The water channel AQP1 is expressed in human atherosclerotic vascular lesions and AQP1 deficiency augments angiotensin II-induced atherosclerosis in mice.

AIM: The water channel aquaporin 1 (AQP1) promotes endothelial cell migration. It was hypothesized that AQP1 promotes neovascularization and growth of atherosclerotic plaques. METHODS: AQP1 immunoreactivity and protein abundance was examined in human and murine atherosclerotic lesions and aortic aneurysms. Apolipoprotein E (ApoE) knockout (-/-) and AQP1-/-ApoE-/- mice were developed and fed Western diet (WD) for 8 and 16 weeks to accelerate the atherosclerosis process. In ApoE-/- and AQP1-/-ApoE-/- mice abdominal aortic aneurysms (AAA) were induced by angiotensin II (ANGII) infusion by osmotic minipumps for 4 weeks. RESULTS: In human atherosclerotic lesions and AAA, AQP1 immunoreactive protein was associated with intralesional small vessels. In ApoE-/- mouse aorta, APQ1 mRNA levels were increased with time on WD (n = 7-9, P < 0.003). Both in murine lesions at the aortic root and in the abdominal aortic aneurysmal wall, AQP1 immunoreactivity was associated with microvascular structures. The atherosclerotic lesion burden was enhanced significantly in ANGII-infused AQP1-/-ApoE-/- mice compared with ApoE-/- mice, but neither incidence nor progression of AAA was different. The aortic lesion burden increased with time on WD but was not different between ApoE-/- and AQP1-/-ApoE-/- mice at either 8 or 16 weeks (n = 13-15). Baseline blood pressure and ANGII-induced hypertension were not different between genotypes. CONCLUSION: AQP1 is expressed in atherosclerotic lesion neovasculature in human and mouse arteries and AQP1 deficiency augments lesion development in ANGII-promoted atherosclerosis in mice. Normal function of AQP1 affords cardiovascular protection.

[Monitoring routines at Danish anesthesia departments]. / Monitoreringspraksis på danske anaestesiafdelinger.

By means of a questionnaire investigation, 84 Danish anaesthetic departments were questioned in January 1987 about their monitoring routines during anaesthesia and recovery. 100% replied. The investigation revealed that measurement of the blood pressure in adults was the routine in all of the departments. Patients were monitored routinely with EGG in 62 departments where minor surgical interventions were concerned while, in major surgical intervention, ECG monitoring was the routine in 91% of the departments. Patients were observed postoperatively in the recovery room or intensive care unit in 51% of the departments. The questionnaire investigation revealed great variation in the monitoring and supervision routines in the anaesthetic departments in Denmark. Hitherto, it has not been possible to demonstrate that monitoring of the functions of vital organs in operation patients can reduce the morbidity and mortality connected with the anaesthesia. It is concluded that it would be desirable to carry out clinically controlled investigations to illustrate whether monitoring equipment can reduce the morbidity connected with anaesthesia and to develop a Danish recommendation concerning peroperative monitoring and postoperative observation.

Serious morbidity attributable to anaesthesia. Considerations for prevention.

The types and frequency of complications attributable solely to anaesthesia, and which caused serious morbidity and substantial negative outcome, were examined in a prospective study of 7306 anaesthetics. The analysis demonstrated that severe complications and mortality attributable to anaesthesia occurred in 0.59% (1:170) and 0.04% (1:2500) of patients respectively. The data suggest that "high-risk' patients are more likely to be affected by errors and a substantial negative outcome than more healthy patients. We judged one-third of the anaesthesia-related morbidity to be preventable. Anaesthetists are faced with an increasing number of patients who are at high risk, and who undergo increasingly extensive surgical interventions. Concomitant with the increasing complexity of care and increasing demands on the anaesthetists may be an expected increase in the incidence of errors. Recognition of the importance of human factors in morbidity and mortality attributable to anaesthesia is a necessary first step.

Hypoxemia in the postanesthesia care unit: an observer study.

To determine the incidence and duration of hypoxemia in the postanesthesia care unit (PACU), 200 patients were investigated in a single-blind observer study. The number of unrecognized hypoxemic episodes, as well as risk factors and possible association between hypoxemia and postoperative morbidity, were studied. Oxygenation was monitored continuously with a pulse oximeter. One or more hypoxemic episodes (SpO2 less than or equal to 90%) were noted in 55% of the patients. SpO2 values less than or equal to 80% were noted in 13% of the patients. Supplementary oxygen was given during 55% of the 447 hypoxemic episodes registered. The hypoxemic episodes were unrecognized by the staff in 95% of the cases. With stepwise multiple logistic regression analyses, risk factors associated with a higher incidence of hypoxemia were: duration of anesthesia (P less than 0.0001), age (P less than 0.002) and a history of smoking (P less than 0.01). Patients who had undergone regional anesthesia had a lower risk of hypoxemia (P less than 0.0002). The occurrence of hypoxemia in the PACU could not be correlated to postoperative morbidity. We conclude that hypoxemic episodes in our PACU are common and that the routine use of supplemental oxygen combined with normal clinical surveillance did not prevent hypoxemic episodes.

Frequency sweep electromyogram and voluntary effort in volunteers after d-tubocurarine.

A new method for monitoring the effect of muscle relaxants on the myoneural junction was tested in unanesthetized volunteers. Evoked electromyographic responses to stimulation, sweeping exponentially from 1 to 100 Hz over 10 seconds, were recorded from the hand and abdominal muscles. d-Tubocurarine (dTc) was given intravenously in incremental doses until head lift was abolished. Thumb twitch tension, vital capacity, peak expiratory flow, maximal inspiratory force, and hand grip strength were recorded during partial paralysis and recovery. The frequency sweep electromyogram (FS-EMG) of the musculus rectus abdominis was more depressed than the FS-EMG of the musculus abductor digiti V at the time head lift was abolished. The abdominal muscle recovered faster from dTc paralysis than did the hand muscle. The latter failed to respond normally to the highest frequencies of stimulation during the entire period of observation lasting 72 minutes after dTc injection. At the time of maximal neuromuscular blockade, respiratory function showed less depression than the FS-EMG of the abdominal muscle.