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Biomedical subjects

D Amar

Publications and source records attributed to D Amar.

At least 37 records · Page 2Linked to original sources
PubMed1996

Relationship of early postoperative dysrhythmias and long-term outcome after resection of non-small cell lung cancer.

STUDY OBJECTIVES: To determine whether supraventricular tachydysrhythmias (SVTs) occurring early after thoracic surgery for non-small cell lung cancer (NSCLC) are associated with poor long-term survival. DESIGN: Prospective, cohort. SETTING: Referral cancer center. PATIENTS: Seventy-eight patients undergoing resection of NSCLC. INTERVENTIONS: Examination of univariate and multivariate effects of factors that might influence long-term survival: advanced age, sex, perioperative chemotherapy, extent of pulmonary resection, tumor stage, and SVT occurrence. RESULTS: In this group of patients, 10 of 78 (13%) developed early postoperative SVT. Log-rank analysis showed SVT occurrence (p = 0.01), age of 70 years or older (p = 0.04), and perioperative chemotherapy (p = 0.005) to predict poor long-term survival. Multivariate Cox regression analysis identified SVT occurrence (p = 0.007; relative risk [RR], 2.8; 95% confidence interval [CI], 1.3 to 6.1) and perioperative chemotherapy (p = 0.004; RR, 2.6; 95% CI, 1.4 to 5.1) to be independently associated with decreased survival. No other clinical or laboratory characteristic tested differentiated those patients who did or did not develop postoperative SVT. CONCLUSIONS: Early SVT occurrence after resection of NSCLC is associated with poor long-term survival. Although the etiology for this is unclear, this intriguing observation, not previously reported (to our knowledge), may be used in larger trials examining the effects of these and other factors on survival from lung cancer surgery.

Adult↗
PubMed1995

Clinical and echocardiographic correlates of symptomatic tachydysrhythmias after noncardiac thoracic surgery.

BACKGROUND: Supraventricular tachydysrhythmias (SVTs) following thoracic surgery occur with significant frequency and may be associated with increased morbidity. Prospective data on the etiology and importance of these dysrhythmias are sparse. METHODS: In 100 patients undergoing pulmonary resection without history of atrial dysrhythmias or previous thoracic surgery, we examined the effects of predefined risk factors by history, pulmonary function, and echocardiography on the incidence of postoperative SVT. Serial echocardiograms were performed preoperatively, on postoperative day 1, and again between postoperative days 2 to 6 (median = 3) to evaluate cardiovascular function and to estimate right ventricular systolic pressure (RVSP) by the tricuspid regurgitation jet (TRJ) Doppler velocity method. RESULTS: Symptomatic postoperative SVT occurred in 18 (18%) of the 100 patients studied at a median of 3 days after surgery and was disabling in 12 of 18 (67%). Digoxin loading was ineffective in controlling the ventricular response in 16 of 17 episodes. In the patients developing SVT, postoperative echocardiography revealed significant elevation of TRJ Doppler velocity (2.7 +/- 0.6 m/s vs 2.3 +/- 0.6 m/s, p < 0.05) but not right atrial or ventricular enlargement or right atrial pressure increase when compared with patients without SVT. Independent correlates of SVT determined in a stepwise logistic regression included intraoperative blood loss > or = 1 L (p = 0.0001) and a postoperative TRJ Doppler velocity > or = 2.7 m/s (p < 0.05). Patients who developed SVT had a higher rate of intensive care unit admission (p < 0.004), a longer hospital stay (p < 0.02), and higher 30-day mortality (p < 0.02). CONCLUSIONS: These prospective data suggest that increased right heart pressure but not fluid overload or right heart enlargement predisposes to clinically significant SVT after pulmonary resection. SVT may be an important marker of poor cardiopulmonary reserve in patients who develop significant morbidity after thoracic surgery. Early interventions to reduce right heart pressure may decrease the incidence of postoperative SVT and potentially improve overall surgical outcomes.

Aged↗
PubMed1994

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 micrograms.ml-1 with bupivacaine 0.25 mg.ml-1 and epinephrine 2 micrograms.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.

Adult↗
PubMed1994

Should all patients undergoing cardiac catheterization or percutaneous transluminal coronary angioplasty receive oxygen?

