Changes in calcitonin gene-related peptide, atrial natriuretic peptide and brain natriuretic peptide in patients undergoing coronary artery bypass grafting

The initiation of cardiopulmonary bypass creates significant derangements in cardiovascular volume status and both endocrine and autonomic nervous system function. To examine whether such derangements might differ in patients with different pre-operative physical status scores, we measured the plasma concentrations of calcitonin gene-related peptide, atrial natriuretic peptide and brain natriuretic peptide, catecholamines and antidiuretic hormone, as well as haemodynamic variables, during and after cardiopulmonary bypass in 27 consecutive patients undergoing coronary artery bypass grafting. The pre-operative levels of atrial natriuretic peptide and brain natriuretic peptide differed significantly between ASA II patients and III and IV patients [mean (SD) brain natriuretic peptide levels = 14 (8.2) vs. 129 (51) pg.ml-1]. Plasma calcitonin gene-related peptide increased significantly in both groups after the initiation of cardiopulmonary bypass, and remained increased throughout cardiopulmonary bypass. The changes in plasma epinephrine, norepinephrine and antidiuretic hormone were similar to those reported previously. The changes in plasma calcitonin gene-related peptide, atrial natriuretic peptide and brain natriuretic peptide did not correlate with any changes in haemodynamic variables before or after cardiopulmonary bypass. Measurement of plasma brain natriuretic peptide might usefully be included in the pre-operative evaluation of patients with cardiac disease.

The anxiolytic effects of the 5-hydroxytryptamine-1A agonist tandospirone before otolaryngologic surgery

We studied 160 ASA I or II patients undergoing elective otolaryngologic surgery in order to compare the anxiolytic effects of a novel 5-hydroxytryptamine-1A agonist, tandospirone, with diazepam. To monitor preoperative anxiety, the following variables were used: systolic and diastolic arterial pressure, heart rate, and the state anxiety score yielded by the Spielberger State-Trait Anxiety Inventory. We performed pretreatment evaluation on the day before surgery and posttreatment examination immediately after entry into the operating room. In a double-blinded, randomized design, four groups of 40 patients each received one of the following oral medications 90 min before entry into the operating room: 1) tandospirone 10 mg (T10 group); 2) tandospirone 30 mg (T30 group); 3) diazepam 10 mg (D group); or 4) placebo (P group). After premedication, the State-Trait Anxiety Inventory state anxiety decreased in the T10 (P < 0.02), T30 (P < 0.02), and D groups (P < 0.001), but it increased in the P group (P < 0.001). Tandospirone, 10 and 30 mg, safely reduced preoperative anxiety to a similar extent as oral diazepam 10 mg in patients undergoing elective otolaryngologic surgery.

IMPLICATIONS

Oral tandospirone reduces preoperative anxiety to a similar extent as oral diazepam in patients undergoing elective otolaryngologic surgery. This finding implies that tandospirone can be used as an oral premedicant drug for relieving anxiety before surgery.

Pulmonary arterial and right ventricular responses to prophylactic albumin administration before aortic unclamping during abdominal aortic aneurysmectomy

During abdominal aortic aneurysmectomy (AAAectomy) and before aortic unclamping (XU), we studied the effects of albumin administration on pulmonary arterial and right ventricular responses in 39 anesthetized patients using a modified thermodilution technique. Group 1 patients (n = 18) were given no extra IV fluids. Group 2 patients (n = 21) were given additional albumin administration (5% albumin at 10 mL/kg) before XU. After XU, mean arterial blood pressure (MAP) decreased significantly in each group, and MAP and stroke volume index (SVI) were not significantly higher in Group 2 than in Group 1. At 5 min after XU, the patients in Group 2 had a higher mean pulmonary arterial pressure and pulmonary vascular resistance index and a lower right ventricular ejection fraction than those in Group 1 (P < 0.05), but their SVIs were well maintained. These results indicate that albumin administration before XU may not always prevent post-XU hypotension. It caused a significant increase in right ventricular afterload and a significant dilation of the right ventricular cavity; however, right ventricular function was almost equally maintained in both groups. However, because SVI did not increase in some patients (Group 2) with the increase in right ventricular end-diastolic volume index after XU, albumin administration should be performed carefully before XU during AAAectomy.

