Vomiting after ophthalmic surgery

The usefulness of intra-operative antiemetics and postoperative oral fluid restriction in the prevention of vomiting following anaesthesia for ophthalmic surgery, was studied in 200 patients. They were allocated into four groups of 50 and given either saline (as control), droperidol, metoclopramide or prochlorperazine. Oral intake was restricted postoperatively in half of the patients of each group. Anaesthesia comprised morphine and atropine premedication and a halothane, nitrous oxide and oxygen spontaneous breathing technique. No significant beneficial effects resulted from intra-operative antiemetics; vomiting incidences of 26% after saline and droperidol, 28% after metoclopramide and 14% after prochlorperazine were observed. Younger patients and females vomited most frequently. Restriction of oral fluids did not decrease the incidence of vomiting but demonstrated that approximately half of those patients who vomit do so with their first postoperative oral intake. Vomiting was observed more frequently after non intra-ocular surgery than after intra-ocular surgery (37% cf. 16%, p less than 0.01) and postoperative analgesics were required by more non intra-ocular patients than by intra-ocular patients (25% cf. 5%, p less than 0.001). Squint patients vomited most frequently (48%) and most frequently required postoperative analgesia (35%).     

Effects of buffering in hypercapnia and hypercapnic hypoxemia

Anesthetized, paralyzed and mechanically ventilated pigs were exposed to extreme hypercapnia (Paco_2-20 kPa) at Fio₂ 0.4 for 480 min, with (n = 6) or without (n = 6) continuous infusion of isotonic buffers (bicarbonate and trometamol). Arterial pH was higher in buffered animals than controls, 7.21 ±0.01 vs 7.01±0.01 (mean ± s.e.mean, P < 0.01). Serum osmolality and Paco₂ did not differ between groups throughout the experiment. The hemodynamic response to hypercapnia was attenuated in the buffered group, who had lower heart rate, 133 ± 6 vs 189±12 min^-1 (P < 0.01), mean arterial pressure (MAP) 109 ± 4 vs 124 ± 4 mmHg (14.5 ± 0.5 vs 16.5 ± 0.5 kPa) (P < 0.05), mean pulmonary arterial pressure 16±1 vs 23 ± 1 mmHg (2.1 ±0.1 vs 3.1 ±0.1 kPa) (P < 0.01), and pulmonary vascular resistance (PVR) 249 ± 21 vs 343 ± 20 dyn s-cm^-5 (2490±210 vs 3430±200 μN-s-cm^-5) (P < 0.01), compared with the control group. Subsequently, both groups were exposed to hypercapnic hypoxemia by stepwise increases in Fio₂ (0.15, 0.10, 0.05) at 30-min intervals, while Fico₂ was kept at 0.2. PVR increased in both groups (P < 0.05) but, except for heart rate, all hemodynamic differences between the groups disappeared during hypoxia. At Fio₂ 0.15, buffered animals had higher arterial oxygen saturation (73 ± 5%) than the controls (55 ± 5%), (P < 0.05). The control animals died after 1–29 min (mean 14 min) at Fio₂ 0.10, while all buffered animals survived Fio₂ 0.10 with stable MAP (122 ± 14 mmHg (16.3 ± 1.9 kPa). The buffered animals died after 4–22 min (mean 15 min) at Fio₂ 0.05. We conclude that buffering to a pH of 7.21 attenuates the observed hemodynamic response in extreme hypercapnia and improves survival in hypercapnic hypoxemia.     

Heparin–coated circuit during cardiopulmonary bypass

A prospective randomized study was performed to investigate the effect of surface coating with covalently endpoint–attached heparin (Carmeda Bio Active Surface) and reduced general heparinization on haematological indices and complement C5 activation. Care was taken to optimize the rheological design of the system using centrifugal pump and a closed system without venting or machine suction. Twenty patients scheduled for aortocoronary bypass grafting (EF > 0.5) participated in the study. Ten patients were randomized to be treated with heparin–coated equipment (CBAS) and reduced i.v. heparin (1.5 mg kg^-1) while 10 patients treated with identical but noncoated equipment and full heparinization (3 mg–kg^-1) served in a Control group. A vacuum suction was used to collect the blood from the operating field and it was autotransfused at weaning from extracorporeal circulation (ECC). Blood samples were obtained from the venous (precircuit) and arterial (postcircuit) side. We used a new and very specific method for detection of C5a based on monoclonal antibodies. The concentration of C5a was low in both groups during the operation but a significant increase was seen on days 1 and 2. In the Control group there was an increase from 10.2 ngml^-1±1.2 to 27.5 ng ml^-1 ± 4.8 on day 2 and in the CBAS group from 10.7 ng ml^-1 ± 1.2 to 35.6 ng ml^-1 ± 11.6 on day 2 (NS between groups). The granulocytes and total leukocyte count increased at the end of ECC and was maintained at the elevated level throughout the study period. The amount of free haemoglobin was high in the autotransfused blood in both groups. The present results confirm the feasibility of reducing general heparin when using heparin–coated systems but the study does not support the superiority of such coating with regard to biocompatibility in short procedures with a Theologically optimized circuit. The potential benefit from reduced heparin and protamine has not been fully evaluated.     

