Analgesia for outpatient surgery: placebo versus naproxen sodium (a non-steroidal anti-inflammatory drug) given before or after surgery.

One hundred and eighty patients scheduled for day-care surgery were allocated randomly to one of three groups to receive naproxen sodium 1100 mg 1 h prior to surgery, naproxen sodium 1100 mg immediately after surgery, or placebo. The pre-surgery naproxen sodium group had significantly lower pain scores 1 h post-operatively and at discharge than the placebo group. At discharge both treatment groups were better than placebo. At 24 h post-operatively only the post-operative naproxen sodium group had lower pain scores. There was no difference in post-operative analgesic requirements until discharge between the groups, but at 24 h post-operatively the placebo group had required significantly more analgesics than the treatment groups. A questionnaire concerning general acceptability of anaesthesia/analgesia showed similar results. Our conclusion is that naproxen is better than placebo for treatment of post-operative pain. The time of administration pre- or post-operatively is important for the immediate post-operative pain, but we found no support for the existence of 'pre-emptive analgesia'.

Continuous subcutaneous infusion of morphine--an alternative to extradural morphine for postoperative pain relief.

In a randomized, double-blind study of 40 patients undergoing total abdominal hysterectomy, we have compared continuous subcutaneous infusion (CSCI) of morphine with discontinuous extradural injection of morphine for postoperative analgesia at rest and during cough. The CSCI group received a bolus of morphine 0.1 mg kg-1 i.v. at the end of the operation and continued with s.c. infusion of morphine 30 micrograms kg-1 h-1. The extradural group received morphine 4 mg extradurally at 0, 2, 10 and 18 h after operation. Pain and side effects were evaluated at 2, 4, 8, 12 and 24 h after operation. In the extradural group, significantly smaller pain-scores were observed both at rest and during cough compared with the CSCI group. No significant difference was observed between the groups regarding supplementary doses of morphine, peak expiratory flow values or side effects. We conclude that morphine by CSCI is not as effective as morphine injected extradurally. However, CSCI seems to provide simple and relatively effective analgesia with a low rate of side effects.

Prophylactic laryngo-tracheal aerosolized lidocaine against postoperative sore throat.

A randomized, double-blind study was carried out on 193 ASA I-II surgical patients to assess the effect of aerosolized lidocaine on sore throat, hoarseness and cough in connection with tracheal intubation. The study group received aerosolized lidocaine 100 mg 2 min before tracheal intubation, using a spray. The control group received no spray. The patients underwent a standardized general anaesthesia. The patients were interviewed when leaving the recovery room and the next day in the ward. Specific questions were asked regarding sore throat, cough and hoarseness. There were no significant differences between the two groups, which suggests that topical anaesthesia of the mucosa of the upper airway is ineffective as a means of ameliorating airway complaints in connection with tracheal intubation.

Antioxidant treatment with N-acetylcysteine during adult respiratory distress syndrome: a prospective, randomized, placebo-controlled study.

OBJECTIVE: To examine whether the antioxidant N-acetylcysteine could ameliorate the course of the adult respiratory distress syndrome (ARDS) in man. DESIGN: Randomized, double-blind, placebo-controlled study. SETTING: Medical and surgical ICU in a regional hospital. PATIENTS: Sixty-six ICU patients with ARDS. INTERVENTIONS: Patients with ARDS (PaO2/FiO2 ratio less than 250 torr) were treated with either the antioxidant N-acetylcysteine 150 mg/kg as a loading dose and then 20 mg/kg/hr, or with placebo for 6 days. MEASUREMENTS AND MAIN RESULTS: No improvement could be demonstrated in the PaO2/FiO2 ratio in the study group as compared with the control group on any day. Pulmonary compliance was higher in the N-acetylcysteine group than in the placebo group on all days, but this difference did not reach the chosen 5% level of significance. No difference between the two groups could be demonstrated on chest radiograph or on survival rate. We documented that N-acetylcysteine acts as an anticoagulant and perhaps decreases pulmonary fibrin uptake during ARDS. CONCLUSIONS: N-acetylcysteine might be of benefit in ARDS. Before further clinical studies are started, problems with N-acetylcysteine and coagulation have to be elucidated in order to find out whether N-acetylcysteine could have a beneficial effect in the treatment of ARDS.

Reflective blankets used for reduction of heat loss during regional anaesthesia.

