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Biomedical subjects

N Svartling

Publications and source records attributed to N Svartling.

16 recordsLinked to original sources
PubMed2005

Massive intra-abdominal bleeding due to injury in the mesenteric artery during late breast reconstruction with a free TRAM flap: a case report.

We report on a rare case of major intra-abdominal bleeding that occurred in a patient undergoing late breast reconstruction with a transversus rectus abdominis musculocutaneous (TRAM) flap. During the flap-raising procedure, a small rupture was found at the base of the superior mesenteric artery, probably caused by electric current. The ruptured vessel required immediate laparotomy and suturing, and the final outcome of the patient was good. The massive bleeding, almost 8-fold as compared with three normal cases, caused clear activation of coagulation seen with elevated TAT values at the end of the operation, and remarkably enhanced fibrin turnover with elevated D-dimer, up to 25-fold from baseline, on the first postoperative day. As a result of major bleeding, the fibrinolytic system was also activated: a biphasic elevation of tPA was seen, first immediately after the bleeding event at 2 h, and later on the first postoperative day, followed by fibrinolytic shutdown associated with increased PAI-1 values.

Abdomen↗
PubMed2003

Neural nets and prediction of the recovery rate from neuromuscular block.

BACKGROUND AND OBJECTIVE: The aim was to train artificial neural nets to predict the recovery of a neuromuscular block during general anaesthesia. It was assumed that the initial/early neuromuscular recovery data with the simultaneously measured physical variables as inputs into a well-trained back-propagation neural net would enable the net to predict a rough estimate of the remaining recovery time. METHODS: Spontaneous recovery from neuromuscular block (electrically evoked electromyographic train-of-four responses) were recorded with the following variables known to affect the block: multiple minimum alveolar concentration, end-tidal CO2 concentration, and peripheral and central temperature. RESULTS: The mean prediction errors, mean absolute prediction errors, root-mean-squared prediction errors and correlation coefficients of all the nets were significantly better than those of average-based predictions used in the study. The root-mean-squared prediction error of the net - employing minimum alveolar concentrations from the whole recovery period (the recovery time from E2/E1 = 0.30 to E4/E1 = 0.75; E1 = first response of train-of-four, E2 = second response of train-of-four, etc.)--were significantly smaller than those of other nets, or the same net employing minimum alveolar concentrations only from the initial recovery period (from E2/E1 = 0.30 to E4/E1 = 0.25). CONCLUSIONS: Neural nets could predict individual recovery times from the neuromuscular block significantly better than the average-based method used here, which was supposed to be more accurate than guesses by any clinician. The minimum alveolar concentration was the only monitored variable that influenced the recovery rate, but it did not aid neural net prediction.

Anesthesia Recovery Period↗
PubMed2001

Activation of coagulation and fibrinolysis during reconstructive microsurgery in patients with cancer.

Cancer patients are subjected to increased systemic risk of thrombotic events and may therefore be at higher risk of even local thrombosis compromising the outcome of reconstructive microsurgery. Coagulation and fibrinolysis activities were studied serially during and after reconstructive microsurgery in seven patients with oropharyngeal cancer or sarcoma in the extremities. A preoperative hypercoagulable state was found in four patients (elevated fibrinogen, TAT, F1+2, or D-dimer); two of these patients also had a local thrombotic event. In all patients, the plasma markers generally varied perioperatively: fibrinogen decreased, whereas TAT and subsequently D-dimer increased at the end of the operation. However, tPA and PAI-1 remained unaltered, except in the patients with thrombosis in whom PAI-1 activity increased progressively during the operation. F1+2 was also clearly elevated in these two patients at the time of thrombosis. Preoperative assessment of hypercoagulability for this group of patients could be helpful in targeting meticulous antithrombotic protection.

Adult↗
PubMed2001

Activation of coagulation and fibrinolysis in microsurgical reconstructions in the lower extremities.

