Anesthesia and analgesia
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Anesthesia and analgesia · Dec 2002
Randomized Controlled Trial Comparative Study Clinical TrialPercutaneous tracheostomy with single dilatation technique: a prospective, randomized comparison of Ciaglia blue rhino versus Griggs' guidewire dilating forceps.
Percutaneous tracheostomy with single-step dilation technique using Griggs' guidewire dilating forceps (GWDF) is a well-recognized procedure. Recently, Ciaglia has introduced a one-step dilation technique using a curved, gradually tapered dilator, the Ciaglia Blue Rhino (CBR). In a prospective, randomized study, we performed percutaneous tracheostomy in 60 consecutive patients, using either the CBR or the GWDF technique. Postoperatively, all patients had bronchoscopy by a blinded consultant, and stoma characteristics and injuries to the trachea were studied. Mean tracheostomy time (skin incision to insertion of tracheostomy tube) in the two procedures (CBR 7.5 min versus GWDF 6.5 min) was not different (P > 0.05). The GWDF technique was associated with under-dilation and over-dilation of the tracheal stoma, each in almost one-third of patients. In the CBR group, the procedure was associated with a significant increase in peak airway pressure (P < 0.05) in all patients. There were nine cases of tracheal cartilage rupture, three cases of longitudinal tracheal abrasion, and one pneumothorax. Three patients had tracheal in-drawing at the scar site with huskiness of voice at 8 wk after decannulation; however, none had any breathing difficulty. We conclude that the techniques are equally effective in the formation of percutaneous tracheostomy. However, tracheal stoma over-dilation with GWDF and increase in peak airway pressure and rupture of tracheal rings with CBR remain major concerns. ⋯ The tracheas of 60 patients were cannulated through an artificial opening by using a single-step dilation technique with Ciaglia Blue Rhino or Griggs' dilation forceps. The techniques were equally effective for cannulation of the trachea. However, Ciaglia Blue Rhino was associated with rupture of tracheal rings in one-third of patients and increased airway pressure in all, whereas the Griggs' technique was associated with under- or over-formation of the tracheal opening, each in one-third of patients.
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Anesthesia and analgesia · Dec 2002
The effect of alterations in a preoperative assessment clinic on reducing the number and improving the yield of cardiology consultations.
Although preoperative assessment testing clinics (PATCs) can produce efficiency in the evaluation of surgical candidates, their effect on the use of consultants has not been studied. We hypothesized that changes in PATC procedures, education, and staffing could affect the use and yield of cardiology consultations. All PATC anesthesiologist-requested cardiology consultations for patients undergoing elective noncardiac surgery from 1993 to 1999 were reviewed. This period corresponded to 3 yr before and after a change in the PATC leadership, which resulted in more stringent consultation algorithms, a cardiac assessment and electrocardiogram interpretation educational program, and altered staffing of anesthesiologists and ancillary personnel. A single senior cardiologist completed all consultations. Data including age, sex, reason for consultation, resultant testing, consultant conclusions, cancellations, and surgical procedure and outcomes were collected. In the PRE and POST groups, respectively, 917 and 279 consultations (1.46% versus 0.49% [P = 0.0001] of noncardiovascular surgeries) were ordered despite an increase in the surgical case-mix acuity. In the POST group, significantly fewer consultations were ordered and significantly more required further testing to assess cardiac status. We conclude that changes in PATC consultation algorithms, education, and staffing can significantly decrease the use and yield of preoperative cardiology consultations. ⋯ Alterations in preoperative assessment testing clinic consultation algorithms, education, and staffing can significantly reduce the use of preoperative cardiology consultations while improving their overall yield.
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Anesthesia and analgesia · Dec 2002
The impact of a cardioprotective protocol on the incidence of cardiac complications after aortic abdominal surgery.
We analyzed a local database including 468 consecutive patients who underwent elective aortic abdominal surgery over an 8-yr period in a single institution. A new cardioprotective perioperative protocol was introduced in January 1997, and we questioned whether perioperative cardiac outcome could be favorably influenced by the application of a stepwise cardiovascular evaluation based on the American College of Cardiology/American Heart Association guidelines and by the use of antiadrenergic drugs. Clonidine was administered during surgery, and beta-blockers were titrated after surgery to achieve heart rates less than 80 bpm. We compared data of two consecutive 4-yr periods (1993-1996 [control period] versus 1997-2000 [intervention period]). Implementation of American College of Cardiology/American Heart Association guidelines was associated with increased preoperative myocardial scanning (44.3% vs 20.6%; P < 0.05) and coronary revascularization (7.7% vs 0.8%; P < 0.05). During the intervention period, there was a significant decrease in the incidence of cardiac complications (from 11.3% to 4.5%) and an increase in event-free survival at 1 yr after surgery (from 91.3% to 98.2%). Multivariate regression analysis showed that the combined administration of clonidine and beta-blockers was associated with a decreased risk of cardiovascular events (odds ratio, 0.3; 95% confidence interval, 0.1-0.8), whereas major bleeding, renal insufficiency, and chronic obstructive pulmonary disease were predictive of cardiac complications. In conclusion, cardiac testing was helpful to identify a small subset of high-risk patients who might benefit from coronary revascularization. Sequential and selective antiadrenergic treatments were associated with improved postoperative cardiac outcome. ⋯ Implementation of American College of Cardiology/American Heart Association guidelines and use of antiadrenergic drugs were associated with better cardiac outcomes after major vascular surgery.
