Carboxyhaemoglobin formation and ECG changes during hysteroscopic surgery, transurethral prostatectomy and tonsillectomy using bipolar diathermy.

Diathermy is known to produce a mixture of waste products including carbon monoxide. During transcervical hysteroscopic surgery, carbon monoxide might enter the circulation leading to the formation of carboxyhaemoglobin. In 20 patients scheduled for transcervical hysteroscopic resection of myoma or endometrium, carboxyhaemoglobin was measured before and at the end of the surgical procedure, and compared with levels measured in 20 patients during transurethral prostatectomy, and in 20 patients during tonsillectomy. Haemodynamic data, including ST-segment changes, were recorded. Levels of carboxyhaemoglobin increased significantly during hysteroscopic surgery from median (IQR [range]) 1.0% (0.7-1.4 [0.5-4.9])% to 3.5% (2.0-6.1 [1.3-10.3]%, p < 0.001), compared with levels during prostatectomy or tonsillectomy. Significant ST-segment changes were observed in 50% of the patients during hysteroscopic surgery. Significant correlations were observed between the increase in carboxyhaemoglobin and the maximum ST-segment change (ρ = -0.707, p < 0.01), between the increase in carboxyhaemoglobin and intravasation (ρ = 0.625; p < 0.01), and between intravasation and the maximum ST-segment change (ρ = -0.761; p < 0.01). The increased carboxyhaemoglobin levels during hysteroscopic surgery appear to be related to the amount of intravasation and this could potentially be a contributing factor to the observed ST-segment changes.

How safe is the intravasation limit in hysteroscopic surgery?

BACKGROUND: Transcervical resection of myomas (TCR-M) is considered a safe hysteroscopic procedure if intravasation is limited. Complications may occur if gas formation during myoma resection leads to gaseous embolism. However, the incidence of emboli during transcervical myoma resection is unknown. Therefore in this study the occurrence of physiological changes that indicate the formation of emboli was retrospectively determined in patients undergoing hysteroscopic myoma resection. In addition, these changes were related to the amount of fluid intravasation. METHODS: The anesthesia records and operation files of 234 patients were screened for physiological changes that indicate embolism, as measured with standard intraoperative monitoring. These patients underwent surgery for intrauterine myomas with either a monopolar resectoscope with electrolyte-free distension fluid containing 3% sorbitol (limited to 1500-mL intravasation) or a bipolar resectoscope with normal saline solution (limited to 2500-mL intravasation). The patients were grouped according to the amount of fluid intravasation during the operation: Group 1: 500 mL or less, group 2: 500-1000 mL, group 3: 1000-1500 mL, and group 4: 1500-2500 mL. RESULTS: Physiological changes that could be attributed to gaseous embolism were observed in 33% to 43% of patients with 1000 to 2500 mL fluid intravasation during transcervical myoma resection. Nearly half of those patients had cardiovascular disturbances that indicated the formation of emboli. CONCLUSION: During transcervical resection of myomas, physiological changes that could be attributed to gaseous embolism frequently occurred. Therefore cardiovascular disturbances that indicate gaseous embolism during transcervical resection of myomas may occur despite the limitation of intravasation according to current view.

Paradoxical gas embolism by transpulmonary passage of venous emboli during hysteroscopic surgery: a case report and discussion.

After an episode of apparent venous gas embolism in a patient undergoing surgical hysteroscopy, transoesophageal echocardiography revealed air in the left but not in the right heart. Contrast echocardiography failed to demonstrate anatomical right-to-left shunts, making it likely that venous emboli overwhelmed the capacity of lungs to filter emboli, resulting in paradoxical embolization.

Multiple organ dysfunction syndrome induced by whole-body hyperthermia and polychemotherapy in a patient with disseminated leiomyosarcoma of the uterus.

