Paul H. Mayo

Mechanical Complications of Central Venous Catheters

We analyzed 385 consecutive central venous catheter (CVC) attempts over a 6-month period. All critically ill patients 18 years of age or older requiring a CVC were included. The rate of mechanical complications not including failure to place was 14%. Complications included failure to place the CVC (n = 86), arterial puncture (n = 18), improper position (n = 14), pneumothorax (n = 5 in 258 subclavian and internal jugular attempts), hematoma (n = 3), hemothorax (n = 1), and asystolic cardiac arrest of unknown etiology (n = 1). Male patients had a significantly higher complication rate than female patients (37% vs 27%, P = .04). The subclavian approach had a higher complication rate than the internal jugular or the femoral approach (39% vs 33% vs. 24%, P = .02). The complication rate increased with the number of percutaneous punctures, with a rate of 54% when more than 2 punctures were required.

Achieving Housestaff Competence in Emergency Airway Management Using Scenario Based Simulation Training: Comparison of Attending vs Housestaff Trainers

STUDY OBJECTIVESnTo evaluate a teaching protocol comparing a critical care attending to a housestaff team in training medical interns in initial airway management skills using a computer-controlled patient simulator (CPS) and scenario-based simulation training (SST).nnnDESIGNnProspective, randomized, controlled, unblinded trial.nnnSETTINGnInternal medicine residency training program in an urban teaching hospital.nnnPARTICIPANTSnForty-nine starting internal medicine interns in July 2003, all of whom had been certified in advanced cardiac life support in June 2003.nnnINTERVENTIONSnAll interns were tested and scored with a CPS while responding to a standardized respiratory arrest scenario. Random allocation to either training by a single experienced teaching attending or by a housestaff team occurred immediately following testing. All interns were retested using the same scenario 6 weeks following the initial training, and their clinical performance of airway management was scored during actual patient events throughout the year.nnnMEASUREMENTSnInitial airway management was divided into specific scorable steps. For each intern, individual step scores and total scores were recorded before and after training. For 10 consecutive months following training, intern airway management scores were recorded for actual patient airway events.nnnRESULTSnAll starting medical interns demonstrated poor initial airway management skills. SST was effective in improving these skills, both on retesting with the patient simulator and in actual patient situations. Interns trained by a housestaff team performed as well as interns trained by the attending.nnnCONCLUSIONSnSST is effective in training medical interns, and the results are equivalent whether the training is provided by an experienced teaching attending or by a housestaff training team.

Gender disparity in radial and femoral arterial size: an ultrasound study.

Sir: Arterial catheterization is a common intensive care unit (ICU) procedure. We have previously found that women are more likely to fail catheter attempts [1]. Few prior studies have investigated gender differences in arterial size. Men have larger left main and left anterior descending (LAD) coronary arteries, independently of body surface area (BSA) [2]. Herity et al. [3] found increased LAD size in hearts transplanted from female donors to male recipients. Krejza et al. found men have larger carotid arteries [4]. Babuccu et al. [5] studied the diameters of radial, thoracodorsal, and dorsalis pedis arteries in pediatric patients and found that age, weight, and male gender are associated with larger size. The radial and femoral arteries are commonly used for arterial catheter placement. We studied arterial size in these locations to determine whether men have larger arteries. The study was conducted over a 4-month period beginning 11 May 2005 in the medical ICU of an urban teaching hospital. The study was approved by the Beth Israel Medical Center Institutional Review Board and was performed in accordance with the ethical standards of the 1964 Declaration of Helsinki. The requirement for written informed consent was waived. An Acuson Cypress 7.5 MHz ultrasound probe with 0.1-mm resolution was used (Siemens, Malvern, Pa., USA). Arterial diameter was measured in the transverse orientation of arterial diameter in systole. Measurements were taken during three different cardiac cycles and averaged. Radial arteries were measured 2 cm proximal to the distal wrist crease. Femoral arteries were measured one-third of the way from the pubic symphysis to the superior iliac crest. Based on clinical observations prior to the study we estimated that men’s femoral arteries would be 1 mm larger than women’s, and that their radial arteries would be 0.5 mm larger. Setting α at 5% and β at 20%, we calculated that 30 patients would be required to detect this difference in femoral arteries, and 36 patients would be required for radial arteries. Associations between demographic characteristics and arterial size were assessed by

Gender disparity in failure rate for arterial catheter attempts

We examined risk factors associated with failure of arterial catheterization in the medical intensive care unit of a large urban teaching hospital. We analyzed 92 consecutive arterial catheterizations by internal medicine house staff and critical care fellows. Of the 92 attempts, 26.1% were done on femoral arteries, and 73.9% were done on radial arteries. Failure, which occurred in 28% of attempts, was more common in female patients (P < .001). The failure rate was 50.0% for attempts on femoral arteries and 20.6% on radial arteries. Systolic blood pressure was significantly lower in patients where the attempt failed ( P = .024). In univariate analyses, hemoglobin values were lower (P = .028) and number of percutaneous punctures were higher (P = .019) in patients where catheterization failed. After multivariate analysis, only gender and systolic blood pressure remained statistically significant. The strongest predictor of failure was female gender. A possible explanation not explored here could be smaller arterial size in female patients.