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Anesthesia and analgesia · Dec 2002
Vasopressor response in a porcine model of hypothermic cardiac arrest is improved with active compression-decompression cardiopulmonary resuscitation using the inspiratory impedance threshold valve.
During normothermic cardiac arrest, a combination of active compression-decompression (ACD) cardiopulmonary resuscitation (CPR) with the inspiratory threshold valve (ITV) significantly improves vital organ blood flow, but this technique has not been studied during hypothermic cardiac arrest. Accordingly, we evaluated the hemodynamic effects of ACD + ITV CPR before, and after, the administration of vasopressin in a porcine model of hypothermic cardiac arrest. Pigs were surface-cooled until their body core temperature was 26 degrees C. After 10 min of untreated ventricular fibrillation, 14 animals were randomly assigned to either ACD CPR with the ITV (n = 7) or to standard (STD) CPR (n = 7). After 8 min of CPR, all animals received 0.4 U/kg vasopressin IV, and CPR was maintained for an additional 10 min in each group; defibrillation was attempted after 28 min of cardiac arrest, including 18 min of CPR. Before the administration of vasopressin, mean +/- SEM common carotid blood flow was significantly higher in the ACD + ITV group compared with STD CPR (67 +/- 13 versus 26 +/- 5 mL/min, respectively; P < 0.025). After vasopressin was given at minute 8 during CPR, mean +/- SEM coronary perfusion pressure was significantly higher in the ACD + ITV group, but did not increase in the STD group (29 +/- 3 versus 15 +/- 2 mm Hg, and 25 +/- 1 versus 14 +/- 1 mm Hg at minute 12 and 18, respectively; P < 0.001); mean +/- SEM common carotid blood flow remained higher at respective time points (33 +/- 8 versus 10 +/- 3 mL/min, and 31 +/- 7 versus 7 +/- 3 mL/min, respectively; P < 0.01). Without active rewarming, spontaneous circulation was restored and maintained for 1 h in three of seven animals in the ACD + ITV group versus none of seven animals in the STD CPR group (not significant). During hypothermic cardiac arrest, ACD CPR with the ITV improved common carotid blood flow compared with STD CPR alone. Moreover, after the administration of vasopressin, coronary perfusion pressure was significantly higher during ACD + ITV CPR, but not during STD CPR. ⋯ New strategies are needed to improve the efficiency of cardiopulmonary resuscitation (CPR) in hypothermic cardiac arrest. Active compression-decompression CPR with the inspiratory threshold valve improved carotid blood flow (and coronary perfusion pressure with vasopressin) compared with standard CPR.
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Anesthesia and analgesia · Dec 2002
Duration of preoperative fast correlates with arterial blood pressure response to halothane in infants.
In this study, we sought to determine whether the duration of preoperative fasting affects the decrease in blood pressure observed in infants and children during halothane anesthesia. Two-hundred-fifty pediatric patients were divided into 5 age groups: term neonates (n = 50), 1-6 mo (n = 50), 6-24 mo (n = 50), 2-6 yr (n = 50), and 6-12 yr (n = 50). After anesthetic induction with halothane, end-tidal halothane was maintained at 2 minimum alveolar anesthetic concentration (MAC) for 10 min to allow myocardial uptake. Patients were grouped by duration of preoperative fast (0-4 h, 4-8 h, 8-12 h, and >12 h). Changes in heart rate and systolic (SAP) and mean (MAP) arterial blood pressure from preinduction to 2 MAC were compared among fasting groups within each age group. In the 1- to 6-mo age group, the changes in SAP and MAP were significantly greater in infants fasting 8-12 h than in those fasting 0-4 h (SAP, -51 mm Hg versus -31 mm Hg, respectively; MAP, -48 mm Hg versus -32 mm Hg; P < 0.05). No statistically significant differences were noted in the older age groups. The results of this study demonstrate that prolonged preoperative fasting is associated with a greater decrease in blood pressure in infants. This exacerbation of the already significant hemodynamic depression observed in infants during halothane anesthesia underscores the importance of adherence to published fasting guidelines. ⋯ We studied changes in blood pressure during halothane anesthesia in infants and children and found that blood pressure decreased to a greater extent in infants who fasted for longer than 8 h before surgery. This exacerbation of the already significant hemodynamic depression observed in infants during halothane anesthesia underscores the importance of adherence to published fasting guidelines.