David Amar

Effects of diltiazem versus digoxin on dysrhythmias and cardiac function after pneumonectomy

BACKGROUNDnThis prospective study was designed to determine whether diltiazem is superior to digoxin for the prophylaxis of supraventricular dysrhythmias (SVD) after pneumonectomy or extrapleural pneumonectomy (EPP) and to assess the influence of these drugs on perioperative cardiac function.nnnMETHODSnSeventy consecutive patients without previous SVD were randomly allocated immediately after pneumonectomy or EPP to receive diltiazem (n = 35) or digoxin (n = 35). Diltiazem-treated patients received a slow intravenous loading dose of 20 mg, followed by 10 mg intravenously every 4 hours for 24 to 36 hours, then 180 to 240 mg orally daily for 1 month. Digoxin-treated patients received a 1-mg intravenous loading in the first 24 to 36 hours, then 0.125 to 0.25 mg orally daily for 1 month. A concurrent prospective cohort of 40 patients without previous SVD, who did not participate in the study and underwent pneumonectomy or EPP without prophylaxis, served as a comparison group for SVD occurrence. Serial Doppler echocardiograms were performed to assess cardiac function and all patients were continuously monitored with Holter recorders for 3 days. Data were analyzed by intent-to-treat.nnnRESULTSnIn patients undergoing standard or intrapericardial pneumonectomy, diltiazem prevented the overall incidence of postoperative SVD when compared with digoxin, 0 of 21 patients versus 8 of 25 patients, respectively, p < 0.005. When EPP patients were included in the analysis, diltiazem decreased the incidence of all SVD from 11 of 35 patients (31%) to 5 of 35 patients (14%) when compared with digoxin, p = 0.09. Digoxin-treated patients had a similar incidence of all SVD (31%) as concurrent controls (11 of 40 patients [28%]). The two treated groups did not differ in right or left atrial size, left ventricular ejection fraction, or right heart pressure. When all patients were combined, those in whom SVD developed were significantly older (65 +/- 12 years versus 55 +/- 11 years, p = 0.004) and had a longer median hospital stay (9 versus 6 days, p = 0.03), when compared with those in whom SVD did not develop, respectively. The subset of patients undergoing EPP had a greater incidence of atrial fibrillation and electrocardiographic changes suggestive of postoperative pericarditis than all other pneumonectomy patients.nnnCONCLUSIONSnDiltiazem was both safe and more effective than digoxin in reducing the overall incidence of SVD after standard or intrapericardial pneumonectomy. Digoxin therapy had no effect on the incidence of postoperative SVD and is not recommended for prophylaxis of SVD. Dysrhythmias after pneumonectomy or EPP occur in older patients and are associated with a greater length of hospital stay.

2014 AATS guidelines for the prevention and management of perioperative atrial fibrillation and flutter for thoracic surgical procedures

PREAMBLE Our mission was to develop evidence-based guidelines for the prevention and treatment of perioperative/postoperative atrial fibrillation and flutter (POAF) for thoracic surgical procedures. Sixteen experts were invited by the American Association for Thoracic Surgery (AATS) leadership: 7 cardiologists and electrophysiology specialists, 3 intensivists/ anesthesiologists, 1 clinical pharmacist, joined by 5 thoracic and cardiac surgeons who represented AATS (see Online Data Supplement 1 for the list of members and Online Data Supplement 2 for the conflict of interest declaration online).

Decreased incidence of headache after accidental dural puncture in caesarean delivery patients receiving continuous postoperative intrathecal analgesia

To examine the effects of prolonged (> 24 h) intrathecal catheterization with the use of postoperative analgesia on the incidence of post–dural puncture headache (PDPH), charts of 45 obstetric patients who had accidental dural puncture following attempts at epidural block were reviewed retrospectively. Three groups were identified: Group I (n = 15) patients had a dural puncture on the first attempt at epidural block, but successful epidural block on a repeated attempt; Group II (n=17) patients had a dural puncture with immediate conversion to continuous spinal anaesthesia with catheterization lasting only for the duration of caesarean delivery; Group III (n= 13) patients had an immediate conversion to spinal anaesthesia and received post–caesarean section continuous intrathecal patient–controlled analgesia consisting of fentanyl 5 (igml‐1 with bupivacaine 0.25 mg·ml‐1 and epinephrine 2 μg·ml‐1 with catheterization lasting >24 h. No parturient in group III developed a PDPH. This was substantially lower (P < 0.009) than the 33% incidence for group I and the 47% incidence for group II. The incidence of a PDPH did not differ between group I and II. Similarly, there was no difference between group I and II with regard to requests for a blood patch. Patients receiving continuous intrathecal analgesia had excellent pain relief, could easily ambulate and none complained of pruritus, nausea, vomiting, sensory loss or weakness. In conclusion, indwelling spinal catheterization > 24 h with continuous intrathecal analgesia following accidental dural puncture in parturients may for some patients be a suitable method for providing PDPH prophylaxis and postoperative analgesia.

