Safety of early ambulation in patients undergoing ultrasound-guided femoral low angle arterial access technique (FLAT).

PURPOSE: To evaluate the safety of early ambulation in patients undergoing transfemoral arterial interventions via ultrasound-guided femoral low angle arterial access technique (FLAT). MATERIALS AND METHODS: A total of 58 patients undergoing 72 transfemoral arterial procedures that underwent an attempt at FLAT for femoral artery cannulation at our institution from November 2014 to July 2015 were retrospectively identified. Technical success was defined as obtaining less than a 35-degree angle of entry through the anterior wall of the common femoral artery. Patients for which a low angle was achieved were ambulated after 2hours after hemostasis was achieved with manual compression. All patients received out-patient clinic follow-up which included ultrasound examination of the femoral artery. Chart review provided demographic data, pertinent past medical history, procedural information (type of procedure, size of femoral access sheath, time to ambulation), complications related to arterial access and follow up. RESULTS: Twelve patients were excluded from the study due to inability to analyze ultrasound images. A low angle was achieved in 37 patients (17 men, 20 women; mean age: 58.5 years±13.1 [SD]) undergoing 45 procedures who met inclusion criteria for the study, yielding technical success rate of 75%. There was a moderate positive correlation between the access angle and depth of the common femoral artery at the site of puncture (r=0.45; P<0.01). All patients were followed up within 2 weeks of the initial procedure in the outpatient clinic. No arterial access-related complications occurred. CONCLUSIONS: Femoral artery cannulation using FLAT followed by manual compression and ambulation after 2 hours appears to be a safe approach.

Fast-tracking children after ambulatory surgery.

UNLABELLED: This study was designed to determine the feasibility and benefits of fast-tracking children after ambulatory surgery. One-hundred-fifty-five healthy children undergoing surgical procedures lasting <90 min were studied in a randomized manner. After surgery, children who met predefined recovery criteria in the operating room were entered into one of the study groups. Seventy-one patients (control) were first admitted to the postanesthesia care unit (PACU) and then to the second-stage recovery unit (SSRU). Eighty-four children bypassed the PACU and were directly admitted to the SSRU (Fast-Track group). The demographic data, airway management, and surgical procedures were similar in both groups of patients. During the recovery phase, 62.0% of the PACU group patients and 40.5% of the Fast-Track patients received analgesics (P = 0.01). The total recovery time was 79.1 +/- 48.3 min in the Fast-Track group and 99.4 +/- 48.6 min in the Control group (P = 0.008). A larger percentage of parents in the Fast-Track group (31% vs 16%) reported that their child was restless on arrival at the SSRU (P = 0.037). There were no clinically significant adverse events. However, adequate pain control must be provided before transfer to SSRU. In conclusion, fast-tracking children after ambulatory surgery is feasible and beneficial when specific selection criteria are used. IMPLICATIONS: The results of this study show that the total recovery time is shorter in children who are fast-tracked (bypass the postanesthesia care unit) after ambulatory surgery. A higher percentage of parents of the Fast-Track group felt that their child was restless on arrival at the second-stage recovery unit. Fast-tracking children after ambulatory surgery is feasible and beneficial when specific selection criteria are used.

Comparison of three techniques for internal jugular vein cannulation in infants.

Central venous cannulation allows accurate monitoring of right atrial pressure and infusion of drugs during the anaesthetic management of infants undergoing cardiopulmonary bypass. In this prospective, randomized study, we compared the success and speed of cannulation of the internal jugular vein in 45 infants weighing less than 10 kg using three modes of identification: auditory signals from internal ultrasound (SmartNeedle, SM), external ultrasound imaging (Imaging Method, IM) and the traditional palpation of the carotid pulsation and other landmarks (Landmarks Method, LM). The cannulation time, number of attempts with LM and SM techniques were greater than those with IM technique. The incidence of carotid artery puncture and the success rate were not significantly different among the three groups. In infants, a method based on visual ultrasound identification (IM) of the internal jugular vein is more precise and efficient than methods based on auditory (SM) and tactile perception (LM).

Retrospective comparison of the Amplatz thrombectomy device with modified pulse-spray pharmacomechanical thrombolysis in the treatment of thrombosed hemodialysis access grafts.

