3 research outputs found
Non-invasive respiratory monitoring in surgical intensive care
The need to monitor postsurgical patients for signs of respiratory deterioration was
recognized long before the first intensive care units were introduced during World War
II. In the early days of the intensive care nnit, reports were published about the high
incidence of postoperative mortality which was often heralded by the onset of apnea or
airway obstruction. Soon it became clear that these effects were induced by either the
surgical procedure itself, or by the type of anesthesia used. It was demonstrated that these
potentially lethal conditions could be easily prevented and treated if patients were
monitored scrupulously in the early postoperative period for signs of respiratory failure
and rapid action was taken if pulmonary deterioration occurred. These experiences
probably mark the beginning of the development of techniques to monitor the respiratory
condition of patients after surgery
Effect of L-NAME, an inhibitor of nitric oxide synthesis, on cardiopulmonary function in human septic shock
STUDY OBJECTIVES: We tested the effects of continuous infusion of
N(G)-nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide
(NO) synthesis, on cardiovascular performance and pulmonary gas exchange
in patients with hyperdynamic septic shock. DESIGN: Prospective clinical
study. SETTING: ICU of a university hospital. PATIENTS: Eleven critically
ill patients with severe refractory septic shock. INTERVENTIONS: Standard
hemodynamic measurements were made and blood samples taken before, during,
and after 12 h of continuous infusion of 1 mg/kg/h of L-NAME. MEASUREMENTS
AND RESULTS: Continuous infusion of L-NAME increased mean arterial
pressure (MAP) from 65+/-3 (SEM) to 93+/-4 mm Hg and systemic vascular
resistance (SVR) from 962+/-121 to 1,563+/-173 dyne x s x cm(-5)/m2.
Parallel to this, cardiac index (CI) decreased from 4.8+/-0.4 to 3.9+/-0.4
L/min/m2 and myocardial stroke volume (SV) was reduced from 43+/-3 to
34+/-3 mL/m2. Left ventricular stroke work was increased in the first hour
of L-NAME infusion from 31+/-3 to 43+/-4 g x m/m2 (all p<0.01 compared
with baseline). Heart rate, cardiac filling pressures, and right
ventricular stroke work did not change significantly (p>0.05). L-NAME
increased the ratio of arterial PO2 to the fraction of inspired O2 from
167+/-23 to 212+/-27 mm Hg (p<0.05). Venous admixture (QVA/QT) was reduced
from 19.4+/-2.6% to 14.2+/-2.1% (p<0.05) and oxygen extraction ratio
increased from 21.1+/-2.4% to 25.3+/-2.7% (p<0.05). Oxygen delivery (DO2)
was reduced following L-NAME, whereas oxygen uptake and arterial lactate
and pH were unchanged. CONCLUSIONS: Prolonged inhibition of NO synthesis
with L-NAME can restore MAP and SVR in patients with severe septic shock.
Myocardial SV and CI decrease, probably as a result of increased
afterload, since heart rate and stroke work were not reduced. L-NAME can
improve pulmonary gas exchange with a concomitant reduction in QVA/QT.
L-NAME did not promote anaerobe metabolism despite a reduction in DO2