Radioimmunoassay of antidiuretic hormone during morphine anaesthesia

Effects of systemic and epidural morphine on antidiuretic hormone levels in children

BACKGROUND

Although the use of opioids during general anaesthesia suppresses stress response to surgery and pain, the effects on antidiuretic hormone (ADH) are controversial. The aim of this study was to find the effects of morphine with either intravenous infusion or epidural route on ADH and other stress hormones.

METHODS

Fifty children aging (1-15 years) undergoing major genito-urinary or abdominal operations were included in this study. The patients were allocated randomly to two groups receiving either a single dose of epidural morphine 0.1 mg.kg-1 (EP group, n = 25) postinduction or morphine infusion (INF group; n = 25) at 0.02 mg.kg-1.h-1 following 0.05 mg.kg-1 bolus. Blood samples were withdrawn for plasma ADH, osmolality, glucose, cortisol, insulin and morphine level analysis following induction and 1, 5, 12 and 24 h after initial morphine administration.

RESULTS

The two groups were similar in demographic factors, pain scores, sedation scores, and incidence of nausea and vomiting. The amount of morphine received was different between groups and the changes in serum levels of morphine were statistically significant in EP group ( P < 0.05). The changes in cortisol, blood glucose and insulin levels were insignificant in both groups (P > 0.05). The changes of ADH levels were significant at time-points in both groups, reaching control levels at the 24th hour (P < 0.05).

CONCLUSION

Despite the effective pain therapy and suppression of cortisol and insulin response to surgical stimulus, the increase in ADH secretion is not effected by systemic or epidural morphine administration.

Effects of acetylpromazine or morphine on urine production in halothane-anesthetized dogs

OBJECTIVE

To assess the influence of preanesthetic administration of acetylpromazine or morphine and fluids on urine production, arginine vasopressin (AVP; previously known as antidiuretic hormone) concentrations, mean arterial blood pressure (MAP), plasma osmolality (Osm), PCV, and concentration of total solids (TS) during anesthesia and surgery in dogs.

ANIMALS

19 adult dogs.

PROCEDURE

Concentration of AVP, indirect MAP, Osm, PCV, and concentration of TS were measured at 5 time points (before administration of acetylpromazine or morphine, after administration of those drugs, after induction of anesthesia, 1 hour after the start of surgery, and 2 hours after the start of surgery). Urine output and end-tidal halothane concentrations were measured 1 and 2 hours after the start of surgery. All dogs were administered lactated Ringer's solution (20 ml/kg of body weight/h, i.v.) during surgery.

RESULTS

Compared with values for acetylpromazine, preoperative administration of morphine resulted in significantly lower urine output during the surgical period. Groups did not differ significantly for AVP concentration, Osm, MAP, and end-tidal halothane concentration; however, PCV and concentration of TS decreased over time in both groups and were lower in dogs given acetylpromazine.

CONCLUSIONS AND CLINICAL RELEVANCE

Preanesthetic administration of morphine resulted in significantly lower urine output, compared with values after administration of acetylpromazine, which cannot be explained by differences in AVP concentration or MAP When urine output is used as a guide for determining rate for i.v. administration of fluids in the perioperative period, the type of preanesthetic agent used must be considered.

Reversible renal failure following opioid administration

A patient who received intravenous papaveretum during and after operation developed anuria and biochemical evidence of impaired renal function in the first 6 hours after surgery. Administration of naloxone 0.4 mg was associated with a sustained improvement in urine output. Mean arterial pressure did not change significantly. The impairment of renal function may have been related to high plasma concentrations of codeine, one of the constituents of papaveretum.