Symptomatic tachydysrhythmias after esophagectomy: Incidence and outcome measures

BACKGROUNDnSupraventricular tachydysrhythmias (SVT) after esophageal operations for carcinoma occur frequently and may be associated with increased morbidity. Prospective data on the etiology, incidence, and importance of these dysrhythmias are sparse.nnnMETHODSnIn 100 consecutive patients undergoing esophagectomy without prior history of atrial dysrhythmias or receiving antiarrhythmics, we prospectively examined the effects of predefined risk factors by history and pulmonary function on the 30-day incidence of symptomatic postoperative SVT, need for intensive care unit admission, and mortality rate.nnnRESULTSnSymptomatic postoperative SVT occurred in 13 (13%) of the 100 patients studied at a median of 3 days after operation and was accompanied by hypotension in 9/13 (69%). Univariate correlates of SVT were older age (p = 0.03), perioperative use of theophylline (p = 0.044), and a low carbon monoxide diffusion capacity (measured in 56% of patients) on preoperative pulmonary function. Patients in whom SVT developed had a higher rate of intensive care unit admission (p = 0.0001) and a longer hospital stay (p = 0.036). Although patients in whom SVT developed had a higher (p = 0.013) 30-day mortality rate, SVT was not the direct cause of death.nnnCONCLUSIONSnThese prospective data show that the true incidence of symptomatic SVT within 30 days of esophagectomy is lower than previously reported. Occurrence of SVT was associated with significant morbidity. Older age was the strongest predictor of SVT after esophagectomy. In high-risk patients, continued monitoring (48 to 72 hours) and early interventions to decrease the incidence of postoperative SVT may improve overall surgical outcomes.

Value of perioperative Doppler echocardiography in patients undergoing major lung resection

BACKGROUNDnThe effects of major lung resection on right heart function have not been well established. Our goal was to evaluate these effects using serial Doppler echocardiography in the perioperative period.nnnMETHODSnIn 86 patients undergoing lobectomy (n = 47) and pneumonectomy (n = 39), we examined the effects of pulmonary resection on perioperative changes in right heart function by transthoracic echocardiography. Serial echocardiograms were performed preoperatively, on postoperative day 1, and again between postoperative days 2 and 6 (median, 3 days) to evaluate cardiovascular function and to estimate right ventricular systolic pressure by the tricuspid regurgitation jet Doppler velocity method.nnnRESULTSnRight or left atrial size, right atrial pressure, and estimated right ventricular systolic pressure did not differ between groups on the preoperative or postoperative day 1 examinations. However, on postoperative days 2 through 6 patients who underwent pneumonectomy had higher (mean +/- standard deviation) right ventricular systolic pressure values than lobectomy patients (31 +/- 15 versus 25 +/- 10 mm Hg, respectively; p < 0.05 by analysis of variance). In the subset of patients with percent predicted forced expiratory volume in 1 second less than 60% undergoing pneumonectomy (9/39), preoperative right ventricular systolic pressure was inversely correlated with percent predicted forced expiratory volume in 1 second values (r = -0.78; p < 0.04). This correlation was not significant in corresponding lobectomy patients. Postoperative right ventricular enlargement determined by echocardiography occurred with similar frequency in both groups and was associated with poor short-term prognosis in patients in whom severe respiratory failure developed.nnnCONCLUSIONSnPreoperative indices of right heart function were within the normal range in both groups. Pneumonectomy but not lobectomy was associated with mild postoperative pulmonary hypertension that was not accompanied by significant right ventricular systolic dysfunction. Postoperative echocardiography may be useful to evaluate right heart function in critically ill patients after lung resection.

