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Biomedical subjects

C Jayr

Publications and source records attributed to C Jayr.

28 records · Page 2Linked to original sources
PubMed1994

Alveolar liquid and protein clearance in anesthetized ventilated rats.

Alveolar and lung liquid clearances were studied over 1, 4, and 6 h in intact anesthetized ventilated rats by instillation of 5% albumin solution with 1.5 microCi of 125I-labeled albumin (3 ml/kg into 1 lung or 6 ml/kg into both lungs). Alveolar protein clearance as measured by residual 125I-albumin in the lung over 6 h was similar to the slow rates measured in other species. Alveolar liquid clearance was estimated by the concentration of albumin in the air spaces. After 1 h, this concentration was 7.8 +/- 0.7 g/dl, which was significantly greater than the initial protein concentration of 5.3 +/- 0.2 g/dl (P < 0.05). Amiloride (10(-3) M) inhibited 45% of the basal alveolar liquid clearance, and ouabain (10(-3) M), instilled and intravenously infused (0.004 mg), inhibited 30% of the clearance. beta-Adrenergic agonist instillation increased alveolar liquid clearance to the fastest 1-h rate (48 +/- 3% of instilled volume) that we observed in any intact species. The removal of the instilled fluid from the lung (expressed as lung liquid clearance; 0.96 +/- 0.3 ml/h) was twice as fast as the rate of alveolar and lung liquid clearance reported in the isolated or in situ rat lung models. The rate of alveolar and lung liquid clearance in these intact rats was significantly faster than those in prior studies in dogs and sheep and was similar to the rates in rabbits.

Adrenergic beta-Agonists↗
PubMed1993

Postoperative pulmonary complications. Epidural analgesia using bupivacaine and opioids versus parenteral opioids.

BACKGROUND: Different types of analgesia have been proposed for the prevention of postoperative respiratory complications. The aim of this prospective, double-blind randomized study was to compare the impact of epidural bupivacaine and opioids versus parenteral opioids on respiratory complications in patients who had undergone major abdominal surgery. METHODS: One hundred fifty-three patients undergoing abdominal surgery for cancer were randomly allocated to receive either general anesthesia with intravenous fentanyl and postoperative analgesia with subcutaneous morphine (SC group) or general anesthesia combined with epidural bupivacaine and epidural bupivacaine plus morphine for postoperative pain relief (EP group). Analgesia was tested on a visual analog pain scale. Pulmonary complications were evaluated according to clinical complications, chest radiographs, arterial blood gas analysis, and pulmonary function tests. The evaluation was carried out on the day before the operation and on the first 5 postoperative days. Particular attention also was paid to the episodes of arterial hypotension and hemoglobin oxygen desaturation during the 1st postoperative night. RESULTS: Pain relief was significantly better in the EP group than in the SC group (P < 0.05) especially during recovery and on the 1st and 2nd postoperative days. In the EP group, vital capacity decreased less on the 1st postoperative day (P < 0.05) and arterial oxygen tension was greater in the recovery room (P < 0.05). However, no statistically significant difference was observed between the SC and EP groups in the incidence of clinical pulmonary complications (31% and 27%, respectively) and radiographic chest abnormalities (52% and 46%, respectively). The EP group recovered intestinal function earlier (P < 0.05), but significantly more patients in this group had episodes of systolic hypotension (21% vs. 8%; P < 0.05) during the 1st postoperative night. The length of the hospital stay was similar in both groups of treatment. CONCLUSIONS: Epidural analgesia with a combination of local anesthetic and opioid improves patient comfort. However, this type of analgesia does not decrease the incidence of postoperative pulmonary complications, does not reduce the length of the hospital stay, and carries the risk of complications from episodic systemic hypotension.

Abdomen↗
PubMed1993

Alveolar liquid and protein clearance in the absence of blood flow or ventilation in sheep.