Coagulation and fibrinolysis activities in relation to trauma, surgery and thrombosed microanastomoses were studied during free-flap surgery in eight patients with lower-extremity defects due to recent trauma or chronic ulcers. One patient had an intraoperative thrombosis, and three more patients required reoperations on the same day due to postoperative thromboses; one of these also required a second reoperation due to flap failure. The baseline level of fibrinogen was slightly elevated in all patients except one, and was significantly higher in the patients who underwent reoperation. At the end of the primary surgery, distinct thrombin generation (TAT and F1+2) was seen in three patients with excessive bleeding, and all three later underwent reoperations. One of these patients generated excessive thrombin on the eighth postoperative day, upon removal of a necrotic flap. Thrombin generation (F1+2) was also seen at baseline in the patient with the intraoperative thrombosis, and persisted on the first postoperative day. D-dimer at baseline was higher in patients with recent trauma, and in two of these, both of whom underwent reoperations on the same day, D-dimer remained high perioperatively. Resistance to fibrinolysis with increased PAI-1 levels was seen in these two patients at the time of reoperation. In all, TAT and F1+2 were associated with the threat of flap failure. A preoperative hypercoagulable state and excessive bleeding during the operation were predictors of reoperation. The markers for coagulation and fibrinolysis could be used preoperatively to target antithrombotic control, and postoperatively to detect the threat of flap failure. Meticulous haemostasis during surgery might help to diminish the need for reoperations.

Adult↗
PubMed2000

Comparison of intravenous patient-controlled analgesia with tramadol versus morphine after microvascular breast reconstruction.

Tramadol is a weak centrally acting analgesic and it might provide efficacious postoperative pain relief with minimal sedative effects in the use of intravenous patient-controlled analgesia (PCA). Sixty women scheduled to undergo microvascular breast reconstruction under standard general anaesthesia were enrolled in a study on the performance of patient-controlled analgesia with tramadol or morphine with special emphasis on drug- and technique-related side-effects. Seven patients were re-operated within the same day, leaving 25 patients in the tramadol group and 28 in the morphine group for comparison. When postoperative pain occurred, loading doses of either 10 mg tramadol or 1 mg morphine intravenous increments were administered in a double-blind fashion until the pain control was judged to be satisfactory by the patient. After that the patients received tramadol or morphine by a PCA apparatus (lockout 5 min, tramadol 450 microg kg-1, morphine 45 microg kg-1 bolus). In addition, all patients received 500 mg paracetamol rectally, three times a day. The potency ratio of tramadol to morphine was found to be between 8.5 : 1 (loading) and 11 : 1 (PCA). There was neither a significant difference between the groups in the overall satisfaction of the analgesic medication nor in the visual analogue and verbal rate scales for pain. Women in the tramadol group had more nausea and vomiting during the administration of loading doses (P < 0.05) and more patients in the tramadol group (7) than in the morphine group (3) (NS) wanted to discontinue the PCA therapy before the end of the study due to nausea. Sedation or blurred vision prevented the performance of the psychomotor tests in 22 and 32% of the tramadol and morphine patients, respectively. The remaining patients performed similarly in the Digit Symbol Substitution Test. In women receiving intravenous PCA for analgesia after microvascular breast reconstruction tramadol and morphine provided comparable postoperative analgesia with similar sedative effects. However, tramadol was associated with a disturbingly high incidence of nausea and vomiting.

Acetaminophen↗
PubMed1999

Efficacy and side effects of tramadol versus oxycodone for patient-controlled analgesia after maxillofacial surgery.

Tramadol, a weak opioid mu-receptor agonist, may have a favourable potency and side effect profile for intravenous patient-controlled analgesia (PCA). In a prospective, double-blind, randomized study involving 54 patients, tramadol was compared with oxycodone in PCA after maxillofacial surgery. All the patients were given diclofenac sodium 1 mg kg-1 intramuscularly and dexamethasone 8 mg twice a day. Post-operatively patients received tramadol or oxycodone by a PCA apparatus (lockout 5 min, tramadol 0.3 mg kg-1 bolus, oxycodone 0.03 mg kg-1 bolus). During the immediate recovery period, opioid was administered i.v. in a double-blind fashion, either tramadol 10 mg or oxycodone 1 mg increments until the pain control was judged to be satisfactory by the patient. Pain was assessed at rest and during activity (mouth opening) before and after loading, at 2 h after commencing the PCA, as well as at 21.00 and at 09.00 hours on the following morning. Side effects were recorded. The potency ratio of tramadol to oxycodone was found to be approximately 8:1. There was no significant difference between the groups in the VAS scores for pain. No respiratory depression was identified. Tramadol was found to provide adequate analgesia after maxillofacial surgery without risk of respiratory depression. However, the incidence of nausea was slightly greater in the tramadol group than in the oxycodone group (44% vs. 28%, NS).

