB monotherapy (13.5% vs 4.9%, P = 0.01). CONCLUSIONS: Large proportion of older trauma patients was using pre-injury NPMs. Several regimens involving NPMs and CMs were associated with increased in-hospital mortality. Additionally, use of ≥3 NPMs was associated with lower 90-day survival.

Nasoenteric tube complications.

The use of nasoenteric tubes (NETs) is ubiquitous, and clinicians often take their placement, function, and maintenance for granted. NETs are used for gastrointestinal decompression, enteral feeding, medication administration, naso-biliary drainage, and specialized indications such as upper gastrointestinal bleeding. Morbidity associated with NETs is common, but frequently subtle, mandating high index of suspicion, clinical vigilance, and patient safety protocols. Common complications include sinusitis, sore throat and epistaxis. More serious complications include luminal perforation, pulmonary injury, aspiration, and intracranial placement. Frequent monitoring and continual re-review of the indications for continued use of any NET is prudent, including consideration of changing goals of care. This manuscript reviews NET-related complications and associated topics.

Polyneuropathy and myopathy in the elderly.

Critical illness polyneuropathy and myopathy is associated with intensive care unit therapies; it is an independent predictor of mortality and will be increasingly affecting the practice of critical care. Most patients with this illness are over 50 years of age, and as our population demographics shift in favor of an aging population, physicians must be aware that this malady will have a rising incidence in the perioperative period. Intensivists, anesthesiologists, surgeons, and geriatricians/internists must remain vigilant. Here we present a concise overview of critical illness polyneuropathy and myopathy, its diagnosis, associations, and possible interventions.

Nietzsche's morality: a genealogy of medical malpractice.

Medical malpractice is of increasing concern and 60 billion dollars are added annually to healthcare costs. The practice of defensive medicine, decreased availability of doctors, and increased health insurance premiums are all results of medical malpractice. An argument is made from the perspective of Friedrich Nietzsche's On the Genealogy of Morals that a primal cause of the litigiousness of the public against doctors results from resentment or "ressentiment". The relationship of promises, responsibility, and guilt between doctors and patients is explored, as well as what may be necessary to reduce the public's ressentiment. Modern malpractice in the US is covered by Nietzsche's line of reasoning in On the Genealogy of Morals, although his reasoning is condemned by most Western philosophers. Doctors may be able to better manage their interactions with patients and limit their exposure to litigation by understanding and exploring alternative philosophical and historical origins-or aetiologies-of patient/doctor conflict.

Massive amniotic fluid embolism: diagnosis aided by emergency transesophageal echocardiography.

A 36-year-old woman was hospitalized at term and in labor at 3-cm cervical dilatation. The early labor course was remarkable only for oxytocin augmentation and combined spinal-epidural analgesia. Eight hours after admission, tetanic uterine contractions ensued, followed by persistent fetal bradycardia. An emergency cesarean section was performed and a viable male infant was delivered. Intraoperatively, a placental abruption was identified, and disseminated intravascular coagulation and persistent hypotension developed despite resuscitative efforts. Transesophageal echocardiography revealed normal left ventricular contractility and gross enlargement of the right ventricle and main pulmonary trunk, consistent with acute right ventricular pressure overload and underloading of the left ventricle. Despite resuscitative efforts, the patient died three hours postoperatively. Autopsy showed extensive microvascular plugging of the pulmonary capillaries by fetal cells in all lung fields. This is a rare case of amniotic fluid embolism diagnosed in part and managed pre-mortem with transesophageal echocardiography and confirmed by autopsy findings.