BACKGROUND: Supplemental oxygen is routinely administered to patients with acute coronary syndromes. The risk of significant morbidity during cardiac catheterization or coronary angioplasty has been well described; however, to our knowledge, the need for routine oxygen supplementation in these patients has not been investigated. METHODS: In phase 1, we prospectively studied 142 patients undergoing diagnostic cardiac catheterization (n = 94) or percutaneous transluminal coronary angioplasty (PTCA) (n = 48) to determine the incidence of procedure-related hypoxemia (pulse oximetry derived oxygen saturation [SpO2] < 90 percent of > 1 min duration) while breathing room air (RA). In phase 2, 134 patients undergoing diagnostic cardiac catheterization (n = 78) or PTCA (n = 56) were randomly allocated to breathe either RA or supplemental oxygen (O2, 6 L/min by nasal cannula) to determine the effect of oxygen administration on procedure-related hypoxemia. Oximetry results were compared with pertinent clinical and procedural data that might predispose patients to develop hypoxemia. RESULTS: Phase 1--Moderate to severe hypoxemia occurred in 36 percent (34/94) of patients undergoing diagnostic catheterization and in 56 percent (27/48) of patients undergoing PTCA. In the diagnostic catheterization group, there were a total of 25 episodes of moderate hypoxemia (SpO2 85 to 89 percent) lasting 4.0 +/- 4.3 min and 11 episodes of severe hypoxemia (SpO2 < 85 percent) of greater duration, 11.7 +/- 7.5 min (p < 0.008). In the PTCA group, there were 24 episodes of moderate hypoxemia and six episodes of severe hypoxemia lasting 4.8 +/- 4.3 min and 8.2 +/- 3.8 min, respectively. A history of chronic lung disease was associated with hypoxemia (p < 0.05) in the diagnostic group. In addition, 11 patients undergoing diagnostic catheterization who had baseline SpO2 < 95 percent all developed hypoxemia during the procedure. In this subset of patients, there was a higher incidence of cigarette smoking (p = 0.02), chronic lung disease (p = 0.04), higher left ventricular diastolic pressure (p = 0.02), and lower ejection fraction (p = 0.002) when compared with the 83 remaining patients undergoing diagnostic catheterization with a baseline SpO2 > 95 percent. Phase 2--Oxygen therapy was associated with a reduction in the incidence of hypoxemia from 42 percent to 5 percent (RA vs O2, p < 0.001) in the diagnostic catheterization group and 39 percent to 11 percent (RA vs O2, p < 0.03) in the PTCA group. CONCLUSIONS: Significant hypoxemia is a common finding among patients undergoing cardiac catheterization or angioplasty despite the absence of predictive risk factors. Severe and prolonged hypoxemic episodes occurred in 10 percent (14/142, phase 1) of patients breathing room air. Patients undergoing diagnostic catheterization with history of chronic lung disease or a baseline SpO2 < 95 percent are at high risk to develop moderate-severe hypoxemia. Oxygen therapy significantly reduced the incidence and severity of procedure-induced hypoxemia in both groups. Our data support the use of both pulse oximetry and oxygen supplementation in patients undergoing cardiac catheterization and PTCA.

Angioplasty, Balloon, Coronary↗
PubMed1994

Transmission of health information on leprosy from children to their families in an urban centre.

A health education study utilizing a homework assignment was carried out in a private secondary school in Bangalore, South India, to determine whether health information about leprosy would be transferred from children to their families. After a pre-test questionnaire on knowledge and attitude about leprosy was administered to 3 Standard VII classes and their family members, a different comprehensive health education session was given to each class: (i) leprosy plus a homework assignment; (ii) leprosy alone; and (iii) tuberculosis alone. A post-test questionnaire was administered to all participants 1 month later. Of the 118 children and 229 family members who entered the study, almost 80% of the participants completed it. The children in the leprosy-educated groups showed significant improvement in knowledge compared with controls, but no change in their attitude towards leprosy. Although post-test responses of household members showed modest improvement in knowledge about leprosy, attitudes remained the same or worsened. The homework assignment did not appear to improve the transmission of health information to household members. This study showed that the knowledge level of family members in South India could be improved modestly by educating their children about leprosy. However, attitudes towards leprosy were unaffected or worsened.

Adolescent↗
PubMed1993

Postcesarean delivery epidural patient-controlled analgesia. Fentanyl or sufentanil?

