Mark S. Shulman

Postthoracotomy Pain and Pulmonary Function Following Epidural and Systemic Morphine

Thirty patients undergoing thoracotomy for lung resection were entered in a randomized, double-blind trial comparing the effects of epidural (E) versus intravenous (iv) morphine on postoperative pain and pulmonary function. Postoperatively the patients were given repeated doses of either 5.0 mg of morphine epidurally or 0.05–0.07 mg/kg morphine intravenously until there were no further spontaneous complaints of pain. Two, 8, and 24 h post-operatively, the following indices were measured: linear analogue pain score, somnolence score, vital signs, arterial PaO2, PaCO2 and pH, forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), and peak expiratory flow rate (PEFR). Patients receiving epidural morphine had significantly less pain at 2 h (P < 0.01) and 8 h (P < 0.004) postoperatively. There was no difference in vital signs except for significantly slower respiratory rates at 2 h (P < 0.04), 8 h (P < 0.02) and 24 h (P < 0.01) in the epidural group. No significant differences occurred in the somnolence scores or blood–gas measurements, which were within normal limits. The epidural morphine group has significantly less decrease in both FVC at 2 h (E –1.8 ± 2 l, iv –2.5 ± 0.2 l, P < 0.03), 8 h (E –1.4 ± 0.2 l, iv –2.1 ± 0.2 l, P < 0.01), and 24 h (E –1.2 ± 0.2 l, iv –2.0 ± 0.2 l, P < 0.02), and FEV1 at 2 h (E –1.3 ± 0.2 l, iv –1.9 ± 0.2 l, P < 0.04), 8 h (E –1.0 ± 0.2 l, iv –1.7 ± 0.2 l, P < 0.01), and 24 h (E –0.8 ± 0.1 l, iv –1.5 ± 0.2 l, P < 0.01). In addition, the epidural morphine group had significantly less decrease in PEFR at 24 h (E –134 ± 29 l · min ·-1, iv –238 ± 30 l · min-1, P < 0.03). The authors conclude that lumbar epidural morphine is highly effective in alleviating pain and improving respiratory function in postthoracotomy patients.

Experience with epidural hydromorphone for post-thoracotomy pain relief

Narcotics administered via the lumbar epidural route are useful in providing pain relief and preserving pulmonary function in patients who have undergone thoracotomies (1-3). Hydromorphone (Dilaudid), a hydrogenated ketone derivative of morphine, has been given epidurally for postoperative analgesia (2), but no large series of cases has been reported using this drug for relief of post-thoracotomy pain. A possible advantage of hydromorphone when adrinistered by the epidural route is its segmental effect, similar to that seen with the epidural injection of local anesthetics (4). When compared to other agents, this segmental effect should result in fewer side effects.

Brief review: Coronary drug-eluting stents and anesthesia

PurposeAnesthesiologists managing patients with drug-eluting stents (DES) face the challenge of balancing the risks of bleedingvs perioperative stent thrombosis (ST). This article reviews DES and the influence of antiplatelet medications related to their use. A perioperative management algorithm is suggested. Novel P2Y12 antagonists currently under investigation, including cangrelor and prasugrel are considered, as well as their potential role in modification of perioperative cardiovascular risks and management of patients with DES.SourceA PubMed search of the relevant literature over the period 1985–2005 was undertaken using the terms “drug-eluting stent”, “coronary artery stent”, “bare metal stent”, “antiplatelet medication”, “aspirin”, “clopidogrel.”Principal findingsDelayed re-endothelialization may render both sirolimus-eluting and paclitaxel-eluting stents susceptible to thrombosis for a longer duration than bare metal stents. Stent thrombosis may be associated with resistance to antiplatelet medication. In patients with a DES, a preoperative cardiology consultation is essential. Elective surgery should be postponed if the duration between DES placement and noncardiac surgery is less than six months. For semi-emergent procedures, both aspirin and clopidogrel should be continued during surgery unless clearly contraindicated by the nature of the surgery. If the risk of bleeding is high, then modification of antiplatelet medications should be considered on a case-by-case basis.ConclusionA profound increase in the number of patients with DES requires anesthesiologists to be familiar with their associated antiplatelet medications, and strategies for risk modification of ST and possible hemorrhagic complications in the perioperative setting.RésuméObjectifLes anesthésiologistes qui prennent en charge des patients porteurs de tuteurs coronariens actifs (TCA) font face au défi d’ëvaluer le risque de saignement en regard du risque de thrombose du tuteur dans la période périopératoire. Cet article traite des TCA et de l’influence des agents antiplaquettaires utilisés concurremment. Un algorithme de prise en charge est présenté. Les nouveaux antagonistes P2Y12 maintenant à l’essai, comme le cangrelor et le prasugrel, sont présentés, ainsi que leur rôle éventuel sur la modification du risque cardiovasculaire périopératoire et de la prise en charge des patients avec TCA.SourceUne recherche d’articles pertinents à l’aide de PubMed pour la période 1985–2005 a été entreprise en utilisant les termes “drug-eluting stent”, “coronary artery stent”, “bare metal stent”, “antiplatelet medication”, “aspirin”, “clopidogrel.”Constatations principalesLes tuteurs au sirolimus et au paclitaxel retardent la réendothélialisation. Ils sont donc plus susceptibles de former une thrombose plus longtemps que les tuteurs métalliques nus. Une thrombose due au tuteur peut entraîner une résistance aux agents antiplaquettaires. Une consultation en cardiologie est essentielle pour les patients avec un TCA. Une chirurgie réglée doit être reportée pour les patients porteurs de TCA depuis moins de six mois. Pour les urgences relatives, il est recommandé de poursuivre le traitement à l’aspirine et au clopidogrel à moins que le type de chirurgie ne le contre-indique. Si le risque de saignement est élevé, une modification du traitement antiplaquettaire doit être envisagée au cas par cas.ConclusionÀ cause du nombre croissant de patients porteurs de TCA, les anesthésiologistes doivent se familiariser avec les agents antiplaquettaires et avec les stratégies visant à modifier le risque de thrombose et de complications hémorragiques possibles dans le cadre d’une chirurgie.

