Mark L. Pinosky

The effect of bupivacaine skull block on the hemodynamic response to craniotomy.

The placement of pointed cranial pins into the periosteum is a recognized acute noxious stimulation during intracranial surgery which can result in sudden increases in blood pressure and heart rate, causing increases in intracranial pressure.A skull block (blockade of the nerves that innervate the scalp, including the greater and lesser occipital nerves, the supraorbital and supratrochlear nerves, the auriculotemporal nerves, and the greater auricular nerves) may be effective in reducing hypertension and tachycardia. Twenty-one patients were allocated in a prospective, double-blind fashion to a control group or a bupivacaine group. After a standardized induction and 5 min prior to head pinning, a skull block was performed. Patients in the control group received a skull block of normal saline, while the bupivacaine group received a skull block with 0.5% bupivacaine. Systolic (SAP), diastolic (DAP), mean arterial pressure (MAP), heart rate (HR), and end-tidal isoflurane were recorded at the following times: 5 min after the induction of anesthesia, during performance of the skull block, during head pinning, and 5 min after head pinning. Significant increases in SAP of 40 +/- 6 mm Hg, DAP of 30 +/- 5 mm Hg, MAP of 32 +/- 6 mm Hg, and HR of 22 +/- 5 bpm occurred during head pinning in the control group, while remaining unchanged in the bupivacaine group. These results demonstrate that a skull block using 0.5% bupivacaine successfully blunts the hemodynamic response to head pinning. (Anesth Analg 1996;83:1256-61)

Magnesium supplementation in the prevention of arrhythmias in pediatric patients undergoing surgery for congenital heart defects

Abstract Background The efficacy of magnesium in the prevention of arrhythmias in pediatric patients after heart surgery remains unknown. Therefore we prospectively examined the effect of magnesium treatment on the incidence of postoperative arrhythmias in pediatric patients undergoing surgical repair of congenital heart defects. Methods and Results Twenty-eight pediatric patients undergoing heart surgery with cardiopulmonary bypass were prospectively, randomly assigned in a double-blind fashion to receive intravenous magnesium (magnesium group, n=13; 30 mg/kg) or saline (placebo group, n=15) immediately after cessation of cardiopulmonary bypass. Magnesium, potassium, and calcium levels were measured at defined intervals during surgery and 24 hours after surgery. Continuous electrocardiographic documentation by Halter monitor was performed for 24 hours after surgery. Magnesium levels were significantly decreased below the normal reference range for patients in the placebo group compared with the magnesium group on arrival in the intensive care unit and for 20 hours after surgery. Magnesium levels remained in the normal range for patients in the magnesium group after magnesium supplementation. In 4 patients in the placebo group (27%), junctional ectopic tachycardia developed within the initial 20 hours in the intensive care unit. No junctional ectopic tachycardia was observed in the magnesium group ( P = .026). Conclusions Although this study was originally targeted to include 100 patients, the protocol was terminated because of the unacceptable incidence of hemodynamically significant junctional ectopic tachycardia that was present in the placebo group. Thus low magnesium levels in pediatric patients undergoing heart surgery are associated with an increased incidence of junctional ectopic tachycardia in the immediate postoperative period.

The Effects of Desmopressin and 6% Hydroxyethyl Starch on Factor VIII: C

In moderate doses of 20 mL/kg (1.2 g/kg), hydroxyethyl starch (HES) 6% decreases factor VIII:C activity. Desmopressin (DDAVP) increases circulating levels of factor VIII:C by stimulating the release of factor VIII:C from peripheral storage sites. The objective of this study was to monitor the changes in factor VIII:C associated with sequential HES and DDAVP administration. Thirty patients undergoing surgical procedures with a predicted blood loss of less than 750 mL were enrolled. After induction of anesthesia, HES was administered, 20 mL/kg, to a maximum of 1500 mL, at a rate to meet intraoperative fluid requirements. Patients then randomly received either a 10-mL solution containing 0.3 micro gram/kg of DDAVP (Group 1) or 10 mL of normal saline (Group 2). After HES administration, factor VIII:C levels decreased significantly, to 69% of baseline, in both groups. After study drug administration, factor VIII:C in Group 1 increased significantly to 135% of baseline at 30 min and 115% of baseline at 60 min while in Group 2 average factor VIII:C levels remained below baseline at 30 and 60 min. DDAVP produced an increase in factor VIII:C activity despite HES administration and should be considered a treatment option for the mild coagulopathy infrequently associated with HES administration. (Anesth Analg 1996;83:804-7)

Tranexamic Acid Reduces Bleeding After Cardiopulmonary Bypass When Compared to Epsilon Aminocaproic Acid and Placebo