BACKGROUND: The highly lipid-soluble opioids, fentanyl and sufentanil, frequently are used in combination with local anesthetic agents and/or epinephrine to provide postoperative epidural analgesia. The authors compared the incidence of side effects and patient satisfaction during prolonged epidural patient-controlled analgesia (PCA) infusions of these opioids in combination with bupivacaine and epinephrine. METHODS: Using a double-blind study design, 250 patients scheduled for elective cesarean delivery were, on arrival in the postanesthesia care unit, randomized into two epidural PCA infusion groups: group I (n = 125) received fentanyl 2 micrograms/ml with bupivacaine 0.01% and epinephrine 0.5 micrograms/ml and group II (n = 125) received sufentanil 0.8 micrograms/ml with bupivacaine 0.01% and epinephrine 0.5 microgram/ml. The initial infusion rate was 16 ml/h with self-administered 3-ml boluses every 15 min by PCA as desired. At intervals after discontinuation of the infusion, plasma samples were obtained to determine opioid concentrations. RESULTS: The median overall satisfaction scores were 9.0 for group I and 10.0 for group II (difference not significant). Pain relief was satisfactory and comparable in both groups, and all patients could ambulate easily. The total number of times PCA requests were made was greater (P < 0.05, by Wilcoxon rank-sum test) for group I than for group II (106.7 +/- 312 vs. 70.8 +/- 138). There were no differences between the groups with respect to incidence of pruritus, sedation, and nausea; however, vomiting occurred more frequently with sufentanil than with fentanyl (12% vs. 4.8%, respectively; P < 0.05). At approximately 1-2 h after discontinuation of the infusion, 1 patient receiving fentanyl and 42 patients receiving sufentanil complained of lightheadedness and dizziness (P < 0.0001). CONCLUSIONS: Epidural PCA in both groups had no serious side effects and achieved a high level of patient satisfaction. Those receiving sufentanil made fewer PCA requests but had a significantly greater incidence of vomiting during the infusion and dizziness after the termination of the infusion. Epidural sufentanil offered no advantages over epidural fentanyl.

Adult↗
PubMed1993

Transcutaneous cardiac pacing during thoracic surgery. Feasibility and hemodynamic evaluation by transesophageal echocardiography.

BACKGROUND: Occasionally, emergency perioperative pacing is necessary. Transcutaneous cardiac pacing is noninvasive, safe, and readily available. Its feasibility and hemodynamic effects during thoracic surgery and one-lung ventilation have not been established. METHODS: Twenty anesthetized patients (aged 25-70 yr) without cardiac disease undergoing elective pulmonary resection (right n = 10, left n = 10) were studied in normal sinus rhythm and during transcutaneous cardiac pacing. Patients were paced in supine and lateral decubitus positions (with closed and opened chest) at the minimal current necessary to produce ventricular capture. Invasive arterial monitoring permitted calculation of mean arterial pressure, and transesophageal echocardiography was used to assess atrial and ventricular wall motion and the evaluation of transmitral flow. Twelve patients underwent Doppler analysis of pulmonary venous flow. RESULTS: Pacing was achieved in all patients, with a mean threshold of 86.9 +/- 20.6 mA for the right thoracotomy group, and 106.7 +/- 16.2 mA for the left thoracotomy group. The mean paced heart rates for the right and left thoracotomy groups were 101.6 +/- 18.2 and 105.4 +/- 11.5 beats/min, respectively. During pacing, all patients sustained reversible transient decrements in mean arterial pressure (9-19%) from baseline, the loss of AV synchrony, and the development of paradoxical ventricular septal wall motion. No patient had significant mitral regurgitation during sinus or paced rhythms. Decreased systolic pulmonary venous flow velocity and abnormal systolic flow reversal were seen during pacing in 11 of the 12 patients studied. CONCLUSIONS: Transcutaneous cardiac pacing is effective in patients undergoing thoracotomy and one-lung ventilation. Its use in patients in normal sinus rhythm induces reversible decrements in mean arterial pressure because of the effects of altered atrioventricular association, ventricular wall motion, and pulmonary venous return.

Adult↗
PubMed1993

Acute hyperglycaemic effect of anaesthetic induction with thiopentone.

The acute effects of thiopentone on plasma glucose concentration and regulation in humans have not been well described. We therefore examined the effect of a single dose (6 mg/kg) of thiopentone on plasma glucose, insulin, glucagon, adrenaline and noradrenaline in 16 healthy women undergoing elective abdominal surgery. To assess involvement of the neuroendocrine system in the response to thiopentone, half of the patients received labetalol prior to induction of anaesthesia. Thiopentone injection resulted in a 50% increase in plasma glucose levels (P < 0.001) in both labetalol-treated and non-treated patients 90 s following its administration. This was associated neither with significant increases in plasma glucagon, adrenaline and noradrenaline nor with a decline in plasma insulin. We conclude that acute hyperglycaemia following thiopentone is most likely the consequence of a non-adrenergically-mediated increase in hepatic glucose release.

Acute Disease↗
PubMed1992

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.

Adolescent↗
PubMed1992

Anesthetic implications for children undergoing computerized tomography-guided stereotactic brain biopsy.

