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PubMed1994

The learning curve.

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Cholecystectomy, Laparoscopic↗
PubMed2003

Learning curve for sonographic examination of the fetal nasal bone at 11-14 weeks.

OBJECTIVE: To determine the number of ultrasound examinations necessary for training sonographers to examine accurately the fetal nasal bone at 11-14 weeks' gestation. METHODS: Fifteen sonographers with experience in measuring nuchal translucency were asked to examine the nasal bone during the routine 11-14-week scan. The supervising doctor recorded if the sonographer succeeded in obtaining the correct image. Each sonographer performed a total of 140 examinations, and the data were analyzed in seven groups of 20 examinations. In a second study, two sonographers with extensive experience in examining the nasal bone examined independently 100 consecutive patients at a median fetal crown-rump length of 65 (45-84) mm and median gestational age of 12 (11-14) weeks and recorded whether the nasal bone was absent or present. RESULTS: In the first group of 20 examinations, there was failure to obtain the correct image of the fetal profile in 1-5 (median, 4) cases. In the subsequent three groups, there was failure to obtain the correct image in 0-3 (median, 1) cases. In the fifth and sixth groups failure occurred in 0-2 (median, 0) cases and in the seventh group all sonographers obtained successful images of the fetal profile in all cases. One sonographer obtained successful images of all cases after the first 40 scans, four after the first 60 scans, six after the first 80 and two each after the first 100 and 120 scans. In the second study, there was agreement between the two sonographers that the nasal bone was absent in two and present in 98 of the 100 consecutive patients examined. CONCLUSION: The minimum number of scans required for an experienced sonographer to become competent in examining the fetal nasal bone is on average 80, with a range of 40-120.

Allied Health Personnel↗
PubMed1993

Surfactant therapy in respiratory distress syndrome: the effect of a learning curve in improving outcome.

A retrospective study of all premature neonates who received artificial surfactant (Curosurf) at the Rotunda Hospital was performed. The period from October 1990 to June 1992 (n = 48) was compared with the initial experience from June 1987 to January 1988 (n = 15). In the initial period mortality rate was 67% in surfactant treated infants, and use of surfactant was not associated with an improvement in outcome compared with the previous six years. In the more recent period overall mortality was 21%. Overall survival in normally formed very low birthweight infants improved from 59% in 1986 to 86% in 1991-1992. Improvement in survival rates was most noticeable in infants with birthweight 750-999 grams, with survival increasing from 44% (before introduction of surfactant treatment) to 91% (in 1991-1992). It is probable that a certain level of experience with use of surfactant is required before optimal effects can be obtained.

Female↗
PubMed2000

Decreasing complication rates with stapled esophagojejunostomy following a learning curve.

BACKGROUND: Recently, two reports of clinical trials on gastric cancer surgery have reported high mortality following extended lymph node dissection. In these reports, anastomotic leakage at the esophagojejunostomy was observed in approximately 10% of patients, with high mortality. These data highlight the importance of avoiding this complication. In this article, we report the use of a stapler to achieve a safe anastomosis, with low incidences of leakage and postoperative stenosis. METHODS: From January 1985 to December 1997, we performed 1234 esophagojejunal anastomoses at the National Cancer Center Hospital. Records of the 1234 patients were reviewed to evaluate changes in anastomotic techniques and changes in the incidence of anastomotic leakage. In this series, 588 stapled anastomoses were carried out between 1992 and 1997. These were evaluated to calculate the incidence of leakage and stenosis, with special reference to the use of supplementary sutures around the stapled anastomosis. Statistical analysis was performed by the chi2 test. RESULTS: This series showed an overall increase in the use of staplers to form the esophagojejunal anastomosis, and a decrease in the incidence of leakage. In 1995, all anastomoses were stapled, with a leakage rate of less than 1.0%. In the last 6 years of the series (1992-1997), the leakage rate was 1.0% and the incidence of postoperative stenosis was 1.2%. The results were not improved by supplementary sutures around the stapled anastomosis. CONCLUSION: These data show that a stapled esophagojejunal anastomosis without supplementary sutures is a safe way to create a esophagojejunal anastomosis, with results superior to those with hand suturing. We believe the stapled anastomosis should become the "gold standard" for esophagojejunal anastomosis.