We have studied the ability of reflective blankets to reduce net loss of body heat during regional anaesthesia for total hip arthroplasty. Thirty patients were allocated randomly to either the study group (insulated with reflective blankets) or the control group (no reflective blankets). Surgical and operation room draping, theatre temperature and i.v. fluid administration were standardized for all patients. Total body heat was deduced from core temperature (aural canal) and mean skin temperature (four measuring sites). After 2 h of surgery, loss of body heat was reduced significantly in patients wrapped in reflective blankets (26 kJ) compared with those in the control group (95 kJ).

Cerebral arteriovenous difference of oxygen during gradual and sudden increase of the concentration of isoflurane for induction of deliberate hypotension.

In 20 patients undergoing surgery for cerebral aneurysms, hypotension was induced with either gradual (over 5 min) or sudden increase of inspiratory concentration of isoflurane from 0.5% to 3%. Both modes elicited the same speed of induction of deliberate hypotension and similar decreases of cerebral arteriovenous difference of oxygen (AVDo2). The overall median values of mean arterial blood pressure decreased from 75.5 (range 64-90) mmHg (10 (8.5-12.0) kPa) to 55 (40-66) mmHg (7.3 (5.3-8.8) kPa) and the overall AVDo2 decreased from 6.75 ml/100 ml (3.8-9.4 ml/100 ml) to 5.85 ml/100 ml (2.6-8.1 ml/100 ml) within 10 min. It is concluded that irrespective of gradual or sudden increase of isoflurane concentration, cerebral blood flow is in surplus of metabolism and a favourable oxygen demand/supply ratio is maintained during induction of deliberate hypotension by isoflurane below 2.5 MAC.

Changes of blood pressure and cerebral arterio-venous oxygen content differences (AVDO2) with and without bupivacaine scalp infiltration during craniotomy.

In 20 patients subjected to craniotomy for supratentorial cerebral tumours, the effect of scalp infiltration with bupivacaine before incision was evaluated by measuring mean arterial blood pressure (MABP) and cerebral arterio-venous oxygen content differences (AVDO2) repeatedly during the operation. All patients were given halothane 0.5% anaesthesia. Ten patients were given bupivacaine 0.25% and ten patients were given normal saline for scalp infiltration prior to incision. The study was performed in a double-blind randomized fashion. Significantly higher values of MABP (P less than 0.0005) after incision were found in the saline group compared to the bupivacaine group. Significantly lower values of AVDO2 (P less than 0.0005) after incision were seen in the saline group compared to the bupivacaine group. The results indicate that the increase in MABP associated with a decrease in AVDO2, suggesting an increase in CBF and cerebral hyperperfusion, is reduced by using bupivacaine scalp infiltration prior to incision.

[Treatment of cardiac arrest. Recent aspects of cardiopulmonary resuscitation]. / Hjertestopbehandling. Nyere aspekter af kardiopulmonal genoplivning.

Opinions are still not unanimous about the mechanism behind circulation during external cardiac compression and this leads to uncertainty regarding the correct frequency, force of compression and its duration. Adrenaline and other alpha-stimulators increase blood flow during external cardiac compression and increase survival. Cardiac arrest results in anaerobic metabolism and combined metabolic and respiratory acidosis. On account of relatively low minute volume during external cardiac compression decrease in end-tidal carbon dioxide concentration is observed together with arterial alkalosis on account of hyperventilation and venous acidosis. No communications exist about the favourable effect of administration of bicarbonate during cardiac arrest. On the other hand, several conditions suggest that bicarbonate increases the intracellular acidosis with poorer possibilities for resuscitation with this form of treatment. Ischaemia results inter alia in intracellular accumulation of calcium which initiates potential cell destructive processes. No investigations are available which favour employment of calcium during cardiac arrest. Conversely animal experiments suggest the possibility of favourable effects from calcium-entry blockers. Ischaemia and, in particular, reperfusion release cell and vessel damaging free oxygen redicals. Intensive investigations are being conducted at present about the value of anti-oxidants for cerebral and myocardial protection.

Per- and postoperative changes in the arterio-venous oxygen content difference (AVDO2) in patients subjected to craniotomy for cerebral tumours.