Anesthesiologists spend much of their time administering anesthesia to children outside of the operating room, especially for neuroradiological evaluation. Neuroradiological procedures include magnetic resonance imaging (MRI), computed tomography (CT), positron emission tomography, myelography, pneumoencephalography, and arteriography. Each of these procedures presents a "working environment" that compromises the ability to deliver a safe and well-monitored anesthetic (1). CT-guided stereotactic brain biopsy in children requires two anesthetic locations (2). The stereotactic guidance apparatus renders the airway inaccessible both during CT and during transport to the operating room. We report a case of a child undergoing CT-guided stereotactic brain biopsy to elucidate the anesthetic considerations of this logistically difficult procedure.

Journal Article↗
PubMed1992

Epidural patient-controlled analgesia after cesarean section: buprenorphine-0.015% bupivacaine with epinephrine versus fentanyl-0.015% bupivacaine with and without epinephrine.

We compared the analgesia, side effects, and plasma concentrations of buprenorphine and fentanyl in a double-blind study of 78 parturients receiving one of these drugs by patient-controlled epidural infusion after elective cesarean section with epidural anesthesia. Patients were randomized to three epidural infusion groups: group 1 (n = 26), 3 micrograms/mL buprenorphine with 0.015% bupivacaine and 1 microgram/mL epinephrine; group 2 (n = 26), 3 micrograms/mL fentanyl with 0.015% bupivacaine and 1 microgram/mL epinephrine; and group 3 (n = 26), 3 micrograms/mL fentanyl with 0.015% bupivacaine. Plasma for determination of opioid concentrations was obtained in some subjects in each group at intervals up to 48 h during the infusion and in some subjects from each group at intervals after the infusion was stopped. Pain relief was similar and satisfactory in all three groups. The median overall satisfaction scores were high for all three groups. Pruritus was more common in the fentanyl groups (P less than 0.05). However, vomiting was more disturbing to the patients and seen only with buprenorphine. No patient had a respiratory rate less than 12 breaths/min. Epinephrine use was associated with a slower infusion rate (P less than 0.05, group 2 vs 3). All patients were able to ambulate without difficulty. Mean opioid plasma concentrations did not exceed 1.5 ng/mL. Thus, epidural patient-controlled analgesia in all three groups provided excellent analgesia, permitted ambulation, and was without serious side effects. Epidural buprenorphine offered no advantages over epidural fentanyl.

Analgesia, Epidural↗
PubMed1992

An updated cross-referenced filing system for anesthesiologists.

A filing system that provides a medical-information retrieval system is useful for medical students, physicians-in-training, and practicing physicians. The present system is an expansion and update of the one proposed by Petty and Carden in 1973. This filing system for anesthesiologists contains a simple numerical index of the major categories in the anesthetic, medical, and surgical literatures. The organ system and the anesthetic considerations are combined. A cross-reference index is provided as well. This system allows the user to cross-file reprints, locate ones that have been loaned, and keep track of references that may be found in personal bound volumes. The files may be expanded over the years to any desired degree. Finally, this system may be of use either to the individual anesthesiologist or to a department's library.

Anesthesiology↗
PubMed1992

Adverse effects of epidural 0.03% bupivacaine during analgesia after cesarean section.

To develop a regimen that would provide good analgesia after cesarean section with minimal side effects in the setting of prolonged (> 24 h) epidural infusion, buprenorphine or fentanyl was combined with 0.03% bupivacaine in a double-blind study of 23 parturients. Patients were randomly assigned to two groups: group I (n = 12), patient-controlled analgesia by epidural infusion of buprenorphine (3 micrograms/mL) with 0.03% bupivacaine; group II (n = 11), patient-controlled analgesia by epidural infusion of fentanyl (2 micrograms/mL) with 0.03% bupivacaine. Plasma for determination of opioid concentrations was obtained at intermittent intervals. Pain relief was similar and satisfactory in both groups. The median overall satisfaction score was higher (10.0 vs 7.5; P < 0.03) for group II. Pruritus was mild in most patients. Nausea and vomiting, which were most disturbing to the patients, were seen only with buprenorphine. No patient had a respiratory rate of < 12 breaths/min. Mean plasma opioid concentrations did not exceed 1 ng/mL during the study. However, four patients (33%) in group I and six patients (55%) in group II experienced sensory loss in the lower extremities, which made ambulation difficult. One patient in each group developed extensive pressure blisters on both heels. These complications led us to terminate the study. We conclude that 0.03% bupivacaine used in combination with an opioid in prolonged epidural infusions produces a high incidence of sensory loss in the lower extremities and is unsuitable for situations in which early ambulation is desired.

Analgesia, Epidural↗