Journal Article↗
PubMed2001

Complications of bronchoscopically guided percutaneous dilational tracheostomy: beyond the learning curve.

OBJECTIVE: To assess the complication rate of bronchoscopically guided percutaneous dilational tracheostomy (PDT), with tracheal tube suture fixation and no elective tracheostomy tube exchange, after experience had been gained. DESIGN: Prospective clinical study. SETTING: Anaesthesiological ICU with mixed surgical and medical patients in a university hospital. PATIENTS: Hundred thirty-three mechanically ventilated patients (mean age: 54.8 years, range: 13-87 years) with indication for PDT, many with thrombocytopenia and/or coagulation deficits. INTERVENTIONS: Hundred thirty-six consecutive PDTs performed by residents under bronchoscopic guidance with stepwise dilation ( n=114, Ciaglia's conventional system) or conic dilation ( n=22, "Blue Rhino" approach) and supervision of experienced staff anaesthesiologists. Tracheostomy tubes were fixed to the skin with a suture and no routine exchange of tracheostomy tubes was performed. Complications were categorised and the results were also compared to an earlier prospective study. RESULTS: The incidence of tracheostomy tube-related complications (hypoxaemia, cannula misplacement, accidental decannulation, cuff rupture and hernia, or posterior tracheal wall lesion) was low (0.7%) and significantly less (6.2%, p=0.01) than in our earlier study. No patient died of PDT-associated complications. We recorded four (2.9%) clinically relevant bleeding episodes. Insertion of tracheal tubes was easy or only moderately difficult in 86.7%. CONCLUSION: With experience in performing PDT, fixation of the tracheal cannula, and omission of routine change of tracheostomy tubes complication rate of PDT is low.

Adolescent↗
PubMed2000

Initial experience with intravenous pentobarbital sedation for children undergoing MRI at a tertiary care pediatric hospital: the learning curve.

OBJECTIVE: Our purpose is to describe the initial experience with intravenous pentobarbital sedation in children undergoing MRI at a tertiary pediatric hospital to identify errors associated with inexperience. SUBJECTS AND METHODS: The study included the first 100 children sedated with intravenous pentobarbital prior to magnetic resonance examination at a tertiary pediatric hospital. The protocol included a maximum dose of 6 mg/kg administered in three divided doses with the total dose not to exceed 200 mg. Flow sheets documenting vital signs, administered drug doses, and adverse reactions were maintained contemporaneous to sedation. RESULTS: Sedation was successful in 92 children. Of the eight children who failed sedation, three were at least 12 years old and three weighed more than 50 kg. chi2 tests identified significantly greater failure rates in children older than 11 years or weight greater than 50 kg. Two children had prolonged sedation after the maximum suggested dose was exceeded. CONCLUSIONS: The success rate was good, but could have been improved by restricting the use of pentobarbital to children less than 12 years of age and weighing less than 50 kg. Radiologists inexperienced with intravenous sedation should strictly observe the maximum suggested dose of pentobarbital to prevent prolonged sedation.

Adolescent↗
PubMed2005

The registration of complications in surgery: a learning curve.

Registration of complications in surgery is an important method used for quality improvement. Unfortunately many different definitions and classification systems have been used, which influences the interpretation and the outcome of complication registration. Since 1986 complications have been registered on a daily basis in our surgical department. We focus in this article on the influence of changes in interpretation of the definition and registration methods used on the incidence of registered complications. Between 1986 and 1993 complications registered were strictly related to surgical procedures. In the second period, between 1993 and 2001, the interpretation of the definition changed and all adverse events were registered in a patient-centred way, not only related to the surgical procedure. The definition used in both periods did not change. In 1993 we started with the implementation of a fully automated registration system in our surgical department. In the first period 1699 (7%) complications in 24,201 surgical procedures were registered and in the second period 8335 (27%) complications were registered in 31,161 surgical procedures. A dramatic increase in the total number of registered complications was seen with the implementation of a fully automated registration system and a patient-centred way of registering complications. In the context of the evolving discussion of quality of care, a uniform definition and registration system has to be used to assure reliable outcome data in surgery and to form a basis for comparison.