Persistent Alterations of the Autonomic Nervous System after Noncardiac Surgery

Background Changes in the sympathetic nervous system may be a cause of postoperative cardiovascular complications. The authors hypothesized that changes in both [Greek small letter beta]‐adrenergic receptor ([Greek small letter beta] AR) function (as assessed in lymphocytes) and in sympathetic activity (assessed by plasma catecholamines and by heart rate variability [HRV] measurements obtained from Holter recordings) occur after operation. Methods The HRV parameters were measured in 28 patients having thoracotomy (n = 14) or laparotomy (n = 14) before and for as long as 6 days after operation. Transthoracic echocardiography was performed before and on postoperative day 2. Lymphocytes were also isolated from blood obtained before anesthesia and again on postoperative days 1, 2, 3, and 5 (or 6). They were used to examine beta AR number (Bmax) and cyclic adenosine monophosphate (cAMP) production after stimulation with isoproterenol and prostaglandin E1. In addition, plasma epinephrine, norepinephrine, and cortisol concentrations were determined at similar intervals. Results After abdominal and thoracic surgery, most time and all frequency indices of HRV decreased significantly, as did Bmax and basal and isoproterenol‐stimulated cAMP production. The decrements in HRV correlated with those of Bmax and isoproterenol‐stimulated cAMP throughout the first postoperative week and inversely correlated with the increase in heart rate. Plasma catecholamine concentrations did not change significantly from baseline values, but plasma cortisol levels did increase after operation in both groups. Left ventricular ejection fraction was normal in both groups and unaffected by surgery. Conclusions Persistent downregulation and desensitization of the lymphocyte beta AR/adenylyl cyclase system correlated with decrements in time and frequency domain indices of HRV throughout the first week after major abdominal or thoracic surgery. These physiologic alterations suggest the continued presence of adaptive autonomic regulatory mechanisms and may explain why the at‐risk period after major surgery appears to be about 1 week or more.

Use of propofol for the prevention of chemotherapy-induced nausea and emesis in oncology patients

Nausea and vomiting associated with antineoplastic chemotherapy are distressing and may keep patients from complying with chemotherapy protocols. No drug has emerged among many as an effective antiemetic. It has been speculated that propofol may have intrinsic antiemetic properties. We report the use of low-dose continuous infusion propofol in three oncology patients to treat chemotherapy-associated nausea and vomiting. A bolus of 0.1 mg · kg−1 followed by a continuous infusion of 1 mg · kg−1 hr−1 was effective in both prevention and treatment of nausea and vomiting. All three patients were alert, reported low nausea scores by visual analogue scale, and had no episodes of vomiting. When the infusion was discontinued, nausea and vomiting were noted in two patients. Propofol, given in a subanaesthetic infusion, was safe and effective as an antiemetic in these three patients.RésuméLes nausées et vomissements associés à la chimiothérapie antinéoplasique sont affligeants et peuvent empêcher les patients d’être fidèles aux protocoles de chimiothérapie. Aucun médicament nes ’est avéré être un antiémétique efficace. Il a été suggéré que le propofol peut avoir des propriétés intrinsèques antiémétiques. Nous rapportons l’ utilisation d’une perfusion continue de propofol à bas dosage, chez trois patients oncologiques, afin de traiter les nausées et vomissements associés à la chimiothérapie. Un bolus de 0,1 mg · kg−1 suivi d ’une infusion continue de 1 mg · kg−1 · h−1 était efficace pour la prévention et le traitement des nausées et vomissements. Les trois patients étaient alertes, avaient des pointages bas pour la nausée sur une échelle visuelle analogue et n ’avaient aucun épisode de vomissement. Lorsque l’infusion a été cessée, des nausées et vomissements ont été notés chez deux patients. Le propofol, lorsque donné à l’aide d’une infusion subanesthésique, était sécuritaire et efficace en tant qu’antiémétique chez ces trois patients.