PURPOSE: To retrospectively evaluate the Amplatz thrombectomy device (ATD) in the treatment of thrombosed hemodialysis grafts and compare it with modified pulse-spray pharmacomechanical thrombolysis (PPT). MATERIALS AND METHODS: During a 4-month period, 79 patients presented with 126 episodes of graft occlusion. Percutaneous recanalization was performed by using the ATD (n = 57) or the modified PPT technique (n = 69). Evaluation included the technical success, complications, and primary patency rates. RESULTS: Technical success was achieved in 93% (53 to 57) of the cases treated with the ATD and in 96% (66 of 69) of the cases treated with modified PPT (P = .70). Complications occurred in 6% (four of 69) of modified PPT procedures and 16% (nine of 57) of ATD procedures. This difference was not statistically significant (P = .08); however, there were significantly more local complications in the ATD group (P = .04). The primary patency rates at 30, 90, and 180 days were 65% and 65%, 36% and 50%, and 26% and 33% for modified PPT and ATD, respectively. Survival curves were found not to differ significantly (P = .49). CONCLUSION: The ATD and modified PPT were similarly successful in the recanalization of thrombosed hemodialysis access grafts and achieved comparable primary patency rates. The higher rate of local complications and technical difficulties encountered with use of the 8-F ATD limit its usefulness for this indication.

Trace eyeblink conditioning in the freely moving rat: optimizing the conditioning parameters.

Trace eyeblink conditioning (EBC) parameters, with an airpuff unconditioned stimulus, were examined in male Fischer 344 X Brown Norway F1 rats. Integrated electromyographic activity from the upper eyelid was recorded. An 8-kHz tone was superior to white noise as a conditioning stimulus. Rats trained with 30 or 50 trials per session showed similar learning. Reversal of environmental lighting had no significant effect. Trace intervals of 0 and 250 ms yielded well-timed conditioned responses (CRs); intervals of 500 ms or more did not. These experiments provide parameters that reliably yield CRs and suggest limits on the temporal processing capabilities of the rat. EBC can thus be used as part of a comprehensive test battery for learning and memory in this species. Physiological recording and pharmacological manipulations may also be done easily. This combination of approaches should facilitate a more complete understanding of learning mechanisms and age-related memory impairments.

Ultrasound-guided internal jugular venous cannulation in infants: a prospective comparison with the traditional palpation method.

BACKGROUND: Percutaneous cannulation of the internal jugular vein in infants is technically more difficult and carries a higher risk of carotid artery puncture than in older children and adults. In this prospective study, the authors tested their hypothesis that using an ultrasound scanner would increase the success of internal jugular cannulation and decrease the incidence of carotid artery puncture in infants. METHODS: After approval from the institutional review board and receipt of written informed parental consent, 95 infants scheduled for cardiac surgery were randomized prospectively into two groups. In the landmarks group, the patients' internal jugular veins were cannulated using the traditional method of palpation of carotid pulsation and identification of other anatomic landmarks. In the ultrasound group, cannulation was guided using an ultrasound scanner image. The cannulation time, number of attempts, success rate, and incidence of complications were compared for the two groups. RESULTS: There were no significant differences between the two groups with regard to weight, age, and American Society of Anesthesiologists physical status classification. The success rate was 100% in the ultrasound group, with no carotid artery punctures, and 77% in the landmarks group, with a 25% incidence of carotid artery punctures. Both differences were significant (P > 0.0004). The cannulation time was less, the number of attempts was fewer, and the failure rate was significantly lower in the ultrasound group than in the landmark group. CONCLUSION: Ultrasonographic localization of the internal jugular vein was superior to the landmarks technique in terms of overall success, speed, and decreased incidence of carotid artery puncture.

Endovascular stent placement for angioplasty-induced venous rupture related to the treatment of hemodialysis grafts.