Humans↗
PubMed2005

Laparoscopic cholecystectomy after the learning curve: what should we expect?

BACKGROUND: The introduction of laparoscopic cholecystectomy (LC) in the late 1980s was accompanied an increase in common bile duct (CBD) injuries. This retrospective analysis of 2,005 cholecystectomies performed at a single institution investigates the factors that have contributed to a record of zero CBD injuries in 1,674 consecutive LC. METHODS: The medical records of 1,285 consecutive patients operated on from 7 July 1996 to 6 June 2003 were obtained. We also examined the peer review records of an additional 720 LC performed between 1 January 1990 and 7 July 1996. RESULTS: There were no CBD injuries among 1,674 consecutive LC patients spanning the period since 1990. Of the 954 patients who underwent LC since 1996, six had a cystic duct leak and five had a duct of Luschka leak. Intraoperative cholangiography (IOC) was performed in 20.2% of cases (n = 193/954). Seventy of 157 patients who underwent cholangiography alone demonstrated one or more stones in the CBD (44.6%). In 40 patients (58.0%), endoscopic retrograde cholangio pancreatography (ERCP) was uniformly successful in clearing intraoperatively identified stones. In36.2% of cases, the stones were removed via laparoscopic CBD exploration (CBDE) (n = 25). In 5.8% of positive cases, the stones were removed via open CBDE (n = 4). Among 761 patients who did not undergo IOC, seven patients (0.92%) returned to the hospital for retained stones. Three of these patients had elevated liver function tests (LFT) preoperatively (1.3%) and four had normal LFT (1.1%). CONCLUSIONS: Injuries of the CBD can be avoided by performing an extensive dissection of the triangle of Calot and by developing a critical view of the operative field to ensure the patient's safety during LC. If all LFT are normal and IOC is not performed, the occurrence of clinically significant stones postoperatively is minimal; in this group, only four patients had retained stones. Thus, in the face of normal LFT, routine IOC is unnecessary for a low CBD injury rate, and a return to the hospital for retained bile duct stones is rarely required, regardless of the number of times ductal stones are found on routine cholangiography. This implies that the significance of the stones discovered at IOC is questionable in most cases, thereby providing an argument against routine cholangiography. Most discovered CBD stones can be treated by ERCP, thus obviating the need for the T-tube drainage associated with CBDE. The 21st century finds LC to be a mature and safe surgical procedure.

Adolescent↗
PubMed2006

Laparoscopic fundoplication: a 10-year learning curve.

BACKGROUND: Laparoscopic Nissen fundoplication (LNF) has become the most common surgical treatment for gastroesophageal reflux disease (GERD). Controversies still exist regarding the operative technique and the durability of the procedure. METHODS: A retrospective study of 808 patients undergoing 838 LNF for GERD at a tertiary referral center was undertaken. Demographic, perioperative, and follow-up data had been entered onto the unit database. RESULTS: During a median follow-up period of 60 months (range, 2-120 months), heartburn decreased to 3% of the patients (19/645) and regurgitation to 2% (11/582) (p < 0.01). Respiratory symptoms improved in 69 (85%) of 81 patients (p < 0.01). The incidence of postoperative dysphagia was unaffected by the use of an intraesophageal bougie (odds ratio [OR], 1.16; 95% confidence interval [CI], 0.82-1.64; p = 0.41) or division of the short gastric vessels (OR, 0.84; 95% CI, 0.42-1.07; p = 0.72). In the immediate postoperative period, the incidence of abdominal symptoms increased by 10% (p < 0.01) and dysphagia by 16% (p < 0.01). After 10 postoperative years, only 3% (30/484) were found to have abdominal symptoms, whereas the incidence of dysphagia declined to zero. CONCLUSION: The findings show that LNF is a safe and effective procedure with long-term durability. Abdominal symptoms and dysphagia are the principal postoperative complaints, which improve with time. Personal preference should dictate the use of a bougie, division of the short gastric vessels, or both.