OBJECTIVE: Whole-body hyperthermia (WBH) in combination with chemotherapy is a relatively new promising treatment modality for patients with cancer. The objective of this report is to present the development of an acute systemic inflammatory response syndrome (SIRS) with multiple organ dysfunction syndrome (MODS) following WBH in combination with chemotherapy. Although WBH can also induce cytokine production, MODS has not been described before in association with WBH. DESIGN: Case report. The patient was treated with WBH (core temperature 41.8 degrees C using a radiant heat device (Aquatherm) ) in combination with polychemotherapy (ifosfamide, carboplatin and etoposide (ICE) ) in the context of a clinical trial for metastatic sarcomas. SETTING: Department of medical oncology and intensive care unit of a university hospital. PATIENT: A 58-year-old Caucasian woman treated for disseminated leiomyosarcoma of the uterus, who developed SIRS with brain dysfunction, hypotension, respiratory failure and renal dysfunction following WBH/ICE. INTERVENTIONS: She was successfully treated in the intensive care unit by mechanical ventilation, inotropics and antibiotics. MEASUREMENTS AND RESULTS: There was a remarkable recovery within 2 days: she regained full conciousness, could be extubated, inotropic support was stopped and creatinine levels returned to pre-treatment levels. All cultures remained sterile. After almost complete recovery, 5 days later a second episode of fever during neutropenia occurred and, despite antibiotic treatment, she died of Bacteroides distasonis sepsis. CONCLUSION: WBH should be added as a new cause to the already known list of physical-chemical insults which can result in MODS.

Hemodynamics during laparoscopic extra- and intraperitoneal insufflation. An experimental study.

BACKGROUND: Total extraperitoneal laparoscopic surgery is an alternative to the laparoscopic transperitoneal route; however, its effects on hemodynamics have not been adequately studied. This experimental study compared the effects of intraperitoneal insufflation and extraperitoneal insufflation on hemodynamics and oxygen transport. METHODS: Sixteen pigs were randomly assigned for intraperitoneal insufflation or extraperitoneal insufflation with 15 mmHg carbon dioxide. Hemodynamic and oxygen transport parameters were taken during an hour of insufflation and analyzed for statistical differences. RESULTS: During extraperitoneal CO2 pneumoperitoneum central venous filling pressures (central venous pressure, pulmonary capillary wedge pressure and mean pulmonary arterial pressure) and end-tidal CO2 increased slower but to a similar magnitude in comparison to intraperitoneal insufflation. Cardiac output and indices of oxygen consumption and oxygen delivery were equally affected by both types of insufflation. Arterial CO2 pressure increased significantly more during intraperitoneal insufflation. CONCLUSION: The data from this study suggest that extraperitoneal insufflation might result in less cardiovascular impairment than intraperitoneal insufflation.

Laparoscopy without pneumoperitoneum. Effects of abdominal wall retraction versus carbon dioxide insufflation on hemodynamics and gas exchange in pigs.

Laparoscopic surgery with CO2 insufflation is associated with adverse effects on hemodynamics and gas exchange. The abdominal wall retractor (AWR) is an alternative for pneumoperitoneum. Hemodynamics and gas exchange during the use of an AWR were compared to those of CO2 pneumoperitoneum. In eight pigs subjected to 1 h of CO2 pneumoperitoneum or abdominal wall retraction, hemodynamics, gas exchange, and oxygen transport were studied in a randomized cross-over study design. The only change observed during abdominal wall retraction was mild respiratory alkalosis. In contrast, during CO2 pneumoperitoneum mean arterial blood pressure increased 13%, central filling pressures doubled, and a small increase in cardiac output was observed. Peak airway pressures increased 50%, end-tidal CO2 increased 20%, and respiratory acidosis was induced (arterial pH from 7.46 +/- 0.07 to 7.31 +/- 0.06 and pCO2 from 33 +/- 3 mmHg to 53 +/- 4 mmHg). Arterial PO2 decreased but mixed venous oxygen saturation and oxygen consumption were unaffected. In contrast with CO2 pneumoperitoneum, laparoscopy using abdominal wall retraction was not associated with adverse effects on hemodynamics or gas exchange.

Effects of pneumoperitoneum with helium on hemodynamics and oxygen transport: a comparison with carbon dioxide.