The primary objective of these studies was to test the contribution of ventilation and blood flow to the removal of excess liquid from the air spaces and interstitium of the lung. First, after eliminating ventilation by clamping the left main bronchus in anesthetized sheep, alveolar and lung liquid clearance was not altered over 4 h compared with control sheep that were ventilated normally. Thus, removal of excess liquid across the alveolar epithelium was independent of the change in the transalveolar hydrostatic pressure gradient produced by ventilation. Second, to determine the effect of removing all blood flow to the lung, we developed a new in situ sheep lung model in which lung lymph flow was measured over 4 h with or without ventilation after the sheep had been exsanguinated. Alveolar liquid clearance, as measured by the percent increase in alveolar protein concentration over 4 h, was similar between sheep without blood flow (31 +/- 18%) compared with sheep with normal blood flow to the lungs (31 +/- 17%). Lung lymph flow contributed to only 10-15% of the clearance of the excess alveolar liquid that was transported to the interstitium, indicating that nonlymphatic pathways accounted for most of the excess lung liquid clearance in the absence of microvascular filtration. Third, because ouabain completely inhibited alveolar liquid clearance in this in situ sheep lung model, these data provide evidence that alveolar liquid clearance depends on an intact Na(+)-K(+)-ATPase-dependent pump mechanisms. Finally, this in situ model represents a unique experimental preparation that can be used to study the alveolar epithelial barrier without blood flow or ventilation for a short time (4 h) interval.

Anesthesia↗
PubMed1993

Preoperative and intraoperative factors associated with prolonged mechanical ventilation. A study in patients following major abdominal vascular surgery.

A study of 51 patients undergoing elective major abdominal surgery was carried out to determine the incidence of postoperative respiratory failure requiring mechanical ventilation for more than 24 h and which preoperative and intraoperative factors are associated with this respiratory complication. Mechanical ventilation for more than 24 h was required in 12 of the 51 patients. These 12 patients had a significantly longer stay in the intensive care unit and in the hospital than the patients who were successfully extubated in the postoperative period. Also, there was a trend for a higher mortality in the ventilated group compared to the group of patients who did not require postoperative ventilation. Preoperative abnormalities in FEV1 did not identify which patients were destined to require postoperative ventilation. Significant differences for the ventilated versus the nonventilated patients included a longer history of cigarette smoking, a lower preoperative PaO2, and a large intraoperative blood loss.

Abdomen↗
PubMed1991

Alveolar and lung liquid clearance in anesthetized rabbits.

Alveolar and lung liquid clearance were studied over 8 h in intact anesthetized ventilated rabbits by instillation of either isosmolar Ringer lactate (2 ml/kg) or autologous plasma (2 or 3 ml/kg) into one lower lobe. The half time for lung liquid clearance of the isosmolar Ringer lactate was 3.3 h and that for plasma clearance was 6 h. In the plasma experiments, the alveolar protein concentration after 1 h was 5.2 +/- 0.8 g/dl, which was significantly greater than the initial instilled protein concentration of 4.3 +/- 0.7 g/dl (P less than 0.05). Thus alveolar protein concentration increased by 21 +/- 12% over 1 h, which matched clearance from the entire lung of 19 +/- 11% of the instilled volume. Overall the rate of alveolar and lung liquid clearance in rabbits was significantly faster than in prior studies in dogs and sheep. The fast alveolar liquid clearance rate in rabbits was not due to higher endogenous catecholamine release, because intravenous and alveolar (5 x 10(-5) M) propranolol did not slow the clearance. Also, beta-adrenergic therapy with alveolar terbutaline (10(-5) or 10(-4) M) did not increase the alveolar or lung liquid clearance rates. Phloridzin (10(-3) M) did not slow alveolar liquid clearance. However, amiloride (10(-4) M) inhibited 75% of the basal alveolar liquid clearance in rabbits, thus providing evidence that alveolar liquid clearance in rabbits depends primarily on sodium-dependent transport. This rabbit study provides further evidence for important species differences in the basal rates of alveolar liquid and solute clearance as well as the response to beta-adrenergic agonists and ion transport inhibitors.

Amiloride↗
PubMed1991

Alveolar and lung liquid clearance in the absence of pulmonary blood flow in sheep.

