Treatment of arterial hypoxemia in early period of traumatic disease

Issues of arterial hypoxemia treatment in early period of traumatic disease, taking into account modern approaches, adopted in surgery of injuries and anesthesy-resuscitation. It is recommended to use the method proposed for the arterial oxygen content enhancing in an acute respiratory insufficiency of various genesis, including the cases of progressive posttraumatic disease.     

Dinamap arm and thigh arterial pressure measurement

Two automatic arterial pressure monitors (Model 1846 P) were used in 30 patients to measure arterial pressures and heart rates in the thigh and arm. Significant differences were found in thigh-arm systolic (p less than 0.001) and diastolic pressures (p less than 0.05). Arm pressures could be predicted from leg pressures and correction factors are suggested. Mean pressures in the thigh approximated more closely to the calculated mean pressures than in the arm. These differences were of little clinical importance.     

Continuous cardiac output measurement: arterial pressure analysis versus thermodilution technique during cardiac surgery with cardiopulmonary bypass

This study compared cardiac output measured with an arterial pressure-based cardiac output measurement system and a thermodilution cardiac output measurement system. We studied 36 patients undergoing cardiac surgery with cardiopulmonary bypass. Simultaneous arterial pressure-based and thermodilution cardiac output measurements were compared before and after cardiopulmonary bypass, and after phenylephrine administration. Bland-Altman analysis showed good overall agreement between the two methods. Bias (limits of agreement) before and after cardiopulmonary bypass were - 0.21 (- 2.97-2.55) lxmin(-1) and 0.01 (- 3.79-3.81) lxmin(-1), respectively. Phenylephrine administration decreased thermodilution cardiac output by a mean (SD) of 11 (16)% and increased arterial pressure-based cardiac output by 55 (34)%. We conclude that arterial pressure-based cardiac output and thermodilution cardiac output measurement systems yield comparable results during cardiac surgery with cardiopulmonary bypass. However, after phenylephrine administration, the two measurement systems provided opposing results.     

Anticholinergic pre-treatment in rigid bronchoscopy. Effect on heart rate, arterial blood pressure and cardiac arrhythmias

The effect of anticholinergic pre-treatment on the hemodynamic changes during rigid bronchoscopy was studied. Eighty four adult patients in three groups received intravenous saline (control), atropine or glycopyrrolate several minutes before anesthesia and venturi ventilation with intermittent thiopentone and suxamethonium. The rises in heart rate and blood pressure and the incidence of cardiac dysrhythmias were least in the control group. Transient bradycardia rarely occurred, even in the control group, despite repeat doses of suxamethonium. Although most of the results were not statistically significant, they suggest that preoperative anticholinergic administration may aggravate some of the cardiovascular effects of bronchoscopy resulting from sympathoadrenal stimulation.     

Comparison of femoral arterial blood pressure with radial arterial blood pressure and noninvasive upper arm blood pressure in the reperfusion period during liver transplantation

PURPOSE: The reperfusion period during liver transplantation is hemodynamically unstable. Accurate blood pressure measurements are the mainstay for the efficient management of abrupt cardiovascular changes. We sought to compare femoral arterial blood pressure (FABP) with radial arterial blood pressure (RABP) and noninvasive upper arm blood pressure (NIBP) in the reperfusion period. METHODS: Thirty-six adult living donor liver recipients were enrolled in this prospective study. Blood pressures in 3 locations were simultaneously recorded from 1 minute before reperfusion to 15 minutes after reperfusion. We evaluated agreements between FABP and RABP and between FABP and NIBP using intraclass correlation coefficients. Also, we investigated the rates of postreperfusion syndrome (PRS) based on the measurements from 3 locations. RESULTS: After reperfusion, the mean and diastolic RABP agreed more with the corresponding FABP than NIBP. However, systolic NIBP showed high agreement with FABP from 3 to 10 minutes after reperfusion in contrast with the moderate agreement between systolic RABP with FABP, and systolic values of NIBP than RABP were closer to FABP. The rates of PRS based on FABP, RABP, and NIBP measurements were 50.0% (18/36), 80.6% (29/36), and 50.0% (18/36), respectively. CONCLUSIONS: We believe that NIBP in addition to RABP may be considered to be a reliable alternative when FABP is not available to evaluate hemodynamic instability in the reperfusion period during liver transplantation.     

Continuous, simultaneous measurement of arterial oxygen tension and arterial blood pressure.

This is an investigation of a technique for simultaneously measuring arterial oxygen tension (PaO2) and blood pressure continuously during and after surgical anesthesia. In 27 patients, a special T attachment was placed on the end of an indwelling arterial catheter so that pressurized dilute heparin could be flushed through continuously while blood pressure was being recorded by means of a transducer-oscilloscope system and PaO2 was being recorded through an indwelling polarograph oxygen tension (PO2) readout device. The electrode was left in the artery for an average of 16 hours; the average PaO2 during mechanical ventilation with the patient breathing 50 per cent oxygen was approximately 200 torr at the beginning of anesthesia; it dropped to 158 torr 6 hours later. The average PaO2 in the recovery room 1 hour postoperatively, with the patient spontaneously breathing approximately 30 per cent oxygen, was 122 torr. No significant complications were encountered during this investigation. We believe this dual technique to be a valuable monitoring tandem in the anesthetized and surgical intensive care patient.     

