Limitations in Estimating Critical Closing Pressure by Noninvasive Blood Pressure Measurements To the Editor: We read with interest the article by Aaslid et al, describing the dynamic pressure-flow velocities relationships in the human cerebral circulation.1 The authors help to validate estimates of critical closing pressure (CCP) based on regular heartbeat data against long diastole determinat...

There is evidence that narrowing or collapse of the pharynx can contribute to obstructive sleep-disordered breathing (SDB) in adults and children. However, studies in children have focused on those with relatively severe SDB who generally were recruited from sleep clinics. It is unclear whether children with mild SDB who primarily have hypopneas, and not frank apnea, also have more collapsible ...

OBJECTIVE To explain why investigations of the measurement of central venous pressure (CVP) usually reveal a discrepancy between the clinician's estimate of CVP from physical diagnosis and supine measurement with a catheter. Data from MEDLINE search, personal files, and bibliographies of textbooks on physical diagnosis and cardiology were used. RESULTS The most important reasons for this disa...

BACKGROUND This study was designed to determine the minimal mean flow velocity and pressure-flow relation necessary to preserve human consciousness. METHODS Passive upright tilt provocation was used in conjunction with transcranial Doppler in 80 patients with a history of syncope of unknown etiology. Cerebral blood flow velocity, blood pressure, and heart rate were monitored noninvasively. ...

Pressure ulcers are serious health problems. Although a vast amount of literature addresses prevention and treatment strategies, conceptual difficulties persist regarding pressure ulcer definitions, classifications, and distinction from other tissue lesions. Based on a review of terminologies as well as current state of knowledge on pathophysiology and etiology, questions as to what pressure ul...

BACKGROUND Pressure ulcers are one of the most underrated conditions in critically ill patients. Despite the introduction of clinical practice guidelines and advances in medical technology, the prevalence of pressure ulcers in hospitalized patients continues to escalate. Currently, consensus is lacking on the most important risk factors for pressure ulcers in critically ill patients, and no ris...

Pulmonary hypertension (PH) resulting from left heart failure is an increasingly recognized clinical entity. To distinguish isolated postcapillary PH from combined post- and precapillary PH, the use of a diastolic pressure gradient (DPG = diastolic Pulmonary Artery Pressure - Pulmonary Arterial Wedge Pressure, dPAP - PAWP) has been advocated over the transpulmonary pressure gradient (TPG = mean...

To the Editor: The review—“Brachial vs. Central Systolic Pressure and Pulse Wave Transmission Indicators: A Critical Analysis”—by Dr Izzo1 provided a broad overview of physiology and clinical consequences of pulse wave transmission in the human arterial system. We contend that a “critical analysis” of literature in this field should include consideration of all plausible evidence on the physiol...