The effect of removing pulmonary blood flow on the clearance of excess liquid and protein from the air spaces and interstitium of the normal lung was studied in anesthetized ventilated sheep. To eliminate pulmonary blood flow to one lung, the left pulmonary artery was occluded. Autologous serum (3 ml/kg) with 125I-labeled albumin was then instilled into the left lower lobe. Hemodynamics and lung lymph were measured, and the lungs were removed after 4 h. Alveolar protein concentration over 4 h was used as the index of alveolar liquid clearance. Total lung liquid clearance was measured by the gravimetric method. The percent increase in alveolar protein concentration over baseline was similar between sheep without pulmonary blood flow (33.8 +/- 17.4) and with pulmonary blood flow (31.1 +/- 14.6); thus, alveolar liquid clearance was not changed by the absence of pulmonary blood flow. Also, in the absence of pulmonary blood flow, lung liquid clearance (as percent of instilled) over 4 h was 27.1 +/- 3.8 (n = 7), which was not significantly different from control experiments with pulmonary blood flow (26.4 +/- 7.1, n = 7). In the sheep without pulmonary blood flow, bronchopulmonary anastomotic flow was 41.5 +/- 21.3 ml/min. To further reduce blood flow to the lung, both the left pulmonary artery and the bronchoesophageal artery were occluded, which reduced bronchopulmonary anastomotic flow to the left lung to 12.0 +/- 9.3 ml/min. This further reduction in blood flow did not, however, change alveolar or lung liquid clearance. Even with this low blood flow to the left lung, the removal of 125I-albumin from the lung was not altered.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

[Evaluation of the risk of pulmonary complications after abdominal surgery].

Pulmonary complications are frequent after abdominal surgery. The object of this study was to evaluate the incidence and the predisposing factors of the postoperative pulmonary complications with a particular attention to their definitions. It included 146 patients. The respiratory complications were separated into clinical complications (bronchitis), radiological complications (atelectasis) and hypoxaemia (PaO2 less than 70 mmHg). Clinical complications (23%) were correlated neither with radiological complications (57%) nor hypoxaemia (46%). They particularly occurred in patients with a preoperative history of respiratory disease. Preoperative risk factors were males, low PaO2 and decreased FEV1. Radiological complications were strongly correlated with postoperative hypoxaemia. Their incidence was not affected by a previous history of respiratory disease. Both radiological complications and hypoxaemia were predicted by age.

Abdominal Neoplasms↗
PubMed1988

Postoperative pulmonary complications: general anesthesia with postoperative parenteral morphine compared with epidural analgesia.

In a prospective study, patients undergoing abdominal cancer surgery were randomly allocated to receive either general anesthesia with fentanyl intravenously and postoperative analgesia with parenteral morphine (GA group) or general anesthesia combined with epidural bupivacaine and epidural morphine for postoperative pain relief (EP group). Analgesia was tested on a visual pain scale. Pulmonary complications were evaluated by clinical complications, blood gas analysis, x-ray film changes, and pulmonary volumes (vital capacity, forced expiratory volume in 1 second). Measurements were performed on the day before the operation and on the first 5 postoperative days. In the EP group the pain relief was significantly better on the first day (p less than 0.03). Whatever the criteria used, the rates of pulmonary complications were similar in the two groups: clinical complications 21% versus 26%, radiologic complications 50% versus 64% for GA and EP groups, respectively. Postoperative PaO2 and spirometric values were similar in the two groups. Postoperative epidural analgesia may improve the patient's comfort but does not decrease the incidence of pulmonary complications.

Abdomen↗
PubMed1986

[Tracheal rupture during intubation for general anesthesia].

A case is reported of rupture of the trachea following endotracheal intubation for general anaesthesia. A continuous flow oxygen was used to inflate the cuff, which was thought to be pierced and so responsible for a ventilation leak. This technique had already been successfully used by the authors in cases of leaking cuffed tubes in patients on long-term artificial ventilation. However, this technique appeared to be dangerous in the case described.

Anesthesia, General↗