Low levels of essential fatty acids are related to impaired delayed skin hypersensitivity in malnourished chronically ill elderly people

Abstract Essential fatty acid (FA) deficiency, which may accompany protein-energy malnutrition (PEM), has been associated with impaired inflammatory reactions. We evaluated this relationship by analysing FA profiles and delayed cutaneous hypersensitivity in 20 malnourished elderly non-cancer patients and in 20 age-matched control patients. As indicated by serum cholesterol and serum triglycerides, the lipid levels were decreased by about one-third in the subjects with PEM. In comparison with the controls, there was a reduction in the ω 3 FA (e.g. eicosapentanoate) in total serum lipids (mgl^-1) and serum phospholipids (%) of 40% and 47%, respectively. Reductions in serum ω 6 FA (e.g. linoleate and arachidonate) levels corresponded to the drop in total FA concentrations (30%). The cutaneous hypersensitivity was impaired in 14 of the malnourished patients. The magnitude of the skin reaction was positively correlated ( P < 0·05) to the concentrations of eicosapentanoate in serum lipids and serum phospholipids, as well as to the linoleate concentration in total serum lipids. Six of the malnourished patients took part in a nutritional intervention programme for 3 months. In parallel with an improvement in the nutritional status there was a 35% increase ( P < 0·05) in the total ω 3 FA serum concentration. Negative skin tests became positive and the median skin induration enlarged threefold ( P < 0·05). Thus, deficiency of ω 3 FA might be one factor contributing to cutaneous anergy in elderly malnourished patients.     

Testosterone increases serum 1,25–dihydroxyvitamin D and insulin-like growth factor-I in hypogonadal men

The short-term metabolic effects of testosterone treatment on circulating levels of 1,25-dihydroxyvitamin D and insulin-like growth factor-I (IGF-I) were studied in 13 hypogonadal men. The study group included 11 men with Klinefelter's syndrome, with varying degree of androgen deficiency, and two men with secondary hypogonadism. Pretreatment levels of 1,25-dihydroxyvitamin D, vitamin D-binding protein and IGF-binding protein-I were all within the normal range. The levels of IGF-I were lower than normal in 5/11 of the Klinefelter patients and in one patient with GH-deficiency. Testosterone treatment increased circulating total 1,25-dihydroxyvitamin D significantly from 75 +/- 4 pmol l-1 (mean +/- SEM) to 86 +/- 4 (P less than 0.01) and the free 1,25-dihydroxyvitamin D-index from 1.95 +/- 0.11 to 2.39 +/- 0.12 (P less than 0.01). Serum levels of IGF-I increased from 117 +/- 22 micrograms/l to 143 +/- 23 (P less than 0.01) during androgen treatment. No significant effects on levels of IGF-binding protein-I were seen. It is concluded that androgen therapy increases the availability of 1,25-dihydroxyvitamin D and the level of IGF-I, which may be important links in the action of testosterone.     

An improved technique for treating tracheostomal stenosis following laryngectomy

Stenosis of the tracheostome is an occasional complication following laryngectomy. Having tried a number of procedures recommended for correction of such stenoses with limited results, we developed a new technique. This technique which is based on multiple Y-V plasties has been applied to 20 patients. Measurements of the stomal area following surgery in 18 patients showed an average increase in stomal size by a factor of 3.8. One patient apparently had no increase of the stoma. In 2, no post-operative measurements were available. Post-operative infection resulted in recurrence of the stenosis in one patient. He was successfully reoperated using the same technique. Follow-up revealed that none of the patients had complaints related to their stoma.