PURPOSE: To assess the use of endovascular stents for treating rupture after percutaneous transluminal angioplasty (PTA) in the maintenance of hemodialysis grafts. MATERIALS AND METHODS: From February 1, 1994, to August 1, 1997, 683 hemodialysis-related angioplasty procedures were performed on 277 patients to treat thrombosed or poorly functioning polytetrafluoroethylene (PTFE) hemodialysis bridge grafts. In each of these procedures, angioplasty of the venous anastomosis or the outflow vein was performed. This study is a retrospective review to analyze uncovered endovascular stents placed to treat ruptures after PTA. RESULTS: Fourteen ruptures were treated with use of an uncovered metal stent. Stent placement was technically successful in 11 of 14 patients, with clinical success in 11 of 14 cases. The primary patencies at 30, 60, 90, and 120 days were calculated by means of Kaplan-Meier life-table analysis; these were 63%, 54%, 46%, and 46%, respectively. The secondary patencies at 60, 120, and 180 days were 85%, 75%, and 75%, respectively. No complications were attributable to stent placement. The results are comparable to those of stents placed for reasons other than rupture, and support the efficacy of their use for this indication. CONCLUSION: Endovascular stent placement is a safe and effective means of salvaging angioplasty-induced rupture that occurs during the treatment of hemodialysis grafts.

Hemodialysis graft mechanical thrombolysis with use of the Amplatz Thrombectomy Device: histopathologic evaluation of extracted myointimal tissue.

PURPOSE: To histopathologically evaluate material extracted from thrombosed hemodialysis access grafts by the Amplatz Thrombectomy Device (ATD). MATERIALS AND METHODS: Thrombosed hemodialysis access grafts were recanalized with use of crossed catheter technique with introduction of the ATD through 8-F sheaths. After removal of the ATD from the introducer sheath, the tip of the device was visually inspected. Discernible tissue in the impeller/housing mechanism was gently extracted with a hemostat and preserved in formalin. Specimens were evaluated histologically with hematoxylin-eosin and smooth muscle immunoperoxidase stains. RESULTS: The ATD was utilized in 18 patients with acutely thrombosed grafts. Sufficient tissue for pathologic evaluation was extracted from 10 devices. Histopathologic analysis yielded findings of fibrotic myointima in all 10 cases with positive smooth muscle stains. CONCLUSIONS: The unexpected, although consistent, finding of intimal and myointimal tissue fragments in the impeller/housing mechanism of the ATD raises questions with respect to the mechanism of tissue extraction and concerns regarding the use of the device in native vessels. Further studies are indicated to determine whether this apparent intimal injury will have a deleterious effect on vessel patency.

Patency of Wallstents placed across the venous anastomosis of hemodialysis grafts after percutaneous recanalization.

PURPOSE: To determine the patency of Wallstents placed across the venous anastomosis of prosthetic bridge grafts after percutaneous graft recanalization. MATERIALS AND METHODS: Wallstents were placed across 26 lesions at the venous anastomosis of polytetrafluoroethylene (PTFE) grafts in 25 patients (11 men, 14 women; age range, 29-83 years; mean age, 65.4 years) after pulse-spray pharmacomechanical thrombolysis. Indications for stent deployment included acute angioplasty failure, rapid restenosis, and vessel perforation. RESULTS: The initial success rate was 100%. The mean primary graft patency rates (+/- standard error) at 3 and 6 months were 34% +/- 9 and 27% +/- 9, respectively. Secondary patency rates were 77% +/- 8 at 3 months, 72% +/- 9 at 6 months, and 50% +/- 10 at 12 months. Eight of the 26 grafts continued to be used for hemodialysis at the end of follow-up. CONCLUSION: After angioplasty failure or vessel perforation, Wallstent placement at the venous anastomosis of recanalized PTFE grafts can salvage hemodialysis access function. The results of this study indicate that the 1-year secondary patency rate of these grafts is 50%, which approaches the reported rates of patency after balloon dilation as part of percutaneous graft recanalization.

Preoperative laboratory testing in children undergoing elective surgery: analysis of current practice.

STUDY OBJECTIVE: To evaluate current practice in preoperative testing of healthy children undergoing elective surgery that is not expected to result in significant blood loss. DESIGN: Survey of members of the Society for Pediatric Anesthesia. SETTING: Anesthesiologists practicing in North America. POPULATION: A total of 1,200 questionnaires were mailed. INTERVENTIONS: Questionnaires were mailed to all members of the Society for Pediatric Anesthesia. All members were asked to specify which tests were routinely performed and to state why. Specific questions were asked about performing complete blood count (CBC), hemoglobin (Hb), hematocrit (Hct), and urine analysis (UA) in all patients, pregnancy test in adolescents, prothrombin time (PT) and activated partial thrombin time (PTT) prior to tonsillectomy, and sickle cell testing in black and/or Mediterranean children. MEASUREMENTS AND MAIN RESULTS: 685 of 1,200 (57%) questionnaires were returned. No attempt was made to identify and follow-up with nonresponders. Hb testing is routinely performed in 27% to 48% of the children depending on the age of the patient. UA is ordered preoperatively in less than 15% of the children. Pregnancy test was ordered by 43% of the respondents. Hemostatic tests prior to tonsillectomy were conducted by 45% of the anesthesiologists. CONCLUSION: The results indicate the present practice of routine preoperative laboratory testing for children undergoing elective outpatient surgery. In spite of the many studies that indicate no specific benefits of performing routine preoperative testing in healthy children undergoing scheduled surgery, many physicians continue to order these tests in all such children.

