Elevation of plasma endothelin associated with systemic hypertension in humans following orthotopic liver transplantation.

Endothelin (ET) is a 21-amino-acid peptide of endothelial origin, is a potent systemic and renal vasoconstrictor associated with sodium retention and modulation of the renin-angiotensin-aldosterone system. The present study was designed to determine if plasma ET is elevated in humans with cirrhosis (n = 12), a state characterized by sodium retention and increased plasma renin activity (PRA) and plasma aldosterone (PA), and to determine the effect of orthotopic liver transplantation (OLT) upon plasma ET, PRA, and PA at 1, 3, and 7 days after transplantation. Plasma ET before OLT was 1.62 +/- 0.23 pg/ml, which was not different as compared with normal controls. Plasma ET significantly increased to 4.18 +/- 0.66, 3.87 +/- 0.58, and 4.07 +/- 0.61 pg/ml, respectively following OLT. PRA remained elevated throughout the postoperative course, in contrast to PA that decreased following OLT. Mean arterial pressure increased significantly from 82 +/- 4 pre-OLT to 98 +/- 4 and 103 +/- 2 mmHG on days 3 and 7 respectively.

Preoperative laboratory screening in healthy Mayo patients: cost-effective elimination of tests and unchanged outcomes.

We reviewed the results of preoperative screening laboratory tests in asymptomatic healthy patients who underwent elective surgical procedures at our institution in 1988. Substantially abnormal results were found in 160 of 3,782 patients. All such abnormalities involved five tests: aspartate aminotransferase, glucose, potassium, platelet count, and hemoglobin. Thirty of the abnormal test results were predictable on the basis of the history or physical examination. The abnormal test result prompted further assessment in 47 patients. No surgical procedure was delayed, and no association was noted between adverse outcome and any preoperative laboratory abnormality. Because of our findings in this analysis and similar studies on specific tests from other institutions, we no longer require preoperative laboratory screening tests for healthy patients.

Unrecognized severe postoperative hypercapnia: a case of apneic oxygenation.

Transcutaneous pulse oximetry is increasingly being used to supplant arterial blood gas measurement as a means to monitor oxygenation. Previous studies have demonstrated that, despite inadequate ventilation, oxygenation can be maintained during delivery of supplemental oxygen by a process known as diffusion respiration. In this setting, severe hypercapnia and acidosis rapidly develop. This case report demonstrates that pulse oximetry is an unreliable means to monitor adequacy of ventilation. A 75-year-old woman in good health suffered a fracture of the right hip that necessitated arthroplasty. During postoperative recovery, she remained unresponsive while receiving 100% oxygen through an endotracheal tube; mechanical ventilation was not used. Pulse oximetry indicated a blood oxygen saturation of 94 to 96%; however, results of blood gas studies 3 1/2 hours postoperatively revealed profound hypercapnia (arterial carbon dioxide tension, 265 mm Hg) and acidosis (pH, 6.65) but confirmed normal oxygen levels (arterial oxygen tension, 213 mm Hg). Assisted ventilation resulted in normalization of the blood gases and an improved level of consciousness. The patient was then transferred to Mayo Clinic Rochester and had an uneventful recovery.

Infections related to central venous catheters.

Infection is a potentially life-threatening complication of central venous catheterization. Although line-related bacteremias and sepsis are relatively uncommon, the frequent use of central lines in the intensive-care unit makes these infections a common consideration. Semiquantitative culture techniques for analysis of the catheter tip provide evidence for the diagnosis of catheter-related infections. Bacterial growth of more than 15 colony-forming units/plate is typically considered significant. Preventive measures include using sterile insertion techniques, providing meticulous care for the local site, and minimizing the duration of catheter use. The practice of changing lines over a guidewire is controversial. For treatment of most catheter-related infections, the catheter should be removed and antibiotics should be administered if associated systemic infection occurs.

Intensive-care unit experience in the Mayo liver transplantation program: the first 100 cases.

The first 100 liver transplantations at the Mayo Clinic were performed in 83 patients, who required a total of 917 patient days in the intensive-care unit (ICU). The mean duration of stay in the ICU was 5.91 days after liver transplantation and 6.15 days for patients who subsequently required readmission to the ICU. During the immediate postoperative period, hypothermia and hyperglycemia invariably occurred. Later during the initial admission or on readmission to the ICU, there arose the possibility of infections and renal insufficiency. Prompt diagnosis and treatment are necessary for hypertension, hypokalemia, severe metabolic alkalosis, fever, altered mental status, oliguria, and signs of graft failure in liver transplant patients. In our patient series, selective bowel decontamination minimized the occurrence of gram-negative and fungal sepsis, and use of antihypertensive agents and correction of coagulopathies may have decreased the risk of intracranial bleeding in patients with hypertension and clotting defects. Anticipation of potential conditions postoperatively and early implementation of treatment are key factors in the successful ICU management of patients who have undergone liver transplantation.

Outcomes of patients with no laboratory assessment before anesthesia and a surgical procedure.