Pneumoperitoneum with CO2 is associated with adverse effects, such as hypercarbia, arrhythmias, and circulatory depression, which may limit its use in patients with underlying disease. Some of these effects may be caused by CO2 absorption resulting in acid-base disturbances. Laparoscopic insufflation with helium may be a good alternative for CO2, since it is chemically inert. Because there are few data on the use of helium for laparoscopy, we studied hemodynamics and gas exchange during insufflation with CO2 or helium in 8 pigs at 10, 15, and 20 mm Hg intraabdominal pressure. Heart rate did not change significantly with both gases. Arterial blood pressure increased with CO2 (p < 0.05) but not with helium. Cardiac output, mixed venous oxygen saturation, and oxygen consumption did not decrease, whereas central venous filling pressures increased during insufflation with either gas. Insufflation with CO2 resulted in mild increases in arterial, central venous, and end-expiratory CO2. The results suggest that pneumoperitoneum with helium will not be associated with profound circulatory depression or oxygen transport abnormalities. In addition, the use of helium is not associated with acid-base disturbances, although central venous filling pressures are similarly increased as with the use of CO2 pneumoperitoneum.

Hemodynamics during laparoscopy in the supine or prone position. An experimental study.

During laparoscopy elevations in arterial pressure and a decrease in cardiac output have been reported. Laparoscopic surgery performed in the prone position may be advantageous for some surgical procedures, but the hemodynamic effects of pneumoperitoneum in this position have not been studied. We studied the effects of different levels of increased intraabdominal pressure on hemodynamics and oxygen transport in eight pigs in the prone and the supine position. Increases in intraabdominal pressure did not result in decreased cardiac output or in a reduction of oxygen transport and consumption in either position. These results suggest that laparoscopy in the prone position does not result in more severe hemodynamic depression than laparoscopy in the supine position.

Laparoscopic fundoplication: a new technique with new complications?

We report pneumomediastinum, pneumopericardium, and subcutaneous emphysema occurring in patients who underwent laparoscopic fundoplication in our clinic. These complications might adversely affect hemodynamics during this procedure.

Haemodynamic effects of pneumoperitoneum for laparoscopic surgery: a comparison of CO2 with N2O insufflation.

We studied the haemodynamic effects of intra-abdominal insufflation with either CO2 (n = 15) or N2O (n = 15) in patients undergoing laparoscopic surgery. Haemodynamic variables were measured at increasing levels of intra-abdominal pressure up to 20 mmHg. In the CO2 group cardiac index decreased from 2.6 +/- 0.6 to 2.0 +/- 0.4 litre min-1 m-2 (mean +/- SD, P < 0.001) and in the N2O group from 2.6 +/- 0.5 to 1.8 +/- 0.4 litre min-1 m-2 (P < 0.001)). In the CO2 group, this was accompanied by increases in mean arterial pressure, systemic vascular resistance index and central venous pressure without change in heart rate. In contrast, during N2O insufflation mean arterial pressure decreased (from 77 +/- 8 to 63 +/- 15 mmHg (P < 0.001)) without change in vascular resistance. No further changes in haemodynamic variables were observed during head-up tilt in both groups. After desufflation mean arterial pressure increased in the N2O group to pre-insufflation levels and cardiac index increased in both groups (P < 0.001), but reached pre-insufflation levels only in the CO2 group. In both groups central venous O2 tension and saturation decreased at maximum intra-abdominal pressure and increased after release of the pneumoperitoneum. The results indicate that laparoscopic insufflation with either CO2 or N2O results in cardiovascular depression. Insufflation with N2O may decrease blood pressure, whereas mean arterial pressure is better preserved with CO2 insufflation.

Intraperitoneal local anaesthetics after laparoscopic cholecystectomy: effects on postoperative pain, metabolic responses and lung function.

We have compared the efficacy of 0.9% NaCl 20 ml (n = 15), 0.25% bupivacaine 20 ml (n = 15) and 0.5% lignocaine 20 ml (n = 15), administered i.p., in reducing postoperative pain and opioid requirements, and modifying the metabolic response to surgery and postoperative lung function after laparoscopic cholecystectomy. There were no differences in postoperative pain scores (visual analogue scale and verbal rating scale) between the three groups in the first 4 h after operation and in analgesic requirements during the first 24 h. In all groups, forced vital capacity, peak expiratory flow and forced expiratory volume in 1 s decreased 2 h after surgery (P < 0.001). Ventilatory values recovered only partially in the first 2 days after operation (P < 0.05), with no significant differences between groups. Plasma concentrations of glucose and cortisol increased after surgery (P < 0.05). Cortisol concentrations returned to baseline 48 h after operation. There were no significant differences between the groups in any measured variable. These data suggest that the administration of 20 ml of local anaesthetics i.p. is not effective in reducing postoperative pain, improving lung function, or attenuating the metabolic endocrine response after laparoscopic cholecystectomy.