Brain natriuretic peptide and risk of atrial fibrillation after thoracic surgery

OBJECTIVESnPostoperative atrial fibrillation (POAF) complicating general thoracic surgery is a marker of increased morbidity and stroke risk. Our goal was to determine whether increased preoperative brain natriuretic peptide (BNP) levels are able to stratify patients by the risk of POAF.nnnMETHODSnUsing a prospective database of 415 patients aged 60 years or older, who had undergone lung or esophageal surgery during a 1-year period, the preoperative clinical data, including BNP levels, were compared between patients who developed POAF lasting longer than 5 minutes during hospitalization and those who did not.nnnRESULTSnPOAF occurred in 65 (16%) of the 415 patients and was more frequent among patients who had undergone esophagectomy or anatomic lung resection (22% or 58 of 269) compared with those who did not (5% or 7 of 146; P < .0001). After esophagectomy or anatomic lung resection, 46 (34%) of the 135 patients with BNP levels greater than the median (≥ 30 pg/mL) developed POAF compared with only 12 (9%) of 134 patients with BNP levels less than 30 pg/mL (P < .0001). The rates of POAF in patients undergoing other thoracic procedures were low and not associated with the BNP levels. Multivariate logistic regression analysis showed that in patients undergoing esophagectomy or anatomic lung resection, older age (5-year increments, odds ratio [OR], 1.28; 95% confidence interval [CI], 1.01-1.61; P = .04), male gender (OR, 2.61; 95% CI, 1.12-4.17; P = .02), and BNP level 30 pg/mL or greater (OR, 4.52; 95% CI, 2.19-9.32; P < .0001) were independent risk factors for POAF. The length of hospital stay was significantly increased in patients who developed POAF compared with those who did not (P < .0001).nnnCONCLUSIONSnAmong patients undergoing anatomic lung resection or esophagectomy, increased age, male gender, and preoperative BNP level of 30 pg/mL or greater were significant risk factors for the development of POAF. The identification of patients who are more likely to develop POAF will allow the development of trials assessing prevention strategies aimed at reducing this complication.

Epidural Analgesia for Labour and Delivery: Fentanyl or Sufentanil

PurposeThe highly lipid soluble opioids, fentanyl and sufentanil, are used in combination with local anaesthetics with/ without epinephrine to provide epidural analgesia during labour and delivery. Our aim was to determine whether either opioid was superior when used with low dose local anaesthetic.MethodsIn a double-blind study patients were randomized to two epidural infusion groups: Group I (n = 50) fentanyl 2 μg · ml−1 with bupivacaine 0.015% and epinephrine 2 μg · ml−1, Group II (n = 50) sufentanil 1 μg · ml−1 with bupivacaine 0.015% and epinephrine 2 μg · ml−1. Following a 20 ml bolus of the study solution an infusion was started at 10 ml · h−1. To achieve analgesia patients could receive two boluses of 5 ml of the study solution and if analgesia was still inadequate, a further 5 ml bupivacaine 0.25% was used. Pain and overall satisfaction were assessed with a 10-point visual scale. Plasma samples obtained from the mother at the time the infusion was discontinued and from the umbilical cord vein at delivery were assayed to determine opioid concentration.ResultsPain scores were greater for Group I than for Group II patients throughout the first and second stages of labour (P = 0.002). More patients in Group I (42%) requested a dose of bupivacaine 0.25% than in Group II (6%) (P < 0.0001) and the total dose of bupivacaine given to Group I patients was greater than that of Group II, 26.0 ± 22.0 mg vs. 13.4 ± 12.6 mg, P = 0.005. There were no differences with respect to first or second stage duration, incidence of side effects, infusion duration, outcome of labour or neonatal Apgar scores. There was no opioid accumulation in either maternal or foetal blood.ConclusionEpidural opioid infusion with very low dose bupivacaine (0.015%) achieved an overall high level of patient satisfaction in both groups without serious maternal or neonatal side effects. At the fentanyl-to-sufentanil ratio used here patients receiving sufentanil had lower pain scores and substantially fewer patients required bupivacaine rescue.RésuméObjectifLes morphiniques hautement liposolubles comme le fentanyl et le sufentanil sont utilisés avec les anesthésiques locaux pour procurer l’analgésie épidurale pendant le travail et l’accouchement avec ou sans épinéphrine. Cette étude visait à déterminer lequel des deux morphiniques était supérieur lorsqu’on l’associait à un anesthésiques local à faible dose.MéthodesL’étude randomisée et en double aveugle incluait deux groupes: le groupe I (n = 50) avait reçu du fentanyl 2 μg · ml−1 et de la bupivacaïne 0,015% avec épinéphrine 2 μg · ml−1 alors que le groupe II (n = 50) avait reçu sufentanil 1 μg · ml−1 et bupivacaïne 0,015 avec épinéphrine 2 μg · ml−1. Après un bolus de 20 ml de la solution à l’étude, une perfusion était débutée au rythme de 10 ml · h−1. Pour compléter l’analgésie, les patientes pouvaient recevoir deux bolus de 5 ml de la solution à l’étude. Si l’analgésie était toujours insuffisante, une dose additionnelle de 5 ml de bupivacaïne 0,25% était administrée. La douleur et le degré de satisfaction étaient évalués sur une échelle visuelle de dix points. Des échantillons de plasma maternal à l’arrêt de la perfusion et du cordon ombilical à l’accouchement ont été analysés pour déterminer la concentration du morphinique.RésultatsQuant à la douleur, les scores ont été plus élevés dans le groupe I que dans le groupe II pendant le premier et le deuxième stage du travail (P = 0,002). Plus de patients du groupe I (42%) ont eu besoin de bupivacaïne 0,25% que dans le groupe II (6%) (P < 0,001) et la dose totale de bupivacaïne administrée aux patientes du groupe I a été plus élevée que dans le groupe II, 26,0 ± 22,0 mg vs 13,3 ± 12,6 mg, P = 0,005. En ce qui concerne la durée du premier et du deuxième stage du travail, la différence était nulle, ainsi que l’incidence des effets secondaires, la durée de la perfusion, l’évolution du travail ou les scores sur l’échelle d’Apgar. On n’a pas noté d’accumulation de morphinique dans le sang maternel ni dans le sang foetal.ConclusionAvec une perfusion de morphinique associée à de très faibles doses de bupivacaïne (0,015%), en général, le degré élevé de satisfaction a été élevé dans les deux groupes, sans effets secondaires maternels et foetaux importants. Si on compare le fentanyl au sufentanil, les patientes qui recevaient du sufentanil ont rapportés pour la douleur des scores inférieurs et beaucoup moins de patientes ont eu besoin de bupivacaïne en supplément.