Simultaneous bilateral obturator nerve stimulation during transurethral electrovaporization of the prostate

Transurethral vaporization of the prostate is a new method of electrosurgery used for treating benign prostatic hypertrophy. We observed simultaneous obturator nerve stimulation during spinal anesthesia while the middle lobe of the prostate was being resected. A discussion of why electrovaporization is different from traditional electrocautery devices is presented. Due to the increased power required during electrovaporization, and the arcing at the electrode, a large amount of demodulated, low-frequency current is produced that can stimulate the obturator nerve. This can occur even if the electrode is not close to the lateral bladder wall. The solution to the problem of obturator nerve stimulation, including bilateral obturator nerve blocks using a lower power setting during resection and converting from a regional to general anesthetic with neuromuscular blockade, is discussed.

The use of amrinone and norepinephrine for inotropic support during emergence from cardiopulmonary bypass

D ESPITE MAJOR improvements in techniques of myocardial preservation, the low output state (LOS) following cardiopulmonary bypass (CPB) continues to present challenges in the management of cardiac surgical patients. The factors causing LOS include ischemia leading to a stunned myocardium,’ preoperative severe ventricular dysfunction, long aortic cross-clamp times, and poor myocardial preservation. This “post-ischemic global myocardial dysfunction” requires aggressive treatment.’ Considerable controversy exists regarding the optimal agents for inotropit support during emergence from CPB.*,” Many of the studies conducted to evaluate inotropic agents have been carried out several hours and even days after termination of CPB.4-6 Although these data are obtained in a more stable setting, they do not address the problem of immediate post-CPB myocardial dysfunction. Some studies have compared epinephrine, isoproterenol, dopamine, and dobutamine in the post-CPB period.7,8 These sympathomimetics successfully increase cardiac output, but with varying and undesirable side effects, primarily tachycardias and dysrhythmiss.‘.’ Other approaches include combinations of inotropes and vasodilators,’ norepinephrine (NE) and phentolamine,‘” and the use of the intraaortic balloon pump (IABP).” (PHE) or NE was used as primary therapy for the LOS during emergence from CPB. This combination therapy led to significant improvement in cardiac index and blood pressure without any tachyarrhythmias. Two cases are described below and the results in 7 patients are presented.

Fibreoptic bronchoscopy for tracheal and endobronchial intubation with a double-lumen tube

RésuméChez un malade cédulé pour thoracotomie, ľemploi ďun tube endotrachéal à double lumière fut jugé nécessaire par le chirurgien. A cause de certaines difficultés anatomiques ľintubation ne fut pas possible en employant les méthodes conventionnelles. Pour résoudre ce problème le bout proximal ďun tube à double lumière de calibre 37 fut raccourci permettant ľemploi du bronchoscope fibroptique de 4 mm de diamètre. Celui-ci fut introduit dans le larynx et le tube fut glissé et positionné correctement.Le raccourcissement ďun tube à double lumière nous a permis ďemployer un bronchoscope fibroptique afin de permettre ľintubation trachéale chez un malade dont le larynx était difficile à visualiser.

RETRACTED: Surgical Treatment of an Amniotic Fluid Embolism With Cardiopulmonary Collapse

Amniotic fluid embolism is a rare but devastating condition associated with a very high rate of morbidity and mortality. The treatment has traditionally been aggressive supportive care. We report a case of a term pregnant woman with complete cardiovascular collapse secondary to a paradoxical amniotic fluid embolism. The embolism was seen on transesophageal echocardiogram during an emergency Cesarean section as a free-floating interatrial clot through a patent foramen ovale. She was subsequently and successfully treated with immediate cardiopulmonary bypass, thromboembolectomy, and closure of the patent foramen ovale.