Hemodynamics in the prone jackknife position during surgery

We examined the hemodynamic changes occurring with prone jackknife positioning during colorectal surgery. The operative procedure was restorative proctocolectomy with ileal J-pouch anal anastomosis in five patients with adenomatosis coli and six patients with ulcerative colitis and anoabdominal resection of the rectum with colonic J-pouch anal anastomosis in eight patients with rectal cancer. Nineteen patients (10 men and 9 women aged 41 +/- 19 years) were monitored with arterial and Swan-Ganz catheters during positioning. Measurements were obtained in the supine and prone positions (1 minute, 3 minutes), and the jackknife position (1, 3, 5, and 10 minutes), as well as before and after adoption of the Lloyd-Davies position (1, 3, 5, and 10 minutes). Turning the patient from the supine position to the prone position resulted in a significant decrease in the cardiac index (CI). However, following head-down rotation, the CI increased and returned to the value seen in the supine position (p less than 0.05). Heart rate (HR) slowed and mean arterial pressure (MAP) increased in the prone jackknife position. We concluded that the extent of the changes in cardiac function presented no serious problems.

Variations in hemodynamic and stress hormonal responses in open heart surgery with buprenorphine/diazepam anesthesia

The use of buprenorphine-diazepam-N2O (60%)-O2 anesthesia in open heart surgery was investigated. The authors examined the hemodynamic changes produced and the response of stress hormones. Twenty adult patients with atrial septal defects undergoing surgical correction were studied in two groups of 10, receiving either 6 micrograms/kg of buprenorphine (B6) or 12 micrograms/kg of buprenorphine (B12) for the induction of anesthesia. Both groups received a subsequent dose of 6 micrograms/kg of buprenorphine with the commencement of extracorporeal circulation (ECC). With surgery, mean arterial pressure showed a transient increase in both groups and thereafter was stable. Heart rate in the B6 group was increased from the onset of surgery to the day after, while the B12 group showed no significant change. Filling pressures showed no change in either group. Plasma catecholamine concentrations in the B6 group, in contrast to the B12 group, increased significantly from midoperation to after completion of the operation (ECC 10 minutes, B6 group v B12 group: plasma norepinephrine 616 +/- 231 v 195 +/- 38 pg/mL, plasma epinephrine 1385 +/- 392 v 572 +/- 132 pg/mL, P less than 0.05). Plasma ADH levels in both groups rose with the commencement of surgery, reaching a peak at ECC 10 minutes (B6 group 88.1 +/- 8.4 v B12 group 124.4 +/- 27.2 pg/mL). However, in contrast to plasma catecholamines, the antidiuretic hormone (ADH) levels in the B12 group remained higher until the first postoperative day. Therefore, patients who received the larger dose of buprenorphine had better control of hemodynamics and catecholamines, but a greater elevation of plasma ADH levels.

Opiate anaesthesia

Current use of opioids in anaesthesia is reviewed with particular emphasis on the use of opioids in anaesthetic doses, techniques that recently have become popular in cardiovascular anaesthesia. A major benefit of opioid anaesthesia (particularly fentanyl) is the cardiovascular stability which obtains during induction and throughout operation, even in patients with severely impaired cardiac function. Anaesthetic doses of morphine are associated with a higher incidence of cardiovascular disturbances and other problems. Pethidine is unsuitable for cardiovascular surgery because of severe haemodynamic disturbances when high doses are given. Sufentanil and alfentanil may prove more suitable alternatives. High doses of opioids can reduce or prevent hormonal and metabolic responses to the stress of surgery. Even very large doses of fentanyl or its new analogues do not prevent marked increases in plasma catecholamine concentrations in response to cardiopulmonary bypass. The reduction in hormonal and metabolic stress response does not appear to continue postoperatively.

Excessive antidiuretic hormone secretion after radical cystectomy

Perioperative plasma antidiuretic hormone (vasopressin) levels were determined in 8 patients undergoing radical cystectomy. Marked elevations of antidiuretic hormone were noted immediately postoperatively in all patients and these levels persisted for 48 hours. Plasma antidiuretic hormone was elevated beyond the physiological levels needed for maintenance of intravascular volume and osmolarity. Excessive antidiuretic hormone secretion is common after radical cystectomy and should be considered in the differential diagnosis of postoperative oliguria in these patients.