Adult↗
PubMed1999

Laparoscopic exploration of the common bile duct: beyond the learning curve.

BACKGROUND: Bile duct clearance at open cholecystectomy had become normal surgical practice before the introduction of laparoscopic cholecystectomy. However, perceived technical difficulties have deterred many surgeons from treating common bile duct stones at the time of laparoscopic cholecystectomy. This has led to a reliance on preoperative clearance of ducts known to have stones and postoperative clearance of ducts found to have stones at operation or those that subsequently develop complications of retained stones. METHODS: The authors describe a series of 120 consecutive bile duct explorations carried out between April 1991 and February 1997 in a series of 1,237 laparoscopic cholecystectomies. RESULTS: Laparoscopic exploration and clearance of the bile ducts was achieved in 89% of cases in the whole series, and 97% success was attained in the last 60 cases, which also were associated with a decrease in operating time. CONCLUSIONS: We believe that for surgeons familiar with open common bile duct exploration and laparoscopic cholecystectomy, the next logical step is laparoscopic exploration of the common bile duct at the time of cholecystectomy, which is safe and readily mastered.

Chi-Square Distribution↗
PubMed2002

Islet transplantation: travels up the learning curve.

Great excitement was generated in 2000 by a report from the University of Alberta in Edmonton, Canada, that seven of seven type I diabetic patients transplanted with intrahepatic cadaveric islets were normal glycemic, 1-year post-transplantation without the use of exogenous insulin treatment. The follow-up information from the same researchers with a larger group of patients indicated that in a group of 12 alloislet recipients, five had impaired glucose tolerance and three had post-transplantation diabetes. Great attention is now being directed toward understanding why alloislet recipients who are initially successful may later develop partial failure. At the same time, the Immune Tolerance Network is sponsoring a multicenter trial using the Edmonton protocol to ascertain whether these results can be replicated by other transplant groups in the United States, Canada, and Europe. Detailed studies of islet beta-cell function have revealed intact insulin secretion in autoislet and alloislet transplant recipients. In contrast, glucagon responses to insulin-induced hypoglycemia are absent from islets transplanted intrahepatically; however, alpha cells within intrahepatic islets are capable of releasing glucagon in response to intravenous arginine. Although many technical refinements are underway to make this procedure even more efficacious, supply and demand issues are a major concern and must be dealt with before the procedure of islet transplantation can be considered generally available for patients with diabetes.

Animals↗
PubMed1991

Percutaneous balloon mitral valvuloplasty: the learning curve.

PBMV is a catheter-based approach to nonsurgically relieving obstruction to mitral inflow in patients with symptomatic mitral stenosis. Since 1986, 50 patients at the Mayo Clinic have undergone the procedure, utilizing either the Inoue pillow-shaped balloon or a dual-balloon technique with excellent early hemodynamic and symptomatic results. Mean mitral valve area increased from 1.06 +/- 0.32 cm2 to 2.01 +/- 0.70 cm2, and transmitral gradient decreased from 15.7 +/- 7.1 mm Hg to 7.5 +/- 3.9 mm Hg. This improvement has been sustained during short-term and intermediate-term follow-up. A marked improvement in procedural success and complication rates is attributable to refinement of patient selection criteria, technical advances in the procedure, and operator experience. There have been three procedure-related deaths; one of these was in a patient who developed severe mitral regurgitation after PBMV and underwent emergency valve replacement. Unfavorable outcomes appear to be related to three factors: presence of thick, calcified valve leaflets with extensive subvalvular involvement, poor general medical status, and operator inexperience.

Adult↗