Pulmonary function and stress response after laparoscopic cholecystectomy: comparison with subcostal incision and influence of thoracic epidural analgesia.

Laparoscopic cholecystectomy (LPC) is increasingly used to treat symptomatic cholelithiasis. We compared the effects of cholecystectomy by subcostal incision to those of LPC on lung function and endocrine metabolic response. The effects of thoracic epidural analgesia for LPC were studied as well. Thirty patients undergoing elective cholecystectomy under general anesthesia were allocated to three study groups: group I, cholecystectomy by subcostal incision; group II, LPC; group III, LPC and epidural analgesia with 0.5% bupivacaine with epinephrine, followed by continuous epidural infusion of 6 mL of 0.5% bupivacaine. Forced vital capacity (FVC), peak expiratory flow, and forced expiratory volume in 1 s were measured with the patients in a half-sitting position. In all groups, sustained decreases in FVC, forced expiratory volume in 1 s, and peak expiratory flow were observed up to 24 h after surgery. Reduction of FVC was significantly more in group I compared with groups II and III (P less than 0.05). The FVC in group I decreased from 3.8 +/- 0.42 (SD) to 1.1 +/- 0.27 L (P less than 0.01), in group II from 3.6 +/- 1.46 to 2.1 +/- 0.94 L (P less than 0.05), and in group III from 3.8 +/- 0.92 to 2.8 +/- 0.90 L (P less than 0.05). In all groups, plasma glucose and cortisol increased after surgery compared with baseline levels (P less than 0.05). At 240 min after surgery, a small but significant decrease of cortisol was measured in group III (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of interpleurally administered bupivacaine 0.5% on opioid analgesic requirements and endocrine response during and after cholecystectomy: a randomized double-blind controlled study.

In 30 patients undergoing cholecystectomy, a randomized double-blind saline-controlled study was performed using interpleural 0.5% bupivacaine with or without epinephrine (5 micrograms.ml-1) in combination with 0.8% halothane inspired concentration in oxygen. The aim of the study was to investigate whether interpleural 0.5% bupivacaine could decrease the intraoperative opioid requirements and attenuate the metabolic endocrine response to surgical stress. Patients were randomly allocated to one of three groups: Group 1: 0.5% bupivacaine; Group 2: 0.5% bupivacaine with epinephrine (5 micrograms.ml-1); and Group 3: saline. The interpleural catheter was inserted after induction of anesthesia in the spontaneously breathing patient. The study drug was injected 30 min prior to surgery. Peak plasma bupivacaine concentrations in the respective groups were 1.30 +/- 0.78 and 1.16 +/- 0.48 micrograms.ml-1. In all patients concentrations were below suggested convulsive level. Two patients in Group 1 and two in Group 2 required intraoperative fentanyl (0.1 mg each). In contrast, eight patients in the saline group received an average of 0.21 mg (range 0.1 +/- 0.4 mg) fentanyl (P less than 0.05). Postoperatively, a second dose of the study drug was given. Subsequently, pain was assessed using a visual analog score and a verbal rating scale. Pain scores decreased significantly 30 min after the interpleural injection in both bupivacaine groups and remained unchanged in the saline group (P less than 0.05). Pain management by means of interpleural bupivacaine was successful in 17 of the 20 patients. In the saline group seven out of ten patients needed additional analgesics (P less than 0.05). Cortisol levels increased in response to surgery in all groups: maximum levels in Groups 1, 2 and 3 were: 1.09 +/- 0.29, 1.11 +/- 0.20 and 1.19 +/- 0.16 mumol.l-1, respectively. Plasma glucose concentrations increased significantly in all groups: maximum levels in Groups 1, 2 and 3 were: 7.6 +/- 1.3, 7.3 +/- 1.7 and 8.3 +/- 1.7 mmol.l-1, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)