Abstract Perioperative bleeding following coronary artery bypass grafting (CABG) is associated with increased blood product usage. Although aprotonin is effective in reducing perioperative blood loss, excessive cost prohibits routine utilization. Epsilon aminocaproic acid (EACA) and tranexamic acid (TA) are inexpensive antifibrinolytic agents, which, when give prophylactically, may reduce blood loss. The present study was undertaken to compare the efficacy of TA and EACA in reducing perioperative blood loss. Methods: The study population consisted of first‐time CABG patients. Patients were allocated in a prospective double‐blind fashion: (1) group EACA (loading dose 150 mg/kg, continuous infusion 10 mg/kg per hour for 6 hours, N = 20); (2) group TA (loading dose 15 mg/kg, continuous infusion 1 mg/kg per hour for 6 hours, N = 20); (3) control group (infusion of normal saline for 6 hours, N = 19). Results: Treatment groups were similar preoperatively. No significant difference in intraoperative blood loss or perioperative use of blood products was noted. D‐dimer concentration was elevated in the control group compared to the EACA and TA groups (p < 0.05). Group TA had less postoperative blood loss than the EACA and control groups at 6 and 12 hours postoperatively (p < 0.05). TA had reduced total blood loss (600 ± 49 mL) postoperatively compared to EACA (961 ± 148 mL) and control (1060 ± 127mL, p < 0.05). Conclusion: TA and EACA effectively inhibited fibrinolytic activity intraoperatively and throughout the first 24 hours postoperatively. TA was more effective in reducing blood loss postoperatively following CABG. This suggests that TA may be beneficial as an effective and inexpensive antifibrinolytic in first‐time CABG patients.

Postdural puncture headache in paediatric oncology patients

PurposePrevious studies have not determined the correlation between durai puncture and postural headache in paediatric patients. Furthermore, no studies have evaluated the correlation between atypical headache and durai puncture in the paediatric population. Therefore, we prospectively analyzed the incidence of typical postdural puncture headache (PDPHA) and atypical headache in paediatric oncology patients following durai puncture.MethodsThe study population consisted of 66 paediatric patients undergoing 128 consecutive procedures, including 99 lumbar punctures and 29 bone marrow aspirations without concomitant lumbar puncture. Patients were prospectively randomized into four groups: Group I, preteens (< 13 yr) undergoing lumbar puncture, Group II, adolescents (13–21 yr) undergoing lumbar puncture, Group III, preteens undergoing bone marrow aspiration, and Group IV adolescents undergoing bone marrow aspiration. The presence and description of headache was documented immediately after durai puncture or bone marrow aspiration, and on post-procedure days #1,3 and 5 by personnel blinded to the type of procedure.ResultsThere was an increase in the incidence of headache (9.1%) after lumbar puncture in patients < 21 yr relative to patients undergoing bone marrow aspiration (P < 0.05). No difference was found between the incidence of typical PDPHA after dural puncture in preteens and adolescents. There was also no difference in the incidence of atypical headache after durai puncture or after bone marrow aspiration among preteens and adolescents.ConclusionsPaediatric patients experience an increased incidence of typical postdural puncture headache after durai puncture compared with age-matched patients undergoing bone marrow aspiration only. Atypical headache is relatively common in the paediatric population after dural puncture or bone marrow aspiration.RésuméObjectifLes études antérieures n’ont pas établi de corrélation entre la ponction durale et la céphalée posturale chez les patients pédiatriques. En outre, aucune étude de cette population n’a évalué le lien entre la céphalée atypique et la ponction durale. Par conséquent, à la suite d’une ponction durale, nous avons analysé de façon prospective l’incidence d’une céphalée de ponction postdurale (CPPD) typique et atypique chez des patients d’oncologie pédiatrique.MéthodeLa population de l’étude était constituée de 66 patients de pédiatrie subissant 128 examens consécutifs, comprenant 99 ponctions lombaires et 29 ponctions médullaires sans ponction lombaire concomitante. Les patients ont été répartis au hasard en quatre groupes de façon prospective: Groupe I de pré-adolescents (< 13 ans) subissant une ponction lombaire; Groupe II d’adolescents (13–21 ans) subissant une ponction lombaire; Groupe III de pré-adolescents inscrits pour une ponction médullaire et Groupe IV d’adolescents pour une ponction médullaire. La présence de céphalée a été vérifiée et décrite immédiatement après la ponction durale ou la ponction médullaire et 1, 3 et 5 jours suivant les interventions par du personnel qui ignorait le type de technique employé.RésultatsIl y a eu une incidence accrue de céphalée (9,1 %) à la suite de la ponction lombaire chez les patients < 21 ans par rapport aux patients qui ont subi une ponction médullaire (P < 0,05). Aucune différence n’est apparue dans l’incidence de CPPD typique après une ponction lombaire chez les pré-adolescents et chez les adolescents. Il n’y avait pas non plus de différence dans l’incidence de céphalée atypique après une ponction durale ou une ponction médullaire parmi les pré-adolescents et les adolescents.ConclusionLes patients de pédiatrie ont connu une incidence accrue de céphalée de ponction postdurale à la suite d’une ponction durale quand on les compare aux patients du même âge qui ont subi une ponction médullaire seulement. La céphalée atypique est relativement fréquente dans la population pédiatrique après une ponction durale ou une ponction médullaire.

