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Biomedical subjects

P N Fyman

Publications and source records attributed to P N Fyman.

13 recordsLinked to original sources

Hemodynamic changes after nafcillin administration during coronary artery bypass surgery.

The hemodynamic response to nafcillin administration was studied in 45 patients with good left ventricular function and no known history of hypersensitivity to penicillin during coronary artery bypass grafting (CABG). Group I (15 patients) received 1 gram of nafcillin in 10 mL of saline as an intravenous (IV) bolus, group II (15 patients) received 1 gram of nafcillin in 50 mL of saline as a slow IV infusion over 15 minutes, and group III (15 patients) did not receive nafcillin. Hemodynamic variables and plasma histamine and catecholamine levels were measured before and after nafcillin administration, after 500 mg of CaCl2, and after 0.1 mg of phenylephrine. Bolus nafcillin administration produced profound hypotension secondary to vasodilatation with significant increases in cardiac index and decreases in systemic and pulmonary vascular resistances. Cardiac index increased from 3.15 +/- 0.3 L/min/m2 to 5.75 +/- 0.25 L/min/m2 (P less than 0.005) one minute after nafcillin administration, and remained at 5.1 +/- 0.35 L/min/m2 after administration of CaCl2 (P less than 0.005). All hemodynamic parameters returned toward control values after administration of 0.1 mg of phenylephrine, IV. Plasma epinephrine, norepinephrine, and histamine levels increased more than 100%. In group II, cardiac index increased, while systemic and pulmonary vascular resistances and mean arterial pressure decreased. However, these changes were less significant than those found in group I.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure

Pharmacokinetics of sufentanil in patients undergoing renal transplantation.

Renal failure and chronic haemodialysis are often associated with alterations in fluid status and plasma proteins. These changes, in turn, may result in pharmacokinetic alterations in affected patients. The purpose of this study was to investigate the pharmacokinetics of sufentanil in chronic renal failure patients undergoing kidney transplantation. Ten male patients were studied. Following induction of anaesthesia each patient received sufentanil 2.0 micrograms.kg-1 IV with subsequent serial plasma sampling for drug measurement from one to 360 minutes. A biexponential equation provided the best fit of the sufentanil concentration data with mean +/- SEM distribution (alpha) and elimination (beta) half-lives of 2.9 +/- 1.3 and 176 +/- 87 minutes, respectively. The mean Vc and Vd beta values were 0.15 +/- 0.05 L.kg-1 and 0.85 +/- 0.16 L.kg-1, respectively; plasma drug clearance was 11.5 +/- 3.7 ml.kg-1.min-1. Mean values for K10, K12 and K21 were 0.15 +/- 0.06.min-1, 0.4 +/- 0.14.min-1 and 0.1 +/- 0.04.min-1, respectively. With the exception of Vd beta, these pharmacokinetic values are similar to those reported in previous studies in general surgical, elderly and burn patients. The Vd beta values observed in this study may have resulted from alterations in drug distribution or elimination following revascularization of the implanted kidneys. Nevertheless, it appears that modification of sufentanil doses is unnecessary in chronic renal failure patients undergoing renal transplantation.

Adult

Hemodynamic effects of metocurine during isoflurane anesthesia.

Anesthesia was induced in 42 adults with thiopentone 3-7 mg/kg i.v. and maintained with isoflurane at a constant inspired concentration of 1-2%. After 30 min of hemodynamic stabilization with continuous muscle relaxation and an absence of surgical stimulation, each patient was randomly assigned to one of four metocurine dosage groups: I - control (n = 11); II - 0.2 mg/kg (n = 10); III - 0.3 mg/kg (n = 10); and IV - 0.4 mg/kg (n = 11). There were no significant hemodynamic changes in Groups I or II. In Groups III and IV mean arterial pressure (MAP) decreased 32% and 26% respectively, and systemic vascular resistance (SVR) decreased 42% and 36%, respectively (P less than 0.01). In Group IV, an increase of 24% in cardiac output was also significant (P less than 0.05). These results, especially in Group IV patients, stand in marked contrast to the lack of hemodynamic effects produced by metocurine during balanced anesthesia.