Sixteen patients with supratentorial cerebral tumours were subjected to craniotomy under thiopentone, fentanyl, nitrous oxide, halothane anaesthesia during moderate hypocapnia (PaCO2 level 4.0 kPa). The arterio-venous oxygen content difference (AVDO2) was measured peroperatively, and repeatedly during the first three hours after extubation. Peroperatively the level of AVDO2 averaged 8.0 vol% during opening of the dura, and decreased to 7.0 vol% during closure of the dura (P less than 0.05). Immediately after extubation the AVDO2 decreased to 4.3 vol% (P less than 0.05), and during the next 3 hours a gradual increase to 5.8 vol% (P less than 0.05) was disclosed. In individual cases the postoperative changes in AVDO2 correlated fairly well with changes in mean arterial blood pressure (MABP), but other factors including duration of the operation, age of the patients, size of the tumour, level of PaCO2 and adaptation to prolonged hyperventilation during operation are supposed to be responsible for the low levels of AVDO2 observed in the postoperative period.

Convulsions after treatment with pyrazinamide.

A case is presented of a 2-year-old boy with pulmonary tuberculosis who developed convulsions during treatment which appeared to be caused by pyrazinamide.

Constitutional predisposition to vasovagal syncope: an additional risk factor in patients exposed to electrical injuries?

An hour after a 220 V electric shock a patient who was susceptible to mild vasovagal symptoms in response to emotional stress had a severe episode of cardiac arrest in response to insertion of a cannula. No myocardial damage or conduction abnormalities were detected by serial 12 lead electrocardiograms. Patients with a history of vasovagal reactions may be at high risk of developing lethal sinus node or conduction disturbances after electrical injuries. Psychological stresses should be avoided in the management of such patients.

A comparative study of 'Op-site' and 'Nobecutan gauze' dressings for central venous line care.

A comparative study of 'Op-site' and 'Nobecutan-gauze' dressings for central venous lines was performed. Seventy-seven long antebrachial and 68 infraclavicular subclavian catheters were studied. A statistically significant reduction in the incidence of positive cultures from the catheter tip and from the skin puncture site was found with the 'Nobecutan-gauze' dressing. No difference in the incidence of catheter-related septicaemia was found. The theoretical advantage of being able to observe signs of inflammation when 'Op-site' was used did not reduce the incidence of local infection at the skin puncture site. In conclusion we found that a 'Nobecutan-gauze' dressing was a satisfactory alternative to an 'Op-site' dressing.

Expansion of extracellular volume in early polycystic kidney disease.

Blood volume (BV), extracellular volume (ECV), blood pressure (BP), creatinine clearance (CCr), plasma levels of angiotensin II (AII), aldosterone (Aldo) and arginine vasopressin (AVP), and serum osmolality (Sosm) were determined in 18 patients with adult polycystic kidney disease, 8 normotensive (group I), 10 hypertensive (group II), and in 11 control subjects (group III). ECV but not BV was increased in group I compared with group III, whereas BV and ECV did not differ significantly between groups II and III. In group II, Aldo and AVP were increased and AII tended to be increased, while in group I the hormone levels did not differ significantly from those in group III. Sosm did not differ significantly between the groups. In the combined patient group, CCr correlated positively with BV and ECV and negatively with BP. In the patients, AII and AVP were positively correlated with BP but not with CCr. The results suggest that both the renin-angiotensin system and AVP might be involved in the BP elevation, whereas expansion of ECV can be found without an increase in BP.

Exaggerated natriuresis in adult polycystic kidney disease.

Angiotensin II (AII), aldosterone (Aldo) arginine vasopressin (AVP) in plasma, serum osmolality (Sosm), and renal sodium excretion (UNaV) were studied before and after infusion of hypertonic sodium chloride solution in 20 patients with adult polycystic kidney disease (PKD) with normal or moderately reduced creatinine clearance (Ccr) and in 10 healthy control subjects. UNaV increased after sodium loading in all, significantly more in the PKD patients. AII and Aldo were normal before sodium loading and suppressed after saline in PKD patients and controls. The increase in VNaV correlated with Aldo in patients but not in controls. AVP before loading was increased in hypertensive PKD patients with reduced Ccr, but not in normotensive patients with normal Ccr. After hypertonic saline, Sosm increased to the same degree both in PKD and control subjects, but AVP increased more in those with PKD. The exaggerated natriuresis of PKD is probably not explained by a change in the activity of the renin-angiotensin-aldosterone system. The enhanced response of AVP to osmotic stimuli in PKD may be a compensatory reaction to a reduced renal tubular effect of AVP.