IMPLICATIONS

We studied the effects of albumin administration before aortic unclamping on pulmonary arterial and right ventricular responses during abdominal aortic aneurysmectomy using a modified thermodilution technique. Albumin administration before aortic unclamping may not always prevent hypotension, and it may cause a higher pulmonary arterial pressure than in patients without albumin administration.

[Hemorrhagic shock during laparoscopic cholecystectomy detected by transesophageal echocardiography]

A 47-year-old man was scheduled for laparoscopic cholecystectomy under general anesthesia supplemented with epidural anesthesia. A direct arterial line and a transesophageal echocardiogram probe were inserted before surgery. Anesthesia was maintained with nitrous oxide and isoflurane but without epidural anesthesia. Severe hypotension occurred about 30 minutes after introducing pneumoperitoneum but surgeons denied massive bleeding in the operative field. Although this made us difficult to diagnose the incident as massive bleeding or pulmonary air embolism (PAE), a collapsed heart was detected by transesophageal echocardiography (TEE). Its end-diastolic diameter of the left ventricle was reduced to 20 mm and left ventricular end-systolic cavity obliteration was demonstrated. We could easily diagnose the decrease of blood volume due to PAE using TEE.

Prediction of patients with higher order multifetal pregnancy at risk for postpartum pulmonary edema

OBJECTIVE

This retrospective study aims to verify the factors for the development of maternal pulmonary edema in higher order multifetal pregnancy.

STUDY DESIGN

We analyzed medical profiles of a total of 13 triplet, quadruplet and quintuplet pregnancies for the years 1992 through 1997. Some treatments were applied in attempts to promote these multifetal pregnancies. All underwent cesarean section, two of which developed pulmonary edema within a few hours of delivery. There had been no evidence for the development of pulmonary edema antepartum.

RESULTS

In the patients affected by pulmonary edema, postoperative values of PaO2/FIO2<250 mmHg showed close association to a value perioperative fluid loading index (FLI)>0; the index consists of an intraoperative fluid balance and preoperative infusion volume within 24 h prior to surgery. Two patients with postoperative pulmonary edema had a perioperative FLI>0, whereas the others had values <O. There was no difference between the groups with and without pulmonary edema in other factors known to induce pulmonary edema including intraoperative infusion volume and fluid balance, weight gain and hypertension during pregnancy, preoperative SpO2, and infusion period and rate of ritodrine.

CONCLUSION

These findings demonstrate that patients in whom the perioperative FLI is >0 may have a much higher risk for postoperative pulmonary edema, suggesting the predictive role of the perioperative FLI value.

[Anaphylactic shock associated with a central venous catheter impregnated with chlorhexidine and silver sulfadiazine]

A 28 year-old male patient developed anaphylactic shock on separate occasions, possibly due to the contact with a central venous catheter impregnated with chlorhexidine and silver sulfadiazine. He was successfully resuscitated. On the second operation, blood basophils disappeared and plasma histamine level increased extremely up to 80 ng.ml-1 soon after anaphylactic shock. One year after the first shock, he did not develop anaphylactic shock following the insertion of a central venous catheter without the impregnation. Pin prick test and scratch test showed positive reactions only to chlorhexidine. Latex-specific anti-IgE antibody was not detected. Therefore, chlorhexidine was confirmed as the causative agent of anaphylactic shock. Because chlorhexidine is extensively used as an antiseptic drug in emergency rooms and intensive care units, we should be aware of the possibility of chlorhexidine induced anaphylactic reactions.