Adult

Hemodynamic changes after the administration of protamine.

Hemodynamic changes associated with the administration of protamine were studied in 30 dogs divided into three equal groups. Protamine (1 mg X kg-1 X min-1 for 4 min) was administered 10 min after 4 mg X hg-1 heparin was given via a left atrial (LA) line in group A, via a central vein in group B, and via a peripheral vein in group C. Protamine given through the central venous pressure (CVP) line resulted in an immediate and significant decrease in mean arterial pressure (MAP) to 60 +/- 4.5 mm Hg (P less than 0.025) from 72 +/- 7 mm Hg immediately after the protamine and to 58 +/- 5 mm Hg (P less than 0.025) 5 min later and with an increase in cardiac index (CI) to 3.7 +/- 0.3 L X min-1 X m-2 from 2.8 +/- .25 L X min-1 X m-2 immediately after the protamine (P less than 0.005), followed by a decrease back to 2.7 +/- 0.3 L X min-1 X m-2 5 min later. Mean arterial pressure and CI remained unchanged after administration of protamine via the peripheral vein or the left atrium. Systemic vascular resistance (SVR) decreased significantly only after administration of protamine via the CVP and was statistically unchanged when administered via the peripheral and LA line. Plasma histamine levels increased significantly after administration of protamine through the central line but remained unchanged after administration via a peripheral vein or the left atrium.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

Anaesthesia for aortic arch aneurysm repair: experience with 17 patients.

Mortality and morbidity during aortic arch aneurysm repair is high despite improvements in surgical technique which attempt to assure brain protection during surgery. We successfully managed 17 patients using deep hypothermia and circulatory arrest. Anaesthesia consisted of pancuronium, fentanyl, plus isoflurane or halothane if needed. Pulmonary artery and arterial catheters were inserted. Surface cooling was performed followed by core cooling on cardiopulmonary bypass, using a heat exchanger. Total circulatory arrest was performed when esophageal temperature reached 12-14 degrees C after previous administration of thiopentone 30 mg X kg-1, methylprednisolone 2 gm, furosemide 40 mg and mannitol 25 gm. At that time the head was packed in ice and surgical correction performed. Mean arrest time was 36.5 +/- 13 minutes at a mean oesophageal temperature of 12.5 +/- 0.75 degrees C. No serious, permanent neurological deficit was found. Tracheostomy was required in five patients of whom two had chronic obstructive pulmonary disease (COPD). Two of these patients died of adult respiratory distress syndrome (ARDS) and renal failure. The reported technique is safe and can be easily used in patients undergoing aortic arch aneurysm repair.

Adjuvants, Anesthesia

Intrapulmonary shunting during deliberate hypotension with nifedipine, diltiazem and labetalol in dogs.