Single-dose ondansetron prevents postoperative vomiting in pediatric outpatients.

UNLABELLED: This randomized, double-blind, parallel-group, multicenter study evaluated the safety and efficacy of ondansetron (0.1 mg/kg to 4 mg intravenously) compared with placebo in the prevention of postoperative vomiting in 429 ASA status I-III children 1-12 yr old undergoing outpatient surgery under nitrous oxide- and halothane-based general anesthesia. The results show that during both the 2-h and the 24-h evaluation periods after discontinuation of nitrous oxide, a significantly greater percentage of ondansetron-treated patients (2 h 89%, 24 h 68%) compared with placebo-treated patients (2 h 71%, 24 h 40%) experienced complete response (i.e., no emetic episodes, not rescued, and not withdrawn; P < 0.001 at both time points). Ondansetron-treated patients reached criteria for home readiness one-half hour sooner than placebo-treated patients (P < 0.05). The age of the child, use of intraoperative opioids, type of surgery, and requirement to tolerate fluids before discharge may also have affected the incidence of postoperative emesis during the 0- to 24-h observation period. Use of postoperative opioids did not have any effect on complete response rates in this patient population. We conclude that the prophylactic use of ondansetron reduces postoperative emesis in pediatric patients, regardless of the operant influential factors. IMPLICATIONS: Postoperative nausea and vomiting often occur after surgery and general anesthesia in children and are the major reason for unexpected hospital admission after ambulatory surgery. Our study demonstrates that the prophylactic use of a small dose of ondansetron reduces postoperative vomiting in pediatric patients.

Oral intubation using a lighted stylet vs direct laryngoscopy in older children with cervical immobilization.

OBJECTIVE: To compare the tracheal intubation success rates of blind oral intubation using a lighted stylet vs standard of direct laryngoscopy in anesthetized pediatric patients wearing rigid cervical collars. METHODS: Seventy-eight children were randomly assigned to method of intubation (lighted stylet or direct laryngoscopy) and intubator; five patients were excluded after randomization. After sedation and paralysis, the patients were placed in rigid cervical spine collars to simulate intubating conditions for trauma patients. Three attempts at intubation were allowed. An observer recorded the following parameters during the procedure: 1) number of intubation attempts, 2) duration of each intubation attempt, and 3) complications. The intubators had limited prior experience with the lighted stylet technique. RESULTS: Thirty-three patients were in the lighted stylet group and 40 were in the laryngoscopy group. The patients in the lighted stylet group required more attempts prior to successful intubation (2.2 vs 1.5, p < 0.01), and the success rate was higher for the laryngoscopy group (26/33 vs 39/40, p < 0.05). CONCLUSIONS: Blind oral intubation using a lighted stylet under controlled conditions took longer than direct laryngoscopy. However, among those successful on the first intubation attempt, the times to intubation were not significantly different between groups (44.5 vs 52.9 sec). The lighted stylet technique is a viable alternative technique for intubating children who have concurrent cervical spine immobilization.

Propofol anaesthesia in paediatric ambulatory patients: a comparison with thiopentone and halothane.