Circulating levels of arginine vasopressin before and during the infusion of the hormone in patients presenting with bleeding oesophageal varices

Circulating levels of antidiuretic hormone (ADH) were measured in patients presenting with bleeding oesophageal varices before and during treatment with arginine vasopressin. There was no significant difference in the circulating levels of ADH before and during treatment with arginine vasopressin in patients in which the hormone successfully controlled haemorrhage and those in which it did not. It is concluded that the failure of vasopressin to control variceal haemorrhage in approximately 40% of patients presenting for treatment cannot be attributed to higher circulating levels of the hormone in these subjects.

Antidiuretic hormone response to osmotic stimulus under fentanyl anaesthesia

The effect of fentanyl anaesthesia on the plasma antidiuretic hormone (ADH) response to osmotic stimulus was studied in eight patients. Eight g (137 mmol) NaCl were rapidly injected intravenously the day before anaesthesia and blood samples were collected 5, 10, 20 and 30 min after the injection. This protocol was repeated in the same subjects, under anaesthesia with thiopental, nitrous oxide and fentanyl before surgical incision. Plasma ADH markedly increased after NaCl administration and was significantly correlated with plasma sodium (r = 0.67, P less than 0.005) when the patients were awake, whereas it did not change over 30 min and was not correlated with plasma sodium (r = 0.18, P greater than 0.05) under fentanyl anaesthesia. This inhibitory effect of anaesthesia occurred in spite of a significant fall in the mean arterial pressure during the study. In order to eliminate the role of overnight fasting, premedication and fluid load, the same protocol was performed in six control patients who were fasted overnight, premedicated and fluid loaded. These results demonstrate that fentanyl anaesthesia abolishes the plasma ADH response to both osmotic and low arterial pressure stimuli.

Plasma vasopressin levels and urinary sodium excretion during cardiopulmonary bypass with and without pulsatile flow

The use of pulsatile perfusion during bypass should create a more physiological milieu and thus attenuate the vasopressin stress response. To determine this, 20 patients scheduled for elective coronary artery bypass operation were studied in two groups. Group 1 had a standard nonpulsatile perfusion, and in Group 2 a pulsatile pump was used. Measurements were made before and after anesthesia, after surgical incision, and at 15 and 30 minutes during and after cardiopulmonary bypass. In both groups, vasopressin levels were significantly elevated after sternotomy (4.5 +/- 1.5 to 37 +/- 10 pg/ml in Group 1 and 3.1 +/- 1.2 to 33 +/- 9 pg/ml in Group 2, p less than 0.05) and during bypass (198 +/- 19 pg/ml in Group 1 and 113 +/- 16 pg/ml in Group 2) but were higher in Group 1 (p less than 0.05). With comparable perfusion pressures in both groups, Group 2 required higher flow (4.2 +/- 0.2 versus 3.5 +/- 0.3 L/min, p less than 0.05) and had lower resistance (1,351 +/- 182 versus 1,841 +/- 229 dynes sec cm-5, p less than 0.05) and higher urine Na+ (123 +/- 5 versus 101 +/- 8 mEq/L, p less than 0.05). These data demonstrate that pulsatile flow can significantly attentuate the vasopressin stress response to bypass. Since vasopressin, at these concentrations, is a potent vasoconstrictor and is capable of producing a Na+ diuresis, this may partially explain the higher flow requirements and the decrease in Na+ excretion.

Arginine vasopressin release following surgical operations

A study of plasma arginine vasopressin (AVP) concentrations in 16 patients undergoing uncomplicated cholecystectomy was carried out to determine the relative importance of the various stimuli to AVP secretion during and after an operation. Eight of the 16 patients were given a high epidural blockade from T4 and T12 and blood samples were taken before, at frequent intervals during and for two days after operation for determination of plasma AVP and osmolarity; systolic blood pressure was measured each time a blood sample was taken. In the 16 patients there was a 1.8-fold rise of plasma AVP after induction of anaesthesia (from 1.7 pmol/l median basal value to 13.1 pmol/l) and an 8.8-fold rise after skin incision, the highest concentration during operation being 102 pmol/l. There was no significant difference in AVP concentrations, urine volumes or plasma osmolality in the control and epidural groups. Systolic blood pressure fell in all patients during operation by between 14 and 54 per cent, the fall being significantly greater in the epidural group. Notwithstanding the evidence that certain nervous impulses do cause an increased secretion of AVP during operation, these results clearly show that in the absence of such stimuli there is still an increased secretion, almost certainly caused by a fall in the blood pressure.

