Comparison of external jugular and central venous pressures in mechanically ventilated patient.

We compared central venous pressures, measured via a 150 mm triple lumen catheter in the internal jugular vein with simultaneous external jugular venous pressures, measured with a 5 mm cannula in the external jugular vein, in 24 patients undergoing major surgery. Patients were mechanically ventilated in the supine position. Six sets of paired measurements of mean central venous pressure and mean external jugular venous pressure were taken by a blinded observer, in random order and at end-expiration at 30-min intervals during surgery. Four patients were not studied because of a failure to cannulate the external jugular vein. The remaining 20 patients yielded 111 sets of paired measurements. The mean difference between external jugular venous pressure and central venous pressure was 0.3 mmHg over a range of central venous pressure of 0-22 mmHg. Limits of agreement were 3.6 to +3.0 mmHg (95% CI 4.1 to +3.5 mmHg). We conclude that external jugular venous pressure is an accurate estimate of central venous pressure in surgical patients undergoing mechanical ventilation.

The 50-millilitre syringe as an inexpensive training aid in the application of cricoid pressure.

A recent study in our department demonstrated that depressing the plunger of a 50-mL syringe was reliably and linearly related to the force applied between 20 N and 50 N. Using a 50-mL syringe we constructed a simple device to help train anaesthetic assistants to apply cricoid pressure correctly. We then tested anaesthetists, operating department practitioners (non-physicians) and nurses in our hospital to see if they could correctly apply forces of 20 and 40 N. All subjects were then trained using this apparatus and once confident were retested immediately afterwards, and again 1 week and 1 month later. The results show a wide variation in the force applied with only 30% of subjects applying appropriate force at 20 N, and 40% at 40 N. Training leads to a significant improvement in performance (P < 0.005 at 20 N and P < 0.001 at 40 N) which is maintained for 1 week for both 20 N (P < 0.05) and 40 N (P < 0.05) but not for 1 month. Therefore training should be practised on a weekly basis. This is an inexpensive and simple device that we believe to be useful in helping anaesthetic assistants to apply effective cricoid pressure.

Echocardiography in chronic heart failure in the community.

A total of 128 patients from a single practice population who were receiving loop diuretics for treatment of presumptive cardiac failure were identified from prescribing data captured by the Medicines Monitoring Unit. A subgroup of 78 patients underwent echocardiography to determine the prevalence of true left ventricular systolic dysfunction in this population and the validity of the diagnosis of cardiac failure in primary care. A further 50 patients were studied to assess the workload generated by these patients for both primary health care and hospital services. The estimated prevalence of left ventricular systolic dysfunction was 0.84%, whereas 1.6% of the population received loop diuretics for this indication. A false-positive diagnosis occurred in 47% and was more likely in females (73%) than males (37%). Of all consultations 79% were seen by GPs, 14% as hospital out-patients and 7% as in-patients. Within the hospital general physicians have most contact with these patients. In summary chronic heart failure is common within the community, although the false-positive rate for diagnosis of this condition is high. GPs and general physicians treat the majority of these patients and should therefore receive continuing education regarding recent advances in this area. Echocardiography should be performed early in the management of all patients suspected of having cardiac failure.