Paradoxical embolization by amniotic fluid seen on the transesophageal echocardiography.

A 34-yr-old woman was admitted for delivery. Five minutes after her membranes were ruptured, she had a cardiac arrest. An Advanced Cardiac Life Support Protocol was started, the patient regained consciousness and an arterial blood pressure was obtained. The patient was taken emergently to the operating room for cesarean delivery. Anesthesia was induced with ketamine and succinylcholine to facilitate intubation. Fifteen minutes after the cardiac arrest, the infant was delivered. It was suspected that the patient’s cardiac arrest was due to an amniotic fluid embolism (AFE), but the patient remained hemodynamically stable with the use of minimal vasopressors and did not become hypoxic. Since the clinical picture did not exactly fit the usual finding of hypoxia and severe hypotension of an AFE, a transesophageal echocardiogram (TEE) probe was placed to exclude any other cardiac pathology that may have caused the initial cardiac arrest. The TEE examination was performed about 90 min after the initial cardiac arrest and revealed an enlargement of the right ventricle and moderate hypokinesis of the right ventricle. The right atrium was moderately enlarged (width 6.5 cm), and there was a large mobile mass extending from the right atrium through a patent foramen ovale (PFO) into the left atrium (Figs. 1A and B; Video clips 1 and 2; please see video clips available at www.anesthesia-analgesia.org). The tricuspid annulus was dilated with trace-to-mild tricuspid regurgitation. Pulsed wave Doppler demonstrated a normal pattern of blood flow in the hepatic veins. There was no marked bulging of the interatrial and interventricular septum. The pulmonary arteries were dilated, and there were no visible masses. Pulmonary artery systolic pressure was not measured due to the very small amount of tricuspid regurgitation. Pulse wave Doppler measured a Qp/Qs shunt ratio of 2:1, indicating a left-to-right shunt through the PFO. The mitral and aortic valves were essentially normal, and there was no evidence of hypertrophic cardiomyopathy. There was a hyperdynamic left ventricular systolic function with an ejection fraction of 70%. Because of the high risk of systemic emboli from the interatrial mass, it was determined that the patient should be transferred for immediate cardiac surgery at the conclusion of the cesarean delivery. The TEE findings prebypass (3.5 h after the initial cardiac arrest) were essentially the same as during the cesarean delivery. The patient was placed on cardiopulmonary bypass and underwent right atriotomy with the extraction of the embolus (Fig. 2) from both atria. The PFO was surgically closed and documented by an intact interatrial septum using color flow Doppler. In addition, agitated saline injected while viewing the TEE demonstrated that no contrast bubbles entered the left atrium for five cardiac cycles. Subsequent inspection of the proximal pulmonary arteries did not reveal any masses or thrombotic material. Pathologic examination revealed squamous cell epithelium in the interatrial mass consistent with a diagnosis of AFE. The patient’s recovery was uneventful, without neurologic sequelae, and with complete normalization of cardiac function. The pathophysiology of AFE may resemble anaphylaxis or septic shock. Typically, hypotension, hypoxia, disseminated intravascular coagulation and neurologic symptoms are observed. The limited reports of TEE performed shortly after diagnosis or the early phase syndrome of AFE report normal left ventricular contraction and enlargement of the right ventricle with right This article has supplementary material on the Web site: www.anesthesia-analgesia.org.

Amniotic Fluid Embolism Complicated by Paradoxical Embolism and Disseminated Intravascular Coagulation

Amniotic fluid embolism is a rare syndrome with potentially lethal outcomes. Complications include cardiorespiratory failure, disseminated intra-vascular coagulation, seizures, neurological deficits, and death. A 34-year-old woman had amniotic fluid embolism complicated by paradoxical embolism and disseminated intravascular coagulation. Emergency cesarean section followed by cardiopulmonary bypass with removal of the clot from the atria and closure of the patent foramen ovale was performed, resulting in a good outcome for both the mother and the baby. Subsequent treatment with anticoagulants for 6 months was recommended. A literature review revealed that this clinical scenario is rare but can be successfully managed by cardiopulmonary bypass and thromboembolectomy. Data on guidelines for the use of anticoagulation in this situation are limited.

An anteromedial internal jugular vein successfully cannulated using the assistance of ultrasonography

The internal jugular vein usually is found either lateral or anterolateral to the carotid artery when it is cannulated for central vein access using external anatomical landmarks. We report a case in which the carotid artery was inadvertently punctured, but the right internal jugular vein could not be found. We used ultrasonic guidance to determine that the right internal jugular vein was anteromedial to the carotid artery. A figure showing the ultrasound of this rare anatomical variation is provided. The advantages and utility of ultrasound when used for the placement of internal jugular central vein catheters are reviewed.