Preoperative left atrial dysfunction and risk of postoperative atrial fibrillation complicating thoracic surgery

OBJECTIVEnPostoperative atrial fibrillation complicating general thoracic surgery increases morbidity and stroke risk. We aimed to determine whether preoperative atrial dysfunction or other echocardiographic markers are associated with postoperative atrial fibrillation.nnnMETHODSnIn 191 patients who had undergone anatomic lung or esophageal resection, preoperative clinical and echocardiographic data were compared between patients with and without postoperative atrial fibrillation. Presence of postoperative atrial fibrillation lasting more than 5 minutes during hospitalization was detected using continuous telemetry or 12-lead electrocardiography. Maximal left atrial volume and indices of left atrial function were assessed.nnnRESULTSnPatients with postoperative atrial fibrillation (33/191, 17%) were older (71 ± 5 years vs 64 ± 12 years, P < .0001), were taking β-blockers more often, had greater left atrial volume, had decreased left atrial emptying fraction, and had lower E and A septal velocities compared with patients without postoperative atrial fibrillation. The incidence of postoperative atrial fibrillation in patients with left atrial volume 32 mL/m(2) or greater was 37% (11/30) and greater than in those with left atrial volume less than 32 mL/m(2) (14%, 22/160, P = .002). Length of hospital stay was significantly increased in patients with postoperative atrial fibrillation compared with patients without (P = .04). Older age was significantly associated with greater β-blocker use and left atrial volume and lower left atrial emptying fraction. On multivariate analysis, lower left atrial emptying fraction (odds ratio, 1.03 per unit decrement; 95% confidence interval, 1.002-1.065; P = .04) and preoperative use of β-blockers (odds ratio, 2.82; 95% confidence interval, 1.18-6.77; P = .02) were the only independent risk factors associated with postoperative atrial fibrillation.nnnCONCLUSIONSnThese data show that an echocardiogram before major thoracic surgery, increased use of preoperative β-blockers, and decreased left atrial emptying fraction were associated with postoperative atrial fibrillation. Echocardiographic predictors of left atrial mechanical dysfunction may prove clinically useful in risk stratifying patients in whom postoperative atrial fibrillation is more likely to develop and to benefit from prevention strategies aimed at mitigating atrial function before surgery.