OBJECTIVE: To estimate the frequency of perioperative morbidities in patients who underwent anesthesia and a surgical procedure with no preoperative laboratory testing. MATERIAL AND METHODS: We conducted an electronic database search of medical records of 56,119 patients who underwent surgical or diagnostic procedures and anesthesia at Mayo Clinic Rochester in 1994 and found 5,120 who had no laboratory tests done within 90 days before the procedure. From this group, we randomly selected 1,044 patients (87 from each month) to document the absence of preoperative tests, the presence of preexisting disease (by organ system), the type of anesthetic agent, and the outcomes and tests intraoperatively and postoperatively. RESULTS: The 1,044 patients ranged in age from 0 to 95 years (median age, 21). No deaths or major perioperative morbidities occurred (0.0%; exact 95% confidence interval, 0.00 to 0.35%). Although 10 patients underwent blood typing and screening for antibodies immediately preoperatively, no blood transfusions were necessary. Intraoperatively, 17 laboratory tests and 1 electrocardiogram were obtained, and 3 results were abnormal. Postoperatively, 42 blood tests and 2 electrocardiographic procedures were performed. Five of the 42 blood tests showed abnormal results (hemoglobin levels in 3, serum sodium in 1, and arterial blood gases in 1). One electrocardiogram showed normal findings, and the other revealed normal results except for premature ventricular contractions. No laboratory test done intraoperatively or postoperatively was found to change surgical or medical management substantially. One patient who had unanticipated blood loss during an outpatient procedure was admitted to the hospital for observation. CONCLUSION: All 1,044 patients, 97% of whom were relatively healthy, with no recent laboratory testing safely underwent anesthesia and an operation. We conclude that patients who have been assessed by history and physical examination and determined to have no preoperative indication for laboratory tests can safely undergo anesthesia and operation with tests obtained only as indicated intraoperatively and post-operatively. Current anesthetic and medical practices rapidly identify perioperative indications for laboratory evaluation as they arise.

Pancreas transplantation at Mayo: II. Operative and perioperative management.

Better perioperative and operative management techniques have contributed to an improvement in the success rate of pancreas transplantation. Because of a shortage of donor organs, the criteria for acceptability of the allograft have been liberalized, and the development of techniques such as combined liver and pancreas procurement has increased allograft availability. Major advances have been made in organ preservation. Currently, pancreas allografts can routinely be stored for 18 to 24 hours. The technique of pancreaticoduodenal transplantation with a duodenocystostomy for the exocrine drainage is widely used. Experience with anesthetic and intensive-care unit management of these patients is accumulating. With the evolution of pancreas transplantation and with the help of the excellent transplant centers in our area, we developed a pancreas transplantation protocol and performed transplantation based on this protocol in 16 recipients at the Mayo Clinic from October 1987 through December 1988.

Unilateral bronchospasm during pleurodesis in an asthmatic patient.

A case of unilateral bronchospasm during pleurodesis in a patient with a history of recurrent pneumothorax and asthma is presented. The etiology of this event is not clear; however, it likely includes reflex parasympathetic bronchoconstriction due to physical stimulation of the pleural surface during pleurodesis. Treatment involved independent lung ventilation, corticosteroids, and aminophylline.

The effect of anesthetic patient education on preoperative patient anxiety.

BACKGROUND AND OBJECTIVES: Preoperative time spent with patients has been abbreviated with the advent of same-day admission requirements and outpatient surgery. This study was conducted to evaluate the effects that materials mailed to the home relating to anesthetic-focused patient education may have on preoperative patient anxiety. METHODS: Patients scheduled for a total hip arthroplasty or for a total knee arthroplasty were screened via telephone for inclusion in a prospective, randomized study. Patients were asked about their access to a video cassette recorder/player (VCR) and their limitations regarding hearing or vision. Subjects were randomly assigned to either the intervention group and received two pamphlets and a video describing general and regional anesthesia or to the usual care group. All subjects were mailed a preoperative demographic questionnaire and a State Trait Anxiety Inventory (STAI), as developed by CD Spielberger. Questionnaires were completed at least 96 hours prior to admission and again preoperative on the day of surgery. RESULTS: Of 236 patients screened, 26 had no access to a VCR, 6 were hearing or visually impaired, and 4 declined participation. Of 200 subjects randomized, 134 completed both sets of questionnaires and thus form the basis of this report. A statistically significant difference between the subjects who received the video and pamphlets and the usual care subjects was detected with respect to change in STAI-assessed anxiety from baseline to immediately prior to surgery (P = .035). The intervention subjects experienced a smaller mean increase in anxiety. Forty-nine percent of the usual care subjects expressed interest in having additional information. CONCLUSIONS: Increase in preoperative anxiety is diminished when additional anesthesia information in printed and video format is made available. Useful information can be provided to patients to view or read prior to surgery.

Post-liver transplantation myocardial dysfunction.

Patients with end-stage liver disease usually show a hyperdynamic circulatory state. It has previously been reported that patients who develop myocardial depression in the early post-liver transplantation period are more prone to organ failure and death. We reviewed the records of 754 adult patients undergoing liver transplantation at our institution and identified 7 patients who initially showed hyperdynamic circulation, but then developed reversible dilated cardiomyopathy in the early posttransplantation period. All identifiable causes of cardiac dysfunction, such as myocardial ischemia, thyroid dysfunction, and electrolyte imbalances, were excluded. Left ventricular ejection fraction decreased from a preoperative median baseline of 60% to 20% (P = .02), with four-chamber dilatation on echocardiogram. All these patients required supportive care, including mechanical ventilation, afterload reduction, inotropic support, and monitoring in the intensive care unit. Cardiac function subsequently improved in all patients, with ejection fraction increasing to a median of 50%. All patients were discharged from the hospital. At a median follow-up of 15 months, there was no recurrence of heart failure. The increased peripheral resistance seen after successful liver transplantation may be an important causative factor.