Adolescent↗
PubMed1998

Smoking increases the requirement for rocuronium.

PURPOSE: To compare the potency of rocuronium in non-smokers and smokers during general anaesthesia. METHODS: In a randomized, open clinical study, 40 patients, 17-62 yr of age, were anaesthetized with propofol, alfentanil and nitrous oxide in oxygen. After obtaining individual dose-response curves for rocuronium, bolus doses of rocuronium were given to maintain neuromuscular block at 90-99% for 60 min. Evoked adductor pollicis electromyography (EMG) was used to monitor neuromuscular block. RESULTS: The ED95 values (+/- SEM) for rocuronium were 460.5 +/- 28.9 and 471.5 +/- 22.1 micrograms.kg-1 for non-smokers and smokers, respectively (P:NS). However, doses of rocuronium to maintain 90-99% neuromuscular block (+/- SEM) were 620.1 +/- 46.7 and 747.4 +/- 56.0 micrograms.kg-1.hr-1 for non-smokers and smokers, respectively (P = 0.0504). CONCLUSION: The results may indicate increased metabolism of rocuronium in smokers rather than increased requirement of rocuronium at the receptor site.

Adolescent↗
PubMed1998

Haemostatic disturbances in burned patients during early excision and skin grafting.

Bleeding is a major problem during early excision of burned skin. Therefore, 13 severely burned adult patients operated on during the first week after the trauma were studied. Blood loss was replaced with crystalloids, colloids and packed red cell concentrates (PRC). After ten infused PRCs, four fresh frozen plasma (FFP) units were given and thereafter one FFP unit with one PRC unit. Arterial blood samples were drawn before anaesthesia (SO), during operation after every four units of PRC transfusion (S1-4), 4 h postoperatively (S5) and on the first postoperative morning (S6). Prothrombin time (%) and activated partial thromboplastin time (s) were abnormal before operation (median values 67%, range 22-99% and 44 s, range 30-86 s, respectively). Prothrombin time decreased during operation and reached the critical level for normal haemostasis at S2. Thrombelastography showed decreased clot formation rate and impaired fibrin platelet interaction peri- and postoperatively. Fibrinogen and factor VIII activity were high preoperatively (median 6.1 g/l and 253%) and the critical values for normal haemostasis were not reached. Burned patients have a consumption coagulopathy which, in combination with haemodilution during operation, results in a clinically significant deficiency of coagulation factors II, VII and X, in spite of reactive elevation of coagulation factor VIII and fibrinogen.

Adult↗
PubMed1998

Comparison of analgesic efficacy of oxycodone and morphine in postoperative intravenous patient-controlled analgesia.

BACKGROUND: Morphine has been the standard opioid in patient-controlled analgesia (PCA). Oxycodone, the analgesic potency of which in i.v. administration has been suggested to be slightly greater than that of morphine, has not yet been studied for its efficacy in PCA. METHODS: Fifty patients, undergoing a plastic reconstruction of the breast or a major operation of the vertebrae, such as lumbar spinal fusion, used PCA for postoperative pain. Patients were randomized to receive either morphine 45 microg/kg or oxycodone 30 microg/kg as i.v. bolus doses. Patients were assessed for pain with a visual analogue scale (VAS) and side effects at 3, 9 and 24 h. Venous blood samples for the measurement of plasma concentration of oxycodone and that of morphine and its metabolites were taken. RESULTS: In this study patients needed, on average, the same amount of oxycodone and morphine in the recovery room and on the ward. There was no difference in the quality of analgesia (VAS) or incidence of side effects, such as nausea, vomiting, pruritus and urinary retention. The plasma concentrations of morphine-6-glucuronide showed that this metabolite might contribute to the analgesia resulting from morphine administration. CONCLUSIONS: The same dose of intravenous oxycodone and morphine administered by PCA pump was needed for immediate postoperative analgesia. The two drugs appear to be equipotent.