The purpose of this study was to evaluate the haemodynamic changes during induction, as well as the speed and quality of recovery when propofol (vs thiopentone and/or halothane) was used for induction and maintenance of anaesthesia in paediatric outpatients. One hundred unmedicated children, 3-12-yr-old, scheduled for ambulatory surgery were studied. The most common surgical procedures performed were eye muscle surgery (42%), plastic surgery (21%), dental restoration (15%), and urological procedures (15%). The children were randomized to an anaesthetic regimen for induction/maintenance as follows: propofol/propofol infusion; propofol/halothane; thiopentone/halothane; halothane for both induction and maintenance. Succinylcholine 1.5 mg.kg-1 was used to facilitate tracheal intubation and N2O/O2 were used as the carrier gases in each case. All maintenance drugs were titrated according to the clinical response of the patient to prevent movement and/or maintain BP +/- 20% of baseline. Two patients (4%) who received propofol expressed discomfort during injection. The mean propofol dose required to prevent movement was 267 +/- 83 micrograms.kg-1.min-1. The overall pattern of haemodynamic changes, as well as awakening (extubation) times were not different among the four groups. Children who received propofol recovered faster (22 vs 29-36 min) (P < 0.05), were discharged home sooner (101 vs 127-144 min) (P < 0.05), and had less postoperative vomiting (4 vs 24-48%) (P < 0.05) than all others.(ABSTRACT TRUNCATED AT 250 WORDS)

Abnormal ambulatory left ventricular ejection fraction in heart transplant arteriopathy.

The morbidity and mortality from heart transplantation has been reduced dramatically over the last several years. However, the long-term survival in heart transplant recipients is limited by arteriopathy in the allograft coronary arteries, the pathophysiology of which is poorly understood. The diagnosis of this arteriopathy is at present limited to cardiac catheterization. Noninvasive studies have proven to be of limited benefit in diagnosing this arteriopathy. The authors performed cardiac vest studies in nine heart transplant recipient patients. Six of the vest studies were abnormal; five of the patients had documented transplant coronary artery disease by cardiac catheterization. They found that the sensitivity and negative predictive value of the cardiac vest in identifying arteriopathy in transplant recipients was 100%. The authors propose that cardiac vest could be a sensitive, noninvasive screening test for identifying arteriopathy in heart transplant recipients.

Preoperative screening for pediatric ambulatory surgery: evaluation of a telephone questionnaire method.

The purpose of this study was to determine whether preoperative screening of pediatric patients, accomplished by means of a preoperative telephone call to their parents, would decrease the rate of cancellation or postponement of ambulatory surgical procedures. Data from 5031 patients scheduled for ambulatory surgery were collected. During phase I of the study, when phone calls were attempted only during business hours, we contacted 805 of 1662 (48%) of patients' parents. The contact rate improved to 71% (2403 of 3369 patients) during phase II of the study, when phone calls were made in the evening, and parents were encouraged by the surgeons to call the ambulatory unit. Approximately 13% of the contacted parents reported a history of medical problems in their children. A preoperative anesthesia consultation was required in 2.8% of the patients whose parents were contacted. The rate of postponed or canceled surgery among those who could not be screened was 14.8%; among patients who were screened, it was 9.7% (P less than 0.001). Patients in the former group were more likely than those in the latter group to require inpatient care for monitoring or treatment of underlying medical problems (1.3% vs 0.3%, respectively; P less than 0.05). We conclude that a preoperative telephone interview is an effective method for screening pediatric ambulatory surgical patients.

Emergence airway complications in children: a comparison of tracheal extubation in awake and deeply anesthetized patients.

We compared the differences in oxygen saturation and airway-related complications after tracheal extubation in pediatric patients undergoing elective strabismus surgery or adenoidectomy and/or tonsillectomy who were awake versus anesthetized. Seventy otherwise healthy patients between 2 and 8 yr of age were studied. Anesthesia was induced with halothane or thiamylal and maintained with nitrous oxide and halothane. After induction of anesthesia, the patients were randomly assigned to group 1 (awake extubation) or group 2 (anesthetized extubation). Oxygen saturation was measured continuously and recorded 10 min before extubation and at 1, 2, 3, 5, 7, 10, 15, 20, 25, and 30 min after tracheal extubation. Supplemental oxygen was administered when oxygen saturation values were less than 90% while breathing room air. Oxygen saturation levels were higher in group 2 than in group 1 at 1, 2, 3, and 5 min after extubation. There were no differences between the two groups in the number of patients requiring supplemental oxygen. The incidence of airway-related complications such as laryngospasm, croup, sore throat, excessive coughing, and arrhythmias was not different between the two groups. We conclude that the anesthesiologist's preference or surgical requirements may dictate the choice of extubation technique in otherwise healthy children undergoing elective surgery.