Intravenous sedation for placement of automatic implantable cardioverter-defibrillators

OBJECTIVE To evaluate a change in anesthetic technique for transvenous placement of the automatic implantable cardioverter-defibrillator (ICD). DESIGN Retrospective study. SETTING A university hospital. PARTICIPANTS Twenty-eight patients who underwent placement of ICDs. INTERVENTIONS Thirteen patients had the ICD placed via the transvenous approach with general anesthesia (group GA). Fifteen patients had the ICD placed via the transvenous approach with intravenous sedation (group IV). MEASUREMENTS AND MAIN RESULTS Intraoperative systolic and diastolic blood pressures were significantly higher in group IV compared with group GA. The ICD was successfully placed in all patients in both groups. There were no intraoperative complications noted in either group during induction of fibrillation and defibrillation, and there was no recall by any patient in either group. The average hospital stay was significantly less in group IV (1.8 days) compared with group GA (3.4 days). CONCLUSIONS Intravenous sedation for the placement of ICDs is a safe and effective technique. Patients who had their ICD placed while receiving intravenous sedation experienced higher intraoperative blood pressures and were discharged from the hospital earlier than those patients who received general anesthesia.

The incidence of complications after the double-catheter technique for cannulation of the right internal jugular vein in a university teaching hospital.

P atients at risk for major intraoperative blood loss and hemodynamic instability often require two central venous catheters. There are no studies that compare the complication rate of single cannulation of a central vein with the rate associated with double cannulation of the same vein with two catheters in close proximity to each other. We have used the double cannulation of the right internal jugular vein (RIJV) for the last 3 yr in patients who may require both the monitoring of pulmonary artery pressures and large volume transfusions. Our recently reported avulsion of the right facial vein during double cannulation of the RIJV (1) prompted us to evaluate prospectively the efficacy and safety of double versus single cannulation of the RIJV in a university teaching hospital setting.

MAGNESIUM SUPPLEMENTATION IN THE PREVENTION OF ARRHYTHMIAS IN PEDIATRIC PATIENTS UNDERGOING SURGERY FOR CONGENITAL HEART DEFECTS

BACKGROUND The efficacy of magnesium in the prevention of arrhythmias in pediatric patients after heart surgery remains unknown. Therefore we prospectively examined the effect of magnesium treatment on the incidence of postoperative arrhythmias in pediatric patients undergoing surgical repair of congenital heart defects. METHODS AND RESULTS Twenty-eight pediatric patients undergoing heart surgery with cardiopulmonary bypass were prospectively, randomly assigned in a double-blind fashion to receive intravenous magnesium (magnesium group, n = 13; 30 mg/kg) or saline (placebo group, n = 15) immediately after cessation of cardiopulmonary bypass. Magnesium, potassium, and calcium levels were measured at defined intervals during surgery and 24 hours after surgery. Continuous electrocardiographic documentation by Holter monitor was performed for 24 hours after surgery. Magnesium levels were significantly decreased below the normal reference range for patients in the placebo group compared with the magnesium group on arrival in the intensive care unit and for 20 hours after surgery. Magnesium levels remained in the normal range for patients in the magnesium group after magnesium supplementation. In 4 patients in the placebo group (27%), junctional ectopic tachycardia developed within the initial 20 hours in the intensive care unit. No junctional ectopic tachycardia was observed in the magnesium group (P =.026). CONCLUSIONS Although this study was originally targeted to include 100 patients, the protocol was terminated because of the unacceptable incidence of hemodynamically significant junctional ectopic tachycardia that was present in the placebo group. Thus low magnesium levels in pediatric patients undergoing heart surgery are associated with an increased incidence of junctional ectopic tachycardia in the immediate postoperative period.

Blunting the Hemodynamic Response to Skull-Pin Placement

an anesthetic gas monitor (Rascal II@, Ohmeda, BOC Healthcare, Salt Lake City, UT). When the Rascal probe is used for patient monitoring, the Nellcor probe can be clamped to the intravenous drip chamber (Fig. 1) to detect droplets of intravenous solution. The drip rate, wave form, and Spo, value are displayed on the pulse oximeter. For a given clinical scenario, the wave form and Spo, value are constant, but they differ across various clinical settings. We disable the audio signal (to avoid confusion with the patient’s oxyhemoglobin saturation) and set the low rate alarm to produce an intravenous flow monitor and alarm. We have observed that the oximeter functions with adult (10 drops/ mL) and pediatric (60 drops/ml) drip chambers with both crystalloid and colloid solutions. An inherent limitation to this approach is the inability to detect tubing disconnection or catheter dislocation that is distal to the drip chamber. Additionally, overfilling, tilting, or splashing within the chamber impairs the signal. We place large, easily legible labels on the drip chamber “Spo,” display to prevent it from being mistaken with the patient’s Spo,.