Anesthesia and analgesia
-
Anesthesia and analgesia · Sep 2000
Randomized Controlled Trial Clinical TrialThe effect of patient positioning on intraabdominal pressure and blood loss in spinal surgery.
Intraabdominal pressure (IAP) can influence blood loss during spinal surgery. We examined the relationship of IAP changes to blood loss with a rectal balloon pressure catheter. Forty patients were randomly assigned to narrow (Group 1) or wide (Group 2) pad support widths of the Wilson frame. IAP was measured when the patient was supine after the induction of anesthesia, prone on a gurney, prone on the Wilson frame before and after incision, and then, again supine after tracheal extubation. IAP in the prone position on the Wilson frame before incision (3.6 cm H(2)O) in Group 2 was significantly less than in Group 1 (8.8 cm H(2)O) (P: < 0.05). Intraoperative blood loss per vertebra in Group 2 (190 +/- 65 mL) was significantly less than in Group 1 (381 +/- 236 mL) (P: < 0.05). The correlation between blood loss and IAP in the prone position on the Wilson frame in Group 1 was significant (P: = 0.0022). In conclusion, IAP and intraoperative blood loss were significantly less in the wide, than in the narrow, pad support width of the Wilson frame. Blood loss tended to increase with an increase in IAP in the narrow pad support width of the Wilson frame. ⋯ The relationship of intraabdominal pressure changes to blood loss were examined with a rectal balloon pressure catheter during spinal surgery. Blood loss tended to increase with an increase in intraabdominal pressure in the narrow pad support width of the Wilson frame.
-
Anesthesia and analgesia · Sep 2000
Comparative Study Clinical Trial Controlled Clinical TrialContinuous positive airway pressure at 10 cm H(2)O during cardiopulmonary bypass improves postoperative gas exchange.
Postbypass pulmonary dysfunction including atelectasis and increased shunting is a common problem in the intensive care unit. Negative net fluid balance and continuous positive airway pressure (CPAP) have been used to reduce the adverse effects of cardiopulmonary bypass (CPB) on the lung. To determine whether CPAP at 10 cm H(2)O during CPB results in improved postoperative gas exchange in comparison with deflated lungs during CPB, we examined 14 patients scheduled for elective cardiac surgery. Seven patients received CPAP at 10 cm H(2)O during CPB, and in the other seven patients, the lungs were open to the atmosphere (control). Measurements were taken before and after CPB, after thoracic closure, and 4 h after CPB in the intensive care unit. CPAP at 10 cm H(2)O resulted in significantly more perfusion of lung areas with a normal ventilation/perfusion distribution (V(A)/Q) and significantly less shunt and low V(A)/Q perfusion 4 h after CPB in comparison with the control group. Consequently, arterial oxygen partial pressure was significantly higher and alveolar-arterial oxygen partial pressure difference was significantly smaller. We conclude that CPAP at 10 cm H(2)O during CPB is a simple maneuver that improves postoperative gas exchange. ⋯ Inflation of the lungs at a pressure of 10 cm H(2)O as compared with leaving the lungs deflated during cardiopulmonary bypass was examined. Lung inflation during bypass resulted in significantly improved postoperative gas exchange.
-
Anesthesia and analgesia · Sep 2000
Clinical TrialA preliminary investigation of remifentanil as a labor analgesic.
In this preliminary investigation, we evaluated the safety and analgesic efficacy of IV remifentanil for labor pain. Four women were studied, and then the trial was terminated because administration of this novel synthetic opioid produced significant maternal side effects in the absence of effective pain control.
-
Anesthesia and analgesia · Sep 2000
Case ReportsCortical blindness in a preeclamptic patient after a cesarean delivery complicated by hypotension.
Visual strokes can occur after prolonged hypotension or as a complication of preeclampsia-eclampsia. This case describes the diagnostic dilemma posed by a patient who developed transient blindness after a hypotensive episode during cesarean delivery for severe preeclampsia-eclampsia.
-
Anesthesia and analgesia · Sep 2000
Clinical TrialThe hemodynamic and metabolic effects of tourniquet application during knee surgery.
We evaluated the effects of tourniquet application on the cardiovascular system and metabolism in 10 young men undergoing knee surgery with general anesthesia. The duration of inflation was from 75 to 108 min. Heart rate, mean arterial pressure, cardiac index (CI) by pulse contour method, and systemic vascular resistance were measured before, during, and after tourniquet inflation. pH, PaO(2), PaCO(2), and lactate blood concentrations were also measured. VO(2) and VCO(2) were assessed every minute from tracheal intubation up to 15 min after tourniquet deflation and VO(2) in excess of the basal value over the 15 min after deflation (VO(2)exc) was calculated. Mean arterial pressure increased 26% (P: < 0.05) during inflation and returned to basal values after deflation. CI did not change immediately after inflation; although, thereafter, it increased 18% (P: < 0.05). Five minutes after deflation, CI further increased to a value 40% higher than the basal value. Therefore, systemic vascular resistance increased 20% suddenly after inflation (P: < 0.05) and decreased 18% after deflation (P: < 0.05). VO(2) and VCO(2) remained stable during inflation and increased (P: < 0.05) after deflation. VO(2)exc depended on duration of tourniquet inflation time (Tisch) (P: < 0.05). After deflation, PaCO(2) and lactate increased (P: < 0.05) while Tisch increased. We conclude that tourniquet application induces modifications of the cardiovascular system and metabolism, which depend on tourniquet phase and on Tisch. Whether these modifications could be relevant in patients with poor physical conditions is not known. ⋯ The clinical effects of tourniquet application were evaluated in 10 young men undergoing knee surgery. Our data indicate that tourniquet application causes hemodynamic and metabolic changes which may become clinically relevant after a long period of tourniquet inflation, particularly in patients with concomitant cardiovascular diseases.