Limitations of measurement of transdiaphragmatic pressure in detecting diaphragmatic weakness.

Intrathoracic (oesophageal), intra-abdominal (gastric), and transdiaphragmatic (Pdi) pressures were studied in 20 untrained, healthy subjects during a full inspiration and repeated maximal static inspiratory efforts. The pattern of pressure generation during these two types of respiratory manoeuvre was highly reproducible in each subject. By contrast, it varied over a wide range among individuals. In particular a substantial number of subjects naturally had a strong recruitment of their intercostal and accessory muscles and thus, low Pdi values, during both slowly performed and forceful inspiratory manoeuvres. These observations make it clear that Pdi values, as usually obtained, are commonly open to misinterpretation. For this approach to ensure a reliable assessment of diaphragmatic function and detect diaphragm weakness adequately, it appears essential either to monitor the abdominothoracic configuration or to standardise the pattern of respiratory muscle contraction.     

Blood pressure measurement by arterial tonometry in controlled hypotension

A newly developed arterial tonometer enabled us to measure the blood pressure waveforms in addition to determining systolic and diastolic pressures noninvasively and continuously. Twenty-eight adult patients undergoing orthopedic surgery under controlled hypotension were studied. Systolic blood pressure was reduced to two-thirds of baseline values with an infusion of nitroglycerin during nitrous oxide/enflurane anesthesia. Intraarterial blood pressures were simultaneously measured in either the right or the left radial artery with a cannula and a Gould P23XL calibrated transducer; tonometric monitoring was performed on the contralateral radial artery using a Colin CBM-3000 instrument. The outputs of the two blood pressure measurement instruments were recorded for later data analysis. The shape of the tonometric pressure waveform was nearly identical to the waveform recorded intraarterially even during controlled hypotension. Regression analyses of 2039 paired tonometric and intraarterial blood pressure values during the hypotensive period showed good correlations (r = 0.78 for systolic, r = 0.81 for mean, and r = 0.70 for diastolic pressures). The accuracy of systolic, mean, and diastolic readings was from 4 to 7 mm Hg with negligible bias and did not differ significantly among six systolic, four mean, and four diastolic pressure groups. Our results indicate that arterial tonometry can provide accurate, reliable, and real-time monitoring of blood pressure even during controlled hypotension.     

Monitoring cardiac output using the femoral and radial arterial pressure waveform

This study was performed to determine the interchangeability of femoral artery pressure and radial artery pressure measurements as the input for the PiCCO system (Pulsion Medical Systems, Munich, Germany). We studied 15 intensive care patients following cardiac surgery. Five-second averages of the cardiac output derived from the femoral artery pressure (COfem) were compared to 5-s averages derived from the radial artery pressure (COrad). One patient was excluded due to problems in the pattern recognition of the arterial pressure signal. In the remaining 14 patients, 14 734 comparative cardiac output values were analysed. The mean sample time was 88 min, range [30-119 min]. Mean (SD) COfem was 6.24 (1.1) l.min(-1) and mean COrad 6.23 (1.1) l.min(-1). Bland-Altman analysis showed an excellent agreement with a bias of - 0.01 l.min(-1), and limits of agreement from 0.60 to - 0.62 l.min(-1). If changes in CO were > 0.5 l.min(-1), the direction of changes in COfem and COrad were equal in 97% of instances. We conclude that femoral artery pressure and radial artery pressure are interchangeable as inputs for the PiCCO device.     

Administration of 100% oxygen before removal of the laryngeal mask airway does not affect postanesthetic arterial partial pressure of oxygen

Breathing 100% oxygen at the end of general anesthesia has been shown to worsen postoperative pulmonary gas exchange when an endotracheal tube is used. Counter measures, such as high positive end-expiratory pressure or the vital-capacity maneuver, may limit this effect. Such strategies, however, may be impracticable, or even contraindicated, when the laryngeal mask airway (LMA) is used. Because of the vast differences in design between the LMA and endotracheal tube, we examined postanesthetic blood gas tensions in patients after emergence from anesthesia breathing oxygen via LMA. Sixty-four ASA physical status I-II patients undergoing general anesthesia for 60 min with LMA were randomly assigned to receive either 100% or 30% oxygen during emergence from anesthesia and removal of LMA. Postoperative blood gas measurements were taken at 30 and 60 min after removal of the LMA. At either measurement, patients treated with 100% oxygen essentially had the same arterial partial pressure of oxygen (60-min measurement: 83 +/- 8 versus 85 +/- 7 mm Hg [mean +/- SD], P = 0.14) as those treated with 30% oxygen. We conclude that breathing 100% oxygen at the end of general anesthesia does not worsen postoperative pulmonary gas exchange when an LMA is used. IMPLICATIONS: The endotracheal tube and laryngeal mask airway are substantially different artificial airways used to ventilate the lungs of anesthetized patients. Breathing 100% oxygen before removing the endotracheal tube results in lung function defects. This study shows that oxygen breathing before removing the laryngeal mask airway has no effect on pulmonary function.