[Calcitonin gene-related peptide and human atrial natriuretic hormone levels in response to cardiac operation under high dose fentanyl anesthesia]

To elucidate a role of calcitonin gene-related peptide (CGRP) in anesthesia and surgery with cardiopulmonary bypass (CPB), we measured CGRP which is reported to be a marker for fluid overload, simultaneously with HANP (human atrial natriuretic hormone) in 12 patients during high dose fentanyl anesthesia (50-70 microgram. kg-1). Plasma concentration of CGRP increased to 3 times of the value during preanesthetic phase at 30 min after initiation of CPB. A 3-fold increase compared with control in CGRP occurred 30 min after initiation of CPB. A 3-fold increase in HANP also occurred just before termination of CPB. But, there was no correlation between plasma levels of CGRP and HANP. The changes in CGRP did not relate with those of pulmonary capillary wedge pressure. The results of the present study suggest that the mechanism for the increase is unclear, and CGRP could be influenced during cardiac or coronary artery surgery using CPB.

Mitral prosthetic dehiscence with laminar regurgitant flow signals assessed by transesophageal echocardiography

A patient with a Björk-Shiley mitral prosthesis developed progressive heart failure without heart murmur and hemolysis. The prosthetic dehiscence was not diagnosed using transthoracic echocardiography, but transesophageal echocardiography. The regurgitant signals revealed laminar flow pattern with large regurgitant orifice. In patients with mitral prosthetic dehiscence with laminar flow pattern, transesophageal echocardiography can provide reliable diagnostic information.

Transesophageal Doppler echocardiographic assessment of pulmonary venous flow pattern in subjects without cardiovascular disease

This study was designed to assess pulmonary venous flow dynamics using transesophageal Doppler echocardiography. Under general anesthesia, we studied 54 surgical patients with no history or physical evidence of cardiac disorders. In all patients pulmonary venous flow was easily identified by transesophageal color flow mapping. Pulmonary venous flow pattern, which was obtained clearly in 85% (4654) of patients by transesophageal pulsed Doppler echocardiography, was tri- or quadriphasic. The first wave, which was often biphasic in elderly patients, occurred during ventricular systole (S wave). The second wave occurred in diastole during the early ventricular filling phase of mitral flow (D wave). The third wave was reverse flow toward the pulmonary vein during atrial contraction (A wave). The following variables were measured: the peak flow velocities of each wave (PFVs, PFVd, PFVa), and the ratio of PFVs to PFVd (PFV(S/D)). The PFVd correlated with age (r = -0.56, P < 0.001), indicating age-related decrease. The PFV(S/D) correlated with age (r = 0.61, p < 0.001), indicating age-related increase. These results would indicate that the contribution of pulmonary venous flow during diastole to total pulmonary venous flow decreases with age. Our data suggest that age-related diastolic dysfunction of the left ventricle would affect pulmonary venous flow dynamics and that left atrial storage volume during ventricular systole would increase with age.

Age-related increase in systolic fraction of pulmonary vein flow velocity-time integral from transesophageal Doppler echocardiography in subjects without cardiac disease

The pulmonary vein flow velocity-time profile would be equivalent to the pulmonary vein flow volume-time profile, provided that the cross-sectional area of the pulmonary vein remains unchanged during 1 cardiac cycle. The systolic fraction of the pulmonary vein flow velocity-time integral, a ratio of velocity-time integral of the S wave to the sum of velocity-time integrals of the S and D waves, represents the ratio of left atrial storage volume to left ventricular stroke volume. This systolic fraction may help early filling of the left ventricle through an appropriate storage of blood and generation of driving pressure in the left atrium. Because early filling of the left ventricle is progressively impaired with age, it was hypothesized that this systolic fraction is increased with age. Forty-four noncardiac surgical patients (age range 17 to 70 years) who underwent transesophageal Doppler echocardiography under general anesthesia were studied, and left upper pulmonary vein flow and mitral inflow velocities were recorded. The ratio of peak velocity of the E wave to that of the A wave of mitral inflow velocity-time profile (y) decreased with age (y = -0.0245 x age + 2.41; r = -0.672, p < 0.01). Systolic fraction (y) increased with age (y = 0.00373 x age + 0.514; r = 0.656, p < 0.01). The age-related increase in the systolic fraction of pulmonary vein flow velocity-time integral may account for the compensation for impaired early filling of the left ventricle in elderly patients.