Fentanyl-oxygen anaesthesia for coronary artery surgery: cardiovascular and antidiuretic hormone responses

This study demonstrates that large doses of fentanyl, as the sole anaesthetic with ventilation with oxygen, produces complete anaesthesia and minimal changes in cardiovasuclar dynamics in patients with coronary artery disease. It also indicates that high dose fentanyl anaesthesia blocks the increase in plasma anti-diuretic hormone and cardiovascular dynamics which are so common with morphine and other anaesthetic techniques during tracheal intubation and surgical stimulation in patients with coronary artery disease. Our findings suggest that fentanyl-oxygen anaesthesia is an attractive technique in patients with coronary artery disease.

Plasma vasopressin levels during cardiopulmonary bypass with and without profound haemodilution

In cardiopulmonary bypass the effect on plasma vasopressin levels of the addition of whole blood to the pump priming solution was measured. Six patients (Group I) had blood added to the lactated Ringer's solution for the prime, and six patients (Group II) had only lactated Ringer's solution. Neither group had significant changes in plasma vasopressin levels until surgical stimulation occurred. Comparable significant elevations occurred during bypass in both groups. Greater decreases in haematocrit and urinary K+ and greater increases in urinary Na+ occurred in Group II. The degree of haemodilution does not appear to effect plasma vasopressin levels but may alter the degree of electrolyte shift.

The effect of pain on plasma arginine vasopressin concentrations in man

The effect of pain on plasma AVP concentration in man has previously been studied only during major surgery with general anaesthesia. Plasma AVP concentration (pAVP) and plasma osmolality (pOsm) were measured in thirty-six patients seen in a surgical emergency department complaining of pain and in fifty-one control subjects. No significant difference in pOsm was found, but pAVP was significantly higher in the emergency room patients in pain (M +/- SEM = 4.94 +/- 0.98 pmol/1 compared to 2.31 +/- 0.32 pmol/1 in control subjects, P less than 0.01). In the control subjects, age was found to have a low but significant inverse correlation with pAVP (r = 0.37, P less than 0.01). Chronic smoking was associated with significant elevation of pAVP (3.81 +/- 0.99 pmol/1 in smokers vs. 1.89 +/- 0.28 pmol/1 in non-smokers, P less than 0.02). Neither smoking nor age could account for the difference in pAVP between the pain and control groups. Thus, pain is a non-osmolar factor capable of elevating AVP in conscious man.

The syndrome of inappropriate antidiuretic hormone secretion associated with acute myocardial infarction

A 72-year-old man developed the syndrome of inappropriate antidiuretic hormone secretion after sustaining an acute myocardial infarction. Other documented causes of this syndrome were excluded, and this case is therefore reported as a new association.

The effects of halothane on plasma vasopressin during cardio-pulmonary bypass

Plasma vasopressin concentrations were estimated in twelve patients undergoing cardio-pulmonary bypass for open heart surgery. In six patients anaesthesia was maintained with 66% nitrous oxide in oxygen, whilst the remaining six additionally received halothan as a vasodilator during the bypass period. Induction of anaesthesia had little effect on plasma vasopressin concentrations, whilst marked increases were seen during surgery and bypass in both groups of patients. However, in those patients receiving halothane, significantly higher concentrations were reached, a maximun b36.1 +/- 8.9 (SEM) muu/ml being seen in contrase to 15.4 +/- 2.2 muu/ml in the group receiving nitrous oxide in oxygen alone.