Pulmonary shunt (Qs/Qt) was calculated in 49 mongrel dogs weighing 18-20 kg during mechanical ventilation, before and during deliberate hypotension with either nifedipine (group N), diltiazem (group D), labetalol (group L), or ethyl alcohol and polyethylene glycol (group E). A 30 per cent decrease in mean arterial blood pressure occurred after two minutes of nifedipine infusion, two minutes after diltiazem, and three minutes after labetalol; these effects lasted two hours after nifedipine administration, 90 minutes after diltiazem and three hours after labetalol. There was an accompanying significant decrease in systemic and pulmonary vascular resistance. Qs/Qt and cardiac output increased significantly after nifedipine infusion. Shunt increased (mean +/- S.E.) from 9.7 +/- 0.8 to 18.25 +/- 1.05 per cent at two minutes (p less than 0.0005); 19.05 +/- 1.2 per cent at 30 minutes (p less than 0.005); 17.5 +/- 1.6 per cent at two hours (p less than 0.01); and 12 +/- 1.1 per cent at three hours (p less than 0.025). No increase in shunt occurred after the administration of diltiazem, labetalol or polyethylene glycol and ethyl alcohol. Arterial oxygen tension (PaO2) decreased significantly after nifedipine infusion from 146 +/- 11.5 to 105 +/- 3.5 mmHg two minutes after infusion; to 89.5 +/- 3 mmHg 30 minutes after; 115 +/- 4.75 mmHg two hours after; and 130 +/- 10.75 mmHg three hours later. PaO2 was not significantly different after diltiazem, labetalol, or polyethylene glycol and ethyl alcohol administration. With nifedipine cardiac output increased from 2.25 +/- 0.3 to 3.95 +/- 0.25 after two minutes (p less than 0.005) to 3.85 +/- 0.35 after 30 minutes (p less than 0.005), 3.7 +/- 3 after two hours (p less than 0.01) to 2.9 +/- 1.1 after three hours. No significant increase in cardiac output occurred in groups D or L. These results suggest that only nifedipine infusion significantly alters oxygenation in dogs and therefore its use warrants caution in the presence of a preexisting abnormal Qs/Qt.

Anesthesia

Retrograde intubation in patients undergoing open heart surgery.

Cardiovascular changes during difficult intubation were studied in 25 patients undergoing open heart surgery. The study was divided into two phases. Phase A from the first laryngoscopy to the fourth unsuccessful one; Phase B from a stabilization period until after retrograde intubation was performed. During phase A, heart rate (HR) increased significantly from 75 +/- 6.5 beats/min before laryngoscopy to 95 +/- 8.5 (p less than 0.05) after the last laryngoscopy. Mean arterial pressure (MAP) also increased from 82.5 +/- 4.75 mmHg to 105 +/- 5.15 (p less than 0.005) after the last laryngoscopy. Cardiac index (CI) decreased from 2.9 +/- 0.3 L . min-1 . m-2 before to 2.55 +/-0.2 after the last laryngoscopy. Pulmonary capillary wedge pressure (PCWP) increased from 10.5 +/- 1 mmHg before to 19.25 +/- 1.5 (p less than 0.01) after the last laryngoscopy. No statistically significant changes in HR, MAP, CI, and PCWP occurred before and after intubation during Phase B. Three patients had elevated ST segments during Phase A which responded to IV nitroglycerin and propranolol. None was detected during Phase B. There were more lacerated lips and teeth damaged during Phase A. One patient developed a small peritracheal haematoma after the retrograde intubation, for which no treatment was required. This technique is safe and produces minimal cardiovascular changes for difficult intubation in patients undergoing open heart surgery.

Aortic Valve

Effect of volatile anaesthetics and nitrous oxide-fentanyl anaesthesia on bleeding time.

Fifty-one patients were divided randomly into four groups: halothane in oxygen; fentanyl plus nitrous oxide in oxygen; enflurane in oxygen; or isoflurane in oxygen. Standardized bleeding time was measured using a Simplate II bleeding device before and at least 40 min after the induction of anaesthesia. Arterial pressure was maintained at +/- 20% of control values and temperature was kept at 35-37 degrees C. The bleeding time was prolonged by 33% in the halothane group (P less than 0.01) and by 20% in the nitrous oxide-fentanyl group (n.s.). There was essentially no change in bleeding time in the groups receiving enflurane or isoflurane, although there was considerable variability within each group, which did not seem to be related to differences in sex, age, type of surgery, concentration of agent used or surgical procedure.

Adult

Prevalence of hepatitis B markers in the anesthesia staff of a large inner-city hospital.

Thirty-four of seventy anesthesia staff members from an inner-city hospital evidenced past infection with hepatitis B. This is more than twice the prevalence previously reported for university-affiliated hospitals. Our findings suggest that screening before vaccinating is likely to be cost-effective for senior or foreign-born urban health care personnel in high-risk specialties, and vaccinating without screening is likely to be cost-effective for all persons newly entering high-risk specialties, including anesthesiology.

Anesthesia Department, Hospital