Adult↗
PubMed1988

Detection of embolized material in the right atrium during cementation in hip arthroplasty.

Precordial Doppler ultrasound, hemodynamic changes and end-tidal carbon dioxide (ETCO2) were monitored in 36 patients undergoing hip surgery in general anesthesia. Changes in Doppler ultrasound indicative of embolization were recognized in 22 out of 36 patients during femoral cementation. The character of the ultrasound was suggestive of air emboli, though simultaneous embolization of bone marrow could not be excluded. Embolization was associated with a fall in arterial oxygen tension (PaO2). Both embolization and reduction of PaO2 were influenced by the cementation technique. Digital anterograde insertion and insertion by syringe of acrylic bone cement into the femoral cavity caused ultrasound changes in 92% and 75% respectively, whereas retrograde insertion of low viscosity bone cement was accompanied by ultrasound activity in only one patient (9%). The blood levels of monomeric methylmethacrylate (MMA) released from the low viscosity bone cement ranged from 0.04 to 7.01 micrograms/ml-1. Doppler ultrasound monitoring gave valuable help during cementation, as the ultrasound change immediately signalled a warning of embolism and an imminent decrease in PaO2.

Aged↗
PubMed1986

Blood levels and half-life of methylmethacrylate after tourniquet release during knee arthroplasty.

The blood levels and the half-life of monomeric methylmethacrylate after tourniquet release were studied in nine patients with osteoarthrosis or rheumatoid arthritis of the knee joint, treated with the Townley prosthesis under spinal anesthesia. Several ventricular extrasystoles were monitored in one patient with high blood levels of monomeric methylmethacrylate (119.80 micrograms/ml). The blood levels of monomeric methylmethacrylate ranged between 0.10 and 1.44 microgram/ml in the rest of the patients. The half-life of monomeric methylmethacrylate in vivo was 47-55 min.

Aged↗
PubMed1986

The effect of anaesthesia on changes in blood pressure and plasma cortisol levels induced by cementation with methylmethacrylate.

The effects of cementation on arterial blood pressure, arterial oxygen tension and plasma levels of cortisol were studied in 30 patients with femoral neck fracture treated with the Thompson prosthesis in spinal (n = 15) or general (n = 15) anaesthesia. In spinal anaesthesia hypotension of clinical importance was observed coincidentally with the use of methylmethacrylate, while the levels of plasma cortisol remained unchanged. A significant rise was noted in arterial blood pressure and plasma levels of cortisol after cementation in general anaesthesia. Arterial oxygen tension fell in both groups. These findings indicate that the hypotension frequently reported in connection with cementation is triggered by a complex mechanism which can be modified by the anaesthetic technique.

Aged↗
PubMed1985

Methylmethacrylate blood levels in patients with femoral neck fracture.

The blood levels of monomeric methylmethacrylate were measured in 20 patients with fracture of the femoral neck, treated with a Thompson prosthesis under spinal anesthesia. Monomeric methylmethacrylate was detected in the blood stream in all patients; the maximum levels (mean 6.44 micrograms/ml, range 0.05-31.89 micrograms/ml) were measured 30 s after insertion of the Thompson prosthesis. A moderate drop in systolic blood pressure and a marked reduction of arterial oxygen tension was noted after cementation and insertion of the prosthesis; the mean maximum drops were 10.1 mm Hg (range 0-32 mm Hg) and 6.1 mm Hg (range 0-13.5 mm Hg) No dose-dependent correlation could be established between the levels of monomeric methylmethacrylate and the drop in arterial blood pressure or arterial oxygen tension.

Aged↗